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FXUS06 KWBC 252002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE FEBRUARY 25 2025
6-10 DAY OUTLOOK FOR MAR 03 - 07 2025
TODAY'S NUMERICAL MODELS GENERALLY DEPICT A COMPLEX AND ACTIVE 500-HPA PATTERN
ACROSS MUCH OF THE COUNTRY. THE PERIOD BEGINS WITH ANOMALOUS TROUGHING OVER THE
ALEUTIANS AND A NORTHERN STREAM RIDGE OVER EASTERN ALASKA / NORTHWESTERN
CANADA. MEANWHILE, IN THE SOUTHERN STREAM, A TROUGH IS FORECAST OVER THE
SOUTHWESTERN CONUS. DOWNSTREAM TRANSIENT RIDGING IS DEPICTED OVER THE
EAST-CENTRAL CONUS WHILE A STRONG MID-LEVEL TROUGH IS FORECAST FROM SOUTHERN
GREENLAND SOUTHWARD TO JUST OFF THE COAST OF NEW ENGLAND. AS TIME PROGRESSES
THE SOUTHERN STREAM TROUGH IS FORECAST TO PROGRESS ACROSS THE COUNTRY AND REACH
THE EASTERN CONUS BY DAY 10. IN ITS WAKE, A SECOND TROUGH IS FORECAST TO
APPROACH THE WEST COAST OF THE CONUS BY THE END OF THE PERIOD. FARTHER TO THE
NORTH, THE RIDGE OVER EASTERN ALASKA IS GENERALLY FORECAST TO WEAKEN WHILE THE
ALEUTIAN TROUGH FAIRLY RAPIDLY PROGRESSES SOUTHEASTWARD ACROSS THE GULF OF
ALASKA. THE MEAN 500-HPA MANUAL HEIGHT BLEND CONSISTS OF THE ENSEMBLE MEANS
FROM THE ECMWF, GEFS, AND CANADIAN MODELS WITH THE GREATEST WEIGHT GIVEN TO THE
ECMWF ENSEMBLE MEAN DUE TO CONSIDERATIONS OF RECENT SKILL. THE RESULTANT
PATTERN DEPICTS BELOW NORMAL HEIGHTS ACROSS MUCH OF THE CENTRAL AND WESTERN
CONUS AND FOR PARTS OF WESTERN ALASKA. ABOVE NORMAL HEIGHTS ARE FORECAST OVER
HAWAII WHILE NEAR NORMAL HEIGHTS ARE DEPICTED FOR THE EASTERN SEABOARD, GULF
COAST REGION, AND PARTS OF THE SOUTHERN PLAINS. A NOTABLE CHANGE TOWARD
INCREASED BELOW NORMAL HEIGHTS IS NOTED ACROSS MUCH OF THE LOWER 48 STATES
RELATIVE TO YESTERDAY’S MANUAL BLEND.
ABOVE NORMAL TEMPERATURES ARE LIKELY ACROSS MOST OF ALASKA, DUE TO ANOMALOUS
RIDGING FORECAST OVER THE EASTERN MAINLAND. A WEAK TILT TOWARD ABOVE NORMAL
TEMPERATURES EXTENDS SOUTHWARD TO THE PACIFIC NORTHWEST NEAR THE SOUTHERN
EXTENT OF THIS RIDGE. CONVERSELY, SHORTWAVE TROUGHS ASSOCIATED WITH AN ACTIVE
SOUTHERN STREAM ENHANCES PROBABILITIES OF BELOW NORMAL TEMPERATURES ACROSS
SOUTHERN AND CENTRAL CALIFORNIA AND ADJACENT AREAS OF ARIZONA AND NEVADA. ABOVE
NORMAL TEMPERATURES ARE FAVORED FROM THE GULF COAST AND SOUTHEAST NORTHWARD TO
THE GREAT LAKES REGION DUE TO PREDICTED TRANSIENT RIDGING. A TILT TOWARD BELOW
NORMAL TEMPERATURES IS INDICATED FOR MOST OF MAINE BEHIND A STRONG TROUGH
PREDICTED OFF THE COAST. PREDICTED ABOVE NORMAL MID-LEVEL HEIGHTS AND
ANTICIPATED ABOVE NORMAL SEA SURFACE TEMPERATURES (SSTS) LEAD TO ELEVATED
PROBABILITIES OF ABOVE NORMAL TEMPERATURES ACROSS HAWAII.
