387
FXUS06 KWBC 161911
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE SEPTEMBER 16 2025
6-10 DAY OUTLOOK FOR SEP 22 - 26 2025
TODAY'S NUMERICAL MODELS ARE GENERALLY IN GOOD AGREEMENT IN DEPICTING AN
AMPLIFIED 500-HPA FLOW PATTERN ACROSS THE HIGHER LATITUDES OF NORTH AMERICA AND
SURROUNDING AREAS. THE PERIOD BEGINS WITH A DEEP TROUGH OVER THE EASTERN GULF
OF ALASKA, ANOMALOUS RIDGING OVER CENTRAL CANADA NEAR HUDSON BAY, AND ANOMALOUS
TROUGHING OVER THE WESTERN ATLANTIC SOUTH OF GREENLAND. FARTHER TO THE SOUTH,
RIDGING IS PREDICTED OVER THE WESTERN CONUS, AND CYCLONIC FLOW IS FORECAST OVER
THE MISSISSIPPI VALLEY AND A WEAKNESS IN SUBTROPICAL RIDGING IS FORECAST ACROSS
MUCH OF THE GULF COAST. AS TIME PROGRESSES, THE TROUGH OVER THE EASTERN GULF OF
ALASKA IS EXPECTED TO SLOWLY DRIFT SOUTHEASTWARD TO A POSITION NEAR SOUTHEAST
ALASKA. THE RIDGE OVER CENTRAL CANADA IS FORECAST TO PROGRESS NORTHEASTWARD
TOWARD BAFFIN ISLAND WHILE THE DOWNSTREAM TROUGH OVER THE WESTERN ATLANTIC IS
EXPECTED TO SLOWLY PROGRESS EASTWARD. ACROSS THE CONTIGUOUS U.S. (CONUS),
ANOMALOUS RIDGING INITIALLY OVER THE WEST IS FORECAST TO PROGRESS NORTHEASTWARD
TO THE NORTHERN PLAINS. THE DOWNSTREAM TROUGH OVER THE MISSISSIPPI VALLEY IS
SLOWLY FORECAST TO PUSH EASTWARD TOWARD THE EAST COAST. ACROSS HAWAII, NEAR
NORMAL MID-LEVEL HEIGHTS ARE GENERALLY FORECAST IN THE MEAN.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS ALMOST THE ENTIRE CONTIGUOUS
UNITED STATES DUE TO PREDICTED WIDESPREAD ABOVE NORMAL HEIGHTS. PROBABILITIES
OF ABOVE NORMAL TEMPERATURES EXCEED 80 PERCENT ACROSS MUCH OF THE NORTH-CENTRAL
CONUS, CONSISTENT WITH PREDICTED RIDGING OVER THE NORTHERN PLAINS. MORE MODEST
CHANCES OF ABOVE NORMAL TEMPERATURES (GENERALLY LESS THAN A 50 PERCENT) ARE
INDICATED FOR MUCH OF THE EASTERN SEABOARD AND PARTS OF THE GULF COAST DUE TO
PREDICTED WEAK TROUGHING. NEAR NORMAL TEMPERATURES ARE MORE LIKELY FOR PARTS OF
THE PACIFIC NORTHWEST DUE TO PREDICTED HEIGHT FALLS ASSOCIATED WITH THE TROUGH
NEAR SOUTHEAST ALASKA. A SLIGHT TILT TOWARD ABOVE NORMAL TEMPERATURES IS
INDICATED FOR PARTS OF EASTERN MAINLAND ALASKA, AHEAD OF A WEAK TROUGH FORECAST
OVER THE WESTERN MAINLAND. BELOW NORMAL TEMPERATURES ARE MORE LIKELY FOR PARTS
OF THE WESTERN MAINLAND, CONSISTENT WITH TELECONNECTIONS FROM THE PREDICTED
MEAN TROUGH POSITION NEAR SOUTHEAST ALASKA. BELOW NORMAL TEMPERATURES ARE ALSO
FAVORED FOR SOUTHEAST ALASKA, CLOSE TO THE PREDICTED MEAN TROUGH POSITION.
ABOVE NORMAL TEMPERATURES ARE LIKELY FOR THE WESTERN AND CENTRAL HAWAIIAN
ISLANDS, CONSISTENT WITH ABOVE NORMAL SEA SURFACE TEMPERATURES (SSTS) IN THE
ADJACENT PACIFIC.
