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FXUS06 KWBC 021902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI MAY 02 2025
6-10 DAY OUTLOOK FOR MAY 08 - 12 2025
DYNAMICAL MODELS ARE IN GOOD AGREEMENT REGARDING THE 500-HPA HEIGHT PATTERN
ACROSS NORTH AMERICA AND THE SURROUNDING REGION. A BROAD AREA OF POSITIVE
500-HPA HEIGHT ANOMALIES IS FORECAST FOR THE WESTERN CONTIGUOUS U.S. (CONUS)
AND ACROSS THE NORTHERN TIER AND SOUTHERN CANADA INTO EASTERN NORTH AMERICA. AN
AREA OF NEGATIVE ANOMALIES AND MID-LEVEL TROUGHING IS FORECAST TO UNDERCUT THE
RIDGE ACROSS THE SOUTHEASTERN CONUS. NEGATIVE 500-HPA HEIGHT ANOMALIES ARE
FORECAST ACROSS THE GULF OF ALASKA AND MUCH OF THE SOUTH COAST AND SOUTHERN
MAINLAND. HOWEVER, WITH NEAR TO BELOW NORMAL HEIGHTS FAVORED ACROSS THE
REMAINDER OF ALASKA, THIS FAVORS INCREASED ONSHORE FLOW TO PARTS OF SOUTHEAST
ALASKA.
STRONG POSITIVE MID-LEVEL HEIGHT ANOMALIES BRING ELEVATED CHANCES FOR ABOVE
NORMAL TEMPERATURES TO MUCH OF THE WEST AND NORTH-CENTRAL CONUS, WITH WEAKER
CHANCES LINGERING INTO PARTS OF THE NORTHEAST. MEANWHILE, A SHORTWAVE TROUGH
AND ASSOCIATED FRONTAL SYSTEM PROGRESSING ACROSS PARTS OF THE SOUTH, OHIO
VALLEY, AND MID-ATLANTIC BRINGING ENHANCED CHANCES FOR BELOW NORMAL
TEMPERATURES TO THE SOUTH-CENTRAL CONUS AND NEAR NORMAL FAVORED ACROSS THE
UPPER OHIO VALLEY, MID-ATLANTIC, AND SOUTHERN ATLANTIC STATES. IN ALASKA,
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR PORTIONS OF SOUTHWEST ALASKA AND THE
ALEUTIANS. BELOW NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR PORTIONS OF
NORTHERN AND EASTERN MAINLAND ALASKA INTO SOUTHEAST ALASKA, WITH NEAR NORMAL
FAVORED FOR THE REMAINDER OF MAINLAND ALASKA. IN HAWAII, ABOVE NORMAL
TEMPERATURES REMAIN FAVORED FOR THE ISLAND CHAIN.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE FOUR CORNERS, SOUTHERN
PLAINS, AND THE SOUTHEASTERN CONUS AS RESULT OF A SHORTWAVE TROUGH PROGRESSING
ACROSS THE SOUTHERN TIER. BELOW NORMAL PRECIPITATION IS FAVORED BENEATH THE
MID-LEVEL RIDGING AND POSITIVE 500-HPA HEIGHT ANOMALIES ACROSS THE NORTHERN
TIER OF THE CONUS AND ALONG THE WEST COAST. ABOVE NORMAL PRECIPITATION IS
FAVORED FOR SOUTHERN ALASKA, WITH ONSHORE FLOW BRINGING ENHANCED PROBABILITIES
TO SOUTHEAST ALASKA IN PARTICULAR. A SLIGHT TILT TOWARD BELOW NORMAL
PRECIPITATION IS FAVORED ALONG PARTS OF THE NORTH SLOPE. IN HAWAII,
ABOVE-NORMAL PRECIPITATION CHANCES ARE ELEVATED WITH GOOD AGREEMENT AMONG THE
DYNAMICAL GUIDANCE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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: ABOVE AVERAGE, 4 OUT OF 5. DUE TO
FAIRLY GOOD AGREEMENT IN THE MODEL HEIGHT PATTERN.
8-14 DAY OUTLOOK FOR MAY 10 - 16 2025
THE DYNAMICAL MODELS REMAIN IN GOOD AGREEMENT HEADING INTO THE WEEK-2 PERIOD.
POSITIVE 500-HPA HEIGHT ANOMALIES REMAIN FORECAST ACROSS THE NORTHERN AND
WESTERN CONUS. NEAR TO SLIGHTLY BELOW NORMAL HEIGHTS ARE AGAIN FAVORED FOR THE
SOUTHEASTERN CONUS WITH A SHORTWAVE TROUGH PUSHING THROUGH THE REGION.
