541
FXUS06 KWBC 281902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT SUN SEPTEMBER 28 2025
6-10 DAY OUTLOOK FOR OCT 04 - 08 2025
THE MID-LEVEL HEIGHT PATTERN ACROSS NORTH AMERICA IS FAVORED TO DEAMPLIFY
DURING THE 6-10 DAY PERIOD AS AN AMPLIFIED WAVETRAIN BREAKS DOWN, REPLACED BY
WIDESPREAD RIDGING WITH STRONG POSITIVE 500-HPA HEIGHT ANOMALIES FORECAST
CENTERED OVER QUEBEC, AND EXTENDING ACROSS MUCH OF THE CONTIGUOUS U.S. (CONUS),
AS WELL AS A STRONG RIDGE OVER THE NORTH PACIFIC. AT THE OUTSET OF THE PERIOD A
MODERATE TROUGH IS NOTED OVER THE WEST COAST, BUT THIS FEATURE IS QUICKLY
DEFORMED AS RIDGING SPREADS FROM BOTH THE NORTH PACIFIC AND EASTERN CANADA.
UPSTREAM FROM ALASKA, MODELS DEPICT AN AMPLIFIED TROUGH OVER EASTERN RUSSIA
RESULTING IN STRONG EASTERLY FLOW ALOFT OVER THE WESTERN COAST OF ALASKA.
STRONG RIDGING OVER EASTERN AND CENTRAL NORTH AMERICA SUPPORTS ELEVATED
PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ACROSS MOST OF THE CONUS.
PROBABILITIES EXCEED 80 PERCENT OVER MUCH OF THE GREAT LAKES AND NORTHEAST U.S.
TROUGHING OVER THE WEST COAST RESULTS IN A TILT TOWARDS BELOW -NORMAL
TEMPERATURES FOR MUCH OF THE WESTERN CONUS, WHILE ELEVATED SEA SURFACE
TEMPERATURES (SSTS) IN THE NORTH PACIFIC PUSH TEMPERATURES BACK TOWARDS
NEAR-NORMAL ALONG MUCH OF THE WEST COAST. ALONG THE EAST COAST A PASSING
FRONTAL SYSTEM COMBINED WITH THE POTENTIAL FOR TROPICAL ACTIVITY OFFSHORE
REDUCES ODDS OF ABOVE-NORMAL TEMPERATURES AS A RESULT OF CLOUDS, PRECIPITATION,
AND ONSHORE MARITIME FLOW. ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF
MAINLAND ALASKA, WHILE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY FOR THE NORTH
SLOPE AND PORTIONS OF SOUTHEAST ALASKA. ABOVE-NORMAL TEMPERATURES ARE FORECAST
FOR HAWAII, CONSISTENT WITH THE HAWAII-CON TOOL AND LIKELY DUE TO THE ELEVATED
NORTH PACIFIC SSTS NOTED ABOVE.
AMPLIFIED RIDGING OVER THE NORTH PACIFIC IS FAVORED TO SHIFT THE STORM TRACK
NORTHWARD, RESULTING IN BELOW-NORMAL PRECIPITATION OVER NORTHERN PORTIONS OF
THE WEST COAST, WHILE LEE CYCLOGENESIS DEPICTED OVER THE CANADIAN GREAT PLAINS
FAVORS ABOVE-NORMAL PRECIPITATION FOR THE NORTH-CENTRAL CONUS, WITH
PROBABILITIES EXCEEDING 50% FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER
MISSISSIPPI VALLEY. BELOW-NORMAL PRECIPITATION IS FAVORED FROM NORTHEASTERN
TEXAS THROUGH THE MIDDLE MISSISSIPPI VALLEY, OHIO VALLEY, GREAT LAKES, AND
NORTHEAST UNDERNEATH THE MID-LEVEL RIDGE AND SURFACE HIGH PRESSURE. FOR THE
SOUTHEAST, THE LINGERING POTENTIAL FOR TROPICAL ACTIVITY IN THE ADJACENT WATERS
OF THE ATLANTIC ALONG WITH A POTENTIAL STALLED FRONTAL BOUNDARY RESULT IN
INCREASED CHANCES FOR ABOVE-NORMAL PRECIPITATION ACROSS THE SOUTHEASTERN CONUS,
ALTHOUGH THIS POTENTIAL IS SHIFTING EARLIER INTO WEEK-1 AND OUT OF THE 6-10 DAY
PERIOD. THERE IS MUCH BETTER AGREEMENT AMONG THE TOOLS WITH RESPECT TO
PRECIPITATION OVER THE ALASKAN MAINLAND, WITH A STRONG JET ALOFT AND DEEP LOW
SURFACE PRESSURE NEAR THE BERING STRAIT INDICATED FROM LATE WEEK-1 WELL INTO
WEEK-2. THIS RESULTS IN ENHANCED PROBABILITIES OF ABOVE-NORMAL PRECIPITATION
ACROSS THE ALASKAN MAINLAND, WITH CHANCES EXCEEDING 60% FOR THE SEWARD
PENINSULA AND SURROUNDING AREAS. IN HAWAII, ABOVE-NORMAL PRECIPITATION IS
FAVORED ACROSS THE STATE, CONSISTENT WITH THE HAWAII-CON TOOL.
