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FXUS06 KWBC 211902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE APRIL 21 2026
6-10 DAY OUTLOOK FOR APR 27 - MAY 01, 2026
THE 0Z ECMWF, GEFS AND CANADIAN ENSEMBLE MEAN FORECASTS AGREE ON THE OVERALL
AVERAGE LARGE-SCALE CIRCULATION PATTERN OVER NORTH AMERICA FOR THE 6-10 DAY
PERIOD. HOWEVER, THERE ARE SOME MODEL DIFFERENCES AND INCREASING UNCERTAINTY IN
UNDERLYING VARIATIONS THROUGH THE PERIOD. THE MANUAL HEIGHT BLEND OF 500-HPA
HEIGHT FORECASTS IS BASED ON 0Z ENSEMBLE MEANS, WEIGHTING THE ECMWF MODEL
GREATER DUE TO RECENT MODEL SKILL. ALL ENSEMBLE MEANS PREDICT AN AMPLIFIED
TROUGH OVER THE ALEUTIANS AND THE BERING SEA AT THE START OF THE 6-10 DAY
PERIOD, THAT DEAMPLIFIES AND RETROGRESSES OVER TIME. A RIDGE AND ASSOCIATED
POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER THE NORTHEASTERN PACIFIC
OCEAN EXTENDING INTO SOUTHEAST ALASKA AND EASTERN MAINLAND ALASKA, WHICH IS
SIGNIFICANTLY MORE AMPLIFIED IN THE ECMWF THAN THE GEFS. THE ECMWF ENSEMBLE
MEAN PREDICTS POSITIVE 500-HPA HEIGHT ANOMALIES TO EXTEND OVER THE NORTHWESTERN
CONTIGUOUS UNITED STATES (CONUS) LATER IN THE PERIOD. A TROUGH AND ASSOCIATED
NEGATIVE 500-HPA HEIGHT ANOMALIES EXTEND FROM NEAR THE CALIFORNIA COAST TO THE
NORTHERN INTERIOR CONUS AT THE START OF THE PERIOD IN ALL ENSEMBLE MEANS. THE
ECMWF ENSEMBLE MEAN PREDICTS THE CENTER OF NEGATIVE 500-HPA HEIGHT ANOMALIES
FURTHER WEST OVER THE NORTHERN ROCKIES AND HIGH PLAINS ON DAY 6, RELATIVE TO
NEGATIVE ANOMALIES CENTERED OVER THE NORTHERN PLAINS IN THE GEFS ENSEMBLE MEAN
FORECAST. DURING THE PERIOD, THE TROUGH DEAMPLIFIES SOMEWHAT OVER SOUTHERN
CALIFORNIA AND THE SOUTHWEST, WHILE A TROUGH AMPLIFIES OVER THE NORTHEASTERN
CONUS. A RIDGE AND POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED ALONG MOST
OF THE GULF COAST BY THE ENSEMBLE MEAN FORECASTS AND THE MANUAL BLEND.
BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE FAR WESTERN ALEUTIANS, UNDER
ANOMALOUS NORTHERLY FLOW BEHIND A PREDICTED TROUGH. ABOVE NORMAL TEMPERATURES
ARE FAVORED FOR MOST OF MAINLAND ALASKA, EXCLUDING MOST OF THE SOUTHERN
MAINLAND, UNDER SOUTHERLY MID-LEVEL FLOW, AND FOR SOUTHEAST ALASKA, UNDER
POSITIVE 500-HPA HEIGHT ANOMALIES. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR
PARTS OF THE PACIFIC NORTHWEST, UNDER A PREDICTED RIDGE. BELOW NORMAL
TEMPERATURES ARE FAVORED FOR PARTS OF THE SOUTHWEST ACROSS THE CENTRAL ROCKIES,
AND ARE LIKELY FOR MUCH OF THE NORTHERN CENTRAL CONUS, UNDER A PREDICTED TROUGH
EARLY IN THE PERIOD. ABOVE NORMAL TEMPERATURES ARE LIKELY FOR MOST OF THE
SOUTHERN PLAINS AND THE SOUTHEAST, UNDER WEAK RIDGING AND CONSISTENT WITH THE
CONSOLIDATION OF CALIBRATED ECMWF AND GEFS TEMPERATURE FORECASTS. ABOVE NORMAL
TEMPERATURES ARE FAVORED FOR FAR NORTHERN AREAS OF THE NORTHEAST, UNDER
POSITIVE 500-HPA HEIGHT ANOMALIES EARLY IN THE PERIOD. ABOVE NORMAL
TEMPERATURES ARE LIKELY FOR HAWAII, WITH POSITIVE SEA SURFACE TEMPERATURE
ANOMALIES IN THE VICINITY.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE ALEUTIAN ISLANDS AND MAINLAND
ALASKA, UNDER AND AHEAD OF A PREDICTED TROUGH. BELOW NORMAL PRECIPITATION IS
FAVORED FOR SOUTHERN AREAS OF SOUTHEAST ALASKA, CONSISTENT WITH MOST
PRECIPITATION TOOLS. BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR PARTS
OF NORTHWESTERN OREGON AND WESTERN WASHINGTON, UNDER A PREDICTED RIDGE. ABOVE
NORMAL PRECIPITATION IS FAVORED FROM CALIFORNIA EASTWARD ACROSS MOST OF THE
CONUS AHEAD OF PREDICTED TROUGHS OVER SOUTHERN CALIFORNIA AND THE NORTHERN
CENTRAL CONUS, EXCLUDING SOUTH FLORIDA AND MUCH OF THE NORTHERN TIER FROM THE
PACIFIC NORTHWEST TO THE NORTHERN PLAINS. PROBABILITIES FOR ABOVE NORMAL
PRECIPITATION EXCEED 50 PERCENT FROM CENTRAL CALIFORNIA INTO PARTS OF THE GREAT
BASIN, ALTHOUGH PREDICTED PRECIPITATION ANOMALIES ARE RELATIVELY SMALL.
PROBABILITIES FAVORING ABOVE NORMAL PRECIPITATION EXCEED 50 PERCENT FROM THE
CENTRAL GULF COAST STATES TO THE OHIO VALLEY AND PARTS OF THE NORTHEAST
ATLANTIC COAST, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION. ABOVE NORMAL
PRECIPITATION IS FAVORED FOR HAWAII, CONSISTENT WITH THE PRECIPITATION
CONSOLIDATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 25% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
AGREEMENT AMONG ENSEMBLE MEANS ON THE PREDICTED 500-HPA HEIGHT PATTERN, OFFSET
BY A CHANGING CIRCULATION PATTERN AND SOME DIFFERENCES AMONG MODEL TEMPERATURE
AND PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR APR 29 - MAY 05, 2026
ENSEMBLE MEAN FORECASTS FOR THE 8-14 DAY PERIOD FROM THE 0Z ECMWF, GEFS, AND
CANADIAN MODELS PREDICT SOME PERSISTENT LARGE-SCALE FEATURES FROM THE 6-10 DAY
PERIOD FORECASTS, ALONG WITH WEAKENING OF MID-LEVEL HEIGHT ANOMALIES AND SOME
CHANGES IN THE PATTERN OVER THE CONUS. A TROUGH AND NEGATIVE 500-HPA HEIGHT
ANOMALIES PERSIST BUT DEAMPLIFY AND RETROGRESS OVER THE WESTERN ALEUTIANS. A