DYNAMICAL TOOLS INDICATE THE MID-LEVEL TROUGH MAY RELOAD BY THE MIDDLE OF THE
PERIOD BRINGING CONTINUED CHANCES FOR UNSETTLED WEATHER ACROSS THE SOUTHEAST. A
WEAK TROUGH IS FORECAST TO DEVELOP ON THE WEST COAST DURING THE PERIOD, THIS
BRINGS ONSHORE FLOW INTO PARTS OF THE WEST DURING THE PERIOD. IN ALASKA, MOST
GUIDANCE FORECASTS NEAR NORMAL HEIGHTS FOR WEEK-2 WITH WEAK TROUGHING FAVORED
IN THE BERING SEA AND THE ALEUTIAN ISLANDS.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF THE CONUS DURING WEEK-2,
EXCLUDING PARTS OF THE SOUTH-CENTRAL AND SOUTHEASTERN CONUS. POSITIVE MID-LEVEL
HEIGHT ANOMALIES BRING ELEVATED CHANCES FOR ABOVE NORMAL TEMPERATURES TO MUCH
OF THE WEST, NORTH-CENTRAL AND NORTHEASTERN CONUS. MEANWHILE, A SHORTWAVE
TROUGH PROGRESSING ACROSS THE SOUTHERN TIER IS ASSOCIATED WITH ENHANCED CHANCES
FOR BELOW NORMAL TEMPERATURES FOR MUCH OF THE REGION. IN ALASKA, ABOVE NORMAL
IS FAVORED FOR MUCH OF THE SOUTHWESTERN PORTIONS OF THE STATE WITH A SLIGHT
TILT TOWARDS BELOW NORMAL ALONG THE NORTH SLOPE. IN HAWAII, ABOVE NORMAL
TEMPERATURES REMAIN FAVORED FOR THE ISLAND CHAIN.
ABOVE NORMAL PRECIPITATION REMAINS FAVORED FOR PORTIONS OF SOUTHEASTERN CONUS
AS RESULT OF A SHORTWAVE TROUGH PROGRESSING ACROSS THE SOUTHERN TIER. BEHIND
THIS SYSTEM, A WELCOME DRYING TREND IS FORECAST ACROSS THE PLAINS AND
MISSISSIPPI VALLEY WITH BELOW NORMAL PRECIPITATION FAVORED TO EXTEND FROM THE
RIO GRANDE INTO THE GREAT LAKES REGION. NEAR TO ABOVE NORMAL PRECIPITATION IS
FAVORED FOR PORTIONS OF THE WESTERN CONUS WITH SLIGHTLY MORE ONSHORE FLOW INTO
THE REGION RELATIVE TO THE 6-10 DAY PERIOD INCREASING CHANCES FOR UNSETTLED
WEATHER IN THE REGION. ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHERN
PORTIONS OF ALASKA, WITH ONSHORE FLOW BRINGING ENHANCED PROBABILITIES TO
SOUTH-CENTRAL ALASKA IN PARTICULAR. NEAR-NORMAL PRECIPITATION IS FAVORED ACROSS
THE NORTHERN THIRD OF THE STATE. IN HAWAII, ABOVE-NORMAL PRECIPITATION CHANCES
ARE SLIGHTLY FAVORED FOR MUCH OF THE STATE CONSISTENT WITH THE DYNAMICAL
GUIDANCE.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5. VERY
GOOD AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION DYNAMICAL AND
STATISTICAL TOOLS IS OFFSET BY DIFFERENCES IN ENSEMBLE MEAN 500-HPA HEIGHT
ANOMALIES.
FORECASTER: RYAN BOLT
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 MAY
15.
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:
20040423 - 19820425 - 20010423 - 19850415 - 19560514
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:
20040422 - 20010424 - 19820424 - 19610515 - 19640411
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 08 - 12 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A B
SRN CALIF A B IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A B WYOMING A N
UTAH A A ARIZONA A N COLORADO A A
NEW MEXICO A A N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS B B OKLAHOMA B N
N TEXAS B N S TEXAS B A W TEXAS B A
MINNESOTA A B IOWA A B MISSOURI B B
ARKANSAS B N LOUISIANA B A WISCONSIN A B
ILLINOIS N B MISSISSIPPI B A MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY N B
TENNESSEE B A ALABAMA B A NEW YORK A B
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN N B NEW JERSEY A N W VIRGINIA N B
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN N A AK N SLOPE B N
AK ALEUTIAN N A AK WESTERN N A AK INT BSN N N
AK S INT N A AK SO COAST N A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 10 - 16 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A A NEVADA A A
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A A ARIZONA A N COLORADO A A
NEW MEXICO A A N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A B OKLAHOMA N B
N TEXAS B B S TEXAS B B W TEXAS B N
MINNESOTA A N IOWA A B MISSOURI A B
ARKANSAS N B LOUISIANA B B WISCONSIN A B
ILLINOIS A B MISSISSIPPI B N MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A B
TENNESSEE N N ALABAMA B A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A N
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA N A S CAROLINA N A GEORGIA B A
FL PNHDL B A FL PENIN N A AK N SLOPE B N
AK ALEUTIAN A A AK WESTERN A A AK INT BSN N A
AK S INT N A AK SO COAST A A AK PNHDL N 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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