137
FXUS06 KWBC 262012
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED FEBRUARY 26 2025
6-10 DAY OUTLOOK FOR MAR 04 - 08 2025
THERE IS REASONABLE AGREEMENT AMONG TODAY’S GEFS, ECMWF, AND CMCE DEPICTIONS OF
500-HPA HEIGHT ANOMALIES DURING THE EXTENDED RANGE FORECAST PERIOD, BUT THERE
IS QUITE A BIT OF SPREAD WITH REGARD TO THE AMPLITUDE, LOCATION, AND PHASE
SPEED OF SHORTWAVE TROUGHS IMBEDDED IN THE LARGER FLOW. 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 MOST OF THE CONUS AND FOR PARTS OF WESTERN ALASKA. AN AMPLIFIED
RIDGE IS FAVORED OVER THE ALASKA/CANADA BORDER, AND ABOVE NORMAL HEIGHTS ARE
FORECAST OVER HAWAII WHILE NEAR NORMAL HEIGHTS ARE DEPICTED FOR THE GULF COAST
REGION. 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. CONVERSELY, SHORTWAVE TROUGHS
ASSOCIATED WITH AN ACTIVE SOUTHERN STREAM ENHANCES PROBABILITIES OF BELOW
NORMAL TEMPERATURES ACROSS CALIFORNIA, AS WELL AS PORTIONS OF THE SOUTHERN
GREAT BASIN AND CENTRAL ROCKIES. ABOVE NORMAL TEMPERATURES ARE FAVORED FROM THE
GULF COAST AND SOUTHEAST NORTHWARD TO THE GREAT LAKES REGION DUE TO PREDICTED
TRANSIENT RIDGING. 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 OHIO
VALLEY AND EASTERN GREAT LAKES AS SURFACE LOW PRESSURE SHIFTS OVER THE
NORTHEASTERN CONUS. 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. HAWAII TILTS SLIGHTLY TOWARDS ABOVE NORMAL
PRECIPITATION, CONSISTENT WITH THE HAWAII CON.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 35% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
REASONABLE AGREEMENT AMONG THE FORECAST TOOLS WITH REGARD TO TEMPERATURE AND
PRECIPITATION, OFFSET BY A WIDE SPREAD AMONG ENSEMBLES OF THE MID-LEVEL HEIGHT
PATTERN DURING THE PERIOD.
8-14 DAY OUTLOOK FOR MAR 06 - 12 2025
SPREAD AMONG ENSEMBLE SOLUTIONS REGARDING 500-HPA HEIGHT ANOMALIES CONTINUES
INTO THE WEEK-2 PERIOD. SIMILAR TO THE 6-10 DAY PERIOD THERE IS REASONABLE
AGREEMENT ON THE OVERALL SYNOPTIC PATTERN AND EVOLUTIONS, BUT THERE IS
SIGNIFICANT DISAGREEMENT WITH REGARD TO AMPLITUDE, LOCATION, AND PHASE SPEED OF
VARIOUS TROUGHS AND SHORTWAVE FEATURES DURING THE 8-14 DAY PERIOD. 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 THE
ALEUTIANS, 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, WHILE PORTIONS OF NEW ENGLAND TILT SLIGHTLY TOWARDS BELOW
NORMAL TEMPERATURES UNDER PERSISTENT TROUGHING. 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 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 35% 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, DUE TO
REASONABLE AGREEMENT AMONG THE FORECAST TOOLS WITH REGARD TO TEMPERATURE AND
PRECIPITATION, OFFSET BY A WIDE SPREAD AMONG ENSEMBLES OF THE MID-LEVEL HEIGHT
PATTERN DURING THE PERIOD.
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
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 - 19580223 - 19860307 - 19970216 - 19700217
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:
19860307 - 19870205 - 19580223 - 20040216 - 19800223
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAR 04 - 08 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N A NRN CALIF B A
SRN CALIF B A IDAHO N A NEVADA B A
W MONTANA N A E MONTANA N A WYOMING N A
UTAH B A ARIZONA B A COLORADO B A
NEW MEXICO B A N DAKOTA A N S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA A A
N TEXAS A A S TEXAS A B W TEXAS A B
MINNESOTA A A IOWA A A MISSOURI N A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN N 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 N 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 06 - 12 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B 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 B A ARIZONA B A COLORADO N A
NEW MEXICO A A N DAKOTA A B S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI N N MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE N A ALABAMA N N NEW YORK N A
VERMONT B 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 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 N 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 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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