What to Know and How to Prepare (2026-2027)
A record-strength El Niño does a different thing in every region, and the impacts arrive staggered across two years — a wet winter that suppresses fire in one place while growing next summer's fuel, a dry winter that empties the snowpack in another.
This board maps which hazards are likely to intensify where, and when across the winter, and the 2027 fire and water year where most of the consequences will land.
Each cell carries a confidence mark, and each hazard column shows the kind of evidence behind it, so you can tell a well-forecast hazard from a plausible one.
Reviewed and updated weekly. Free to use. Not an agency product. Verify with sources before making operational decisions. See the method note for more on how the hazard board and action briefs were created, and tips on replicating it for other regions.
Reviewed daily · 2 November 2026
What a historic El Niño makes worse, and where
The 2026–27 event is on track to be the strongest in the instrumental record. This board maps the hazards that intensify by region across two horizons: the winter itself, and the lagged consequences that arrive in the 2027 fire and water year.
- Niño-3.4 anomaly
- +2.5 °CWeekly value, CPC 26 Oct 2026, up from +2.4 °C a week earlier. The September monthly mean is +2.1 °C, CPC 8 Oct 2026, up from +1.8 °C in August; the daily value reached +3.07 °C on 19 Sep, tying the 2015 daily record. Three averaging periods, three correct numbers — press coverage quotes the daily one.
- Basin structure · Niño-1+2
- +4.4 °CAgainst Niño-3 at +3.6 °C and Niño-4 at 0.0 °C, CPC 26 Oct 2026, against +4.4 °C, +3.5 °C and −0.1 °C a week earlier. Niño-3 has risen again and Niño-4 has returned to zero from a marginally cool reading, so the central Pacific now sits at its climatological average while the far eastern Pacific holds above +4 °C: the east-weighted shape holds, and the same update places the change where it matters — above-average sea surface temperatures increased across the east-central and eastern equatorial Pacific, while over the last four weeks equatorial temperatures were above average east of the Date Line and below average near and west of it. The September monthly means carry the same shape — Niño-1+2 at +3.9 °C, Niño-3 at +3.0 °C and Niño-3.4 at +2.1 °C, CPC 8 Oct 2026, with sea surface temperature anomalies above +4.0 °C in parts of the eastern equatorial Pacific. An East Pacific event with no central Pacific warming at all — the 1997–98 shape, which is the analog this board already uses.
- Strong to very strong, to Jan–Mar 2027
- > 83%CPC, 8 Oct 2026, which frames the strength call differently from its predecessor: a strong-to-very-strong event judged likely through Jan–Mar 2027. The 10 Sep figure of >90% applied to a very strong event across fall and winter alone, so the two are not comparable and the lower number is not a downgrade — the record-exceeding probability beside it rose over the same month. NIFC’s outlook of 1 Oct 2026 cites >95% for a very strong event continuing into winter, and records that most of the models used by CPC and internationally now show this as the strongest on record.
- Record-exceeding event
- 83%Oct–Dec 3-month RONI ≥ +2.5 °C, beyond anything since 1950. CPC, 8 Oct 2026, raised from 75% on 10 Sep, which had itself been raised from 69%. The same discussion gives 54% for Sep–Nov and 70% for Nov–Jan, so Oct–Dec remains the season most likely to carry the record. NIFC’s outlook of 1 Oct 2026 still cites the 75% figure, so operational products built on the September call read low until they are reissued. The CPC weekly update of 26 Oct 2026 still puts the most recent observed 3-month RONI, for July–September 2026, at +1.7 °C.
- ENSO-neutral by Apr–Jun 2027
- 55%CPC weekly update, 5 Oct 2026, which expects El Niño to persist through Mar–May 2027 and gives ENSO-neutral the majority by Apr–Jun. The editions of 13, 19 and 26 Oct 2026 carry the same call in words — El Niño expected to persist through Mar–May 2027, chances favouring ENSO-neutral in Apr–Jun and May–Jul 2027 — but publish their per-season probabilities as a figure rather than as text, so the number here stays attributed to the edition it was read from rather than restated for the newer ones. The CPC discussion of 8 Oct 2026 does not state the season: it carries no ENSO-neutral probability and judges a strong-to-very-strong event likely through Jan–Mar 2027, so the weekly update remains the source here. The IRI objective plume of 19 Oct 2026 holds El Niño at 100% for Mar–May and 92% for Apr–Jun, then 60% for May–Jul and 37% for Jun–Aug, where ENSO-neutral becomes the most likely state at 51%; that is model output without forecaster judgement, and it assigns no probability to either La Niña or ENSO-neutral from Sep–Nov 2026 through Mar–May 2027. The edition of 21 Sep 2026 held Mar–May at 99% and Apr–Jun at 90%. Decay begins in spring on both readings; only its pace is in dispute.
- What this is
- An editorial synthesis of published agency forecasts and peer-reviewed findings, assembled to support planning. Every cell is sourced, confidence-marked and evidence-tiered.
- What it is not
- Not an agency product and not an operational forecast. It carries no authority. For decisions, use the agency products it cites and the live monitoring linked below.
- Maintenance
- Reviewed daily against the source products. Corrections are logged in full, with dates, under Revision log at the foot of the page rather than quietly amended.
- Turning this into action
- Every region name in the matrix links to that region's hazards and the actions that serve them. Seven printable briefs sit behind that index, with named counties and agency-attributed steps.
ENSO diagnostics current through the CPC discussion of 8 Oct 2026, the CPC weekly update of 26 Oct 2026 and the IRI Quick Look of 19 Oct 2026 · WMO ENSO Update, 3 Sep 2026 · NIFC outlook, 1 Oct 2026, covering October 2026 through January 2027, which remained the current edition at the time of this review although the product states its next issuance as 2 Nov 2026 — next CPC discussion 12 Nov 2026
Composite hazard load by region
Each tile carries the highest hazard level in that region for the selected horizon, and names the hazard driving it. Geography is schematic, not to scale — the tiles are arranged to echo the continent, not to draw it. Hawaii sits as an inset below, far off its true position.
Region × hazard matrix
Happening now, and what it does and doesn't confirm
These entries sit on opposite sides of the attribution line: one is the board's cleanest confirmation, one is the trap, and one is live and still developing. Each carries the dates it refers to, so it can be read correctly after the event has passed.
