251
FXUS06 KWBC 121907
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON MAY 12 2025
6-10 DAY OUTLOOK FOR MAY 18 - 22 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 AN AMPLIFIED
MID-LEVEL RIDGE AND ABOVE-NORMAL HEIGHTS OVER THE EASTERN PACIFIC AND A PAIR OF
WEAK TROUGHS OVER THE CONTIGUOUS U.S. (CONUS). TROUGHING IS ALSO FORECAST
ACROSS ALASKA, EXTENDING INTO THE GULF OF ALASKA, WITH ASSOCIATED NEGATIVE
500-HPA HEIGHT ANOMALIES ACROSS THE STATE. NEAR-NORMAL 500-HPA HEIGHTS ARE
PREDICTED ACROSS HAWAII.
BELOW-NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE NORTHERN CONUS AS WELL
AS MUCH OF THE GREAT BASIN AND DESERT SOUTHWEST WITH WEAK TROUGHING STRETCHED
ACROSS THE NORTHERN TIER. PROBABILITIES EXCEED 50% FOR PORTIONS OF THE GREAT
LAKES, UPPER MISSISSIPPI VALLEY, AND PACIFIC NORTHWEST. ABOVE-NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED OVER PORTIONS OF THE WEST COAST AND MORE
STRONGLY FAVORED FOR THE SOUTHERN CONUS EAST OF THE ROCKIES, UNDER POSITIVE
500-HPA HEIGHT ANOMALIES. CHANCES OF ABOVE-NORMAL TEMPERATURES GO UP FROM NORTH
TO SOUTH, EXCEEDING 60% IN SOUTHERN TEXAS AND 70% FOR THE FLORIDA PENINSULA.
UNDER PREDICTED NEGATIVE 500-HPA HEIGHT ANOMALIES, BELOW-NORMAL TEMPERATURES
ARE LIKELY OVER MUCH OF ALASKA, WHILE NEAR-NORMAL TEMPERATURES ARE FAVORED FOR
THE ALEUTIANS AND PARTS OF THE SOUTHWESTERN MAINLAND ALASKA, CONSISTENT WITH
THE REFORECAST CONSOLIDATION TEMPERATURE FORECAST TOOL. ABOVE-NORMAL
TEMPERATURES ARE LIKELY FOR HAWAII, WITH POSITIVE SURROUNDING SEA SURFACE
TEMPERATURE ANOMALIES.
WITH A PAIR OF WEAK MID-LEVEL TROUGHS OVER THE GREAT BASIN AND GREAT LAKES,
ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR MUCH OF THE NORTHERN AND
CENTRAL ROCKIES, AS WELL AS MOST POINTS EAST. PROBABILITIES ARE SLIGHTLY
ENHANCED (>40%) FOR MOST OF THE MISSISSIPPI VALLEY, NORTHERN PLAINS, AND
CENTRAL ROCKIES WHERE PRECIPITATION IS FORECAST TO BE ENHANCED BY GULF MOISTURE
INFLOW. BELOW-NORMAL PRECIPITATION IS FAVORED ACROSS MUCH OF THE WEST COAST
WITH AMPLIFIED RIDGING UPSTREAM OVER THE EASTERN PACIFIC, AS WELL AS THE
FLORIDA PENINSULA WHERE SURFACE HIGH PRESSURE IS FAVORED. ABOVE-NORMAL
PRECIPITATION IS FAVORED FOR MOST OF ALASKA, WITH A PREDICTED TROUGH AND
SOUTHERLY FLOW, WHILE NEAR-NORMAL PRECIPITATION IS FAVORED FOR PORTIONS OF THE
WESTERN COAST AND THE ALASKA PENINSULA, WHERE FORECAST TOOLS HAVE WEAK
SIGNALS.. PRECIPITATION CONSOLIDATION TOOL FORECASTS FAVOR ABOVE-NORMAL
PRECIPITATION FOR HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 20% 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. VERY
GOOD AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION DYNAMICAL AND
STATISTICAL TOOLS IS OFFSET BY DIFFERENCES IN ENSEMBLE MEAN 500-HPA HEIGHT
ANOMALIES.
