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FXUS06 KWBC 071902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON APRIL 07 2025
6-10 DAY OUTLOOK FOR APR 13 - 17 2025
DYNAMICAL MODELS ARE IN GOOD AGREEMENT REGARDING THE 500-HPA HEIGHT PATTERN
ACROSS NORTH AMERICA DURING THE 6-10 DAY PERIOD. AT THE OUTSET OF THE PERIOD,
TROUGHING IS FORECAST ALONG THE EAST COAST, WITH RIDGING ACROSS THE CENTRAL
CONUS. PERIODIC SHORTWAVE TROUGHS ARE FORECAST TO PROPAGATE THROUGH THIS
RIDGING LEADING TO SOME DISRUPTION OF THE ASSOCIATED POSITIVE HEIGHT ANOMALIES,
FIRST ACROSS THE NORTHERN TIER, AND THEN ANOTHER WEAK TROUGH POSSIBLY MOVING
INTO THE WEST LATE IN THE PERIOD. AN AMPLIFIED MID-LEVEL HEIGHT PATTERN IS
FORECAST ACROSS THE NORTH-CENTRAL PACIFIC, WITH A GRADUAL EASTWARD SHIFT OF
RIDGING FROM EASTERN RUSSIA TO THE BERING SEA AND TROUGHING PERSISTING ACROSS
MAINLAND ALASKA, BUT WEAKENING WITH TIME. FOR THE PERIOD AS A WHOLE, THE 6-10
DAY MANUAL HEIGHT BLEND DEPICTS THE LARGEST POSITIVE HEIGHT ANOMALIES (+60
METERS) ACROSS THE LOWER MISSISSIPPI AND TENNESSEE VALLEYS, WITH ABOVE-NORMAL
HEIGHTS ALSO PREDICTED ALONG THE WEST COAST. NEAR-NORMAL HEIGHTS ARE FAVORED
OVER THE INTERMOUNTAIN REGION AND ALONG THE NORTHERN TIER, WITH BELOW-NORMAL
HEIGHTS INDICATED ACROSS THE NORTHEAST AND SOUTHERN MAINLAND ALASKA.
ABOVE-NORMAL HEIGHTS ARE FORECAST ACROSS THE ALEUTIANS, THE NORTHEASTERN
MAINLAND, AND SOUTHEAST ALASKA.
INCREASED CHANCES FOR BELOW-NORMAL TEMPERATURES ARE FORECAST ACROSS THE EASTERN
CONUS AT THE OUTSET OF THE PERIOD. HOWEVER, MODERATION IS LIKELY AS THE INITIAL
TROUGH EXITS. THE PREVAILING PATTERN GENERALLY FAVORS ABOVE-NORMAL TEMPERATURES
ACROSS MUCH OF THE CONUS, HOWEVER, CONTINUED PROPAGATION OF SHORTWAVE TROUGHS
FAVOR ADDITIONAL TRANSIENT PERIODS OF BELOW-NORMAL TEMPERATURES ACROSS THE
WESTERN AND NORTHEASTERN CONUS. FOR THE PERIOD AS A WHOLE, NEAR-NORMAL
TEMPERATURES ARE FAVORED FOR MUCH OF THE EASTERN THIRD OF THE CONUS, WITH THE
RELATIVELY COOLER START TO THE PERIOD AND STRONGER SIGNALS FOR BELOW-NORMAL
TEMPERATURES IN THE UNCALIBRATED GUIDANCE OFFSETTING THE WARMER SIGNAL IN THE
REFORECAST TOOLS. THERE IS BETTER AGREEMENT IN THE TOOLS SUPPORTING INCREASED
CHANCES OF BELOW-NORMAL TEMPERATURES ACROSS THE FLORIDA PENINSULA. ENHANCED
PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS THE CENTRAL CONUS
UNDERNEATH THE LARGEST POSITIVE HEIGHT ANOMALIES. NEAR- TO BELOW-NORMAL
TEMPERATURE PROBABILITIES ARE INCREASED CLOSER TO THE WEST COAST TIED TO
ADDITIONAL SHORTWAVE TROUGHING. ELEVATED ODDS FOR BELOW-NORMAL TEMPERATURES ARE
FORECAST FOR MUCH OF ALASKA, EXCLUDING THE NORTHEASTERN PART OF THE STATE,
WHERE WEAK PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE FAVORED.
ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR HAWAII, CONSISTENT WITH THE
REFORECAST CONSOLIDATION TOOL.
SURFACE HIGH PRESSURE BUILDING BEHIND A DEPARTING FRONTAL SYSTEM FAVORS
ENHANCED CHANCES OF BELOW-NORMAL PRECIPITATION ACROSS MUCH OF THE SOUTH-CENTRAL
AND SOUTHEASTERN CONUS. CONVERSELY, SHORTWAVE TROUGHING IN THE WEST FAVORS
ELEVATED ABOVE-NORMAL PRECIPITATION CHANCES ACROSS MOST OF THE GREAT PLAINS AND
UPPER MIDWEST WITH POTENTIAL FOR A SURFACE LOW TO DEVELOP BY THE END OF THE
PERIOD, ALTHOUGH SIGNALS IN THE MODELS ARE WEAK. BELOW-NORMAL PRECIPITATION
PROBABILITIES ARE ENHANCED ACROSS THE SOUTHWEST AND GREAT BASIN TIED TO
INCREASING POSITIVE HEIGHT ANOMALIES NEAR THE WEST COAST AND SUPPORTED BY THE
GEFS AND ECENS REFORECAST AND UNCALIBRATED TOOLS. SHORTWAVE TROUGHING
PROGRESSING INTO THE GULF OF ALASKA FAVORS ENHANCED SOUTHERLY FLOW, AND
SUBSEQUENT INCREASED PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION FOR MAINLAND
AND SOUTHEAST ALASKA. NEAR- TO BELOW-NORMAL PRECIPITATION CHANCES ARE INCREASED
ACROSS THE ALEUTIANS BEHIND THE TROUGH. ABOVE-NORMAL PRECIPITATION IS FORECAST
ACROSS HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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: AVERAGE, 3 OUT OF 5, DUE TO
GENERALLY GOOD MODEL AGREEMENT, OFFSET BY A MORE TRANSIENT PATTERN WITH ONE OR
MORE SHORTWAVE TROUGHS POTENTIALLY MOVING ACROSS THE CONUS.
8-14 DAY OUTLOOK FOR APR 15 - 21 2025
DURING WEEK-2, RIDGING IS FORECAST ACROSS MUCH OF THE WESTERN AND CENTRAL
CONUS, WITH TROUGHING PERSISTING ACROSS NORTHEASTERN NORTH AMERICA. THE LARGEST
UNCERTAINTY IS IN REGARDS TO THE BROADENING OF THE RIDGE AND THE EXPANSION OF
POSITIVE HEIGHTS ANOMALIES ACROSS THE EAST, WITH THE 0Z CMCE DEPICTING
ABOVE-NORMAL HEIGHTS, BUT WITH NEAR-NORMAL HEIGHTS IN THE 0Z ECENS AND GEFS.
TROUGHING INITIALLY FORECAST ACROSS THE GULF OF ALASKA IS PREDICTED TO WEAKEN
WITH RIDGING AND POSITIVE HEIGHTS ANOMALIES OVERSPREADING MUCH OF ALASKA DURING
THE PERIOD. THE WEEK-2 MANUAL 500-HPA HEIGHT BLEND DEPICTS NEAR-TO BELOW-NORMAL
HEIGHTS OVER THE GREAT LAKES AND NORTHEAST, WITH ABOVE-NORMAL HEIGHTS FORECAST
OVER THE REMAINDER OF THE CONUS. ABOVE-NORMAL HEIGHTS ARE FAVORED FOR MOST OF
ALASKA, WITH THE LARGEST POSITIVE HEIGHT ANOMALIES (+120 METERS) CENTERED
ACROSS THE ALEUTIANS.