Hurricane Lowell · on signal
This is the teleconnection working exactly as documented. Lowell passed northwest of Kauai as a weakening major hurricane — 85 mph gusts at Waimea, nearly 18 inches of rain in Kauai's mountains, 90% of the island without power, 30-foot surf, and Hawaii's first known tornado watch. NOAA had already called a 70% chance of an above-normal Central Pacific season, 5 to 13 storms against a normal 4 to 5, on the strength of El Niño alone.
Kiritimati · the ocean is already there
At the geographic center of the event, the reef is bleaching before the winter peak. Researchers working on Christmas Island in the Central Pacific in August reported sea surface temperatures of 30 to 30.5 °C, at least two degrees above average, with active coral bleaching and rainfall heavy enough to cut the island's dirt roads. The winter peak is still months out. This is the marine heat and ecosystems column arriving early at the one place the index is actually measured, and it is the strongest live confirmation on this page that the ocean is behaving as forecast.
The Central Pacific timing gap
The Central Pacific hurricane season peaks August through October, before the winter panel opens. The hazard El Niño raises most reliably in the Pacific therefore falls between the two horizons shown here. Track it directly through the Central Pacific Hurricane Center rather than reading it off the winter panel.
Post-Tropical Cyclone Olana · a remnant low on its final advisory, and the Central Pacific basin carries no tropical cyclone again
Olana has become a remnant low and the Central Pacific Hurricane Center has issued its last advisory on the system. Public advisory 7 of 5:00 p.m. HST on 26 October 2026, the final advisory, carried as CP032026, places Post-Tropical Cyclone Olana near 13.0°N 175.9°W, about 500 miles west-south-west of Johnston Island, at 30 mph and 1007 mb, moving south-south-east at 7 mph with a turn to the east expected overnight. The advisory forecasts additional weakening and dissipation on Tuesday, and states that the Center will issue no further public advisories on the system. The 40 mph and 1002 mb near 14.9°N 176.6°W, read from advisory 4 of 11:00 p.m. HST on 25 October, are superseded; no advisory cited on this page carried Olana above tropical storm strength. No coastal watch or warning was in effect at any point in the system’s life, and the final advisory states no hazards affecting land. The basin carries no tropical cyclone, but it is no longer without a watch item. The Central Pacific Tropical Weather Outlook of 8:00 p.m. HST on 26 October 2026 carried no formation area. The outlook of 8:00 a.m. HST on 1 November 2026, which carries the same formation area and the same chances as the 2:00 a.m. HST cycle of the same day, carries no tropical cyclone either, but it does carry a formation area: a broad area of low pressure forecast to develop well to the south-east of the Hawaiian Islands in a couple of days, in conditions it describes as favourable for gradual development, with a tropical depression possible from the middle to the end of the week as the system moves westward to west-north-westward. Formation chances are near 0 per cent through 48 hours and 50 per cent, medium, through seven days. The eastern Pacific Tropical Weather Outlook of 5:00 a.m. PDT on 31 October 2026 carries the same disturbance from its own side of 140°W at near 0 per cent and 40 per cent over the same two windows. The basin’s previous system was Hurricane Nolo, whose Central Pacific peak stands at 110 mph and 963 mb — a strong category 2, short of the major hurricane the Center’s earlier cycles allowed for — and which crossed the International Date Line westward out of the Center’s area of responsibility on 4 October 2026, on the schedule its final Central Pacific advisory cycle gave. The statewide emergency proclamation of 3 September 2026 ran through 1 November 2026 and has now expired. No level on this board moves on a single storm, and the Hawaii & Central Pacific ratings are seasonal. Olana stated no Hawaii exposure at any point: it tracked west-south-west of Johnston Atoll, itself well south-west of the main Hawaiian islands, and no coastal watch or warning was in effect anywhere in the basin. What the system did was hold open, a third time this season after Lowell and Nolo, the Central Pacific timing gap this board records — the hazard El Niño raises most reliably in the Pacific peaks August through October, before the winter panel opens, and it is tracked through the Central Pacific Hurricane Center rather than read off the winter matrix. For watches, warnings and evacuation guidance use the Central Pacific Hurricane Center, NWS Honolulu and the Hawaiʻi Emergency Management Agency, not this board.
Remnants of Vance · the final advisory, offshore and without a landfall, and the moisture is now a Southwest and Southern Plains flash flood threat
The National Hurricane Center has issued its final advisory on this system, and it ended where the Thursday forecast placed it: offshore, with no landfall by a tropical cyclone or by a remnant low. Advisory 35 of 8:00 p.m. MST on 29 October 2026, 0300 UTC on 30 October, carries the Remnants of Vance near 20.7°N 107.7°W, about 190 miles south-south-west of Mazatlán and about 205 miles south-east of the southern tip of the Baja California peninsula, at 30 mph and 1008 mb, moving north-north-east at 8 mph, and records that the system no longer has a well-defined centre. It is marked the final advisory, with no further advisories to follow and the National Weather Service High Seas Forecasts named as the continuing source. The 40 mph and 1001 mb near 21.0°N 108.4°W of advisory 32 of 2:00 a.m. MST on 29 October are superseded. The storm’s peak stands at the 110 mph and 965 mb of advisory 12 of 3:00 a.m. CST on 24 October, one mile per hour below the category 3 threshold; the system lost 80 mph and filled 43 mb from that peak in five and three-quarter days. It was first carried as Tropical Depression Twenty-Two-E in public advisory 1 of 9:00 a.m. CST on 21 October 2026, near 9.5°N 99.3°W at 35 mph and 1005 mb. The Center’s advisories on this system moved from CST to MST as it tracked west, so the clock times are not directly comparable between cycles. No coastal watch or warning was in effect anywhere on the Mexican coast at any point in the system’s life. The land hazards the final advisory states are rain and surf. It forecasts 1 to 2 inches of rain across central and southern Sinaloa, far south-western Durango and far north-western Nayarit into early Friday morning, with isolated totals over 4 inches in coastal Sinaloa, which may cause flooding and mudslides, especially on steep terrain — a lower and shorter footprint than the 2 to 4 inches through Thursday of the previous cycle. Swells will affect coastal south-western and west-central Mexico and the southern Baja California peninsula over the next day or so, with life-threatening surf and rip currents. The final advisory also carries the moisture forward onto the regions this board rates: it states that moisture from the system will enhance rainfall over the south-western United States and the southern Plains, creating a flash flood threat over the next few days. That is the part of this system that reaches this board, and the live Arizona event is set out in the entry below. All three basins now carry no tropical cyclone. The eastern Pacific Tropical Weather Outlook of 5:00 a.m. PDT on 30 October 2026 carries no tropical cyclone and the same broad area of low pressure well south-east of Hawaii as the previous cycle, with formation chances near 0 per cent through 48 hours and 30 per cent through seven days; the Atlantic Tropical Weather Outlook of 2:00 a.m. EDT on 30 October 2026 expects no tropical cyclone formation during the next seven days; and the Central Pacific Tropical Weather Outlook of 2:00 a.m. HST on 30 October 2026 carries no tropical cyclones. Formation chances and watch and warning geography change between outlook cycles, so they should be read from the Center rather than from this board. No hazard level, confidence mark or evidence tier moves on these systems, including in Interior & Southern Mexico, Baja California & NW Mexico, Southern California and Hawaii & Central Pacific, whose ratings are seasonal and are not set by a single system or by a seven-day formation chance. This board states no landfall from Vance. The timing gap this entry describes still holds, and a fortnight of eastern Pacific activity now illustrates it in full: that activity, which El Niño raises while it quiets the Atlantic, peaks before the winter panel opens, and it has produced a hurricane that peaked as a major and wandered offshore without landfall, a tropical storm that steered moisture into southern California and the Southwest, a storm that dissipated off Baja California Sur, a hurricane that carried a coastal warning in west-central Mexico and then weakened and left without making landfall, and now a system that reached category 1, stayed offshore, unwound over water without reaching the coast, and has handed its moisture to the continent — all outside the horizons shown above. For warnings, forecast tracks and evacuation guidance use the National Hurricane Center, Mexico’s SMN and the local National Weather Service forecast offices, not this board.
