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FXUS06 KWBC 171902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU SEPTEMBER 17 2026
6-10 DAY OUTLOOK FOR SEP 23 - 27 2026
DYNAMICAL MODELS ARE IN GOOD AGREEMENT REGARDING ANOMALOUS MID-LEVEL RIDGING
ACROSS THE CENTRAL AND EAST-CENTRAL CONUS DURING THE 6-10 DAY FORECAST PERIOD.
THIS IS REFLECTED IN THE MANUAL 500-HPA HEIGHT BLEND WHICH DEPICTS A +180 METER
POSITIVE HEIGHT ANOMALY CENTERED TO THE SOUTH OF HUDSON BAY AND ABOVE-NORMAL
HEIGHTS EXTENDING THROUGHOUT MUCH OF THE CONUS. COMPARED TO YESTERDAY, MODELS,
PARTICULARLY THE 0Z ECMWF ENSEMBLE, DEPICT MORE AMPLIFIED TROUGHING DEVELOPING
OVER THE NORTHEAST. ACROSS THE NORTH PACIFIC, TROUGHING IS FORECAST TO SHIFT
FROM THE GULF OF ALASKA TO NEAR THE WEST COAST OF THE CONUS, WITH TRANSIENT
RIDGING EXPANDING ACROSS SOUTHWESTERN AND SOUTHERN ALASKA AND ADDITIONAL
TROUGHING PROGRESSING OVER THE BERING SEA. AS A RESULT OF THIS EVOLUTION, THE
MANUAL HEIGHT BLEND INDICATES ABOVE-NORMAL HEIGHTS ACROSS THE ALEUTIANS AND
ALASKA PENINSULA, AND CLOSER TO NORMAL HEIGHTS OVER SOUTHERN MAINLAND ALASKA.
BELOW-NORMAL HEIGHTS ARE MORE LIKELY ACROSS THE NORTHERN MAINLAND AND SOUTHEAST
ALASKA. THE TROPICAL EASTERN AND CENTRAL PACIFIC REMAINS ACTIVE AND MAY
INFLUENCE THE SENSIBLE WEATHER ACROSS HAWAII, WITH NEAR-TO ABOVE-NORMAL HEIGHTS
FAVORED FOR THE PERIOD AS A WHOLE.
AS A RESULT OF BROAD MID-LEVEL RIDGING, PROBABILITIES FOR ABOVE-NORMAL
TEMPERATURES ARE INCREASED ACROSS MOST OF THE CONUS. THE HIGHEST PROBABILITIES
(GREATER THAN 70 PERCENT) ARE FAVORED NEAR THE SOUTHEAST TEXAS COAST AND THE
NORTHERN HIGH PLAINS. RELATIVELY WEAKER PROBABILITIES FOR ABOVE-NORMAL
TEMPERATURES ARE FORECAST ACROSS THE SOUTHWEST THROUGH THE MIDWEST GIVEN A
POTENTIAL INFLUX OF MOISTURE AND POTENTIALLY SATURATED GROUND. PROBABILITIES
FOR ABOVE-NORMAL TEMPERATURES ALSO DECREASE CLOSER TO THE WEST COAST DUE TO
TROUGHING MOVING INTO THE NORTHEASTERN PACIFIC, WITH NEAR-NORMAL TEMPERATURES
MORE LIKELY ACROSS WESTERN PORTIONS OF WASHINGTON AND OREGON. THERE HAS BEEN A
NOTABLE TREND TOWARD COOLER TEMPERATURES IN THE EAST ASSOCIATED WITH MORE
AMPLIFIED TROUGHING AS DEPICTED IN THE UNCALIBRATED 0Z ECMWF AND GEFS
ENSEMBLES. THEREFORE, PROBABILITIES FOR NEAR- TO BELOW-NORMAL TEMPERATURES ARE
INCREASED ACROSS THE NORTHEAST AND NORTHERN MID-ATLANTIC. A VARIABLE MID-LEVEL
HEIGHT PATTERN RESULTS IN NEAR-NORMAL TEMPERATURES BEING FAVORED ACROSS MUCH OF
INTERIOR MAINLAND AND SOUTHEAST ALASKA. ABOVE-NORMAL TEMPERATURE CHANCES ARE
INCREASED ACROSS PORTIONS OF SOUTHWESTERN AND NORTHEASTERN MAINLAND ALASKA, AND
THE ALEUTIANS. ABOVE-NORMAL TEMPERATURES ARE PREDICTED ACROSS HAWAII DUE TO
WIDESPREAD ABOVE-NORMAL SSTS IN THE TROPICAL EASTERN AND CENTRAL PACIFIC
ASSOCIATED WITH THE CURRENT EL NINO.
PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE INCREASED ACROSS MUCH OF THE
WESTERN CONUS, WITH CHANCES EXCEEDING 60 PERCENT ACROSS PORTIONS OF THE FOUR
CORNERS. THIS IS TIED TO THE POTENTIAL ADVECTION OF TROPICAL MOISTURE INTO THE
REGION, WITH THE NATIONAL HURRICANE CENTER (NHC) MONITORING MULTIPLE SYSTEMS
OFF THE COAST OF MEXICO THAT MAY DEVELOP IN THE NEXT WEEK. FARTHER EAST,
UNDERNEATH MORE INFLUENCE FROM MID-LEVEL RIDGING AND WITH LOW PRECIPITATION
TOTALS IN THE UNCALIBRATED ECMWF AND GEFS ENSEMBLES, NEAR- TO BELOW-NORMAL
PRECIPITATION CHANCES ARE INCREASED ACROSS PORTIONS OF THE MISSISSIPPI VALLEY,
MIDWEST, AND GREAT LAKES. PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE
INCREASED CLOSER TO THE EASTERN SEABOARD TIED TO FRONTAL ACTIVITY, WITH THE
POTENTIAL FOR A COASTAL LOW AROUND THE OUTSET OF THE PERIOD, WHICH MAY SLOWLY
DRIFT OFFSHORE PROLONGING PRECIPITATION CHANCES. SURFACE LOW PRESSURE OVER THE
BERING SEA FAVORS INCREASED CHANCES FOR ABOVE-NORMAL PRECIPITATION ACROSS MUCH
OF MAINLAND ALASKA. AN ACTIVE EASTERN AND CENTRAL TROPICAL PACIFIC FAVORS ABOVE
NORMAL PRECIPITATION ACROSS HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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: AVERAGE, 3 OUT OF 5, DUE TO GOOD
MODEL AGREEMENT REGARDING THE MID-LEVEL PATTERN EVOLUTION ACROSS MUCH OF THE
FORECAST DOMAIN, OFFSET BY DECREASING PREDICTABILITY OF TRANSIENT FEATURES,
PARTICULARLY ACROSS ALASKA AND NEAR THE EAST COAST.
8-14 DAY OUTLOOK FOR SEP 25 - OCT 01, 2026
THE 500-HPA PATTERN ACROSS NORTH AMERICA IS FORECAST TO BE STABLE, WITH MANY OF
THE FEATURES DISCUSSED IN THE 6-10 DAY PERIOD REMAINING IN PLACE DURING WEEK-2.
BROAD RIDGING IS FORECAST ACROSS THE CENTRAL CONUS ASSOCIATED WITH POSITIVE
HEIGHT ANOMALIES ACROSS THE NORTHERN AND CENTRAL PLAINS INTO THE MIDWEST, AND A
+90 METER POSITIVE HEIGHT ANOMALY CENTER OVER HUDSON BAY IN THE MANUAL BLEND.
COMPARED TO YESTERDAY, MODELS ARE MORE ROBUST WITH TROUGHING NEAR THE EAST
COAST WITH NEAR-NORMAL HEIGHTS BEING INDICATED IN THE MANUAL BLEND. TROUGHING
IS ALSO FAVORED ACROSS THE EASTERN PACIFIC, RESULTING IN NEAR-NORMAL HEIGHTS
ACROSS THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA AND A -30 METER NEGATIVE
HEIGHT ANOMALY CENTER JUST OFF THE COAST. INITIAL RIDGING OVER SOUTHERN ALASKA
IS FORECAST TO RETREAT INTO THE NORTH-CENTRAL PACIFIC, WITH A MORE VARIABLE
HEIGHT PATTERN EMERGING ACROSS ALASKA. AS A RESULT, NEAR-NORMAL HEIGHTS ARE
INDICATED IN THE MANUAL BLEND ACROSS MUCH OF MAINLAND ALASKA, SOUTHEAST ALASKA,
AND THE EASTERN ALEUTIANS, WITH ABOVE-NORMAL HEIGHTS ACROSS THE WESTERN
ALEUTIANS. NEAR-NORMAL HEIGHTS ARE FORECAST ACROSS HAWAII.
WITH MID-LEVEL RIDGING THE DOMINANT FEATURE ACROSS THE CONUS DURING WEEK-2,
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED OVER MOST AREAS.
