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FXUS06 KWBC 111902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI APRIL 11 2025
6-10 DAY OUTLOOK FOR APR 17 - 21 2025
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS DURING THE
6-10 DAY PERIOD. THE MANUAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY ON THE
ENSEMBLE MEANS FROM THE GEFS, ECMWF AND CANADIAN MODELS DUE TO RECENT MODEL
SKILL. THE RESULTANT MANUAL BLEND FEATURES A GRADUAL EASTWARD SHIFT OF RIDGING
AND ABOVE-NORMAL HEIGHTS TO THE BERING SEA TO THE ALEUTIANS AND WESTERN
MAINLAND ALASKA, WITH TROUGHING AND NEAR-NORMAL 500-HPA HEIGHTS OVER EASTERN
MAINLAND ALASKA AND SOUTHEAST ALASKA. RIDGING AND POSITIVE 500-HPA HEIGHT
ANOMALIES ARE GENERALLY FAVORED ACROSS THE WESTERN AND CENTRAL CONTIGUOUS
UNITED STATES (CONUS), WITH ANOTHER TROUGH AND BELOW NORMAL 500-HPA HEIGHTS
OVER THE NORTHEASTERN CONUS. SLIGHTLY BELOW-NORMAL 500-HPA HEIGHTS ARE
PREDICTED ACROSS HAWAII.
ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF
THE WESTERN AND CENTRAL CONUS UNDERNEATH PREDOMINANT RIDGING AND ABOVE NORMAL
500-HPA HEIGHTS, SUPPORTED BY MOST OF THE DYNAMICAL GUIDANCE. THE STRONGEST
PROBABILITIES (>70%) ARE FORECAST ACROSS PARTS OF OREGON, NEVADA, IDAHO AND
UTAH. BELOW-NORMAL TEMPERATURES ARE MOST LIKELY OVER MUCH OF THE EASTERN CONUS
IN ASSOCIATION WITH THE BELOW-NORMAL 500-HPA HEIGHTS AND TROUGHING. THE
RIDGE-TROUGH PLACEMENT AND PROGRESSION ACROSS ALASKA FAVORS ELEVATED ODDS FOR
BELOW-NORMAL TEMPERATURES FOR PORTIONS OF THE NORTHERN MAINLAND, WITH
ABOVE-NORMAL TEMPERATURES OVER THE ALEUTIANS AND PARTS OF SOUTHWESTERN MAINLAND
ALASKA. 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 THE GULF COAST STATES.
CONVERSELY, ABOVE-NORMAL PRECIPITATION IS FORECAST ACROSS PORTIONS OF THE
NORTHERN TIER OF THE CONUS, AND MOST OF THE SOUTHWESTERN QUARTER OF THE CONUS,
SUPPORTED BY MOST OF THE DYNAMICAL PRECIPITATION FORECAST TOOLS. BELOW-NORMAL
PRECIPITATION PROBABILITIES ARE ALSO ENHANCED ACROSS PARTS OF THE WEST TIED TO
INCREASING POSITIVE HEIGHT ANOMALIES AND SUPPORTED BY THE GEFS AND ECENS
REFORECAST TOOLS. SHORTWAVE TROUGHING PROGRESSING INTO EASTERN ALASKA FAVORS
ENHANCED SOUTHERLY FLOW, AND SUBSEQUENT INCREASED PROBABILITIES FOR
ABOVE-NORMAL PRECIPITATION FOR MUCH OF ALASKA. ABOVE-NORMAL PRECIPITATION IS
SLIGHTLY FAVORED IN HAWAII WITH BETTER AGREEMENT AMONG MODEL GUIDANCE.
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: ABOVE-AVERAGE, 4 OUT OF 5. GOOD
AGREEMENT AMONG THE DYNAMICAL AND STATISTICAL TOOLS IS OFFSET BY A PROGRESSIVE
PATTERN.
8-14 DAY OUTLOOK FOR APR 19 - 25 2025
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY CONSISTENT
500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY PERIOD ACROSS NORTH
AMERICA AND THE SURROUNDING REGIONS. ANOMALOUS RIDGING IS FORECAST ACROSS MUCH
OF THE CENTRAL AND EASTERN CONUS, WITH CYCLONIC FLOW ACROSS THE WESTERN CONUS.
