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FXUS05 KWBC 211231
PMD90D
PROGNOSTIC DISCUSSION FOR LONG-LEAD SEASONAL OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
830 AM EDT THU MAY 21 2026
SUMMARY OF THE OUTLOOK FOR NON-TECHNICAL USERS
EL NINO SOUTHERN OSCILLATION (ENSO)-NEUTRAL CONDITIONS CONTINUED THROUGH
MID-MAY, BUT POSITIVE SEA SURFACE TEMPERATURE (SST) ANOMALIES HAVE INCREASED
ACROSS THE CENTRAL AND EASTERN PACIFIC OCEAN DURING THE SPRING. EL NINO IS
LIKELY TO EMERGE SOON (82% CHANCE IN MAY-JUNE-JULY) AND CONTINUE THROUGH THE
NORTHERN HEMISPHERE WINTER 2026-27 (96% CHANCE IN DECEMBER 2026-FEBRUARY 2027).
THE JUNE-JULY-AUGUST (JJA) TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL TEMPERATURES
THROUGHOUT THE WEST, MUCH OF THE GREAT PLAINS, LOWER MISSISSIPPI VALLEY, AND
EAST. THE HIGHEST FORECAST CONFIDENCE FOR ABOVE-NORMAL TEMPERATURES IS ACROSS
THE PACIFIC NORTHWEST. ABOVE-NORMAL TEMPERATURES ARE ALSO FAVORED FOR A
MAJORITY OF ALASKA.
THE JJA PRECIPITATION OUTLOOK DEPICTS ELEVATED ABOVE-NORMAL PRECIPITATION
PROBABILITIES FOR PARTS OF THE SOUTHWEST, GREAT BASIN, CENTRAL TO SOUTHERN
ROCKIES, AND THE NORTHEAST. THE OUTLOOK LEANS TOWARDS BELOW-NORMAL
PRECIPITATION ALONG THE WESTERN GULF COAST, ALONG WITH PORTIONS OF THE NORTHERN
GREAT PLAINS AND UPPER MISSISSIPPI VALLEY. ABOVE-NORMAL PRECIPITATION IS
FAVORED FOR WESTERN AND NORTHERN ALASKA.
AREAS DEPICTED IN WHITE AND LABELED "EQUAL-CHANCES" OR "EC" ARE REGIONS WHERE
CLIMATE SIGNALS ARE WEAK, AND SO THERE ARE EQUAL CHANCES FOR EITHER ABOVE-,
NEAR- OR BELOW-NORMAL SEASONAL MEAN TEMPERATURES OR TOTAL PRECIPITATION AMOUNTS.
BASIS AND SUMMARY OF THE CURRENT LONG-LEAD OUTLOOKS
NOTE: FOR GRAPHICAL DISPLAYS OF THE FORECAST TOOLS DISCUSSED BELOW SEE:
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/90DAY/TOOLS/BRIEFING
CURRENT ATMOSPHERIC AND OCEANIC CONDITIONS
WEEKLY OBSERVED SST DEPARTURES IN THE NINO 3.4 REGION ARE +0.5 DEGREES C AND
HAVE INCREASED STEADILY SINCE MARCH. FROM APRIL 19 TO MAY 16, EQUATORIAL SSTS
WERE ABOVE-AVERAGE (AT OR MORE THAN 0.5 DEGREES C) ACROSS THE CENTRAL AND
EASTERN PACIFIC OCEAN. BY MID-MAY, EQUATORIAL SUBSURFACE TEMPERATURE ANOMALIES
WERE MORE THAN +2 DEGREES C BETWEEN 100 AND 150 METERS AT DEPTH, NEAR THE DATE
LINE. DURING LATE APRIL THROUGH MID-MAY, NEGATIVE OUTGOING LONGWAVE RADIATION
(OLR) ANOMALIES (ENHANCED CONVECTION AND PRECIPITATION) WAS OBSERVED NORTH OF
THE EQUATOR NEAR THE DATE LINE. ABOVE-AVERAGE OLR (SUPPRESSED CONVECTION AND
PRECIPITATION) WAS OBSERVED OVER INDONESIA, THE PHILIPPINES, AND SOUTH OF THE
EQUATOR NEAR THE DATE LINE. LOW-LEVEL (850-HPA) WINDS WERE CLOSE TO AVERAGE
ACROSS MOST OF THE EQUATORIAL PACIFIC OCEAN, WHILE UPPER-LEVEL (200-HPA) WIND
ANOMALIES WERE WESTERLY OVER THE CENTRAL AND EAST-CENTRAL PACIFIC.