AN ACTIVE PATTERN IS ANTICIPATED ACROSS MUCH OF THE COUNTRY AS MULTIPLE LOW
PRESSURE SYSTEMS ARE EXPECTED AT VARIOUS LOCATIONS DURING THE PERIOD. ABOVE
NORMAL PRECIPITATION IS FAVORED FOR MOST OF ALASKA, ESPECIALLY ACROSS THE KENAI
PENINSULA AND ADJACENT AREAS, DUE TO PREDICTED ONSHORE FLOW AHEAD OF A MEAN
TROUGH CENTERED OVER THE EASTERN ALEUTIANS. AN ACTIVE PERIOD IS EXPECTED FOR
MUCH OF THE WESTERN CONUS AS ONE SOUTHERN STREAM TROUGH EXITS THE SOUTHWEST
EARLY IN THE PERIOD ONLY TO BE REPLACED BY ANOTHER TROUGH APPROACHING THE WEST
COAST LATER. DUE TO THIS ANTICIPATED ACTIVE PATTERN, ABOVE NORMAL PRECIPITATION
IS FAVORED FOR MOST OF THE WESTERN HALF OF THE CONUS, PARTICULARLY FROM CENTRAL
AND SOUTHERN CALIFORNIA NORTHEASTWARD TO THE CENTRAL ROCKIES. THE INITIAL
SOUTHERN STREAM TROUGH IS FORECAST TO PROGRESS EASTWARD ACROSS THE COUNTRY,
DRAWING AMPLE GULF MOISTURE NORTHWARD, LEADING TO INCREASED PROBABILITIES FOR
ABOVE NORMAL PRECIPITATION FOR THE EASTERN THIRD OF THE CONUS AS WELL.
CONFIDENCE FOR INCREASED PRECIPITATION AMOUNTS IS HIGHEST ACROSS THE TENNESSEE
VALLEY WHERE GULF MOISTURE ADVECTION IS LIKELY TO BE THE MOST PRONOUNCED. A
SLIGHT TILT TOWARD BELOW NORMAL PRECIPITATION IS INDICATED FOR PARTS OF THE RIO
GRANDE VALLEY DUE TO POTENTIAL MID-LEVEL RIDGE DEVELOPMENT LATER IN THE PERIOD.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% 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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
A PREDICTED COMPLEX 500-HPA FLOW PATTERN.
8-14 DAY OUTLOOK FOR MAR 05 - 11 2025
DURING THE EARLY PORTION OF THE WEEK-2 PERIOD, A COMPLEX SPLIT-FLOW MID-LEVEL
PATTERN IS FORECAST TO CONTINUE. THE PERIOD BEGINS WITH A STRONG TROUGH NEAR
THE EASTERN ALEUTIANS AND ANOMALOUS RIDGING CENTERED OVER NORTHWESTERN CANADA.
A TROUGH IN THE SOUTHERN STREAM IS FORECAST TO APPROACH THE WEST COAST OF THE
CONUS AND A POTENTIAL FULL-LATITUDE TROUGH IS PREDICTED OVER THE MISSISSIPPI
VALLEY. A TRANSIENT RIDGE IS FORECAST NEAR EASTERN NEW ENGLAND. AS TIME
PROGRESSES, THE TROUGH OVER THE EASTERN ALEUTIANS IS FORECAST TO PROGRESS
SOUTHEASTWARD, OVERSPREADING THE WESTERN CONUS BY THE END OF THE PERIOD. THE
INITIAL SOUTHERN STREAM TROUGH NEAR THE WEST COAST IS FORECAST TO WEAKEN AS IT
PROGRESSES EASTWARD, POTENTIALLY BEING ABSORBED BY A FULL-LATITUDE TROUGH OVER
THE EASTERN CONUS NEAR THE MIDDLE OF THE PERIOD. THIS TROUGH OVER THE EAST IS
THEN FORECAST TO QUICKLY WEAKEN BY THE END OF THE PERIOD AS TROUGHING OVER THE
WEST BECOMES THE MORE DOMINANT FEATURE. THE MEAN 500-HPA HEIGHT BLEND FAVORS
THE ECMWF ENSEMBLE MEAN SOLUTION DUE TO EVALUATION OF RECENT SKILL. THE MEAN
PATTERN FEATURES BELOW NORMAL HEIGHTS ACROSS MOST OF THE COUNTRY. EXCEPTIONS
ARE THE EXTREME SOUTHERN TIER OF THE CONUS AND EASTERN ALASKA, WHERE NEAR
NORMAL HEIGHTS ARE FORECAST, AND HAWAII, WHERE SLIGHTLY ABOVE NORMAL HEIGHTS
ARE EXPECTED.
DUE TO THE COMPLEX TRANSITIONAL PATTERN EXPECTED, PROBABILITIES OF ABOVE OR
BELOW NORMAL TEMPERATURES ARE FORECAST TO BE VERY MODEST OVER THE VAST MAJORITY
OF THE COUNTRY WITH THE EXCEPTION OF HAWAII. A TILT TOWARD ABOVE NORMAL
TEMPERATURES IS INDICATED FOR EASTERN AND CENTRAL ALASKA ASSOCIATED WITH A
WEAKENING RIDGE. BELOW NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE WESTERN
THIRD OF THE CONUS AS A TROUGH OVERSPREADS THE AREA DURING THE MIDDLE AND
LATTER PARTS OF THE PERIOD. A STRIPE OF MODESTLY ENHANCED PROBABILITIES OF
ABOVE NORMAL TEMPERATURES IS INDICATED FROM THE RIO GRANDE VALLEY NORTHWARD
ACROSS MUCH OF THE GREAT PLAINS AND THE NORTHERN HALF OF THE MISSISSIPPI VALLEY
DUE TO PREDICTED TRANSIENT RIDGING NEAR THE MIDDLE OF THE PERIOD. NEAR NORMAL
TEMPERATURES ARE FAVORED FOR MOST OF THE EASTERN CONUS UNDERNEATH A PREDICTED
VARIABLE PATTERN. PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE GENERALLY
REDUCED RELATIVE TO YESTERDAY ACROSS THIS AREA DUE TO PREDICTED INCREASES IN
BELOW NORMAL HEIGHTS IN THE MEAN PATTERN. ABOVE NORMAL TEMPERATURES ARE LIKELY
FOR HAWAII DUE IN LARGE PART TO ANTICIPATED ABOVE NORMAL SSTS ACROSS ADJACENT
WATERS.
