192
FXUS06 KWBC 201902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU AUGUST 20 2026
6-10 DAY OUTLOOK FOR AUG 26 - 30 2026
THE 0Z ECMWF, GEFS, AND CMCE ENSEMBLE MODEL FORECASTS CONTINUE TO PREDICT A
RELATIVELY AMPLIFIED 500-HPA HEIGHT PATTERN FOR SUMMER OVER THE NORTH AMERICAN
REGION, BUT SHOW A SLIGHT WESTWARD RETROGRESSION OF THE LARGE-SCALE PATTERN
RELATIVE TO YESTERDAY'S 6-10 DAY FORECAST. 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 NEAR NORTHWESTERN
MAINLAND ALASKA. MOST MODELS AGREE IN PREDICTING A WESTWARD SHIFT OF A
MID-LEVEL RIDGE THAT IS CENTERED OVER THE HIGH PLAINS AND PERSISTS 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 PACIFIC COAST TO THE
NORTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. A WEAK TROUGH IS PREDICTED OVER
THE NORTH PACIFIC, SLIGHTLY TO THE WEST OF YESTERDAY'S FORECAST, AND A SECOND
TROUGH IS PREDICTED OVER THE NORTHEASTERN CONTIGUOUS UNITED STATES (CONUS),
WITH BROADER WEAK NEGATIVE ANOMALIES OVER THE NORTHEASTERN CONUS RELATIVE TO
YESTERDAY'S FORECAST.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE ALEUTIAN ISLANDS, SOUTHEASTERN
MAINLAND ALASKA, AND SOUTHEAST ALASKA, UNDER PREDICTED POSITIVE 500-HPA HEIGHT
ANOMALIES. BELOW NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR NORTHWESTERN AND
PARTS OF INTERIOR MAINLAND ALASKA, WITH ENHANCED CYCLONIC FLOW AND CLOUD COVER.
WITH A BROAD AMPLIFIED RIDGE PREDICTED TO BE CENTERED OVER THE WESTERN 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, AND PARTS OF THE NORTHEAST, WITH PROBABILITIES EXCEEDING 80
PERCENT FOR PARTS OF THE SOUTHWEST AND SOUTHERN TEXAS. NEAR TO BELOW NORMAL
TEMPERATURES ARE FAVORED FOR THE GREAT LAKES REGION AND NORTHERN NEW YORK AND
VERMONT, 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. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE WESTERN AND
CENTRAL ALEUTIAN ISLANDS WHILE BELOW NORMAL PRECIPITATION IS FAVORED FOR THE
ALASKA PENINSULA, CONSISTENT WITH THE CONSOLIDATION OF CALIBRATED MODEL
PRECIPITATION FORECASTS. WHILE MOST DYNAMICAL MODEL FORECASTS FAVOR ABOVE
NORMAL PRECIPITATION FOR A LARGE AREA OF THE CONUS, PRECIPITATION ANOMALIES ARE
PREDICTED TO BE VERY SMALL IN MANY AREAS. ABOVE NORMAL PRECIPITATION IS
THEREFORE ONLY FAVORED FOR PARTS OF THE NORTHERN AND CENTRAL GREAT PLAINS,
WHERE PRECIPITATION SIGNALS ARE GREATER IN THE PRECIPITATION CONSOLIDATION.
BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR SOUTH TEXAS, CONSISTENT WITH
THE CONSOLIDATION. PREDICTED WEAK TROUGHING OVER THE NORTHEASTERN CONUS FAVORS
ABOVE NORMAL PRECIPITATION FOR THE EASTERN SEABOARD FROM THE CAROLINAS TO THE
NORTHEAST. ABOVE NORMAL PRECIPITATION IS FAVORED ACROSS HAWAII, 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 28 - SEP 03, 2026
THE OVERALL PREDICTED 500-HPA HEIGHT PATTERN IS RELATIVELY PERSISTENT INTO THE
8-14 DAY PERIOD IN ENSEMBLE MODEL FORECASTS, WITH SMALL CHANGES RELATIVE TO THE
6-10 DAY PERIOD FORECAST. THE RIDGE OVER THE CONUS BEGINS TO DEAMPLIFY LATER IN
THE WEEK-2 PERIOD. THE AMPLIFIED RIDGE OVER THE ALEUTIANS ALSO BEGINS TO
DEAMPLIFY LATER IN WEEK 2, WHILE THE TROUGH OVER THE NORTH PACIFIC AT THE START
OF THE PERIOD PROGRESSES EASTWARD INTO THE PACIFIC NORTHWEST. 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, SOUTHERN
MAINLAND ALASKA, AND SOUTHEAST ALASKA. A TROUGH IS FORECAST NEAR AND OVER THE
PACIFIC COAST OF THE NORTHWESTERN CONUS IN THE WEEK-2 MANUAL BLEND WITH GREATER
AMPLITUDE THAN YESTERDAY'S FORECAST. 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, WITH LOWER AMPLITUDE RELATIVE
TO THE 6-10 DAY PERIOD. A TROUGH AND SLIGHTLY NEGATIVE 500-HPA HEIGHT ANOMALIES
PERSIST OVER THE NORTHEASTERN CONUS THROUGH MOST OF THE 8-14 DAY PERIOD.
ABOVE NORMAL TEMPERATURES CONTINUE TO BE FAVORED ACROSS THE ALEUTIAN ISLANDS IN
THE WEEK-2 PERIOD, UNDER POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED FOR PARTS OF INTERIOR MAINLAND ALASKA, WITH
INCREASED PRECIPITATION AND CLOUDINESS UNDER ANOMALOUS CYCLONIC FLOW. ABOVE
NORMAL TEMPERATURES ARE FAVORED FOR THE SOUTH COAST, SOUTHEASTERN MAINLAND
ALASKA, AND SOUTHEAST ALASKA, UNDER 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, WITH PROBABILITIES EXCEEDING 70
PERCENT IN PARTS OF THE SOUTHWEST AND SOUTHERN TEXAS. NEAR NORMAL TEMPERATURES
ARE FAVORED FOR PARTS OF NORTHERN CALIFORNIA, OREGON AND WASHINGTON, UNDER A
PREDICTED WEAK TROUGH. NEAR TO BELOW NORMAL TEMPERATURES ARE SLIGHTLY FAVORED
FOR THE NORTHEASTERN CONUS IN WEEK 2, UNDER A PERSISTENT TROUGH. DYNAMICAL
MODEL FORECASTS AGREE ON LIKELY ABOVE NORMAL TEMPERATURES FOR HAWAII.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE WESTERN AND CENTRAL ALEUTIANS AND
MOST OF MAINLAND ALASKA, EXCLUDING THE SOUTH COAST, IN THE WEEK-2 PERIOD,
CONSISTENT WITH MOST MODEL FORECASTS AND THE CONSOLIDATION. ABOVE NORMAL
PRECIPITATION IS FAVORED FOR MOST OF THE PACIFIC NORTHWEST AND PARTS OF THE
NORTHERN AND CENTRAL PLAINS, WHERE DYNAMICAL MODEL FORECASTS ARE MOST
CONSISTENT AND THE CONSOLIDATION SHOWS POSITIVE PRECIPITATION ANOMALIES. THE
WESTWARD SHIFT OF THE RIDGE OVER THE CONUS FAVORS ENHANCED PROBABILITIES FOR
ABOVE NORMAL PRECIPITATION FOR PARTS OF THE SOUTHWEST MONSOON REGION. BELOW
NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR SOUTH TEXAS, CONSISTENT WITH
THE CONSOLIDATION. 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
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:
20100802 - 20160825 - 20220731 - 19970813 - 20100816
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:
20100801 - 20050815 - 20230826 - 20090806 - 20180730
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 26 - 30 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 N E MONTANA A N 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 A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA N N IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN N N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO N N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN N 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 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 A N AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 28 - SEP 03, 2026
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N N NRN CALIF N N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A N
UTAH A N ARIZONA A A COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN N N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA N N OHIO N 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 N A NEW JERSEY N A W VIRGINIA A N
MARYLAND N A DELAWARE N A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE N A
AK ALEUTIAN A N AK WESTERN N A AK INT BSN N A
AK S INT A N AK SO COAST A N 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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