THE MADDEN-JULIAN OSCILLATION (MJO) BRIEFLY STALLED OVER THE INDIAN OCEAN
DURING EARLY MAY AND BECAME LESS COHERENT. HOWEVER, THE MJO RECENTLY BEGAN TO
RESUME ITS EASTWARD PROPAGATION TO THE MARITIME CONTINENT. DYNAMICAL MODEL
FORECASTS ARE IN GOOD AGREEMENT THAT A ROBUST MJO PROPAGATES EAST OVER THE WEST
PACIFIC AND EVENTUALLY SHIFTS TO THE WESTERN HEMISPHERE BY EARLY JUNE.
PROGNOSTIC DISCUSSION OF SST FORECASTS
THE CPC SST CONSOLIDATION FORECAST FOR NINO 3.4 DEPICTS SST ANOMALIES
INCREASING THROUGH THE SUMMER AND REACHING +1.5 DEGREES C (STRONG EL NINO
THRESHOLD) BY SEP-OCT-NOV. A MAJORITY OF THE NORTH AMERICAN MULTI-MODEL
ENSEMBLE MEMBERS (NMME) ALONG WITH THE ECMWF MODEL ALSO INDICATE A STRONG EL
NINO BY THE FALL. LATER IN THE 2026-27 WINTER, THE CPC SST CONSOLIDATION
FORECAST DEPICTS ANOMALIES DECREASING BUT REMAINING ABOVE +0.5 DEGREES C
THROUGH FEB-MAR-APR 2027. AS OF MAY 14, THE CPC ENSO OUTLOOK INDICATES THAT EL
NINO IS LIKELY TO EMERGE SOON (82% CHANCE IN MAY-JUN-JUL) AND CONTINUE THROUGH
DEC 2026-FEB 2027 (96% CHANCE). BY THE LATE FALL AND EARLY WINTER
(OCTOBER-NOVEMBER-DECEMBER), THERE IS NEAR A 2 IN 3 CHANCE OF A STRONG EL NINO.
PROGNOSTIC TOOLS USED FOR U.S. TEMPERATURE AND PRECIPITATION OUTLOOKS
THE TEMPERATURE AND PRECIPITATION OUTLOOKS FOR JJA 2026 WERE BASED ON DYNAMICAL
MODELS SUCH AS THE NORTH AMERICAN MULTI-MODEL ENSEMBLE (NMME) AND THE
COPERNICUS (C3S) MULTI-MODEL ENSEMBLE SYSTEM. A CALIBRATION, BRIDGING, AND
MERGING (CBAM) VERSION OF THE NMME WAS ALSO USED IN THE OUTLOOKS. SOIL MOISTURE
INFLUENCE ALONG WITH ITS CONSTRUCTED ANALOG WERE FACTORS IN THE JJA TEMPERATURE
AND PRECIPITATION OUTLOOKS AN OBJECTIVE, HISTORICAL SKILL-WEIGHTED
CONSOLIDATION THAT INCLUDES THE NMME ALONG WITH STATISTICAL TOOLS SUCH AS THE
SST-BASED CONSTRUCTED ANALOG AND THE ENSO-OCN WAS USED THROUGH OCT-NOV-DEC.
