636
FXUS06 KWBC 181920
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE AUGUST 18 2026
6-10 DAY OUTLOOK FOR AUG 24 - 28 2026
THE ECMWF, GEFS, AND CMCE ENSEMBLE MODEL FORECASTS AGREE IN PREDICTING A
RELATIVELY AMPLIFIED 500-HPA HEIGHT PATTERN FOR SUMMER OVER THE NORTH AMERICAN
REGION. MODELS PREDICT AN AMPLIFIED RIDGE AND POSITIVE 500-HPA HEIGHT ANOMALIES
ACROSS THE ALEUTIAN ISLANDS INTO SOUTHWESTERN MAINLAND ALASKA DURING THE
PERIOD. A TROUGH AND NEGATIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED FURTHER
NORTH OVER THE ARCTIC. MODELS AGREE IN PREDICTING AN AMPLIFIED MID-LEVEL RIDGE
THAT IS CENTERED OVER THE GREAT PLAINS DURING LATE AUGUST, PERSISTING
THROUGHOUT THE 6-10 DAY PERIOD. THE MANUAL HEIGHT BLEND IS BASED ON THE 0Z
ECMWF, GEFS, AND CANADIAN MODEL 500-HPA HEIGHT FORECASTS, WEIGHTING THE ECMWF
ENSEMBLE MEAN GREATER DUE TO RECENT MODEL SKILL. THE MANUAL BLEND PREDICTS AN
EXPANSIVE AREA OF HEIGHT DEPARTURES GREATER THAN 30 METERS FROM THE INTERIOR
WEST TO THE MISSISSIPPI VALLEY. RELATIVELY WEAK TROUGHS ARE PREDICTED TO THE
WEST OVER THE NORTH PACIFIC AND TO THE EAST OVER THE NORTHEASTERN CONTIGUOUS
UNITED STATES (CONUS).
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS MOST OF THE ALEUTIAN ISLANDS UNDER
PREDICTED POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURES ARE
FAVORED FOR WESTERN MAINLAND ALASKA, WITH ENHANCED CYCLONIC FLOW AND CLOUD
COVER. WITH A BROAD AMPLIFIED RIDGE PREDICTED TO BE CENTERED OVER THE WESTERN
CENTRAL CONUS, ABOVE NORMAL TEMPERATURES ARE LIKELY FOR MOST OF THE WEST,
EXCLUDING THE COASTS OF NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST. UNDER
POSITIVE 500-HPA HEIGHT ANOMALIES, ABOVE NORMAL TEMPERATURES ARE LIKELY FOR THE
CENTRAL AND SOUTHEASTERN CONUS, WITH PROBABILITIES EXCEEDING 80 PERCENT FOR
PARTS OF THE SOUTHERN PLAINS. NEAR TO BELOW NORMAL TEMPERATURES ARE FAVORED FOR
THE NORTHEASTERN CONUS, UNDER A PREDICTED WEAK TROUGH. SUPPORTED BY MOST
TEMPERATURE TOOLS, ABOVE NORMAL TEMPERATURES ARE LIKELY FOR HAWAII.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR MOST OF MAINLAND ALASKA, EXCLUDING
THE SOUTH COAST, AHEAD OF ENHANCED WESTERLY FLOW AND A PREDICTED TROUGH TO THE
NORTHWEST. WHILE MOST DYNAMICAL MODEL FORECASTS FAVOR ABOVE NORMAL
PRECIPITATION FOR A LARGE AREA OF THE WESTERN CONUS AHEAD OF A WEAK TROUGH,
PRECIPITATION AMOUNTS ARE PREDICTED TO BE SMALL. ABOVE NORMAL PRECIPITATION IS
THEREFORE ONLY SLIGHTLY FAVORED FOR THE CENTRAL ROCKIES AND NORTHERN AND
CENTRAL HIGH PLAINS, WHERE PRECIPITATION SIGNALS ARE GREATER. UNDER THE
PREDICTED RIDGE, BELOW NORMAL PRECIPITATION IS FAVORED FOR PARTS OF THE
SOUTHERN PLAINS AND CENTRAL GULF COAST. PREDICTED WEAK TROUGHING OVER THE
NORTHEASTERN CONUS SLIGHTLY FAVORS ABOVE NORMAL PRECIPITATION FOR THE COASTS OF
THE CAROLINAS AND MID-ATLANTIC AND MOST OF THE NORTHEAST. ABOVE NORMAL
PRECIPITATION IS FAVORED ACROSS HAWAII WITH HIGHER PROBABILITIES FOR THE BIG
ISLAND, CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS.
