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FXUS06 KWBC 111915
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI SEPTEMBER 11 2026
6-10 DAY OUTLOOK FOR SEP 17 - 21 2026
TODAY'S DYNAMICAL MODELS DEPICT A SIGNIFICANT PATTERN TRANSITION DURING THE 6
TO 10 DAY PERIOD. THE PERIOD BEGINS WITH A STRONGLY POSITIVE NORTH ATLANTIC
OSCILLATION (NAO) PATTERN, CHARACTERIZED BY BELOW NORMAL HEIGHTS ACROSS MUCH OF
THE HIGHER LATITUDES OF THE WESTERN HEMISPHERE FROM GREENLAND ACROSS BAFFIN BAY
AND THE LABRADOR SEA AND INTO MUCH OF NORTHERN AND EASTERN CANADA. ABOVE NORMAL
MID-LEVEL HEIGHTS STRETCH ACROSS ALMOST THE ENTIRETY OF THE CONTIGUOUS UNITED
STATES (CONUS). ANOMALOUS RIDGING IS FORECAST OVER SOUTHEAST ALASKA AND A WEAK
TROUGH IS FORECAST OVER THE EASTERN BERING SEA. AS TIME PROGRESSES, THE
POSITIVE NAO PATTERN BREAKS DOWN, AS THE ANOMALOUS RIDGE OVER SOUTHEAST ALASKA
QUICKLY PROGRESSES EASTWARD AND HEIGHTS BEGIN TO RISE OVER CENTRAL CANADA AND
EVENTUALLY PARTS OF EASTERN CANADA. AS THIS TRANSITION TAKES PLACE, A TROUGH
INITIALLY OVER CENTRAL CANADA IS FORECAST TO BE DISPLACED TO THE SOUTH AND
EAST, CLIPPING THE GREAT LAKES AND NORTHEAST DURING THE MIDDLE AND LATER PARTS
OF THE PERIOD. REMNANT RIDGING AND ASSOCIATED ABOVE NORMAL HEIGHTS ARE
GENERALLY FORECAST TO PERSIST FARTHER TO THE SOUTH AND WEST, PARTICULARLY
ACROSS THE INTERIOR WEST. A WEAK TROUGH OR CLOSED LOW IS FORECAST OFF THE COAST
OF NORTHERN CALIFORNIA EARLY IN THE PERIOD, WITH UNCERTAINTY HIGH AS TO ITS
EVOLUTION THEREAFTER. HEIGHTS ARE FORECAST TO FALL ACROSS MUCH OF ALASKA AS THE
TROUGH OVER THE EASTERN BERING SEA PROGRESSES TO THE WESTERN MAINLAND AND
DEEPENS. AN ACTIVE EASTERN AND CENTRAL TROPICAL PACIFIC CONTINUES WITH THE
NATIONAL HURRICANE CENTER DEPICTING ONE NAMED STORM (NORBERT) AND TWO
ADDITIONAL AREAS OF POTENTIAL CYCLONE DEVELOPMENT. THE ACTIVE TROPICAL EASTERN
AND CENTRAL TROPICAL PACIFIC MAY, IN TURN, FAVOR AN ACTIVE PATTERN FOR HAWAII.
WITH A POSITIVE NAO IN PLACE EARLY IN THE PERIOD, NEAR TO ABOVE NORMAL
TEMPERATURES ARE FAVORED FOR MUCH OF THE CONUS. CONFIDENCE IS HIGH (50 TO 70
PERCENT CHANCE) FOR ABOVE NORMAL TEMPERATURES ACROSS THE INTERIOR WEST AND
EXTENDING TO SOUTHERN CALIFORNIA AND THE PACIFIC NORTHWEST, WHERE MID-LEVEL
RIDING IS FORECAST TO BE MOST PERSISTENT. HOWEVER, NEAR TO BELOW NORMAL
TEMPERATURES ARE FAVORED FOR THE NORTHEAST, GREAT LAKES, AND ADJACENT AREAS, AS
A TROUGH PROGRESSES THROUGH THESE REGIONS DURING THE MIDDLE AND LATER PARTS OF
THE PERIOD. ABOVE NORMAL TEMPERATURES ARE LIKELY ACROSS THE SOUTHEASTERN
QUADRANT OF THE CONUS, AS A FRONTAL BOUNDARY MAY STALL WELL NORTH OF THE
REGION. SOUTHEASTERN ALASKA IS LIKELY TO EXPERIENCE WARMER THAN NORMAL
TEMPERATURES AS ANOMALOUS RIDGING DOMINATES EARLY IN THE PERIOD. INCREASED
TROUGHING AND PREDICTED HEIGHT FALLS LEAD TO A TILT TOWARD NEAR OR BELOW NORMAL
TEMPERATURES ACROSS THE REMAINDER OF THE MAINLAND. PARTS OF THE ALEUTIANS LEAN
WARM, AS ABOVE NORMAL HEIGHTS OVERSPREAD THE AREA FROM A FLAT BUT EXPANSIVE
RIDGE TO ITS EAST. HAWAII IS LIKELY TO BE WARMER THAN NORMAL DUE TO EXPANSIVE
ABOVE NORMAL SEA SURFACE TEMPERATURES IN THE TROPICAL EASTERN AND CENTRAL
PACIFIC ASSOCIATED WITH THE CURRENT EL NINO.