An inland-penetrating atmospheric river over Arizona · live, with the Verde River above major flood stage, evacuations and swift water rescues, and flood warnings across ten counties in a level 3 Desert Southwest
The event has passed its peak on the upper Verde and is routing downstream, and the crests it produced went far beyond the levels the warnings of the previous morning forecast. The Flagstaff office’s flood warning of 9:24 p.m. MST on 1 November 2026, in effect until 8:00 p.m. MST on 2 November, covers Gila and Yavapai counties and records the Verde River at Clarkdale at 23.83 ft at 9:00 p.m. against a flood stage of 12.0 ft and the Verde River near Camp Verde at 22.59 ft at 9:00 p.m. against a flood stage of 17.0 ft, both risen above major flood stage, with evacuations reported along the Verde River and swift water rescues under way. The same office’s flood statement of 12:54 a.m. MST on 2 November 2026, carrying the warning to 8:00 p.m. MST, records Camp Verde at 23.51 ft at 11:00 p.m., forecast to crest at 23.97 ft at 2:00 a.m., and a Clarkdale crest of 20.91 ft at midnight, and again records evacuations reported by emergency management; it names Cottonwood, Camp Verde, Clarkdale, Middle Verde, Verde Village, Verde Lakes, Horseshoe Bend and Beasley Flat among the affected places, and states that 21 ft at the Camp Verde gauge inundates homes from Horseshoe Bend to Beasley Flat. The margin against forecast is the part of this event a planner should read. The Flagstaff office’s warning of 5:05 a.m. MST on 1 November had forecast Camp Verde to crest at 14.65 ft and Clarkdale at 9.98 ft, both below flood stage, and the intermediate warning of 4:52 p.m. MST had raised the Camp Verde forecast to 24.33 ft at 1:00 a.m. while recording Clarkdale already above major flood stage at 22.47 ft at 4:00 p.m. against a Camp Verde reading of 12.52 ft and rising. Oak Creek crested above moderate flood stage and is falling. The warning of 8:35 p.m. MST on 1 November recorded Oak Creek at Cornville at 16.93 ft at 8:00 p.m. against a flood stage of 8.0 ft, above moderate flood stage, and Oak Creek at Sedona at 12.88 ft at 7:45 p.m. against 14.0 ft. The warning of 5:39 a.m. MST on 2 November, covering Coconino and Yavapai counties, records Cornville at 10.57 ft at 5:00 a.m., still above its flood stage, and Sedona at 7.06 ft at 4:45 a.m., falling but at action stage, with minor flooding likely at Page Springs four to six hours after the Sedona gauge reaches 7.0 ft. The upper basin is still rising. The warning of 5:29 a.m. MST on 2 November records the Verde River below Paulden risen above minor flood stage at 5:24 a.m., with further rises possible, and covers Big Chino Wash and Williamson Valley Wash with Paulden and Perkinsville named. Tributary flooding reached homes. The warning of 8:29 p.m. MST on 1 November on Wet Beaver Creek and Dry Beaver Creek records emergency management reporting water six feet below the Montezuma Avenue bridge and 150 to 200 homes impacted in Lake Montezuma and Rimrock. The warning of 7:22 p.m. MST put the Agua Fria River at Rock Springs above flood stage, and that of 8:40 p.m. MST put Granite Creek at Prescott at its 11.0 ft flood stage and falling. Tonto Creek is still under evacuation. The Flagstaff office’s warning of 7:49 a.m. MST on 2 November, in effect until 2:00 p.m. MST, records river gauges falling but still elevated across northern Gila County and evacuations still under way along Tonto Creek near Gisela; the Phoenix office’s warning of 7:51 a.m. MST, until 10:00 a.m. MST, records flooding occurring on Tonto Creek and in Tonto Basin and expects it to keep rising slowly through the afternoon. The Salt River carries the event’s one historical comparison. The Phoenix office’s flood warning of 2:03 a.m. MST on 2 November, until noon MST, covering Maricopa and Gila counties, records the Salt River near Roosevelt at 30.5 ft at 1:30 a.m. against a flood stage of 30.0 ft and a bankfull stage of 24.0 ft, with a 24-hour maximum of 30.6 ft, and compares that crest with one of 30.1 ft in January 1993. Its flood advisory of 5:44 a.m. MST records the Salt River near Chrysotile at 12.8 ft at 5:30 a.m., back below its 15.0 ft action stage and 18.0 ft flood stage, with further rises possible on upstream gauges. The Flagstaff office also carries warnings across Apache, Gila and Navajo counties issued at 2:58 a.m. and 5:58 a.m. MST on 2 November, on the drainages its area forecast discussion had named. What this confirms. The Desert Southwest carries level 3 winter flood and debris flow at moderate confidence on this board, and its regional note states that flash flooding is the winter hazard. The Flagstaff area forecast discussion of 4:24 a.m. MST on 31 October 2026 had expected both flash flooding and longer-term river flooding, major and serious hydrological issues on ground already saturated, and larger stem waterways flooding for days after the event, naming the Little Colorado and the Verde. Two main-stem Verde gauges above major flood stage, with evacuations, swift water rescues and homes affected on the tributaries, is that lagged-crest mode arriving as the discussion described it, rather than the desert flash flood most Southwest plans are built around. What it does not confirm. One moisture plume at the turn of October and November is weather. The rating is a cool-season reading drawn from the agency outlooks and the analog record, and it does not move on a single event; no hazard level, confidence mark or evidence tier moves here. Nor does this board attribute the plume to Vance. The National Hurricane Center’s final advisory on that system states that its moisture will enhance rainfall over the south-western United States and the southern Plains; neither Arizona forecast discussion mentions Vance or any tropical remnant. The two statements are recorded separately rather than joined into a cause. Warnings of this kind are reissued or allowed to expire within hours, so they should be read from the issuing office rather than from this board. For watches, warnings and evacuation guidance use the National Weather Service forecast offices in Flagstaff and Phoenix, the Arizona Department of Emergency and Military Affairs and county emergency management, not this board.