BEYOND THAT TIME, THE CONSOLIDATION ONLY INCLUDES STATISTICAL TOOLS. LONG-TERM
CLIMATE TRENDS WERE CONSIDERED FOR ALL LEADS, BUT WERE RELIED UPON MOST DURING
THE 2027 SPRING AND SUMMER.
PROGNOSTIC DISCUSSION OF OUTLOOKS - JJA 2026 TO JJA 2027
TEMPERATURE
THE HIGHEST FORECAST CONFIDENCE FOR ABOVE-NORMAL TEMPERATURES (PROBABILITIES
MORE THAN 60%) DURING JUN-JUL-AUG (JJA) IS ACROSS THE PACIFIC NORTHWEST WHERE
THERE IS EXCELLENT AGREEMENT AMONG DYNAMICAL MODELS AND CONSISTENT WITH FAVORED
BELOW-NORMAL PRECIPITATION. IN ADDITION, EL NINO SUMMERS TEND TO BE
WARMER-THAN-NORMAL. BASED ON A CONSENSUS OF DYNAMICAL MODELS AND STATISTICAL
TOOLS, ENHANCED ABOVE-NORMAL TEMPERATURE PROBABILITIES (GREATER THAN 40%)
COVER THE REMAINDER OF THE WESTERN CONTIGUOUS U.S. (CONUS), MUCH OF THE CENTRAL
TO SOUTHERN GREAT PLAINS, AND EXTEND FROM THE SOUTHEAST NORTH TO SOUTHERN NEW
ENGLAND. EQUAL CHANCES (EC) OF BELOW, NEAR, OR ABOVE-NORMAL TEMPERATURES ARE
FORECAST FOR THE MIDWEST WHERE A MORE VARIABLE TEMPERATURE PATTERN IS EXPECTED
THIS SUMMER AND THE WARMER DYNAMICAL MODEL OUTPUT IS OFFSET BY THE COLDER EL
NINO COMPOSITES. ALTHOUGH THE CBAM VERSION OF THE NMME DEPICTS ELEVATED
BELOW-NORMAL TEMPERATURE PROBABILITIES FOR PARTS OF THE MIDWEST, A LEAN TOWARDS
BELOW-NORMAL TEMPERATURES WAS NOT INTRODUCED UNTIL THE JUL-AUG-SEP (JAS)
OUTLOOK AS THERE ARE SIGNS THAT JUNE COULD BE WARMER-THAN-NORMAL. DYNAMICAL
MODEL OUTPUT AND EL NINO COMPOSITES FAVOR ABOVE-NORMAL TEMPERATURES THROUGHOUT
ALASKA, EXCEPT FOR THE NORTH SLOPE. ALTHOUGH THE JUNE OUTLOOK LEANS ON THE
COLDER SIDE FOR COASTAL SOUTHWESTERN ALASKA AND THE ALASKA PENINSULA, ELEVATED
ABOVE-NORMAL TEMPERATURE PROBABILITIES (33-40%) ARE FORECAST ACROSS THESE AREAS
DURING THE THREE-MONTH PERIOD OF JJA.
LATER IN THE SUMMER AND INTO THE EARLY FALL, INCLUDING JUL-AUG-SEP AND
AUG-SEP-OCT, THE OUTLOOK SLIGHTLY FAVORS BELOW-NORMAL TEMPERATURES FOR PARTS OF
THE MIDWEST BASED ON EL NINO INFLUENCES HISTORICALLY. GIVEN THE INCREASING
CHANCE OF A STRONG EL NINO BY NEXT WINTER, ABOVE-NORMAL TEMPERATURE
PROBABILITIES WERE INCREASED TO MORE THAN 50% ACROSS THE NORTHERN TIER OF THE
CONUS, FROM THE PACIFIC NORTHWEST EAST TO THE NORTHERN GREAT PLAINS, DURING
DEC-JAN-FEB 2026-27. EC WAS MAINTAINED FOR THE SOUTHERN TIER OF THE CONUS
THROUGH NEXT WINTER WHICH IS CONSISTENT WITH THE SST-CONSTRUCTED ANALOG TOOL.