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: ABOUT AVERAGE, 3 OUT OF 5. GOOD
AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION DYNAMICAL AND STATISTICAL
TOOLS IS OFFSET BY UNCERTAINTY SURROUNDING THE TROPICS.
8-14 DAY OUTLOOK FOR OCT 06 - 12 2025
DURING THE 8-14 DAY PERIOD TROUGHING IS FAVORED TO REDEVELOP OVER THE WEST
COAST, RESULTING IN SYNOPTIC CONDITIONS SIMILAR TO THE OUTSET OF THE 6-10 DAY
PERIOD. POSITIVE 500-HPA HEIGHT ANOMALIES REMAIN FORECAST OVER MUCH OF THE
NORTHERN CONUS AND EASTERN CANADA DURING THE WEEK-2 PERIOD. THE OVERALL
AMPLITUDE OF THE FEATURE IS REDUCED RELATIVE TO THE PRIOR PERIOD BUT MAY BE THE
RESULT OF INCREASED ENSEMBLE SPREAD OVER TIME. WEAK NEGATIVE HEIGHT ANOMALIES
ARE NOTED OVER THE NORTH ATLANTIC, POTENTIALLY A WASHED-OUT SIGNAL FROM
PROBABLE TROPICAL CYCLONE ACTIVITY LEFT OVER FROM THE WEEK-1 PERIOD. THE
TROUGH-RIDGE PATTERN OVER EASTERN RUSSIA AND ALASKA IS FAVORED TO REMAIN IN
PLACE AS WELL, ALTHOUGH THE ENSEMBLES GENERALLY DEPICT A SLIGHT RETROGRESSION
AND CONSOLIDATION OF THE RIDGE.
THE AMPLIFIED RIDGE EARLY IN WEEK-2 COMBINED WITH INCREASING PACIFIC FLOW
SUPPORTS ELEVATED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES FOR MOST OF THE
CONUS DURING THE PERIOD. ODDS EXCEEDING 50% ARE ALMOST UNIVERSAL EAST OF THE
ROCKIES, WITH CHANCES TOPPING 70% FOR PORTIONS OF THE GREAT LAKES AND NORTHEAST
U.S. REDEVELOPING TROUGHING AND AND ONSHORE FLOW LATE IN THE WEEK-2 PERIOD WILL
LIKELY BRING INCREASED CLOUDINESS AND MODERATING TEMPERATURES FROM THE PACIFIC
OCEAN, RESULTING IN NEAR-NORMAL TEMPERATURES FOR MUCH OF THE WESTERN CONUS. IN
THE SOUTHEAST, CONTINUED CHANCES FOR INCREASED MOISTURE SUPPLIED BY THE TROPICS
PAIRED WITH A STATIONARY FRONTAL BOUNDARY COULD ENHANCE MARITIME FLOW ACROSS
THE SOUTHEASTERN U.S., SLIGHTLY WEAKENING PROBABILITIES OF ABOVE-NORMAL
TEMPERATURES IN THIS REGION. TROUGHING OVER THE GULF OF ALASKA FAVORS
INCREASING SOUTHERLY TO SOUTHWESTERLY FLOW ACROSS MAINLAND ALASKA. MOST
FORECAST TOOLS ARE TRENDING TOWARDS ABOVE-NORMAL TEMPERATURES ACROSS THE STATE,
WITH CHANCES INCREASING FROM NORTHEAST TO SOUTHWEST, WHILE NEAR-NORMAL
TEMPERATURES ARE INDICATED FOR THE NORTH SLOPE. ABOVE-NORMAL TEMPERATURES ARE
LIKELY TO CONTINUE ACROSS HAWAII, SUPPORTED BY THE CONSOLIDATED REFORECAST TOOL.
