937
FXUS06 KWBC 231917
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED SEPTEMBER 23 2026
6-10 DAY OUTLOOK FOR SEP 29 - OCT 03, 2026
THE 0Z ECMWF, GEFS, AND CANADIAN ENSEMBLE SOLUTIONS FOR 500-HPA HEIGHT
ANOMALIES ARE IN GOOD AGREEMENT WITH REGARD TO THE SYNOPTIC PICTURE OVER NORTH
AMERICA AND ADJACENT REGIONS DURING THE 6-10 DAY PERIOD, DEPICTING A DEEP
TROUGH OVER THE GULF OF ALASKA, SHORTWAVE TROUGHING OVER THE CENTRAL CONTIGUOUS
U.S. (CONUS), AND POSITIVE HEIGHT ANOMALIES OVER MUCH OF CENTRAL AND EASTERN
CANADA. MODELS GENERALLY INDICATE THE CENTRAL CONUS TROUGH TO MOVE EASTWARD
FAIRLY QUICKLY, WITH WEAK RIDGING FILLING IN OVER THE WESTERN AND CENTRAL CONUS
BY THE END OF THE 6-10 DAY PERIOD.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR MOST OF THE EASTERN CONUS, AHEAD OF
THE SHORTWAVE TROUGH, PARTICULARLY ALONG THE EASTERN SEABOARD AND ALONG THE
GULF COAST WHERE CHANCES EXCEED 50%. ODDS OF ABOVE-NORMAL TEMPERATURES ARE ALSO
ENHANCED FOR SOUTHERN CALIFORNIA AND THE DESERT SOUTHWEST UNDER SOUTHEASTERLY
FLOW AND CONSISTENT WITH MOST FORECAST GUIDANCE. NEAR-NORMAL TEMPERATURES ARE
FAVORED FOR THE NORTHWESTERN CONUS DUE TO ENHANCED ONSHORE FLOW STEMMING FROM
TROUGHING OVER THE GULF OF ALASKA, AND FOR MUCH OF THE NORTHERN AND CENTRAL
PLAINS, UNDER AND BEHIND A SHORTWAVE TROUGH. IN ALASKA, THE AXIS OF THE DEEP
TROUGH RUNS ROUGHLY NORTH-SOUTH THROUGH THE MIDDLE OF THE STATE, RESULTING IN A
SIMILAR SPLIT FOR THE TEMPERATURE OUTLOOK. BELOW-NORMAL TEMPERATURES ARE
FAVORED ALONG THE WESTERN COAST OF ALASKA, WHILE ABOVE-NORMAL TEMPERATURES ARE
MORE LIKELY FOR THE EASTERN MAINLAND AND SOUTHEAST ALASKA. ANOMALOUSLY WARM SEA
SURFACE TEMPERATURES IN THE REGION KEEP HAWAII TILTING TOWARDS ABOVE-NORMAL
TEMPERATURES.
THE DEPICTED SHORTWAVE TROUGH MOVING OFF THE ROCKIES IS FAVORED TO PRODUCE A
WIDE BAND OF PRECIPITATION, TILTING THE ODDS TOWARDS ABOVE-NORMAL PRECIPITATION
FOR MOST OF THE CONUS EAST OF THE ROCKIES, ESPECIALLY OVER THE MISSISSIPPI
VALLEY WHERE CHANCES EXCEED 50%. ABOVE-NORMAL PRECIPITATION IS ALSO FAVORED FOR
PORTIONS OF THE PACIFIC NORTHWEST, AT THE SOUTHERN PERIPHERY OF INFLUENCE FROM
TROUGHING OVER THE NORTH PACIFIC. NEAR- TO BELOW-NORMAL PRECIPITATION IS MOST
LIKELY FOR MUCH OF CALIFORNIA, THE GREAT BASIN, NORTHERN ROCKIES, AND NORTHERN
HIGH PLAINS CONSISTENT WITH THE ERF PRECIPITATION CONSOLIDATION. ABOVE-NORMAL
PRECIPITATION IS MOST LIKELY FOR EASTERN PORTIONS OF THE ALASKAN MAINLAND AND
SOUTHEAST ALASKA DUE TO STRONG ONSHORE FLOW TIED TO TROUGHING IN THE REGION,
WHILE THE WESTERN MAINLAND IS FAVORED FOR NEAR-NORMAL PRECIPITATION. THE
PACIFIC TROPICS CONTINUE TO BE QUITE ACTIVE AT LEAST PARTIALLY DUE TO FORCING
FROM THE BUILDING EL NINO, AND HAWAII REMAINS FAVORED FOR ABOVE-NORMAL
PRECIPITATION.