AN ACTIVE PATTERN IS FAVORED FOR MUCH OF THE WESTERN CONUS DUE TO ENHANCED
MOIST FLOW FROM THE PACIFIC. THE HIGHEST CONFIDENCE (GREATER THAN A 60 PERCENT
CHANCE) OF ABOVE NORMAL PRECIPITATION IS ACROSS THE PACIFIC NORTHWEST AND
NORTHERN CALIFORNIA AS TELECONNECTIONS FROM THE UPSTREAM TROUGH POSITION
OFFSHORE OF SOUTHEAST ALASKA FAVOR A WET PATTERN. BELOW NORMAL PRECIPITATION IS
FAVORED FROM THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY TO THE CENTRAL
ROCKIES, CONSISTENT WITH PREDICTED MEAN RIDGING. ABOVE NORMAL PRECIPITATION IS
FAVORED FOR THE SOUTHEAST, GULF COAST, AND LOWER MISSISSIPPI VALLEY DUE TO A
PREDICTED WEAKNESS IN SUBTROPICAL RIDGING ACROSS THESE AREAS. A TILT TOWARD
ABOVE NORMAL PRECIPITATION IS INDICATED FOR SOUTHEAST ALASKA, ASSOCIATED WITH A
PREDICTED SURFACE LOW NEAR THE SOUTH COAST. CONVERSELY, BELOW NORMAL
PRECIPITATION IS MORE LIKELY FOR WESTERN MAINLAND ALASKA DUE TO PREDICTED
ANOMALOUS OFFSHORE FLOW. WEAKLY ENHANCED PROBABILITIES OF ABOVE NORMAL
PRECIPITATION ARE INDICATED FOR WESTERN AND CENTRAL HAWAII, CONSISTENT WITH
CONSOLIDATED CALIBRATED PRECIPITATION AMOUNTS FROM THE GEFS AND ECMWF ENSEMBLES.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 50% 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: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
FAIR AGREEMENT AMONG TODAY’S ENSEMBLE MEANS.
8-14 DAY OUTLOOK FOR SEP 24 - 30 2025
DURING WEEK-2, MODELS HAVE COME INTO BETTER AGREEMENT IN MAINTAINING A STRONG
TROUGH NEAR SOUTHEAST ALASKA THROUGHOUT MUCH OF THE PERIOD. A SECOND WEAKER
TROUGH IS FORECAST OVER WESTERN MAINLAND ALASKA. FARTHER TO THE SOUTH, STRONG
RIDGING IS FORECAST FROM THE NORTHERN PLAINS TO THE SOUTHWEST EARLY IN THE
PERIOD. BY THE MIDDLE OF THE PERIOD, SIGNIFICANT HEIGHT FALLS ARE FORECAST FOR
MUCH OF THE WEST WHILE ABOVE NORMAL HEIGHTS LINGER OVER THE NORTHERN PLAINS.
TROUGHING REMAINS FORECAST ALONG THE EAST COAST EARLY IN THE PERIOD WITH MODELS
GENERALLY FORECASTING HEIGHT RISES THEREAFTER, PARTICULARLY ACROSS THE
NORTHEAST. MODELS GENERALLY DEPICT A WEAKNESS IN SUBTROPICAL RIDGING FARTHER TO
THE SOUTH NEAR THE GULF COAST. MID-LEVEL RIDGING IS FORECAST TO DEVELOP WELL TO
THE NORTH OF HAWAII WITH MEAN NEAR NORMAL HEIGHTS EXPECTED ACROSS THE ISLAND
CHAIN.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE ENTIRE CONUS WITH THE EXCEPTION
OF THE FAR WEST, CONSISTENT WITH PREDICTED NEAR TO ABOVE NORMAL MID-LEVEL
HEIGHTS AND LOW AMPLITUDE FLOW. THE GREATEST CONFIDENCE OF ABOVE NORMAL
TEMPERATURES (ABOVE 70 PERCENT CHANCE) IS FORECAST FOR THE NORTHERN PLAINS AND
UPPER MISSISSIPPI VALLEY, WHERE PREDICTED POSITIVE HEIGHT ANOMALIES ARE THE
GREATEST. NEAR NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE FAR WEST DUE TO
PREDICTED MID-LEVEL HEIGHT FALLS. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR
PARTS OF EASTERN ALASKA AHEAD OF WEAK TROUGHING PREDICTED OVER WESTERN PARTS OF
THE MAINLAND. BELOW NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR THE WESTERN
MAINLAND, CONSISTENT WITH TELECONNECTIONS FROM THE PREDICTED MEAN RIDGE NEAR
BAFFIN ISLAND. BELOW NORMAL TEMPERATURES ARE FAVORED FOR SOUTHEAST ALASKA AND
PARTS OF THE PACIFIC NORTHWEST CLOSE TO PREDICTED DEEP TROUGHING NEAR OR JUST
OFFSHORE OF THE COAST. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE WESTERN
AND CENTRAL HAWAIIAN ISLANDS, CONSISTENT WITH POSITIVE SST ANOMALIES IN THE
ADJACENT PACIFIC.