SIGNALS FOR PRECIPITATION ARE WEAK ACROSS THE CONUS DURING WEEK-2 AS THE
MID-LEVEL PATTERN FAVORS A NORTHWARD DISPLACEMENT OF THE JET STREAM AND
ASSOCIATED WEATHER, AS WELL AS MOSTLY ZONAL FLOW EARLY IN THE PERIOD. THE WEAK
PACIFIC FLOW PATTERN ALONG WITH POSITIVE 500-HPA HEIGHT ANOMALIES MOSTLY OVER
NORTHEASTERN NORTH AMERICA DOES LITTLE TO ENHANCE PRECIPITATION OVER MOST OF
THE CONUS. AN AREA OF ABOVE-NORMAL PRECIPITATION IS FAVORED OVER THE NORTHERN
PLAINS AND UPPER MISSISSIPPI VALLEY DURING WEEK-2 WITH MODEL GUIDANCE
INDICATING AN AREA OF LOW-PRESSURE MAY DEVELOP IN THE LEE OF THE CANADIAN
ROCKIES. A SLIGHT TILT TOWARD BELOW-NORMAL PRECIPITATION IS FAVORED ACROSS THE
NORTHEAST TIED TO SURFACE HIGH PRESSURE AND POSITIVE MID-LEVEL HEIGHT
ANOMALIES. THERE IS BETTER AGREEMENT ACROSS THE SOUTHEAST AND FLORIDA WHERE
CONTINUED FRONTAL ACTIVITY AND POTENTIAL INTERACTIONS WITH TROPICAL MOISTURE
SUPPORT AN UPTICK IN ABOVE-NORMAL PRECIPITATION CHANCES. FORECAST GUIDANCE IS
VERY CONSISTENT WITH THE 6-10 DAY PERIOD FOR ALASKA WITH CONTINUED SURFACE LOW
PRESSURE NEAR THE BERING STRAIT AND GOOD SUPPORT ALOFT. THE WHOLE STATE TILTS
TOWARDS ABOVE-NORMAL PRECIPITATION, WITH THE HIGHEST CHANCES (>50%) FOR THE
SEWARD PENINSULA. THE PRECIPITATION FORECAST ACROSS HAWAII REMAINS CONSISTENT
WITH A SLIGHT TILT TOWARD ABOVE-NORMAL PRECIPITATION OVER THE ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 33% 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. GOOD
AGREEMENT AMONG THE TEMPERATURE AND PRECIPITATION DYNAMICAL AND STATISTICAL
TOOLS IS OFFSET BY THE UNCERTAINTY REGARDING TROPICAL CYCLONE ACTIVITY DURING
WEEK-2.
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
OCTOBER 16.
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:
19551007 - 19920927 - 19620926 - 20071008 - 19620911
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:
19551006 - 19820907 - 19920926 - 19620911 - 19611011
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 04 - 08 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B B OREGON B B NRN CALIF N B
SRN CALIF N N IDAHO B N NEVADA B N
W MONTANA B A E MONTANA N A WYOMING N A
UTAH N N ARIZONA A N COLORADO A A
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A A
ILLINOIS A N MISSISSIPPI A N MICHIGAN A N
INDIANA A B OHIO A B KENTUCKY A B
TENNESSEE A N 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 N 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 A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 06 - 12 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N N NRN CALIF N N
SRN CALIF N N IDAHO N N NEVADA N N
W MONTANA A N E MONTANA A A WYOMING A N
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A A
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A N 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 N NEW JERSEY A N W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
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 A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL N 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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