Southern California's early-September heat · off signal
88 to 108 °F under an NWS extreme heat warning across Los Angeles County from the morning of 9 September to the evening of 10 September 2026, and El Niño was not why. The warning has since expired. Early-September heat is climatological in Southern California. This board puts the region's winter warm anomaly at level 1 — the wet signal is the strong one there, not the hot one. Attributing an episode of this kind to El Niño is the exact error the confidence tiers exist to prevent.
Why it still matters operationally
Wrong cause, real consequence. That heat landed inside the window NIFC then flagged for elevated fire potential, on fuels that had been curing all summer, weeks before the storm door opens. NIFC’s outlook of 1 Oct 2026 now carries near-normal potential for southern California from October through January on explicit El Niño reasoning, which is the sequence arriving, not the exposure cancelled. The sequence that matters is heat first, ignition risk alongside it, then a wet winter that grows next year's grass — and the same warmth is what holds sea surface temperatures up off the coast. The attribution is wrong; the operational exposure is not.
California’s October heat · off signal, second instance
Extreme Heat Warnings ran across southern California through 8 October and have since expired; El Niño was not the cause. Warnings cover Los Angeles, Ventura, Santa Barbara, Orange, San Diego and the San Bernardino and Riverside valleys, with Heat Advisories reaching the Sacramento Valley, the Bay Area and north to Mendocino and Lake counties; more than 35 million people are under heat alerts, at 10 to 25 °F above average, with warnings holding to 8:00 p.m. on 8 October, when they expired. Eight southern California cities broke daily records on 3 October — Vista reached 108 °F, tying an all-time high set on 30 June 1985. NWS forecasters attribute the episode to high pressure aloft with offshore flow, Santa Ana winds in the south, warming by compression as it descends; the documented El Niño pathway into California is a strengthened subtropical jet and a displaced North Pacific storm track, which is a precipitation mechanism and is not expected to emerge before November, and possibly not until mid-to-late December. This board rates southern California’s winter warm anomaly at level 1; the strong signal there is wet. At the review of 8 October no Red Flag Warnings or Fire Weather Watches were posted anywhere in California, a status that can turn over within hours and should be read from the National Weather Service rather than from this page. The contrary claim now circulating — that a hot, dry early October shows the event to be a bust — is the same error reversed, and the winter panel on this board is not evidence either way until the storm track responds. No level, confidence mark or evidence tier moves on a heat episode of this kind. Where the event is arriving on this coast is in the coastal sea-level column, not the temperature columns: see Coastal sea level · weeks below.
Isaias · inland and accelerating north-east, and a suppressed season was still not an empty one
Isaias came ashore on the western Florida Panhandle on the evening of 9 October 2026, is no longer a tropical cyclone, and all coastal watches and warnings have been discontinued. The National Hurricane Center has issued its last advisory on the system and the Weather Prediction Center now carries it. The Weather Prediction Center’s advisory 19 of 4:00 a.m. CDT on 11 October 2026 places the post-tropical cyclone near 35.4°N 85.9°W, about 65 miles south-east of Nashville, Tennessee and 70 miles north-east of Huntsville, Alabama, with maximum sustained winds of 25 mph and a minimum central pressure of 1010 mb, moving north-east at 23 mph and accelerating, with the next complete advisory at 10:00 a.m. CDT. The Center’s own final product, post-tropical public advisory 15 of 4:00 a.m. CDT on 10 October 2026, had placed Isaias near 32.0°N 86.5°W at 35 mph and 1002 mb, 25 miles south-south-west of Montgomery, Alabama; those figures are superseded, and responsibility passed to the Weather Prediction Center from 10:00 a.m. CDT that day. The Center issued no landfall statement, so this board states no landfall intensity. The last pre-landfall product, intermediate advisory 13A of 7:00 p.m. CDT on 9 October, carried Isaias at 110 mph and 967 mb near 30.1°N 86.6°W, 45 miles south-east of Pensacola, with landfall on the western Panhandle forecast within the next hour or two, and recorded a sustained wind of 83 mph with a gust of 97 mph at Gulf Breeze, Florida; the hourly update of 9:00 p.m. CDT already had the centre inland near 30.5°N 86.4°W at 100 mph and 978 mb. Landfall therefore fell between those two products, and the last measured value before it was category 2. Coverage describing a category 2 landfall and coverage describing a major-hurricane landfall are both in circulation; neither is an agency statement, and this board does not adopt either. Isaias reached 120 mph offshore earlier on 9 October, which is the figure carried here while it was over water, and it remains both the first Atlantic hurricane and the first Atlantic major hurricane of the 2026 season. The warnings came down in stages. Advisory 14 of 10:00 p.m. CDT discontinued the Hurricane Warning west of the Mississippi/Alabama border, the Tropical Storm Warning west of Ocean Springs, Mississippi, the Storm Surge Warning west of Dauphin Island and the Storm Surge Watch east of the Suwannee River; the remaining Hurricane, Tropical Storm and Storm Surge Warnings were discontinued with the final advisory. The hazard has travelled with the system, and it is still water. The advisory of 11 October carries rainfall of 1 to 3 inches, with localized maxima near 5 inches, from the central Appalachians into the Mid-Atlantic and up to about an inch along coastal North Carolina, with isolated flash and urban flooding possible in both, and significant river flooding on the western Florida Panhandle cresting through Sunday. A couple of tornadoes are possible through the day across the Piedmont and Coastal Plain of Virginia and North Carolina. Flood Watches cover coastal portions of the Carolinas and the Blue Ridge of the central and southern Appalachians, and a Wind Advisory covers parts of the Southeast and the southern Appalachians, with scattered power outages and downed trees likeliest in elevated terrain; swells continue along the Gulf and south-east United States coasts, Mexico and western Cuba with life-threatening