RIDGE PERSISTS INTO THE WEEK-2 PERIOD OVER MAINLAND ALASKA AND SOUTHEAST
ALASKA, WHILE POSITIVE 500-HPA HEIGHT ANOMALIES WEAKEN. WITH INCREASING
UNCERTAINTY AND DIFFERENCES AMONG MODEL ENSEMBLE MEANS, WEAK TROUGHING IS
PRESENT OVER CALIFORNIA AND PARTS OF THE SOUTHWEST IN THE MANUAL BLEND FOR WEEK
2. ALL ENSEMBLE MEANS PREDICT AMPLIFICATION OF NEGATIVE 500-HPA HEIGHT
ANOMALIES ASSOCIATED WITH A TROUGH OVER THE WEST COAST LATE IN WEEK 2. A TROUGH
IS PREDICTED FROM THE NORTHERN CENTRAL CONUS ACROSS THE NORTHEAST AND
MID-ATLANTIC, IN ALL DYNAMICAL MODEL FORECASTS, WITH SOME DIFFERENCES IN THE
AMPLITUDE AND EXTENT OF NEGATIVE 500-HPA HEIGHT ANOMALIES BETWEEN MODELS.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR CENTRAL AND NORTHERN MAINLAND ALASKA,
AS WELL AS MOST OF SOUTHEAST ALASKA, UNDER A PREDICTED RIDGE AND CONSISTENT
WITH A CONSENSUS OF MODEL TEMPERATURE TOOLS. ABOVE NORMAL TEMPERATURES ARE
FAVORED FOR MOST OF THE PACIFIC NORTHWEST, THE NORTHERN ROCKIES, AND THE
CALIFORNIA COAST, CONSISTENT WITH CALIBRATED ECMWF TEMPERATURE FORECASTS. BELOW
NORMAL TEMPERATURES ARE FAVORED FOR THE CENTRAL AND NORTHERN PLAINS EASTWARD
ACROSS THE MIDWEST TO THE MID-ATLANTIC AND MOST OF THE NORTHEAST, EXCLUDING
NORTHERN MAINE, UNDER A PREDICTED TROUGH. ABOVE NORMAL TEMPERATURES ARE FAVORED
FOR MUCH OF THE SOUTHWEST BORDER WITH MEXICO, SOUTHERN TEXAS AND THE GULF
COAST, CONSISTENT WITH THE TEMPERATURE CONSOLIDATION. ABOVE NORMAL TEMPERATURES
ARE LIKELY FOR HAWAII, SURROUNDED BY POSITIVE SEA SURFACE TEMPERATURE
ANOMALIES.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE ALEUTIANS AND WESTERN MAINLAND
ALASKA IN THE 8-14 DAY PERIOD, UNDER AND AHEAD OF THE PREDICTED TROUGH. BELOW
NORMAL PRECIPITATION IS FAVORED FOR SOUTHERN AREAS OF SOUTHEAST ALASKA,
CONSISTENT WITH CALIBRATED ECMWF MODEL PRECIPITATION FORECASTS. AHEAD OF
PREDICTED TROUGHING, ABOVE NORMAL PRECIPITATION CONTINUES TO BE FAVORED INTO
THE WEEK-2 PERIOD ACROSS MOST OF THE WESTERN CONUS, EXCLUDING PARTS OF THE
PACIFIC NORTHWEST. ENHANCED PROBABILITIES FOR ABOVE NORMAL PRECIPITATION EXTEND
ACROSS MOST OF THE CENTRAL AND SOUTHERN PLAINS INTO THE SOUTHEAST, AND
NORTHWARD THROUGH THE MID-ATLANTIC COAST INTO THE NORTHEAST, CONSISTENT WITH
THE PRECIPITATION CONSOLIDATION. ABOVE NORMAL PRECIPITATION IS FAVORED FOR
HAWAII, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 25% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, WITH
GENERAL AGREEMENT ON THE OVERALL 500-HPA HEIGHT PATTERN FORECAST, OFFSET BY
WEAKER ANOMALIES IN THE MANUAL BLEND OF MID-LEVEL HEIGHT FORECASTS AND
UNCERTAINTY AMONG THE TEMPERATURE AND PRECIPITATION TOOLS.
FORECASTER: D COLLINS
NOTES:
THE NOTATION FOR THE CATEGORICAL FORECAST INDICATED ON THE MAPS IS
THE SAME AS THAT IN THE TABLES: A-ABOVE N-NEAR NORMAL B-BELOW
THE TEMPERATURE MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING WARMER
(ORANGE, "A"), COLDER (BLUE, "B"), OR CLOSE TO (GRAY, "N") NORMAL.
