107
FXUS06 KWBC 131912
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT SAT SEPTEMBER 13 2025
6-10 DAY OUTLOOK FOR SEP 19 - 23 2025
TODAY'S MODEL SOLUTIONS CONTINUE TO BE 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 ON THE ENSEMBLE
MEANS FROM THE GEFS, ECMWF AND CANADIAN MODELS. THE RESULTANT MANUAL BLEND
DEPICTS A HIGH-LATITUDE WAVETRAIN FEATURING LARGE POSITIVE HEIGHT ANOMALIES
SOUTH OF THE ALEUTIAN ISLANDS AND A SHORTWAVE TROUGH DOWNSTREAM OVER THE GULF
OF ALASKA, BROAD RIDGING OVER MOST OF CANADA EXTENDING DOWN INTO THE NORTHERN
CONTIGUOUS U.S. (CONUS), AND BROAD TROUGHING OVER NORTH ATLANTIC. WEAK NEGATIVE
HEIGHT ANOMALIES ARE ALSO DEPICTED OVER THE SOUTHEASTERN CONUS AND ALONG THE
WEST COAST.
EXPANSIVE POSITIVE 500-HPA HEIGHT ANOMALIES OVER MUCH OF NORTH AMERICA BROADLY
FAVORS ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE CONUS, WITH PROBABILITIES OF
AT LEAST 40% ALMOST UNIVERSAL FROM COAST TO COAST. HIGHER PROBABILITIES OF
ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR THE SOUTHERN PLAINS, ALONG THE GULF
COAST AND UP THE LOWER MISSISSIPPI, TENNESSEE, AND OHIO VALLEYS (>50%), AS WELL
AS FOR MUCH OF THE NORTHERN HIGH PLAINS AND ALONG THE WEST COAST NORTH OF SAN
FRANCISCO BAY. SEVERAL AREAS OF INCREASED CLOUDINESS AND ENHANCED PRECIPITATION
RESULT IN WEAKER PROBABILITIES OF ABOVE-NORMAL TEMPERATURES OVER THE DESERT
SOUTHWEST, CENTRAL PLAINS, UPPER MISSISSIPPI VALLEY, AND NORTHERN GREAT LAKES,
CENTRAL APPALACHIANS, AND THE MID-ATLANTIC STATES, WHILE NEAR-NORMAL
TEMPERATURES BECOME MORE LIKELY FOR THE NORTHEAST U.S. UNDER THE INFLUENCE OF
BROAD TROUGHING JUST OFFSHORE OVER THE NORTH ATLANTIC. SOUTHERLY FLOW OFF THE
GULF OF ALASKA FAVORS ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE MAINLAND AND
SOUTHEAST ALASKA, WHILE STRONG SURFACE HIGH PRESSURE OVER THE ARCTIC OCEAN
FAVORS NEAR- TO BELOW-NORMAL TEMPERATURES FOR THE NORTH SLOPE. CONTINUED
POSITIVE SEA SURFACE TEMPERATURE ANOMALIES NEAR HAWAII FAVOR PERSISTENT
ABOVE-NORMAL TEMPERATURES FOR THE STATE.
DESPITE EXPANSIVE MID-LEVEL RIDGING OVER CANADA ABOVE-NORMAL PRECIPITATION IS
FAVORED FOR MUCH OF THE CONUS DUE TO TROPICAL MOISTURE ADVECTING INTO THE
DESERT SOUTHWEST AS WELL AS A SURFACE LOW PRESSURE DEPICTED IN ENSEMBLE
SOLUTIONS MOVING ALONG THE U.S.-CANADA BORDER DURING THE FORECAST PERIOD. THE
EASTERN PACIFIC HAS SEEN INCREASED TROPICAL CYCLONE (TC) ACTIVITY, AND MODEL
SOLUTIONS FAVOR THIS TROPICAL MOISTURE TO MOVE WELL NORTH INTO THE SOUTHWESTERN
CONUS, RESULTING IN ENHANCED PROBABILITIES OF ABOVE-NORMAL PRECIPITATION (>60%
FOR THE LOWER COLORADO, >50% FOR MUCH OF THE SOUTHWESTERN CONUS). THE
AFOREMENTIONED CLIPPER-TYPE SURFACE LOW IS DEPICTED WITH A TRAILING COLD FRONT,
ENHANCING PRECIPITATION OVER THE CENTRAL PLAINS AND OHIO VALLEY AND GENERALLY
TILTING MOST OF THE CONUS EAST OF THE ROCKIES TOWARDS ABOVE-NORMAL
PRECIPITATION. NEAR-NORMAL PRECIPITATION IS MOST LIKELY FOR PORTIONS OF THE
GREAT LAKES AND NEW ENGLAND, CONSISTENT WITH MOST FORECAST TOOLS. NEAR- TO
BELOW-NORMAL IS ALSO FAVORED FOR PORTIONS OF TEXAS AND THE GULF COAST, WHILE
CONTINUED INTERACTION BETWEEN TROPICAL MOISTURE AND A LINGERING
QUASI-STATIONARY FRONT OVER THE SOUTHEAST U.S. TILTS THE ODDS TOWARDS
ABOVE-NORMAL PRECIPITATION FOR MUCH OF FLORIDA AND UP THE MID-ATLANTIC REGION.