surf and rip currents. The figures of 4 to 8 inches with localized totals to 15 inches across southern Alabama, the Florida Panhandle and Big Bend and south-western Georgia, and the tornado risk across the eastern Florida Panhandle, Georgia and the Carolinas, are superseded. Florida declared a state of emergency for 25 counties on 6 October 2026. This board rates the seasonal tropical cyclone hazard for Southeast & Gulf Coast as suppressed, at high confidence, and that rating does not move. Suppression under El Niño is a statement about basin-wide activity — vertical wind shear reducing the number of storms a season produces — and it is not a statement about how strong the storms that do form become, nor a promise that none reaches a coastline. A suppressed basin that produces its first hurricane in October, and whose first hurricane reaches major strength offshore before coming ashore on the Panhandle, is closer to what suppression looks like than to evidence against it: the count is low and late, while the intensity of an individual system is governed by the environment it finds rather than by the seasonal signal. A single storm is not evidence that the seasonal signal has failed, in the same way that no single storm was taken as evidence that it held. The suppressed mark should be read by emergency managers on the Gulf coast as a reason to expect fewer such weeks this season, never as a reason to prepare less for the one in front of them. No hazard level, confidence mark or evidence tier moves on this storm. For the continuing flood, wind and tornado threat use the Weather Prediction Center, the local National Weather Service forecast offices and state and county emergency management, not this board.
Post-Tropical Cyclone Josephine · became a powerful extratropical low on its final advisory, the Atlantic basin is clear again, and the mid-Atlantic coastal flooding is the part that reached this board
Josephine became a powerful extratropical low on 22 October 2026, and the National Hurricane Center has issued its last public advisory on the system. It formed as a subtropical storm off the mid-Atlantic coast on 21 October 2026, from a precursor the Center carried as AL93 in a special Tropical Weather Outlook of 3:40 p.m. EDT on 21 October 2026 — a storm-force low a few hundred miles off the mid-Atlantic coast that might become subtropical, raised to 70% through 48 hours and 70% through seven days. The final advisory, number 5 of 5:00 p.m. AST on 22 October 2026, places Josephine near 40.0°N 65.8°W, about 235 miles east-south-east of Nantucket, Massachusetts and 335 miles south-south-west of Halifax, Nova Scotia, at 65 mph and 988 mb, moving north-east at 17 mph and expected to accelerate, with winds of 40 mph extending 415 miles from the centre — a very broad wind field for that intensity, which is what a subtropical structure looks like. Buoy 44001, north of the centre, reported sustained winds of 49 mph with a gust of 58 mph. The Center forecast further strengthening into a powerful extratropical cyclone carrying hurricane-force winds that night or early on 23 October, on a track turning gradually east on 23 October and into the weekend, south of Nova Scotia and Newfoundland, and directed further information to the High Seas Forecasts rather than to its own advisories. No coastal watch or warning was in effect at any point in the system’s life. The Atlantic basin now carries no tropical cyclone, and the Atlantic Tropical Weather Outlook of 2:00 a.m. EDT on 30 October 2026 expects no formation during the next seven days. The land hazards stated in the final advisory are gale-force gusts along parts of the north-eastern United States coast through that evening, minor to locally moderate coastal flooding along the mid-Atlantic coast, ongoing and continuing through the rest of the week around the times of high tide, and large swells along the eastern United States seaboard and parts of Atlantic Canada with life-threatening surf and rip currents. The coastal flooding is the part that touches a column on this board, and it outlasts the storm. It is arriving on the coast NOAA names as most susceptible this season, with 15 to 20 high-tide flood days projected for the mid-Atlantic and 5 to 11 for the Northeast — see The flood-day numbers exist. Use them. below. A single storm’s high-tide flooding is an instance of that exposure, not a change in it, and no hazard level, confidence mark or evidence tier moves in Northeast, Ohio Valley & Mid-Atlantic or Atlantic Canada. The seasonal tropical cyclone rating for Southeast & Gulf Coast remains suppressed, at high confidence, and Josephine does not bear on it. Suppression under El Niño is a statement about basin-wide activity driven by vertical wind shear in the deep tropics; a subtropical storm that develops from a non-tropical low near 38°N in late October is a different kind of system, and the Center classified it as subtropical for that reason. It was, with Isaias, the second named Atlantic system this board recorded in a fortnight, and a suppressed basin is a quieter basin rather than an empty one. For warnings, forecast tracks and coastal flood guidance use the National Hurricane Center, the Weather Prediction Center and the local National Weather Service forecast offices, not this board.
Sea level and ice: one fast hazard, one slow one
These two behave differently from everything else on the board. Sea level responds within weeks and gives the height back when the event decays. Ice responds a season late and never gives it back.
Coastal sea level · weeks
Weakened trade winds launch downwelling Kelvin waves that travel east and then poleward along the Americas, warming and expanding the coastal ocean. Three different quantities are in circulation and all three are measured. The winter seasonal anomaly averaged +11 cm across the US West Coast in 2015–16, +17 cm on the Oregon coast — a coast-wide seasonal mean, the most smoothed figure available, and Barnard et al. record it as significantly below 1997–98 across all regions. Months-long elevation at a single coast ran 6 to 10 inches in 1982–83 and 1997–98. Peak water levels during winter storms at high tide reached 1.5 to 3 feet above predicted in those events, and San Diego, La Jolla and Santa Barbara set record highs on 25 November 2015. The foot now being quoted for California is a total-water-level figure of the second and third kind, not a seasonal mean, and it sits well inside the gauge record. Match the quantity to the decision: seasonal means for budgeting, storm peaks for operations.