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, DUE TO
GOOD AGREEMENT BETWEEN MODEL FORECASTS OF THE MEAN LARGE-SCALE MID-LEVEL HEIGHT
PATTERN, OFFSET BY DIFFERENCES AMONG MODEL ENSEMBLE MEAN HEIGHT FORECASTS FOR
THE CONUS.
8-14 DAY OUTLOOK FOR OCT 01 - 07 2026
THE OVERALL PREDICTED 500-HPA HEIGHT PATTERN IS RELATIVELY SIMILAR IN THE 8-14
DAY PERIOD ENSEMBLE MODEL FORECASTS, WITH SOME EVOLUTION OF THE PATTERN AND
DEAMPLIFICATION RELATIVE TO THE 6-10 DAY PERIOD FORECAST. A RIDGE AND POSITIVE
500-HPA HEIGHT ANOMALIES PERSIST OVER PARTS OF THE WESTERN ALEUTIANS WHILE
DEAMPLIFYING IN THE 8-14 DAY PERIOD IN ALL MODEL FORECASTS, WITH A TROUGH AND
NEGATIVE 500-PA HEIGHT ANOMALIES OVER SOUTHERN MAINLAND ALASKA, THE
NORTHEASTERN PACIFIC, AND ADJACENT AREAS OF WESTERN CANADA. WHILE ALL MODEL
WEEK-2 500-HPA HEIGHT FORECASTS ARE SIMILAR TO THEIR RESPECTIVE 6-10 DAY
FORECASTS, THERE ARE SIGNIFICANT DIFFERENCES IN THE ECMWF, GEFS AND CANADIAN
ENSEMBLE MEANS. THE MANUAL BLEND CONTINUES TO WEIGHT THE ECMWF MODEL GREATER,
PREDICTING POSITIVE 500-HPA HEIGHT ANOMALIES THAT EXTEND FROM THE CENTRAL
ROCKIES TO THE NORTHERN CENTRAL CONUS AND WESTERN GREAT LAKES REGION. WEAK
NEGATIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER PARTS OF THE PACIFIC
NORTHWEST AS WELL AS PORTIONS OF THE NORTHEASTERN CONUS IN THE 8-14 DAY PERIOD
MANUAL BLEND, WHILE NEAR NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER THE
SOUTHEASTERN CONUS.
ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED ACROSS MOST OF THE ALEUTIANS
IN WEEK 2, UNDER POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW-NORMAL TEMPERATURES
ARE FAVORED FOR THE WESTERN MAINLAND, UNDER TROUGHING AND CONSISTENT WITH THE
TEMPERATURE CONSOLIDATION. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR EASTERN
MAINLAND ALASKA AND SOUTHEAST ALASKA, UNDER ANOMALOUS SOUTHERLY FLOW.
