914
FXUS06 KWBC 221901
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU MAY 22 2025
6-10 DAY OUTLOOK FOR MAY 28 - JUN 01, 2025
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT IN DEPICTING A HIGH
AMPLITUDE 500-HPA HEIGHT PATTERN ACROSS MUCH OF NORTH AMERICA. THE PERIOD
BEGINS WITH A POWERFUL TROUGH OVER THE GULF OF ALASKA WITH A SECOND TROUGH TO
ITS NORTH NEAR NORTHWESTERN MAINLAND ALASKA. AN ANOMALOUS RIDGE IS FORECAST
DOWNSTREAM STRETCHING FROM WEST-CENTRAL CANADA TO THE INTERIOR WESTERN
CONTIGUOUS UNITED STATES (CONUS). ANOMALOUS TROUGHING IS FORECAST ACROSS MUCH
OF THE EASTERN CONUS CENTERED NEAR THE GREAT LAKES AND OHIO VALLEY. GENERALLY
NEAR NORMAL HEIGHTS ARE FORECAST FOR HAWAII. AS TIME PROGRESSES, THE TROUGH
OVER THE GULF OF ALASKA IS EXPECTED TO WEAKEN BY DAY 10 AS THE FLOW PATTERN
BECOMES MORE ZONAL. HOWEVER, THE SECOND TROUGH NEAR THE NORTHWESTERN MAINLAND
IS FORECAST TO PERSIST AND RETROGRADE SLIGHTLY TO THE BERING SEA. THE RIDGING
ACROSS THE WEST IS FORECAST TO PERSIST THROUGHOUT MOST OF THE PERIOD WITH ABOVE
NORMAL HEIGHTS PREVAILING ACROSS THE REGION. HOWEVER, THE FLOW BECOMES MORE
ZONAL BY DAY 10. THE TROUGH OVER THE EASTERN CONUS IS EXPECTED TO PROGRESS
TOWARD THE COAST AND TEMPORARILY STRENGTHEN AROUND DAY 8 BEFORE WEAKENING AT
THE END OF THE PERIOD. NEAR NORMAL HEIGHTS ARE GENERALLY FORECAST TO PERSIST
FOR HAWAII WITH TROUGHING INDICATED NORTHWEST OF THE STATE AND RIDGING FORECAST
SOUTHEAST OF THE STATE.
WITH MULTIPLE TROUGHS EXPECTED IN THE VICINITY OF ALASKA, BELOW NORMAL
TEMPERATURES ARE FAVORED FOR MOST OF THE STATE. ABOVE NORMAL TEMPERATURES ARE
LIKELY DOWNSTREAM ACROSS MOST OF THE WESTERN CONUS AND NORTHERN PLAINS.
PROBABILITIES OF ABOVE NORMAL TEMPERATURES EXCEED 80 PERCENT FOR PARTS OF THE
NORTHERN HIGH PLAINS NEAR THE CENTER OF THE PREDICTED MEAN RIDGE AXIS. BELOW
NORMAL TEMPERATURES ARE LIKELY FOR MUCH OF THE SOUTH-CENTRAL AND SOUTHEASTERN
CONUS NORTHWARD TO THE MIDDLE MISSISSIPPI VALLEY AND MID-ATLANTIC STATES. THE
AREA MOST LIKELY TO EXPERIENCE BELOW NORMAL TEMPERATURES EXTENDS FROM THE
TENNESSEE VALLEY WESTWARD TO ADJACENT AREAS OF THE MISSISSIPPI VALLEY. A SLIGHT
TILT TOWARD ABOVE NORMAL TEMPERATURES ARE INDICATED FOR PARTS OF NORTHERN NEW
ENGLAND AHEAD OF THE PREDICTED MEAN TROUGH AXIS. ABOVE NORMAL TEMPERATURES ARE
FAVORED FOR MUCH OF THE FLORIDA PENINSULA TO THE SOUTH OF THE PREDICTED MEAN
FRONTAL BOUNDARY. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR HAWAII, DUE IN
LARGE PART TO ABOVE NORMAL SEA SURFACE TEMPERATURES (SSTS) IN ADJACENT WATERS.
AN ACTIVE PERIOD IS ANTICIPATED ACROSS ALASKA WITH MULTIPLE TROUGHS AFFECTING
THE STATE. ABOVE NORMAL PRECIPITATION IS FAVORED FOR MOST OF THE STATE
EXTENDING SOUTHWARD TO EXTREME NORTHERN PARTS OF THE PACIFIC NORTHWEST. THE
HIGHEST LIKELIHOOD OF ABOVE NORMAL PRECIPITATION IS FORECAST FOR SOUTHEAST
ALASKA, DUE TO ANTICIPATED ANOMALOUS ONSHORE FLOW AHEAD OF THE STRONG TROUGH
FORECAST OVER THE GULF OF ALASKA. SURFACE HIGH PRESSURE IS FORECAST ACROSS MUCH
OF THE NORTH-CENTRAL CONUS. AS SUCH, BELOW NORMAL PRECIPITATION IS MOST LIKELY
FROM THE WESTERN AND CENTRAL GREAT LAKES, THE NORTHERN HALF OF THE MISSISSIPPI
VALLEY, AND PARTS OF THE NORTHERN PLAINS. THIS SURFACE HIGH IS EXPECTED TO PUSH
A FRONTAL BOUNDARY FARTHER TO THE SOUTH THAN TYPICAL THIS TIME OF YEAR, LEADING
TO INCREASED PRECIPITATION CHANCES ACROSS MUCH OF THE SOUTHERN CONUS. THE TAIL
END OF THIS FRONTAL BOUNDARY WILL LIKELY BE A FOCAL POINT FOR INCREASED
PRECIPITATION CHANCES FOR THE SOUTHERN HIGH PLAINS INTO THE SOUTHERN ROCKIES.