BY THE LATE SPRING AND FOLLOWING SUMMER OF 2027, DECADAL TRENDS WERE THE MAJOR
FACTOR IN THOSE TEMPERATURE OUTLOOKS.
PRECIPITATION
SIMILAR TO PREVIOUS FORECAST REASONING WITH LOW SOIL MOISTURE FAVORING ENHANCED
HEATING AND A ROBUST START TO THE MONSOON ALONG WITH GOOD DYNAMICAL MODEL
AGREEMENT AND CONSISTENCY, THE JJA OUTLOOK FAVORS ABOVE-NORMAL PRECIPITATION
FOR MUCH OF THE SOUTHWEST. DYNAMICAL MODEL OUTPUT HAS TRENDED WETTER FARTHER TO
THE NORTH INTO THE CENTRAL ROCKIES, AND THIS IS CONSISTENT WITH EL NINO SUMMERS
HISTORICALLY. THEREFORE, THE JJA OUTLOOK DEPICTS ELEVATED ABOVE-NORMAL
PRECIPITATION PROBABILITIES AS FAR NORTH AS WYOMING WITH THE LARGEST
PROBABILITIES (> 40%) CENTERED OVER THE FOUR CORNERS. SURROUNDING THIS ENHANCED
MONSOON SIGNAL, BELOW-NORMAL PRECIPITATION IS FAVORED FOR PARTS OF THE PACIFIC
NORTHWEST, NORTHERN TO CENTRAL GREAT PLAINS, AND UPPER MISSISSIPPI VALLEY
DURING JJA. THIS FAVORED DRYNESS HAS SUPPORT FROM A NUMBER OF TOOLS INCLUDING
THE NMME, SST-CONSTRUCTED ANALOG, AND DECADAL TRENDS. IN ADDITION, SOIL
MOISTURE IS LOW FOR NEBRASKA, SOUTHERN SOUTH DAKOTA, AND PARTS OF MINNESOTA
WHERE THERE IS A SIGNIFICANT POSITIVE CORRELATION BETWEEN LOW MAY SOIL MOISTURE
AND BELOW-NORMAL PRECIPITATION DURING JJA. FORECAST CONFIDENCE FOR A PARTICULAR
CATEGORY OF PRECIPITATION (BELOW, NEAR, OR ABOVE) IS LOWER FOR THE REMAINDER OF
THE GREAT PLAINS AND MIDWEST AS THE NMME TRENDED NOTABLY WETTER COMPARED TO ONE
MONTH AGO. THE JJA OUTLOOK LEANS SLIGHTLY TOWARDS BELOW-NORMAL PRECIPITATION
ALONG THE WESTERN GULF COAST BASED ON COMPOSITES AND DYNAMICAL MODEL OUTPUT.
FOR THE EASTERN CONUS, MANY OF THE TOOLS LEAN ON THE WETTER SIDE BUT VARY
REGIONALLY. THEREFORE, THE JJA PRECIPITATION OUTLOOK RELIED UPON THE
CONSOLIDATION WITH A SLIGHT LEAN (33-40% CHANCE) TOWARDS ABOVE-NORMAL
PRECIPITATION ACROSS THE NORTHEAST. BASED ON THE NMME, ELEVATED ABOVE-NORMAL
PRECIPITATION PROBABILITIES ARE FORECAST ACROSS WESTERN AND NORTHERN MAINLAND
ALASKA. EL NINO SUMMERS TEND TO BE DRIER FOR SOUTHERN ALASKA, BUT THE JJA
OUTLOOK CALLS FOR EQUAL CHANCES OF BELOW, NEAR, OR ABOVE-NORMAL PRECIPITATION
SINCE LAST MONTH'S OUTLOOK FAVORED ABOVE-NORMAL PRECIPITATION.