The flood-day numbers exist. Use them.
NOAA's 2026–27 High Tide Flooding Outlook projects a national record of 7–12 flood days. Mid-Atlantic 15–20, Pacific Northwest 7–18, Northeast 5–11, Southern California 3–6, with Toke Point WA at 17–29 and Duck NC at 22–27. NOAA names El Niño as the driver and the Mid-Atlantic and Pacific coasts as most susceptible.
Global mean sea level · temporary
Expect a spike in the global record, then a partial retreat. The 2014–16 event added 9.16 mm and 2023–24 added 7.70 mm. Ocean mass — not thermal expansion — was 68% and 81% of it, driven mainly by terrestrial water storage depletion in the Americas and Africa. Read a 2026–27 jump as the event, not as an acceleration in the trend.
Glacier mass balance · a year late, permanent
The mechanism is accumulation, not melt. A warm dry winter starves the snowpack, the transient snowline runs high the following summer, bare ice and firn are exposed, and albedo feedback finishes the job. Snowline rise across western North America has already gone fourfold, from 2.1 to 8.9 m per year since 2010.
Where the ice signal concentrates
Alaska, the Coast Mountains, the Cascades and the Canadian Rockies sit under the warm-dry pole all winter, and they are already the world's fastest-losing region — 22.2 Gt a year across western Canada and the conterminous US from 2021 to 2024, double the prior decade, and 12% of remaining volume gone since 2020. Alaska glaciers lose up to three additional weeks of melt per 1 °C of summer warming. The ENSO correlation is positive but often not statistically significant; temperature and snowpack do most of the work.
Fire and ice are now coupled
Wildfire soot is a named driver of the recent acceleration in western North American glacier loss, alongside reduced winter snowfall and early heat waves. A season that burns hard darkens the ice that a snow-short winter already exposed. That is a feedback, not a coincidence, and it runs in the direction this event pushes both variables.
The trap for water managers
Ice melt masks the snow deficit, then stops. A long, hot melt season can hold late-summer streamflow up in glacier-fed basins even as snow water equivalent collapses, so gauges look tolerable in the year the storage is actually being spent. Plan on the snowpack number, not the hydrograph.
Heat and wind in 2027
These two columns are the least alike on the board. The heat signal is among the most confident things anyone can say about 2027. The wind signal is the least — and it is still the one that decides fire outcomes.
Heat runs a season behind the ocean
Global temperature peaks three to six months after the ENSO peak, so an October–December 2026 crest lands on 2027, not 2026. WMO puts an 86% chance that some year in 2026–2030 beats 2024, and names 2027 as the leading candidate on the strength of this event.
Where the heat concentrates
The warm-dry pole carries it. Environment and Climate Change Canada’s CanSIPSv3 forecast issued 21 August 2026 puts western Canada at at least a 90% probability of above-normal temperatures for March to May 2027, and the same signal runs south through the Northern Rockies and Great Basin, and separately across interior Mexico and Central America. Heat on a depleted snowpack is a different hazard from heat alone.
Wet winter, then flash drought
The Southwest's relief is not durable. Saturated soils moderate early-summer heat, then dry down fast once the profile is spent. A soaked winter followed by a record-warm summer is the recipe for rapid onset drought over a landscape carrying an unusually heavy grass crop.
Wind has almost no seasonal forecast
No skillful seasonal wind outlook exists at this range, so most wind cells here stay low confidence. The Southern Plains is a moderate-confidence call because its spring wind season is climatological — it arrives whether or not El Niño has an opinion. Southern California is moderate for a different reason, below.
Santa Ana
Three independent studies — an observational pressure-field climatology, a 6 km downscaled simulation and a 65-year downscaled reanalysis — all point the same way: El Niño winters run about 10% stronger in seasonal Santa Ana intensity, La Niña winters about 10% weaker, with the signal strongest when PDO is in phase. Modest, seasonal-aggregate, and silent about any individual event.
The decay scenario
Roughly 70% of strong events transition to La Niña within four to six months. That autumn would be dry with heavy fuels — but on the wind literature above, offshore wind intensity would run lower, not higher. The compound worth planning against is a cured landscape with reduced ignition-to-conflagration wind.
Where the signal is weak
Snowpack
The least reliable line on the board. Western sites are roughly equally likely to land above or below average snowfall in El Niño years, and the Central Sierra Snow Lab has come in above average in only half of them. Precipitation totals carry the signal; snow water equivalent does not.
The Great Basin hinge
The dividing line sits further south than the region's name suggests. Within Utah the practical boundary runs near 37–38°N, so the reliable El Niño wet signal is a southern Utah phenomenon. CPC's composite gives northern Utah near-normal precipitation at best in moderate-to-strong events, and Wasatch snowfall correlates weakly negative while southern Utah correlates strongly positive. For this event CPC calls northern Utah and north-central Colorado a toss-up on precipitation and warmer than normal — which is why this column stays low confidence.
Strength ≠ certainty
CPC says so explicitly: with an event of this magnitude the chances of El Niño-consistent impacts are larger, but they are not guaranteed, and a very strong event will not produce the expected effects everywhere.
Does magnitude even matter?
Three defensible positions, and they disagree. One line of modeling says only strong events shift California's odds at all. A second finds the southern dipole scaling continuously with amplitude. A third argues amplitude is the wrong variable entirely — that the pattern of warming decides the response, which is why 2015–16 matched 1997–98 on Niño-3.4 and delivered near-average California precipitation. That counterexample is the one every skeptic will raise, and they are entitled to.
The models are not independent
Every outlook on this board runs downstream of an overlapping model pool. NMME and the Copernicus multi-system share members; the Met Office system is itself inside Copernicus. Agreement between them is weaker evidence than it looks — it partly reflects shared initialization and the sheer size of the ENSO forcing. This is the argument for checking against observations rather than against another forecast. There is a second split worth knowing about, because it runs the other way. Statistical models learn from past events; dynamical models solve the physics from current conditions. With ocean heat outside the range of anything in the training record, the statistical approach has the weaker footing this year — and the dynamical models are the ones forecasting the more disruptive event. Where the two disagree, the historical-analog answer is the one carrying the larger unstated assumption.