AN ACTIVE PATTERN IS ANTICIPATED TO CONTINUE ACROSS MUCH OF THE COUNTRY DURING
WEEK-2. AS A TROUGH APPROACHES AND EVENTUALLY OVERSPREADS THE WEST COAST OF THE
CONUS, INCREASED ONSHORE FLOW AND INSTABILITY ARE LIKELY. THEREFORE, CHANCES OF
ABOVE NORMAL PRECIPITATION ARE ELEVATED FOR MOST OF THE WESTERN THIRD OF THE
CONUS. PROBABILITIES OF ABOVE NORMAL PRECIPITATION EXCEED 50 PERCENT ACROSS
MOST OF THE WEST COAST AND ADJACENT AREAS WHERE ADVECTION OF PACIFIC MOISTURE
MAY BE MOST PRONOUNCED. A TILT TOWARD ABOVE NORMAL PRECIPITATION IS ALSO
INDICATED FOR THE EASTERN SEABOARD DUE PRIMARILY TO A DEPARTING SURFACE LOW
EARLY IN THE PERIOD AND THE POTENTIAL FOR AN ADDITIONAL ROUND OF PRECIPITATION
TOWARD THE END OF THE PERIOD. BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED
FOR PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY DUE TO PREDICTED
TRANSIENT HIGH PRESSURE BEHIND THE INITIAL DEPARTING SYSTEM OVER THE EAST
COAST. MUCH OF THE SOUTHERN PLAINS ALSO LEANS TOWARD BELOW NORMAL PRECIPITATION
DUE TO PREDICTED TRANSIENT RIDGING NEAR THE MIDDLE OF THE PERIOD. ONSHORE FLOW
IS EXPECTED TO CONTINUE FOR MUCH OF SOUTHERN ALASKA FOR AT LEAST PART OF THE
WEEK-2 PERIOD, LEADING TO A TILT TOWARD ABOVE NORMAL PRECIPITATION ACROSS THIS
REGION. THIS ONSHORE FLOW MAY BEGIN TO TAMP DOWN LATER IN THE PERIOD FOR MANY
AREAS OF ALASKA, RESULTING IN ONLY MODESTLY ENHANCED ABOVE NORMAL PRECIPITATION
CHANCES FOR THE PERIOD AS A WHOLE. NEAR NORMAL PRECIPITATION IS FAVORED FOR
HAWAII, CONSISTENT WITH A CONSOLIDATION OF CALIBRATED PRECIPITATION OUTPUT FROM
THE ECMWF AND GEFS ENSEMBLES.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 25% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
A PREDICTED COMPLEX VARIABLE PATTERN ACROSS MUCH OF THE COUNTRY.
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
MARCH 20.
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:
20040217 - 19870205 - 19770219 - 19940228 - 19960206
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:
19870204 - 20040218 - 19860307 - 19940228 - 19770220
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAR 03 - 07 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N N NRN CALIF B A
SRN CALIF B A IDAHO N A NEVADA N A
W MONTANA N A E MONTANA N A WYOMING N A
UTAH N A ARIZONA N A COLORADO N A
NEW MEXICO N N N DAKOTA A N S DAKOTA A A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS A A S TEXAS A A W TEXAS N B
MINNESOTA A N IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT N A NEW HAMP N A MAINE B A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA A A
MARYLAND N A DELAWARE N A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAR 05 - 11 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON B A NRN CALIF B A
SRN CALIF B A IDAHO B A NEVADA B A
W MONTANA B A E MONTANA N N WYOMING N A
UTAH N A ARIZONA N A COLORADO N A
NEW MEXICO N N N DAKOTA A B S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS N B S TEXAS A B W TEXAS A B
MINNESOTA A B IOWA A N MISSOURI A N
ARKANSAS N N LOUISIANA N N WISCONSIN A N
ILLINOIS A N MISSISSIPPI N N MICHIGAN N N
INDIANA N N OHIO N N KENTUCKY N N
TENNESSEE N A ALABAMA N A NEW YORK N A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN N A AK N SLOPE A N
AK ALEUTIAN A A AK WESTERN N N AK INT BSN A N
AK S INT A A AK SO COAST A A AK PNHDL A 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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