STARTING IN JUL-AUG-SEP (JAS) AND CONTINUING THROUGH SEP-OCT-NOV, ELEVATED
ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE FORECAST FOR SOUTHERN CALIFORNIA
DUE TO THE LIKELIHOOD OF AN ACTIVE EAST PACIFIC HURRICANE SEASON AND ITS
ASSOCIATED INFLUENCE ON PRECIPITATION. A DRY SIGNAL IN EL NINO COMPOSITES PEAKS
IN JAS THROUGHOUT THE SOUTH-CENTRAL CONUS AND THE PRECIPITATION OUTLOOK
FOLLOWED THIS HISTORICAL GUIDANCE. GIVEN THE INCREASING CHANCE OF A STRONG EL
NINO BY THE LATE FALL, THE MID-ATLANTIC IS FAVORED TO HAVE ABOVE-NORMAL
PRECIPITATION BEGINNING IN OCT-NOV-DEC. COMPARED TO LAST MONTH, ABOVE-NORMAL
PRECIPITATION PROBABILITIES WERE INCREASED ACROSS THE SOUTHERN TIER OF THE
CONUS DURING THE LATE FALL AND 2026-27 WINTER, NOW EXCEEDING 60% FOR PARTS OF
THE SOUTHEAST. EL NINO COMPOSITES ALSO SUPPORTED A COUPLE OF AREAS WITH FAVORED
BELOW-NORMAL PRECIPITATION ACROSS PARTS OF THE MIDWEST AND NORTHERN ROCKIES. EC
IS FORECAST FOR NEARLY ALL OF THE WEST COAST DURING THE WINTER 2026-27 DUE TO
THE WEAK SIGNAL FROM THE ENSO-OCN TOOL. BY THE SUMMER OF 2027, THE
PRECIPITATION OUTLOOK IS BASED ON DECADAL TRENDS.
FORECASTER: BRAD PUGH
THE CLIMATIC NORMALS ARE BASED ON CONDITIONS BETWEEN 1991 AND 2020, FOLLOWING
THE WORLD METEROLOGICAL ORGANIZATION CONVENTION OF USING THE MOST RECENT 3
COMPLETE DECADES AS THE CLIMATIC REFERENCE PERIOD. THE PROBABILITY ANOMALIES
FOR TEMPERATURE AND PRECIPITATION BASED ON THESE NEW NORMALS BETTER REPRESENT
SHORTER TERM CLIMATIC ANOMALIES THAN THE FORECASTS BASED ON OLDER NORMALS.
FOR A DESCRIPTION OF OF THE STANDARD FORECAST TOOLS - THEIR SKILL- AND THE
FORECAST FORMAT PLEASE SEE OUR WEB PAGE AT
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/PREDICTIONS/LONG_RANGE/TOOLS.HTML
(USE LOWER CASE LETTERS)
INFORMATION ON THE FORMATION OF SKILL OF THE CAS FORECASTS MAY BE FOUND AT:
HTTP://WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/SOILMST_MONITORING/US/OUTLOOK/OUTLOOK.SHTM
L
(USE LOWERCASE LETTERS)
NOTES - THESE CLIMATE OUTLOOKS ARE INTENDED FOR USE PRIOR TO THE START OF THEIR
VALID PERIOD. WITHIN ANY GIVEN VALID PERIOD OBSERVATIONS AND SHORT AND MEDIUM
RANGE FORECASTS SHOULD BE CONSULTED.
THIS SET OF OUTLOOKS WILL BE SUPERSEDED BY THE ISSUANCE OF THE NEW SET NEXT
MONTH ON JUN 18 2026
1991-2020 BASE PERIOD MEANS WERE IMPLEMENTED EFFECTIVE WITH THE MAY 20, 2021
FORECAST RELEASE.
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