INCREASED TROPICAL MOISTURE ADVECTION CONTINUES TO RESULT IN ELEVATED
PROBABILITIES FOR ABOVE-NORMAL PRECIPITATION ACROSS MUCH OF THE WEST. THE
HIGHEST PROBABILITIES (GREATER THAN 50 PERCENT) ARE FOCUSED ACROSS THE
SOUTHWEST AND ADJACENT AREAS. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED FROM
THE NORTHEAST AND MID ATLANTIC TOWARD THE MIDDLE MISSISSIPPI VALLEY ASSOCIATED
WITH A PREDICTED FRONTAL BOUNDARY. AS SURFACE HIGH PRESSURE BUILDS BEHIND THIS
FRONTAL BOUNDARY, AREAS OF THE UPPER MISSISSIPPI AND NORTHERN PLAINS TILT DRY.
A TILT TOWARD ABOVE NORMAL PRECIPITATION IS INDICATED WELL TO THE SOUTH OF THIS
SURFACE HIGH, ACROSS THE FLORIDA PENINSULA AND SOUTH TEXAS, UNDERNEATH ENHANCED
EASTERLY LOW LEVEL FLOW. THE PACIFIC NORTHWEST AND EXTREME SOUTHERN PORTIONS OF
SOUTHEAST ALASKA LEAN DRY DUE TO PREDICTED MID LEVEL RIDGING EARLY IN THE
PERIOD. AN ACTIVE PERIOD IS LIKELY FOR MUCH OF THE REMAINDER OF EASTERN AND
SOUTHERN ALASKA, AS A STUBBORN AREA OF SURFACE LOW PRESSURE PERSISTS NEAR THE
SOUTH COAST OF THE MAINLAND. AN ACTIVE EASTERN AND CENTRAL TROPICAL PACIFIC,
INCLUDING POTENTIAL INFLUENCES FROM NORBERT, FAVORS ABOVE NORMAL PRECIPITATION
ACROSS HAWAII. PLEASE STAY TUNED TO THE NATIONAL HURRICANE CENTER FOR THE
LATEST DEVELOPMENTS IN THE TROPICS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 25% 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 EARLY IN THE PERIOD, OFFSET BY UNCERTAINTIES IN THE
EVOLUTION OF A TRANSITIONAL PATTERN LATER IN THE PERIOD.
8-14 DAY OUTLOOK FOR SEP 19 - 25 2026
BY THE BEGINNING OF THE WEEK-2 PERIOD, A SIGNIFICANT PATTERN TRANSITION IS
FORECAST TO BE WELL UNDERWAY AS THE POSITIVE NAO WEAKENS. THE PERIOD BEGINS
WITH ANOMALOUS RIDGING OVER THE INTERIOR WEST AND DOWNSTREAM TROUGHING OVER THE
GREAT LAKES AND NORTHEAST. ANOMALOUS TROUGHING IS ALSO FORECAST IN THE VICINITY
OF THE ALASKA PENINSULA. AS TIME PROGRESSES, ABOVE NORMAL HEIGHTS BEGIN TO
OVERSPREAD THE NORTH-CENTRAL CONUS AS THE RIDGE PUSHES EAST. CORRESPONDINGLY,
THE TROUGH OVER THE NORTHEAST BEGINS TO WEAKEN TOWARD THE MIDDLE AND END OF
WEEK-2. UNCERTAINTY REMAINS HIGH ACROSS THE WEST COAST, REGARDING THE POTENTIAL
EVOLUTION OF A WEAK TROUGH NEAR OR JUST OFF THE COAST. MODELS ARE IN GENERALLY
GOOD AGREEMENT IN PREDICTING INCREASED TROUGHING ACROSS MUCH OF WESTERN
MAINLAND ALASKA, AT LEAST THROUGH THE MIDDLE OF WEEK-2. ENHANCED TROPICAL
ACTIVITY OVER EASTERN AND CENTRAL TROPICAL PACIFIC IS LIKELY TO CONTINUE,
PROLONGING THE POTENTIAL FOR AN ACTIVE PATTERN ACROSS HAWAII.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE WESTERN TWO-THIRDS OF THE
CONUS AS WELL AS ACROSS THE GULF COAST REGION AND SOUTHERN PARTS OF THE
SOUTHEAST. CONFIDENCE IS HIGH (50 TO 70 PERCENT CHANCE) FOR ABOVE NORMAL
TEMPERATURES ACROSS MUCH OF THE INTERIOR WEST AND NORTHERN HIGH PLAINS, WHERE
RIDGING IS FORECAST TO BE MOST PERSISTENT. NEAR TO BELOW NORMAL TEMPERATURES
ARE FAVORED ACROSS THE GREAT LAKES AND NORTHEAST, DUE TO ANOMALOUS TROUGHING,
ESPECIALLY DURING THE EARLY AND MIDDLE PARTS OF WEEK-2. ENHANCED CHANCES OF
NEAR NORMAL TEMPERATURES EXTEND SOUTHWARD ACROSS THE MID-ATLANTIC, AS
NORTHEASTLY MID-LEVEL FLOW ADVECTS A MARITIME AIRMASS ACROSS THE REGION. WITH
INCREASED TROUGHING PREDICTED, NEAR OR BELOW NORMAL TEMPERATURES ARE FAVORED
FOR WESTERN AND NORTHERN ALASKA. ELEVATED ODDS OF ABOVE NORMAL TEMPERATURES ARE
RESTRICTED TO SOUTHEASTERN PARTS OF THE STATE, DUE TO RIDGING PREDICTED EARLY
IN THE PERIOD. A TILT TOWARD ABOVE NORMAL TEMPERATURES PERSISTS ACROSS THE
ALAUTIANS, AS SEA SURFACE TEMPERATURES ADJACENT TO THE ISLANDS ARE ABOVE
NORMAL. HAWAII IS LIKELY TO BE WARMER THAN NORMAL, DUE TO WIDESPREAD ABOVE
NORMAL SSTS IN THE EASTERN AND CENTRAL TROPICAL PACIFIC.