8-14 DAY OUTLOOK FOR MAY 20 - 26 2025
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A PROGRESSIVE AND
DE-AMPLIFIED 500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY PERIOD ACROSS
NORTH AMERICA AND THE SURROUNDING REGIONS. RIDGING OVER THE EASTERN PACIFIC IS
FAVORED TO WEAKEN, BUT ALSO SPREAD INTO THE WESTERN CONUS, WHILE THE PAIR OF
TROUGHS IN THE 6-10 DAY PERIODS CONSOLIDATE INTO A SINGLE VERY WEAK TROUGH OVER
THE GREAT LAKES. LARGE POSITIVE HEIGHT ANOMALIES OVER THE CANADIAN MARITIMES
HELP TO FLATTEN OUT UPPER-LEVEL FLOW, RESULTING IN A VERY ZONAL PATTERN OVER
THE CONUS. WEAK TROUGHING CONTINUES OVER ALASKA, WITH AN AMPLIFIED RIDGE
UPSTREAM OVER THE BERING SEA.
ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED ACROSS MOST OF THE SOUTHERN
HALF OF THE CONUS IN THE WEEK-2 PERIOD, UNDER RIDGING AND POSITIVE 500-HPA
HEIGHT ANOMALIES. PROBABILITIES EXCEED 50% FOR THE FLORIDA PENINSULA AND
PORTIONS OF THE SOUTHWESTERN CONUS WHERE POSITIVE HEIGHT ANOMALIES ARE
GREATEST. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEAST QUARTER OF
THE CONUS UNDER PERSISTENT TROUGHING. FORECAST TOOLS ALSO INDICATE A SLIGHT
TILT TOWARDS BELOW-NORMAL TEMPERATURES FOR PORTIONS OF THE PACIFIC NORTHWEST.
ABOVE-NORMAL TEMPERATURES REMAIN FAVORED FOR PORTIONS OF SOUTHWESTERN ALASKA,
WHILE BELOW-NORMAL TEMPERATURES ARE INDICATED ALONG THE SOUTHEASTERN COAST,
ALONG THE ALASKA-CANADA BORDER, AND MUCH OF NORTHERN ALASKA, CONSISTENT WITH
MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS. ABOVE-NORMAL TEMPERATURES ARE
PREDICTED TO PERSIST ACROSS HAWAII DURING WEEK-2 BY DYNAMICAL MODELS.
NEAR- TO ABOVE-NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE EASTERN AND
CENTRAL CONUS, SUPPORTED BY MOST DYNAMICAL MODEL PRECIPITATION FORECAST TOOLS.
ABOVE-NORMAL PRECIPITATION IS INDICATED FOR THE NORTHEAST QUARTER OF THE CONUS,
AND SLIGHTLY ENHANCED (>40%) OVER PORTIONS OF THE GREAT LAKES AND OHIO VALLEY.
NEAR- TO BELOW-NORMAL PRECIPITATION IS SLIGHTLY FAVORED OVER THE WESTERN CONUS,
UNDER MEAN POSITIVE 500-HPA HEIGHT ANOMALIES. SIMILAR TO THE 6-10 DAY PERIOD,
ABOVE-NORMAL PRECIPITATION IS FAVORED FOR MOST ALASKA UNDER PERSISTENT
TROUGHING, WHILE NEAR-NORMAL PRECIPITATION IS FORECAST OVER THE WESTERN
ALEUTIANS. ABOVE-NORMAL PRECIPITATION IS FAVORED FOR HAWAII DURING THE WEEK-2
PERIOD, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 0Z 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: ABOUT AVERAGE, 3 OUT OF 5. GOOD
AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION DYNAMICAL AND STATISTICAL
TOOLS IS OFFSET BY WEAK ENSEMBLE MEAN 500-HPA HEIGHT ANOMALIES.
FORECASTER: DANIEL BARANDIARAN
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:
19880526 - 20010428 - 19530505 - 19800521 - 20070509
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:
19880525 - 20010428 - 19910525 - 19770430 - 19720426
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 18 - 22 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B B NRN CALIF A B
SRN CALIF A B IDAHO B N NEVADA N B
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B A ARIZONA B N COLORADO B A
NEW MEXICO B N N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS N A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A N
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS A A LOUISIANA A A WISCONSIN B A
ILLINOIS B A MISSISSIPPI A A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY N A
TENNESSEE A A ALABAMA A A 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 N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A B AK N SLOPE B A
AK ALEUTIAN N N AK WESTERN N A AK INT BSN B A
AK S INT A A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 20 - 26 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B B OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA N B E MONTANA N N WYOMING N B
UTAH A B ARIZONA A N COLORADO A B
NEW MEXICO A N N DAKOTA B N S DAKOTA B N
NEBRASKA B B KANSAS N N OKLAHOMA N N
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A N WISCONSIN B A
ILLINOIS B A MISSISSIPPI A N MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE B A ALABAMA N 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 N A S CAROLINA N N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE B A
AK ALEUTIAN N A AK WESTERN N A AK INT BSN B A
AK S INT N A AK SO COAST A 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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