AN ACTIVE PATTERN REMAINS LIKELY FOR THE NORTHWESTERN CONUS INTO THE NORTHERN
PLAINS DUE TO PREDICTED ENHANCED PACIFIC FLOW. PROBABILITIES OF ABOVE NORMAL
PRECIPITATION EXCEED 60 PERCENT ALONG THE PACIFIC NORTHWEST COASTLINE. BELOW
NORMAL PRECIPITATION IS MORE LIKELY ACROSS MUCH OF THE MID-ATLANTIC, NORTHEAST,
AND THE EASTERN HALF OF THE GREAT LAKES REGION, DUE TO PREDICTED SURFACE HIGH
PRESSURE. A SLIGHT TILT TOWARD ABOVE NORMAL PRECIPITATION IS INDICATED FOR MUCH
OF THE GULF COAST AND LOWER MISSISSIPPI VALLEY AND ADJACENT AREAS OF THE
SOUTHERN PLAINS, SOUTHEAST, AND TENNESSEE VALLEY DUE TO A PREDICTED WEAKNESS IN
SUBTROPICAL RIDGING NEAR THE AREA AND MODESTLY ENHANCED SOUTHEASTERLY LOW-LEVEL
FLOW FROM THE GULF. BELOW NORMAL PRECIPITATION IS FAVORED FOR WESTERN MAINLAND
ALASKA, CONSISTENT WITH PREDICTED OFFSHORE FLOW. ABOVE NORMAL PRECIPITATION IS
MORE LIKELY FOR SOUTHEAST ALASKA, ASSOCIATED WITH PREDICTED SURFACE LOW
PRESSURE NEARBY. WEAKLY ENHANCED PROBABILITIES OF ABOVE NORMAL PRECIPITATION
ARE INDICATED FOR WESTERN AND CENTRAL HAWAII, CONSISTENT WITH CONSOLIDATED
CALIBRATED PRECIPITATION AMOUNTS FROM THE GEFS AND ECMWF ENSEMBLES.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 20% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 50% 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 GOOD
MODEL AGREEMENT ON THE 500-HPA FLOW PATTERN OFFSET BY WEAK OR CONFLICTING
SIGNALS AMONG THE PRECIPITATION GUIDANCE ACROSS MUCH OF THE FORECAST DOMAIN.
FORECASTER: SCOTT H
NOTES:
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
SEPTEMBER 18.
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:
20090915 - 20090910 - 20010927 - 20060902 - 19670913
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:
20090911 - 20090918 - 20010926 - 20060902 - 20090906
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 22 - 26 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF A A IDAHO A A NEVADA A A
W MONTANA A A E MONTANA A B WYOMING A B
UTAH A N ARIZONA A N COLORADO A B
NEW MEXICO A N N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A N
N TEXAS A N S TEXAS A A W TEXAS A N
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS A N LOUISIANA A A WISCONSIN A B
ILLINOIS A N MISSISSIPPI A A MICHIGAN A B
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A A NEW YORK A N
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A N NEW JERSEY A N W VIRGINIA A N
MARYLAND A N DELAWARE N N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A A
FL PNHDL A A FL PENIN A N AK N SLOPE N N
AK ALEUTIAN B N AK WESTERN B B AK INT BSN N N
AK S INT N B AK SO COAST A N AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 24 - 30 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON N A NRN CALIF N A
SRN CALIF N N IDAHO N A NEVADA N N
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A A S TEXAS A A W TEXAS A N
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A A LOUISIANA A A WISCONSIN A N
ILLINOIS A N MISSISSIPPI A A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE A A ALABAMA A A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A B
MARYLAND A B DELAWARE A B VIRGINIA A B
N CAROLINA A B S CAROLINA A N GEORGIA A A
FL PNHDL A A FL PENIN A N AK N SLOPE N N
AK ALEUTIAN N N AK WESTERN B B AK INT BSN N N
AK S INT N N AK SO COAST A N 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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