ELEVATED TROPICAL ACTIVITY IN THE EASTERN AND CENTRAL PACIFIC FAVORS AN ACTIVE
PATTERN ACROSS HAWAII. THE POTENTIAL FOR INCREASED MOISTURE FROM THE TROPICAL
PACIFIC ALSO FAVORS ELEVATED ODDS FOR ABOVE NORMAL PRECIPITATION ACROSS MUCH OF
THE WEST. UNCERTAINTY IS HIGH AS TO HOW FAR TO THE NORTH THE REGION OF ABOVE
NORMAL PRECIPITATION MAY EXTEND, AND IS DEPENDENT ON THE EVOLUTION OF A WEAK
TROUGH OFF OF THE WEST COAST. TELECONNECTIONS FROM THE TROUGH POSITION AS WELL
AS FROM ANOMALOUS RIDGING OVER SOUTH-CENTRAL CANADA ARE SUPPORTIVE OF A
NORTHWARD PUSH OF MOISTURE INTO THE GREAT BASIN AND CALIFORNIA, WHERE ABOVE
NORMAL PRECIPITATION IS MODESTLY FAVORED. CONVERSELY, STRONG SURFACE HIGH
PRESSURE FAVORS BELOW NORMAL PRECIPITATION FARTHER TO THE EAST, ACROSS THE
GREAT LAKES, OHIO VALLEY, AND INTERIOR NORTHEAST. ENHANCED NORTHEASTERLY LOW
LEVEL FLOW ON THE SOUTHERN AND EASTERN PERIPHERY OF THIS SURFACE HIGH PRESSURE
FAVORS ADVECTION OF MARITIME AIR ACROSS MUCH OF THE EAST COAST AND SOUTHEAST,
WHERE NEAR OR ABOVE NORMAL PRECIPITATION IS FAVORED. ABOVE NORMAL
PRECIPITATION IS ALSO FAVORED ACROSS MOST OF ALASKA, AS CYCLONIC FLOW BECOMES
MORE DOMINANT AND MID-LEVEL HEIGHTS FALL.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 50% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 25% 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
REDUCED CONFIDENCE INHERENT IN A TRANSITIONAL PATTERN AS WELL AS UNCERTAINTIES
REGARDING THE EVOLUTION OF AN ACTIVE EASTERN AND CENTRAL TROPICAL PACIFIC.
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 (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
SEPTEMBER 17.
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:
20050909 - 20020904 - 20160827 - 20230903 - 20100909
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:
20050910 - 20220919 - 20020903 - 20240821 - 20100909
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 17 - 21 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A N NRN CALIF A N
SRN CALIF A A IDAHO A N NEVADA A A
W MONTANA A N E MONTANA A B WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A B S DAKOTA A N
NEBRASKA N N KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA N B IOWA N N MISSOURI A A
ARKANSAS A A LOUISIANA A N WISCONSIN N N
ILLINOIS N A MISSISSIPPI A N MICHIGAN N N
INDIANA A A OHIO N A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT B A NEW HAMP B A MAINE B A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA A A
MARYLAND N A DELAWARE N 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 A N AK WESTERN N N AK INT BSN N A
AK S INT A A AK SO COAST A A AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR SEP 19 - 25 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A A NRN CALIF A A
SRN CALIF A A IDAHO A A NEVADA A A
W MONTANA A N E MONTANA A N WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A A N DAKOTA A N S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A B
ARKANSAS A N LOUISIANA A N WISCONSIN A B
ILLINOIS A B MISSISSIPPI A N MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY N B
TENNESSEE A N ALABAMA A N NEW YORK B B
VERMONT B B NEW HAMP B N MAINE B B
MASS B N CONN B N RHODE IS B N
PENN N B NEW JERSEY B N W VIRGINIA N B
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N N S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A A AK N SLOPE N A
AK ALEUTIAN A A AK WESTERN N N AK INT BSN N A
AK S INT A 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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