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
AGREEMENT BETWEEN MODEL FORECASTS OF THE MEAN LARGE-SCALE MID-LEVEL HEIGHT AND
TEMPERATURE PATTERNS, OFFSET BY WEAK SIGNALS IN PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR AUG 26 - SEP 01, 2026
THE PREDICTED 500-HPA HEIGHT PATTERN IS RELATIVELY PERSISTENT INTO WEEK-2 IN
ENSEMBLE MODEL FORECASTS, WHILE INDICATING INCREASED UNCERTAINTY AND WEAKER
ANOMALIES LATER IN THE PERIOD. THE MANUAL BLEND OF ECMWF, GEFS, AND CMCE
ENSEMBLE MODEL FORECASTS PREDICTS POSITIVE 500-HPA HEIGHT ANOMALIES TO CONTINUE
BUT WEAKEN ACROSS THE ALEUTIAN ISLANDS AND SOUTHERN MAINLAND ALASKA, WITH
RISING HEIGHTS OVER SOUTHEAST ALASKA. A WEAK TROUGH PERSISTS OVER THE NORTH
PACIFIC IN THE WEEK-2 MANUAL BLEND AND PUSHES EASTWARD INTO THE WEST COAST OF
THE CONUS. A RIDGE AND POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED TO
PERSIST ACROSS THE WEST-CENTRAL CONUS THROUGH MOST OF THE PERIOD BY ALL MODELS
AND THE MANUAL BLEND. A SECOND TROUGH PERSISTS OVER THE NORTHEASTERN CONUS IN
THE 8-14 DAY PERIOD WITH WEAKER NEGATIVE 500-HPA HEIGHT ANOMALIES THAN IN THE
6-10 DAY PERIOD.
ABOVE NORMAL TEMPERATURES CONTINUE TO BE FAVORED ACROSS MOST OF THE ALEUTIAN
ISLANDS IN THE WEEK-2 PERIOD, DESPITE THE FORECAST OF WEAKER POSITIVE 500-HPA
HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURES ARE FAVORED FOR WESTERN AND
NORTHERN MAINLAND ALASKA, WITH INCREASED PRECIPITATION AND CLOUDINESS UNDER
ANOMALOUS CYCLONIC FLOW. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR
SOUTHEAST ALASKA AND ADJACENT AREAS OF THE SOUTHEASTERN MAINLAND, DUE TO
PREDICTED RISING POSITIVE 500-HPA HEIGHT ANOMALIES. PERSISTENCE OF THE RIDGE
OVER THE WESTERN CENTRAL CONUS LEADS TO LIKELY ABOVE NORMAL TEMPERATURES FOR
MOST OF THE CONUS. NEAR NORMAL TEMPERATURES ARE FAVORED FOR NORTHERN
CALIFORNIA, AND WESTERN OREGON AND WASHINGTON, UNDER A PREDICTED WEAK TROUGH.
NEAR TO BELOW NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR MOST OF THE
NORTHEASTERN CONUS, UNDER A PERSISTENT WEAK TROUGH. DYNAMICAL MODEL FORECASTS
AGREE ON LIKELY ABOVE NORMAL TEMPERATURES FOR HAWAII.
ABOVE NORMAL PRECIPITATION IS FAVORED ACROSS ALL OF MAINLAND ALASKA IN THE
WEEK-2 PERIOD, CONSISTENT WITH MOST MODEL FORECASTS AND THE CONSOLIDATION.
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FROM THE NORTHERN AND CENTRAL
ROCKIES INTO THE WESTERN NORTHERN AND CENTRAL PLAINS, WHERE DYNAMICAL MODEL
FORECASTS ARE MOST CONSISTENT AND THE CONSOLIDATION SHOWS POSITIVE
PRECIPITATION ANOMALIES. BELOW NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR
PARTS OF THE SOUTHERN PLAINS, UNDER THE CENTER OF A PREDICTED RIDGE. DYNAMICAL
MODEL FORECASTS CONTINUE TO SUPPORT ABOVE NORMAL PRECIPITATION FOR COASTAL
AREAS OF THE CAROLINAS, MID-ATLANTIC, AND NORTHEAST, AHEAD OF A PREDICTED WEAK
TROUGH. ABOVE NORMAL PRECIPITATION IS LIKELY FOR HAWAII IN THE 8-14 DAY PERIOD,
CONSISTENT WITH MOST DYNAMICAL MODEL FORECAST TOOLS.
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: AVERAGE, 3 OUT OF 5, DUE TO GOOD
AGREEMENT AMONG DYNAMICAL MODELS ON THE HEIGHT AND TEMPERATURE FORECASTS,
OFFSET BY WEAK PRECIPITATION SIGNALS.
FORECASTER: D COLLINS
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
AUGUST 20.
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:
20100801 - 20230824 - 20050816 - 20230831 - 20160825
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:
20100731 - 20050815 - 20090806 - 20240806 - 20230826
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 24 - 28 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A A ARIZONA A N COLORADO A A
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A B WISCONSIN N N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO B N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK B A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN B N NEW JERSEY N A W VIRGINIA N N
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE N A
AK ALEUTIAN N N AK WESTERN B A AK INT BSN N A
AK S INT N N AK SO COAST N N AK PNHDL N N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 26 - SEP 01, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N N NRN CALIF N N
SRN CALIF A N IDAHO A A NEVADA A N
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO N N KENTUCKY N N
TENNESSEE A N ALABAMA A N NEW YORK N A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN B A NEW JERSEY N A W VIRGINIA B N
MARYLAND B A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE B A
AK ALEUTIAN N N AK WESTERN B A AK INT BSN B 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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