A second ocean mode is pulling the other way
The wet winter this board forecasts for the south-west is an El Niño signal landing on a Pacific Decadal Oscillation in its negative phase, and the two do not agree. NIFC’s outlook of 1 Oct 2026 names this explicitly for the Southwest: a record-strength El Niño typically enhances winter moisture and snowpack, but a negative PDO can counteract some of that influence, which is part of why the agency holds significant fire potential at normal rather than suppressed across the region through January. The board’s southern-tier wet ratings rest on the ENSO signal alone and do not net this out. Read the high-confidence wet cells as the ENSO contribution, not as a full seasonal forecast, and treat a drier-than-advertised south-west winter as a live possibility rather than a forecast failure.
Fuel is not fire weather
The 2027 fire column and the fine-fuel column now point in opposite directions across the southern tier, and that is deliberate. A 1984–2022 analysis of ENSO against area burned across the nine US coordination centers — Hoell et al., JGR Atmospheres, 2026 — finds autumn El Niño reduces the chance of extensive area burned in the Southern, Southwest and Rocky Mountain regions through the following spring and summer, while raising it in the Eastern and Northern Rockies regions. Fuel still accumulates. What the event suppresses is the weather that converts an ignition into a large fire — and the same work finds the suppression lifts in the subsequent summer and early autumn where an El Niño persists into spring. Read this as deferred, not removed. Two things to hold alongside it: this is a climatological base rate drawn from 39 years of observed events, not a forecast for this one, and no operational product yet covers spring or summer 2027 — NIFC's outlook horizon reaches March 2027 with its 1 December issuance and June 2027 with its 1 March issuance.
A warm winter is not a cold-free winter
The warm northern-tier signal is a seasonal mean, and planning against the mean is how a cold snap catches an agency short. El Niño winters carry an increased chance of the stratospheric polar vortex breaking down: planetary wave activity reaches the stratosphere more often, the late-winter vortex runs weaker, and major disruptions become more frequent. A breakdown can shift surface temperatures for days to weeks afterwards, pushing Arctic air far south of where a seasonal outlook would put it. Two things bound this. It is not forecastable at seasonal range — NOAA puts the limit at 10 to 15 days even for the stratospheric event itself, let alone its surface consequences. And the relationship is loose: there were no major sudden stratospheric warmings during 1997–98, the closest analog this event has. Warm on average, with cold outbreaks that arrive on two weeks' notice, is the shape to staff for.
Alaska is not an El Niño story
USGS states the linkage plainly: weak for most of Alaska. The odds of a warmer-than-normal winter shift by 5–10%, strongest in Southeast Alaska and unchanged in the northwest, with a small increase in the odds of storms in the south. Autumn sea ice decline is overwhelming whatever influence the event carries. Alaska's coastal erosion and storm exposure are among the most severe hazards on this continent — and this is the clearest case on the board of a place where a low signal level says nothing about how much is at stake.
Plains wind in 2027
No seasonal wind forecast exists, and no published ENSO signal in spring Plains wind speed was located. Spring wind on the Southern Plains is driven by lee cyclogenesis and the dryline, both robust climatological features of March through May in any phase. The fine-fuel pathway is real but conditional: it requires a wet winter followed by a spring drying, and the direct ENSO record argues against the second half. The operational answer is a measurement, not a forecast — assess the actual cured grass load in February 2027 and re-rate from it.
The Colorado River
The wet signal falls where the water is used, not where it is made. The El Niño dipole puts its reliable wet half south of roughly 35°N, and about 90% of the river's flow is born north of that line, in headwaters the teleconnection barely reaches. The Upper Basin therefore sits near a null line, which is why its signal is not merely weak but sign-unstable — flipping between sub-basins and between indices. Reclamation applies no ENSO adjustment at all. And the 2027 decision is already taken. Consensus among the seven basin states did not materialise, so Interior's Record of Decision of 21 August 2026 adopted a ten-year framework with guidelines for a two-year interval, in force 1 October 2026 as the 2007 interim guidelines expire. The August 24-month study puts Lake Powell in the Low Elevation Infrastructure Protection range, below 3,510 feet in water year 2027 on inflow of 37% of average, with Lake Mead in shortage through 2027. Could a strong southern winter change that? Not through the headwaters, where the signal dies, and not through allocation, which is now set by rule. Plan against the declared tier; read a wet winter as local supply relief, not basin inflow.
Great Salt Lake
One winter cannot move this lake, and the binding constraint is not weather. Elevation lags watershed precipitation by roughly three years and tracks a decadal cycle, not individual events. The 1982–83 analog is over-attributed: that El Niño produced the initial rise, but the lake climbed three further years to its 1986 record through a wet cycle that was not a strong event — in northern Utah, where the Great Basin hinge above already puts the signal at its weakest. What decides the outcome is how much water is allowed to reach the lake. The south arm closed water year 2025 at 4,191.1 feet, third-lowest since 1903 and about seven feet under the 4,198-foot healthy target, and Utah's Great Salt Lake Strike Team puts recovery by 2055 at a sustained additional inflow of 800,000 acre-feet a year — against roughly 400,000 delivered in total across 2021–2025. So the question to put to a wet winter is not whether it snows but whether the water is left in the river. Inflow is an allocation outcome, reached through leases, donated water rights, conservation and causeway salinity management. A wet year raises the ceiling on what those instruments can deliver; it does not operate them.
The spring predictability barrier
March through June 2027 are scenarios, not forecasts. Model runs at that range spread from −0.5 to +1.5 °C in Niño-3.4, and seasonal outlooks for key agricultural regions sit at roughly equal odds across all three terciles. Everything in the 2027 panel is a conditional read on how the decay actually goes.
The 2027 tropical season
Atlantic suppression is the safest call for 2026 and the least safe for 2027. El Niño still holds a 78% probability through Apr–Jun 2027, but a decaying event, or a swing toward La Niña, would remove the shear that is currently holding the basin down.