CONSISTENT WITH THE TEMPERATURE CONSOLIDATION, ABOVE-NORMAL TEMPERATURES ARE
FAVORED ACROSS MUCH OF THE CONUS IN WEEK 2, AS A PREDICTED RIDGE PERSISTS WITH
POSITIVE 500-HPA HEIGHT ANOMALIES FROM THE CENTRAL ROCKIES TO THE NORTHERN
CENTRAL CONUS AND PARTS OF THE NORTHEASTERN CONUS. NEAR-NORMAL TEMPERATURES ARE
FAVORED FOR THE MIDDLE AND UPPER MISSISSIPPI VALLEY, INFLUENCED BY A PREDICTED
TROUGH EARLY IN THE FORECAST PERIOD. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR
HAWAII WITH GREATER PROBABILITIES FOR THE BIG ISLAND, CONSISTENT WITH THE
TEMPERATURE CONSOLIDATION.
ABOVE NORMAL PRECIPITATION CONTINUES TO BE FAVORED ACROSS MOST OF THE ALEUTIANS
IN WEEK 2, CONSISTENT WITH THE AUTOMATED BLEND OF FORECAST TOOLS. ABOVE-NORMAL
PRECIPITATION REMAINS MOST LIKELY FOR EASTERN PORTIONS OF THE ALASKAN MAINLAND
AND SOUTHEAST ALASKA AS WELL AS MUCH OF THE NORTHWESTERN CONUS DUE TO STRONG
ONSHORE FLOW TIED TO TROUGHING IN THE REGION, WHILE THE WESTERN MAINLAND OF
ALASKA IS FAVORED FOR NEAR-NORMAL PRECIPITATION. ABOVE NORMAL PRECIPITATION IS
FAVORED FOR THE SOUTHWEST, WITH CONTINUED MOISTURE FLOW FROM THE EASTERN
PACIFIC. NEAR- TO BELOW-NORMAL PRECIPITATION REMAINS MOST LIKELY FOR MUCH OF
CALIFORNIA, THE GREAT BASIN, ROCKIES, AND THE NORTHERN AND CENTRAL HIGH PLAINS
AS POSITIVE 500-HPA HEIGHT ANOMALIES BUILD IN OVER THE HIGH PLAINS. CONSISTENT
WITH ANOMALY FORECASTS FROM THE PRECIPITATION CONSOLIDATION, ABOVE NORMAL
PRECIPITATION IS FAVORED FOR THE CENTRAL AND EASTERN CONUS, WITH PROBABILITIES
EXCEEDING 40 PERCENT FOR PORTIONS OF THE GULF COAST AND SOUTHEAST U.S. ABOVE
NORMAL PRECIPITATION IS FAVORED FOR HAWAII, CONSISTENT WITH THE CALIBRATED
ECMWF PRECIPITATION FORECAST.
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, DUE TO
GOOD AGREEMENT BETWEEN MODEL FORECASTS OF THE MEAN LARGE-SCALE MID-LEVEL HEIGHT
PATTERN, OFFSET BY WEAKENING ANOMALIES AND INCREASING MODEL SPREAD TOWARDS THE
END OF THE FORECAST PERIOD.
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 (GRAY, "N") NORMAL.
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 (GRAY, "N")
NORMAL. 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
OCTOBER 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:
20250921 - 20250912 - 20220904 - 20200921 - 20090912
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:
20250926 - 20250921 - 20250911 - 20240904 - 20220904
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 29 - OCT 03, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N N NRN CALIF A N
SRN CALIF A N IDAHO N B NEVADA A B
W MONTANA N N E MONTANA N N WYOMING N N
UTAH A N ARIZONA A A COLORADO N A
NEW MEXICO A A N DAKOTA N A S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA N 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 A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
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 A FL PENIN A A AK N SLOPE N A
AK ALEUTIAN B N AK WESTERN B N AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 01 - 07 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A B
UTAH A N ARIZONA A A COLORADO A N
NEW MEXICO A A N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS N N OKLAHOMA N A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA N A IOWA N A MISSOURI N A
ARKANSAS A A LOUISIANA A A WISCONSIN N A
ILLINOIS N A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
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 A FL PENIN A A AK N SLOPE N N
AK ALEUTIAN B N AK WESTERN B N AK INT BSN A A
AK S INT N 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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