POTENTIAL MOISTURE ADVECTION FROM BOTH THE GULF AND FROM POTENTIAL TROPICAL
ACTIVITY IN THE PACIFIC ALSO CONTRIBUTE TO INCREASED TOTALS ACROSS THIS REGION.
ABOVE NORMAL PRECIPITATION IS ALSO FAVORED ALONG THE EASTERN SEABOARD AHEAD OF
THE PREDICTED MEAN TROUGH AXIS OVER THE EASTERN CONUS AND DUE TO POTENTIAL
SURFACE LOW DEVELOPMENT NEAR THE MID ATLANTIC EARLY IN THE PERIOD. A SLIGHT
TILT TOWARD ABOVE NORMAL PRECIPITATION IS INDICATED FOR HAWAII, CONSISTENT WITH
CALIBRATED PRECIPITATION AMOUNTS FROM THE ECMWF AND GEFS ENSEMBLES.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG TODAY’S ENSEMBLE MEANS.
8-14 DAY OUTLOOK FOR MAY 30 - JUN 05, 2025
THE WEEK-2 PERIOD BEGINS WITH A HIGHLY AMPLIFIED PATTERN FEATURING ANOMALOUS
RIDGING ACROSS MUCH OF THE WEST AND NORTHERN PLAINS. TROUGHS ARE PREDICTED OVER
ALASKA AND THE EASTERN SEABOARD. A TROUGH OR CLOSED LOW IS FORECAST OVER THE
EASTERN PACIFIC NEAR THE BAJA CALIFORNIA PENINSULA ASSOCIATED WITH A POTENTIAL
TROPICAL SYSTEM. AS TIME PROGRESSES THE PATTERN BECOMES SIGNIFICANTLY MORE
ZONAL AS THE TROUGH OVER THE GULF OF ALASKA WEAKENS AND THE RESULTANT
DOWNSTREAM FLOW FLATTENS. BY THE END OF WEEK-2, MOST MODEL SOLUTIONS PREDICT
ABOVE NORMAL HEIGHTS OVERSPREADING MOST OF THE CONUS IN THIS LOWER AMPLITUDE
PATTERN. AN EXCEPTION IS FOR WESTERN PARTS OF MAINLAND ALASKA WHERE RESIDUAL
TROUGHING IS FORECAST TO PERSIST BUT WITH DIMINISHED AMPLITUDE. PERSISTENT
TROUGHING IS ALSO FORECAST OVER THE SOUTHEAST OR GULF COAST WITH MODELS
GENERALLY FORECASTING A SLOW RETROGRESSION OF THIS FEATURE TOWARD THE CENTRAL
GULF COAST BY THE MIDDLE OF WEEK-2. GENERALLY NEAR NORMAL HEIGHTS ARE EXPECTED
FOR HAWAII THROUGHOUT THE PERIOD.
BELOW NORMAL TEMPERATURES REMAIN LIKELY ACROSS ALASKA DUE TO PREDICTED
TROUGHING, ESPECIALLY EARLY IN THE PERIOD. RIDGING AND ABOVE NORMAL HEIGHTS ARE
FORECAST TO PERSIST ACROSS MOST OF THE WEST AND NORTHERN PLAINS THROUGHOUT MUCH
OF THE PERIOD, LEADING TO INCREASED PROBABILITIES OF ABOVE NORMAL TEMPERATURES
ACROSS THESE REGIONS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE
SOUTHEASTERN AND SOUTH-CENTRAL CONUS, DUE TO MEAN TROUGHING PREDICTED FROM THE
EASTERN SEABOARD TO THE GULF COAST REGION. ABOVE NORMAL TEMPERATURES ARE
FAVORED ACROSS THE NORTHEAST AS HEIGHTS ARE PREDICTED TO RISE ACROSS THE REGION
AS TIME PROGRESSES. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE SOUTHERN HALF
OF THE FLORIDA PENINSULA TO THE SOUTH OF A MEAN FRONTAL BOUNDARY. A TILT TOWARD
ABOVE NORMAL TEMPERATURES IS ALSO FORECAST FOR HAWAII DUE TO ABOVE NORMAL SSTS.