HAWAII TILTS TOWARDS ABOVE-NORMAL PRECIPITATION, CONSISTENT WITH THE HAWAII CON
AND TODAY’S AUTOBLEND.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 33% 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 UNCERTAINTY SURROUNDING THE TROPICS.
8-14 DAY OUTLOOK FOR SEP 21 - 27 2025
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT THE WAVETRAIN PATTERN
SEEN IN THE 6-10DAY PERIOD TO FLATTEN OUT SOMEWHAT, DUE MOSTLY TO DEFORMATION
AND WEAKENING OF THE RIDGES OVER THE NORTH PACIFIC AND CANADA. THE MID-LEVEL
TROUGH DEPICTED IN THE 6-10 DAY PERIOD IS FAVORED TO AMPLIFY AND DRIFT
SOUTHWARD IN THE WEEK-2 PERIOD, WHILE WEAK NEGATIVE HEIGHT ANOMALIES OVER THE
SOUTHEAST SHIFT EASTWARD MOSTLY OFFSHORE.
SINCE A NEARLY STATIONARY MID-LEVEL FLOW PATTERN IS DEPICTED IN WEEK-2 WITH
ONLY SLIGHT CHANGES IN AMPLITUDE, THE 8-14 DAY TEMPERATURE OUTLOOK IS VERY
SIMILAR TO THE EARLY FORECAST PERIOD. ENHANCED MONSOON ACTIVITY IS FAVORED TO
CONTINUE OVER THE DESERT SOUTHWEST TILTING THE ODDS TOWARDS NEAR-NORMAL
TEMPERATURES FOR THE CALIFORNIA DESERTS AND SOUTHERN NEVADA. THE REST OF THE
LOWER 48 IS FAVORED FOR ABOVE-NORMAL TEMPERATURES, WITH THE HIGHEST
PROBABILITIES (>50%) FOR THE SOUTHERN PLAINS EAST INTO THE SOUTHEAST U.S. AND
FLORIDA, AND FOR THE NORTHERN PLAINS. IN ALASKA SOUTHERLY FLOW IS FAVORED TO
CONTINUE OVER MUCH OF THE STATE, RESULTING IN CONTINUED CHANCES OF ABOVE-NORMAL
TEMPERATURES FOR THE SOUTHERN AND EASTERN MAINLAND AND SOUTHEAST ALASKA, WHILE
THE NORTH SLOPE CONTINUES TO TILT TOWARD BELOW-NORMAL TEMPERATURES.
MONSOON MOISTURE IS FAVORED TO CONTINUE SPREADING INTO THE SOUTHWESTERN CONUS,
SLIGHTLY TILTING THE ODDS TOWARDS ABOVE-NORMAL PRECIPITATION FROM THE DESERT
SOUTHWEST. MODELS DEPICT PACIFIC MOISTURE SPREADING SOUTH INTO THE PACIFIC
NORTHWEST, SLIGHTLY ENHANCING PROBABILITIES OF ABOVE-NORMAL PRECIPITATION. A
LINGERING COLD FRONT OVER THE CENTRAL CONUS INCREASES THE ODDS OF ABOVE-NORMAL
PRECIPITATION FOR PORTIONS OF THE GREAT PLAINS. PORTIONS OF THE MID-ATLANTIC
AND SOUTHEASTERN U.S. ARE ALSO FAVORED FOR HIGHER PROBABILITIES OF ABOVE-NORMAL
PRECIPITATION POTENTIALLY DUE TO CONTINUED TROPICAL MOISTURE/STATIONARY FRONT
INTERACTIONS. IN ALASKA PORTIONS OF THE EASTERN MAINLAND AND THE PANHANDLE TILT
TOWARDS ABOVE-NORMAL PRECIPITATION, ALTHOUGH WITH LOWER PROBABILITIES COMPARED
TO THE 6-10 DAY PERIOD AS THE DRIVING MID-LEVEL TROUGH IS FAVORED TO SHIFT
SOUTHWARD.
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: GOOD AGREEMENT AMONG THE
TEMPERATURE AND PRECIPITATION DYNAMICAL AND STATISTICAL TOOLS IS OFFSET BY
UNCERTAINTY SURROUNDING THE TROPICS.
FORECASTER: DANIEL BARANDIARAN
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:
20090913 - 20010924 - 20090827 - 20090918 - 19620924
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:
20090914 - 20090909 - 20010925 - 20090826 - 19870920
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 19 - 23 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 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 N W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A N WISCONSIN A N
ILLINOIS A A MISSISSIPPI A N MICHIGAN A N
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A N NEW YORK A N
VERMONT A N NEW HAMP N N MAINE N N
MASS N N CONN N N RHODE IS N N
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A N FL PENIN A A AK N SLOPE B A
AK ALEUTIAN N N AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 21 - 27 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF N A IDAHO A A NEVADA N A
W MONTANA A 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 N S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A A MISSISSIPPI A N MICHIGAN A N
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A N 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 A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE B N
AK ALEUTIAN N N AK WESTERN N N AK INT BSN A N
AK S INT A N AK SO COAST A N 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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