THERE CONTINUES TO BE A TREND TOWARD COOLER TEMPERATURES ACROSS THE EAST AS
REFLECTED IN THE UNCALIBRATED 0Z ECMWF AND GEFS ENSEMBLES, WITH NEAR-NORMAL
TEMPERATURES FORECAST ACROSS MUCH OF THE NORTHEAST AND NORTHERN MID-ATLANTIC
FOR WEEK-2 AS A WHOLE. CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE ALSO LOWERED
ACROSS THE WEST, WITH NEAR-NORMAL TEMPERATURES MORE LIKELY ACROSS THE PACIFIC
NORTHWEST AND NORTHWESTERN CALIFORNIA. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR
MUCH OF INTERIOR MAINLAND ALASKA DUE TO UNCERTAINTY REGARDING THE MID-LEVEL
PATTERN EVOLUTION AND SOME DISCREPANCIES AMONG THE TOOLS, WITH THE REFORECAST
TOOLS GENERALLY LEANING WARMER THAN THEIR UNCALIBRATED VERSIONS. CHANCES FOR
ABOVE-NORMAL TEMPERATURES ARE SLIGHTLY INCREASED ACROSS THE FAR NORTHWESTERN
AND SOUTHWESTERN MAINLAND, SOUTHEAST ALASKA, WITH THE HIGHEST CHANCES FAVORED
OVER THE ALEUTIANS. ODDS FOR ABOVE-NORMAL TEMPERATURES REMAIN ELEVATED ACROSS
HAWAII.
PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE ENHANCED ACROSS THE WESTERN
HALF OF THE CONUS INTO THE UPPER MISSISSIPPI VALLEY, DUE TO THE COMBINATION OF
CYCLONIC FLOW OFF THE PACIFIC COAST AND POTENTIAL ADVECTION OF MOISTURE FROM AN
ACTIVE EASTERN TROPICAL PACIFIC AND ENTRAINMENT INTO SHORTWAVES PROPAGATING
ALONG THE DOWNSTREAM RIDGE AXIS. BELOW-NORMAL PRECIPITATION CHANCES ARE
INCREASED FARTHER TO THE EAST, ACROSS THE GREAT LAKES, OHIO VALLEY, AND
INTERIOR NORTHEAST, UNDERNEATH RIDGING AND SUPPORTED BY STATISTICAL TOOLS
(ANALOGS AND TELECONNECTIONS). ENHANCED CHANCES FOR ABOVE-NORMAL PRECIPITATION
REMAIN FAVORED ALONG THE EAST COAST, WITH A POTENTIAL COASTAL LOW LINGERING OFF
THE NORTHEAST COAST EARLY IN THE PERIOD. THE ORIENTATION OF THE FRONT BECOMES
MORE UNCERTAIN LATER IN THE PERIOD, WITH THE ECMWF GENERALLY FAVORING A MORE
OFFSHORE BOUNDARY, LEADING TO RELATIVELY DRIER CONDITIONS SPREADING INTO THE
EAST, BUT WITH ELEVATED CHANCES FOR ENHANCED PRECIPITATION CONTINUING ACROSS
THE SOUTHEAST WHERE PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ARE AT LEAST
40 PERCENT. IN ALASKA, ABOVE-NORMAL PRECIPITATION IS FAVORED FOR MOST OF THE
MAINLAND TIED TO POTENTIAL SURFACE LOW PRESSURE. NEAR-NORMAL PRECIPITATION IS
MORE LIKELY ACROSS THE ALEUTIANS, NORTHEASTERN MAINLAND, AND SOUTHEAST ALASKA.
ELEVATED PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION PERSIST ACROSS HAWAII.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% 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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
INCREASING UNCERTAINTY ACROSS THE NORTH PACIFIC, IN ADDITION TO VARYING SIGNALS
REGARDING THE TEMPERATURE FORECAST ACROSS EASTERN AND WESTERN PARTS OF THE
CONUS.
FORECASTER: THOMAS COLLOW
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:
20180829 - 20180923 - 20050923 - 20041001 - 20200912
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:
20180923 - 20180830 - 20190929 - 20200912 - 20050923
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 23 - 27 2026
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 A W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A B
ARKANSAS A B LOUISIANA A A WISCONSIN A B
ILLINOIS A B MISSISSIPPI A N MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A B
TENNESSEE A N ALABAMA A A NEW YORK N A
VERMONT N N NEW HAMP B A MAINE N N
MASS B A CONN B A RHODE IS B A
PENN N A NEW JERSEY N A W VIRGINIA A A
MARYLAND N A DELAWARE N A VIRGINIA N 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 A A AK WESTERN N A AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL N N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 25 - OCT 01, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON N 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 A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A A WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE A N ALABAMA A A NEW YORK N N
VERMONT N N NEW HAMP N N MAINE N N
MASS N A CONN N A RHODE IS N A
PENN N N NEW JERSEY N A W VIRGINIA A N
MARYLAND N N DELAWARE N A VIRGINIA N 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 N AK WESTERN N A AK INT BSN N A
AK S INT N A AK SO COAST N A AK PNHDL A N
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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