Evidence base, by hazard
Not every column on this board rests on the same kind of evidence. Tier A is an operational agency forecast for this event. Tier B is a peer-reviewed teleconnection with this event's conditions applied to it. Tier C is mechanism and inference, where this board extends published findings rather than citing a source that makes the claim directly.
| Hazard | Tier | What it rests on |
|---|---|---|
| Flood & debris flow | A | CPC seasonal outlooks and the USGS Southwest CASC multi-model synthesis, with the ENSO precipitation dipole (wet south of ~35°N, dry north of ~40°N) as the published mechanism. |
| Snowpack & water deficit | B | Strong agency agreement on precipitation, weak published agreement on snow water equivalent. The most-cited line and the least-supported one. |
| Cool-season fire | A | NIFC significant wildland fire potential outlook, 1 Oct 2026, covering October 2026 through January 2027, and the trinational North American assessment co-authored with Natural Resources Canada and Mexico's SMN. |
| Severe storm & ice | B | Cold-season tornado climatology, which runs opposite to intuition — ENSO explains only about 10% of variance and the Arctic Oscillation more. The ice-storm signal for eastern Canada rests on the 1998 analog, not on a forecast. |
| Sea level & tidal flooding | A | The strongest-sourced column here. NOAA's 2026–27 Annual High Tide Flooding Outlook gives per-station flood-day projections, backed by tide-gauge measurement of the 2015–16 event. |
| Marine heat & ecosystems | C | Mechanism and prior-event analogy. No operational marine heatwave outlook for this event is cited here, and none should be inferred. |
| Warm anomaly · Extreme heat | A | CPC and ECCC seasonal temperature outlooks, plus the WMO decadal update for the global 2027 framing. The most confident row on the board. |
| Wildfire potential (2027) | B | No agency has issued a 2027 outlook yet, so this column rests on a peer-reviewed 1984–2022 analysis of ENSO against area burned by US coordination center — Hoell et al., JGR Atmospheres, 2026 — rather than on any forecast. The nearest current corroboration is NIFC's call, in the outlook of 1 Oct 2026, of near-normal potential for southern California through January on explicit El Niño reasoning. The analysis's own stated limits: it measures area burned, not severity, ignition count or extreme single events, and excludes wind, terrain and vegetation type. |
| Fine-fuel loading | B | The best-documented lag here: one to three years in open ponderosa systems, within the following year in low-elevation grassland, and about eight months in the Southern Great Plains. CONAFOR makes the same argument for Mexico independently. |
| Drought & water shortfall | A | US Drought Monitor and CPC drought outlooks, the Canadian Drought Monitor, and the Central American climate forum with FEWS NET food-security classifications. |
| Glacier & icefield loss | B | Strong peer-reviewed measurement of the trend and its drivers. The ENSO-specific attribution is the weak part — the published correlation is positive but often not significant. |
| Wind potential | C | No seasonal wind forecast exists. Southern California is the exception, where three independent studies agree on a modest ENSO modulation of Santa Ana intensity. |
| Tropical cyclone | A | NOAA's Central Pacific outlook put this season at a 70% chance of above normal on El Niño grounds, and Hurricane Lowell delivered. Atlantic shear suppression is textbook and well supported for 2026. Only the 2027 season, which depends on decay timing, drops to inference. |
Check it against reality
Everything above is a forecast. These are observations, and they will tell you within weeks whether this board is holding. If the snowpack column is going to fail, SNOTEL will show it long before anyone reissues an outlook.
Snow
NRCS SNOTEL interactive map — real-time snow water equivalent as percent of the 1991–2020 median. California B-120 forecasts run February through June, so the first Sierra verification point is Feb 2027.
Drought
US Drought Monitor, released Thursdays. NOAA NIDIS for the portal view. Canadian Drought Monitor, monthly. CPC seasonal drought outlook for the forward view.
Coastal water levels
NOAA Coastal Inundation Dashboard and the monthly high tide flooding outlook. Station-level observed flood days against the projections above — the cleanest scoreboard on this page.
ENSO itself
CPC diagnostic discussion, second Thursday monthly — next 12 Nov 2026. WMO ENSO Update. IRI plume for the model spread.
Fire
NIFC outlooks, reissued the 1st of each month. CWFIS for Canada. Mexico's SNIF for CONAFOR fire statistics.
Tropical cyclones
Central Pacific Hurricane Center and the National Hurricane Center. The Central Pacific count against NOAA's 5-to-13 forecast is the fastest-settling verification on this board — the season closes 30 November.
Seasonal outlooks
CPC monthly and seasonal outlooks, reissued around mid-month. ECCC probabilistic seasonal forecast for Canada — maps only, no written narrative.
Updated 2 November 2026
What to do, by region and by hazard
Start with By region to see which hazards the board rates level 3 where you work, and the actions that serve them. The seven hazard briefs behind it carry the full sequence for each. Every action is attributed to the agency that recommends it — and where no agency has published guidance, this says so rather than filling the gap.
What this is.
An editorial synthesis of published agency forecasts and peer-reviewed findings, assembled by Wonder Labs to support planning across regions that are usually forecast separately. The tool draws on NOAA's Climate Prediction Center, the IRI plume, the WMO ENSO update, NIFC's fire potential outlooks, NOAA's high tide flooding outlook, the US and Canadian Drought Monitors, Environment and Climate Change Canada, CONAGUA and CONAFOR in Mexico, and CRRH-SICA with FEWS NET for Central America, alongside the peer-reviewed literature on ENSO teleconnections, glacier mass balance, cold-season severe weather and offshore wind. Please use this tool for general planning guidance.
What it is not.
This is not an agency product, or an operational forecast. For operational decisions, use the agency products cited and the live monitoring it links to. Every source is named on the page. See the method note for more on how to use the hazard board and action briefs.
How to read the levels.
Levels describe the strength of the El Niño signal for that hazard, not absolute risk. A level 3 where nobody lives is not the same problem as a level 2 where they do. Alaska is the clearest case: its coastal erosion exposure is among the most severe on the continent and its El Niño signal is close to zero, and the board only measures the second. Dotted cells are low confidence. Blue cells mark hazards El Niño turns down — a quieter Atlantic hurricane season, drought relief in the Southwest — which is planning information too.
How to get from a rating to an action.
Every region name in the matrix links to that region's entry in the action briefs, which lists its level 3 hazards and the specific steps that serve them, each attributed to the agency that recommends it. Where no brief covers a region's hazard, the entry says so.
How to cite it.
Wonder Labs, El Niño Hazard Board: North & Central America 2026–27, accessed [date]. wonder-labs.org
Spotted an error, or know a better source?
This board is reviewed daily and every material change is logged with the date it was made. Corrections raised here go into that log.
Most useful: a regional detail that is wrong or out of date, an agency product this should be citing and isn't, a program deadline that has moved, or a hazard in your region the board doesn't cover. A link to the source helps.
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