AN ACTIVE PATTERN IS ANTICIPATED TO CONTINUE INTO WEEK-2 FOR MUCH OF THE
SOUTHERN TIER OF THE CONUS. A PREDICTED FRONTAL BOUNDARY EARLY IN THE PERIOD
LEADS TO INCREASED CHANCES OF ABOVE NORMAL PRECIPITATION FROM THE SOUTHERN AND
CENTRAL HIGH PLAINS AND SOUTHERN AND CENTRAL ROCKIES EASTWARD ACROSS THE GULF
COAST REGION TO SOUTHERN PORTIONS OF THE EAST COAST. THE TROPICS MAY ALSO BE A
PLAYER IN INCREASING PRECIPITATION CHANCES IN THE SOUTHERN CONUS. THE POTENTIAL
DEVELOPMENT OF A TROPICAL SYSTEM IN THE EASTERN PACIFIC MAY LEAD TO INCREASED
MID-LEVEL MOISTURE ADVECTION TO PORTIONS OF THE SOUTHERN HIGH PLAINS.
ADDITIONALLY, DAILY MODEL OUTPUT IS INDICATING THE POTENTIAL FOR INCREASED
TROPICAL MOISTURE FLOW INTO THE FLORIDA PENINSULA LATER IN WEEK-2. A SLIGHT
TILT TOWARD ABOVE NORMAL PRECIPITATION IS ALSO INDICATED FOR PARTS OF NORTHERN
NEW ENGLAND, DUE TO PREDICTED SURFACE LOW DEVELOPMENT OVER SOUTHEASTERN CANADA
EARLY IN THE PERIOD. CONVERSELY, PREDICTED EXPANSIVE SURFACE HIGH PRESSURE
FAVORS A DRIER THAN NORMAL PATTERN ACROSS MOST OF THE NORTHERN CONUS FROM THE
GREAT LAKES AND OHIO VALLEY WESTWARD TO THE NORTHERN PLAINS. A SLIGHT TILT
TOWARD BELOW NORMAL PRECIPITATION ALSO EXTENDS WESTWARD TO INCLUDE THE NORTHERN
ROCKIES, MUCH OF THE COLUMBIA RIVER BASIN, AND PARTS OF NORTHWESTERN
CALIFORNIA, AND SOUTHERN PORTIONS OF THE PACIFIC NORTHWEST DUE TO PREDICTED
MID-LEVEL RIDGING. AN ACTIVE PATTERN REMAINS LIKELY FOR MOST OF ALASKA, DUE TO
PREDICTED MEAN CYCLONIC MID-LEVEL FLOW. A SLIGHT TILT TOWARD ABOVE NORMAL
PRECIPITATION IS INDICATED FOR HAWAII, CONSISTENT WITH CALIBRATED PRECIPITATION
AMOUNTS FROM THE ECMWF AND GEFS ENSEMBLES.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
MODEL AGREEMENT ON AN AMPLIFIED PATTERN EARLY IN THE PERIOD OFFSET BY INCREASED
UNCERTAINTY ASSOCIATED WITH A POTENTIAL CHANGE TO A MORE ZONAL PATTERN LATER IN
THE PERIOD.
FORECASTER: SCOTT H
NOTES:
AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES. IN
THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT ISSUED.
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 (UNSHADED, "N"). HISTORICAL AVERAGE
VALUES FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "F"). 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 (UNSHADED, "N"). HISTORICAL MEDIAN VALUES
FOR THE CALENDAR PERIOD OF THE FORECAST (DASHES, "INCHES"). 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
JUNE 19.
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:
20040530 - 20010603 - 19620603 - 20060511 - 20030515
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:
20010602 - 20040602 - 19620604 - 20060511 - 19750501
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 28 - JUN 01, 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A N
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO N A N DAKOTA A B S DAKOTA A B
NEBRASKA N N KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A B IOWA N B MISSOURI B B
ARKANSAS B N LOUISIANA B A WISCONSIN A B
ILLINOIS B B MISSISSIPPI B A MICHIGAN N B
INDIANA B B OHIO B B KENTUCKY B N
TENNESSEE B N ALABAMA B A NEW YORK N N
VERMONT N A NEW HAMP N A MAINE A A
MASS N A CONN N A RHODE IS N A
PENN B N NEW JERSEY B A W VIRGINIA B N
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL N A FL PENIN A A AK N SLOPE B A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 30 - JUN 05, 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO N A N DAKOTA A B S DAKOTA A B
NEBRASKA N N KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS N A W TEXAS B A
MINNESOTA A B IOWA N B MISSOURI B N
ARKANSAS B A LOUISIANA B A WISCONSIN A B
ILLINOIS N B MISSISSIPPI B A MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY B B
TENNESSEE B N ALABAMA B A NEW YORK N N
VERMONT A N NEW HAMP A N MAINE A A
MASS A N CONN A N RHODE IS A N
PENN N N NEW JERSEY N N W VIRGINIA B B
MARYLAND N N DELAWARE N N VIRGINIA B N
N CAROLINA B N S CAROLINA B A GEORGIA B A
FL PNHDL N A FL PENIN A A AK N SLOPE B A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B A
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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