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED OVER MUCH OF THE
CONUS DURING WEEK-2 GIVEN THE TENDENCY TOWARD MORE RIDGING. NEAR-TO
BELOW-NORMAL TEMPERATURES CHANCES ARE ELEVATED ACROSS THE GREAT LAKES, OHIO
VALLEY, AND NORTHEAST TIED TO A STRONGER SIGNAL IN THE UNCALIBRATED GUIDANCE,
AND THE POTENTIAL FOR ENHANCED BACKDOOR COLD FRONT ACTIVITY GIVEN THE NEGATIVE
HEIGHT ANOMALY CENTER ACROSS SOUTHEASTERN CANADA. A VARIABLE TEMPERATURE
PATTERN IS FORECAST ACROSS ALASKA WITH THE EASTWARD SHIFTING RIDGE AXIS
FAVORING MORE MID-LEVEL NORTHERLY FLOW ACROSS WESTERN MAINLAND ALASKA, WITH
BELOW-NORMAL TEMPERATURE PROBABILITIES ELEVATED OVER THE REGION. WEAK
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE
ALEUTIANS AND NORTHEASTERN MAINLAND. ABOVE-NORMAL TEMPERATURES ARE FORECAST
ACROSS HAWAII.
SIGNALS ARE GENERALLY WEAK FOR PRECIPITATION ACROSS THE U.S. DURING WEEK-2,
WITH SHORTWAVE TROUGHING POTENTIALLY SERVING AS A FOCUS FOR A SURFACE LOW TRACK
ACROSS THE SOUTHERN PLAINS THROUGH THE OHIO VALLEY AND NORTHEAST WHERE WEAK
PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE POSTED. THE GEFS AND ECENS
REFORECAST TOOLS SUPPORT ENHANCED CHANCES FOR BELOW-NORMAL PRECIPITATION ACROSS
THE WESTERN CONUS AND THE FLORIDA PENINSULA, WITH THESE AREAS FURTHER DISPLACED
FROM THE MEAN STORM TRACK AND UNDERNEATH MORE INFLUENCE FROM SURFACE HIGH
PRESSURE. NEAR- TO ABOVE-NORMAL PRECIPITATION CHANCES ARE ELEVATED ACROSS
ALASKA AND HAWAII.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% 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
CONTINUED GOOD MODEL AGREEMENT, OFFSET BY DECREASING AMPLIFICATION AND LACK OF
ROBUST SYNOPTIC FEATURES IN THE GUIDANCE.
FORECASTER: THOMAS COLLOW
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
APRIL 17.
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:
19590410 - 19980419 - 19860318 - 19770405 - 19940329
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:
19590409 - 19980419 - 19860321 - 19770405 - 19600405
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 13 - 17 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON N B NRN CALIF N B
SRN CALIF N B IDAHO N N NEVADA A B
W MONTANA N N E MONTANA A A WYOMING A N
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A N
MINNESOTA A A IOWA A N MISSOURI A N
ARKANSAS A B LOUISIANA A B WISCONSIN A N
ILLINOIS A N MISSISSIPPI A B MICHIGAN A N
INDIANA A N OHIO N N KENTUCKY N N
TENNESSEE A B ALABAMA A B NEW YORK N N
VERMONT N N NEW HAMP N N MAINE N N
MASS N N CONN N N RHODE IS N N
PENN N N NEW JERSEY N N W VIRGINIA N N
MARYLAND N B DELAWARE N B VIRGINIA N B
N CAROLINA N B S CAROLINA N B GEORGIA N B
FL PNHDL N B FL PENIN B B AK N SLOPE N A
AK ALEUTIAN B N AK WESTERN B A AK INT BSN N A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 15 - 21 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA A N E MONTANA A N WYOMING A B
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A A N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN N N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO N A KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK N A
VERMONT N A NEW HAMP N A MAINE N A
MASS N N CONN N N RHODE IS N N
PENN N A NEW JERSEY N N W VIRGINIA A A
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A B AK N SLOPE N A
AK ALEUTIAN N N AK WESTERN B N AK INT BSN N A
AK S INT N A AK SO COAST N 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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