LABELS ON THE SHADED LINES GIVE THE PROBABILITY (> 33%) OF THE MORE
LIKELY CATEGORY (B OR A). PROBABILITY OF N IS ALWAYS < 40%.
THE PRECIPITATION MAP SHOWS REGIONS WITH > 33% CHANCE OF BEING
WETTER (GREEN, "A"), DRIER (TAN, "B"), OR CLOSE TO (GRAY, "N")
NORMAL. LABELS ON THE SHADED LINES GIVE THE PROBABILITY (> 33%) OF
THE MORE LIKELY CATEGORY (B OR A). PROBABILITY OF N IS ALWAYS < 40%.
IN THE SOUTHWEST AND OTHER CLIMATOLOGICALLY DRY REGIONS - THERE WILL
BE A GREATER THAN 33.3% CHANCE OF NO PRECIPITATION AND OCCASIONALLY
EVEN A NORMAL (I.E. MEDIAN) VALUE OF ZERO - ESPECIALLY DURING THE DRY
SEASONS. IN SUCH CASES A FORECAST OF NEAR NORMAL IS EFFECTIVELY A
FORECAST OF LITTLE OR NO PRECIPITATION.
THE CLIMATE PREDICTION CENTER USES 1991-2020 BASE PERIOD MEANS AS
REFERENCE IN THE CLIMATE OUTLOOKS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MAY
21.
ANALOGS TO THE 5 DAY MEAN OBSERVED PATTERN CENTERED 3 DAYS AGO (D-3)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 5 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
20180502 - 20040417 - 20090424 - 20150405 - 20180427
ANALOGS TO THE 7 DAY MEAN OBSERVED PATTERN CENTERED 4 DAYS AGO (D-4)
FOR THE REGION FROM 20N TO 70N LATITUDE AND 175E TO 60W LONGITUDE
INCLUDE THE 7 DAY PERIODS CENTERED ON THE FOLLOWING DATES:
20180502 - 20040417 - 20210331 - 20020417 - 20150406
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 27 - MAY 01, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON N N NRN CALIF N A
SRN CALIF N A IDAHO N A NEVADA N A
W MONTANA N N E MONTANA B N WYOMING B A
UTAH B A ARIZONA B A COLORADO B A
NEW MEXICO N A N DAKOTA B N S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA N A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B A IOWA B A MISSOURI N A
ARKANSAS A A LOUISIANA A A WISCONSIN N A
ILLINOIS N A MISSISSIPPI A A MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT A A NEW HAMP N A MAINE A A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A N AK N SLOPE A A
AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A
AK S INT N A AK SO COAST N A AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 29 - MAY 05, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A A NRN CALIF N A
SRN CALIF N A IDAHO N A NEVADA N A
W MONTANA N A E MONTANA B N WYOMING N A
UTAH N A ARIZONA N A COLORADO N A
NEW MEXICO N A N DAKOTA B N S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA N A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B N IOWA B N MISSOURI B A
ARKANSAS N A LOUISIANA A A WISCONSIN B N
ILLINOIS B N MISSISSIPPI N A MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B A ALABAMA N A NEW YORK B A
VERMONT B A NEW HAMP B A MAINE N A
MASS B A CONN B A RHODE IS B A
PENN B N NEW JERSEY B A W VIRGINIA B N
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA N A S CAROLINA N A GEORGIA A A
FL PNHDL A A FL PENIN A N AK N SLOPE A A
AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A
AK S INT N A AK SO COAST N A AK PNHDL A B
LEGEND
TEMPS WITH RESPECT TO NORMAL PCPN WITH RESPECT TO MEDIAN
A - ABOVE N - NEAR NORMAL A - ABOVE N - NEAR MEDIAN
B - BELOW B - BELOW
THE FORECAST CLASSES REPRESENT AVERAGES FOR EACH STATE. NORMAL
VALUES - WHICH MAY VARY WIDELY ACROSS SOME STATES - ARE
AVAILABLE FROM YOUR LOCAL WEATHER SERVICE FORECAST OFFICE.
FOR ADDITIONAL INFORMATION SEE MESSAGE FXUS06 KWBC - ON AWIPS AS
PMDMRD.
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