TROUGHING INITIALLY FORECAST ACROSS THE GULF OF ALASKA IS PREDICTED TO WEAKEN
WITH RIDGING AND POSITIVE HEIGHT ANOMALIES OVERSPREADING MUCH OF ALASKA DURING
THE PERIOD. THE WEEK-2 MANUAL 500-HPA HEIGHT BLEND DEPICTS SLIGHTLY
BELOW-NORMAL HEIGHTS OVER PARTS OF WASHINGTON, IDAHO AND MONTANA, 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. SLIGHTLY BELOW-NORMAL
500-HPA HEIGHTS ARE FORECAST ACROSS HAWAII.
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED OVER MUCH OF THE
CONUS DURING WEEK-2 TIED TO RIDGING AND POSITIVE 500-HPA HEIGHTS, WITH THE
HIGHEST PROBABILITIES (GREATER THAN 60 PERCENT) OVER THE CENTRAL AND SOUTHERN
PLAINS. BELOW-NORMAL TEMPERATURES CHANCES ARE ELEVATED ACROSS PARTS OF
WASHINGTON, IDAHO AND MONTANA DUE TO THE NEGATIVE HEIGHT ANOMALY OVER THE
REGION. SLIGHTLY BELOW-NORMAL TEMPERATURES ARE FAVORED OVER PORTIONS OF
NORTHEASTERN MAINLAND ALASKA, WHILE WEAK PROBABILITIES FOR ABOVE-NORMAL
TEMPERATURES ARE FORECAST FOR PARTS OF SOUTHWESTERN MAINLAND ALASKA AND THE
ALEUTIANS. IN HAWAII, ABOVE-NORMAL TEMPERATURES CONTINUE TO BE LIKELY.
ABOVE-NORMAL PRECIPITATION IS FORECAST OVER MUCH OF THE CENTRAL CONUS AND PARTS
OF MAINE DUE TO THE SOUTHEASTERLY FLOW AND ACTIVE FRONTAL SYSTEM DURING WEEK-2,
CONSISTENT WITH MOST DYNAMIC PRECIPITATION FORECAST TOOLS. THE GEFS AND ECENS
REFORECAST TOOLS SUPPORT ENHANCED CHANCES FOR BELOW-NORMAL PRECIPITATION ACROSS
PARTS OF THE WESTERN CONUS. BELOW-NORMAL PRECIPITATION IS ALSO LIKELY FROM THE
EASTERN GULF REGION TO THE MID ATLANTIC, UNDER THE INFLUENCE OF SURFACE HIGH
PRESSURE. NEAR- TO ABOVE-NORMAL PRECIPITATION CHANCES ARE ELEVATED ACROSS
ALASKA AND ALL OF HAWAII’S ISLANDS, SUPPORTED BY MOST OF THE DYNAMICAL
PRECIPITATION FORECAST TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% 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: LUKE 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
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:
19980420 - 19620416 - 20080324 - 19770407 - 19690420
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:
19620415 - 19600406 - 19980420 - 19690419 - 20080323
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 17 - 21 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF A A IDAHO A B NEVADA A N
W MONTANA A N E MONTANA A A WYOMING A N
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A N IOWA N N MISSOURI N N
ARKANSAS N N LOUISIANA A B WISCONSIN N N
ILLINOIS B N MISSISSIPPI N N MICHIGAN B A
INDIANA B N OHIO B A KENTUCKY B N
TENNESSEE B N ALABAMA B N NEW YORK B A
VERMONT B A NEW HAMP B A MAINE B A
MASS B A CONN B A RHODE IS B A
PENN B A NEW JERSEY B A W VIRGINIA B A
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA B N S CAROLINA B N GEORGIA B N
FL PNHDL B B FL PENIN B B AK N SLOPE B A
AK ALEUTIAN A A AK WESTERN N A AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 19 - 25 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON N N NRN CALIF N N
SRN CALIF N N IDAHO A N NEVADA A N
W MONTANA N A E MONTANA A A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A N OHIO A N KENTUCKY A B
TENNESSEE A B ALABAMA A B NEW YORK A N
VERMONT A N NEW HAMP N N MAINE A N
MASS N N CONN N N RHODE IS N N
PENN A N NEW JERSEY N B W VIRGINIA N B
MARYLAND N B DELAWARE N B VIRGINIA N B
N CAROLINA N B S CAROLINA A B GEORGIA A B
FL PNHDL A B FL PENIN A B AK N SLOPE N A
AK ALEUTIAN A A AK WESTERN N A AK INT BSN N A
AK S INT N A AK SO COAST A A AK PNHDL N N
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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