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FXUS06 KWBC 132019
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST MON NOVEMBER 13 2023
6-10 DAY OUTLOOK FOR NOV 19 - 23 2023
TODAY’S 0Z GEFS, CMCE, AND ECMWF SOLUTIONS FOR THE 500-HPA HEIGHT ANOMALY
PATTERN ARE IN GOOD AGREEMENT DURING THE 6-10 DAY PERIOD, PREDICTING AN
AMPLIFIED RIDGE AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE
SOUTHWEST COAST OF MAINLAND ALASKA. ENSEMBLE MEANS PREDICT A VARIABLE PATTERN,
WITH A TROUGH AND ASSOCIATED NEGATIVE 500-HPA HEIGHT ANOMALIES OVER THE
SOUTHWEST PROGRESSING EASTWARD ACROSS THE CONTIGUOUS U.S. (CONUS) DURING THE
PERIOD, AS THE POSITIVE 500-HPA HEIGHT ANOMALY OVER ALASKA AMPLIFIES. THE ECMWF
ENSEMBLE MEAN RE-AMPLIFIES THE TROUGH OVER THE WEST AT THE END OF THE PERIOD,
WHILE THE GEFS ENSEMBLE MEAN PREDICTS WEAKER NEGATIVE 500-HPA HEIGHT ANOMALIES
OVER THE WEST.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR WESTERN AND NORTHERN MAINLAND ALASKA,
UNDER PREDICTED WESTERLY ONSHORE FLOW ALOFT, WHILE BELOW NORMAL PRECIPITATION
IS FAVORED FOR SOUTHEASTERN ALASKA INCLUDING THE PANHANDLE, UNDER ANOMALOUS
NORTHERLY FLOW AHEAD OF THE PREDICTED RIDGE. THE VARIABLE MID-LEVEL TROUGH
PATTERN OVER THE CONUS GENERALLY FAVORS ABOVE NORMAL PRECIPITATION FOR MUCH OF
THE LOWER FORTY-EIGHT STATES. THE ECMWF ENSEMBLE PRECIPITATION FORECAST FAVORS
ABOVE NORMAL PRECIPITATION FOR THE SOUTHWEST WITH THE PREDICTED AMPLIFICATION
OF A TROUGH OVER THE WEST COAST LATER IN THE PERIOD, WHILE THE GEFS ENSEMBLE
FAVORS A DRIER PATTERN. NEAR NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHWEST
IN THE OFFICIAL 6-10 DAY PERIOD OUTLOOK, DUE TO UNCERTAINTY IN THE TOOLS FOR
THIS REGION. ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE HAWAIIAN ISLANDS,
FOLLOWING THE PRECIPITATION CONSOLIDATION.
ABOVE NORMAL TEMPERATURES ARE LIKELY FOR WESTERN AND NORTHERN ALASKA, UNDER
SOUTHWESTERLY FLOW UNDER THE AMPLIFYING RIDGE. BELOW NORMAL TEMPERATURES ARE
FAVORED FOR SOUTHEASTERN ALASKA UNDER ANOMALOUS NORTHERLY FLOW. THE 6-10 DAY
PERIOD OUTLOOK FAVORS BELOW NORMAL TEMPERATURES FOR MUCH OF THE PACIFIC
NORTHWEST AND NORTHERN HIGH PLAINS, UNDER NORTHERLY FLOW BEYOND THE PREDICTED
MEAN TROUGH DURING THE PERIOD. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST
OF THE EASTERN HALF OF THE CONUS, EXCEPT FOR PARTS OF THE NORTHEAST, FOLLOWING
THE CONSOLIDATION OF REFORECAST-CALIBRATED ECMWF AND GEFS TEMPERATURE
FORECASTS. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR PARTS OF CENTRAL
CALIFORNIA, UNDER PREDICTED POSITIVE MEAN 500-HPA HEIGHT ANOMALIES. ABOVE
NORMAL TEMPERATURES ARE FAVORED FOR THE HAWAIIAN ISLANDS, FOLLOWING THE
TEMPERATURE CONSOLIDATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% 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, WITH GOOD
AGREEMENT ON THE MEAN 500-HPA HEIGHT FORECAST FOR THE PERIOD, OFFSET BY A
VARIABLE PATTERN AND LOW PROBABILITIES IN THE FORECAST TOOLS.
8-14 DAY OUTLOOK FOR NOV 21 - 27 2023
THE 500-HPA CIRCULATION PATTERN FOR THE 8-14 DAY PERIOD IS PREDICTED TO BE
GENERALLY SIMILAR TO THE 6-10 DAY PERIOD FORECASTS, WITH AN AMPLIFIED RIDGE AND
ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES OVER ALASKA AND A TROUGH
DOWNSTREAM OVER THE CENTRAL CONUS. PREDICTED 500-HPA ANOMALIES ARE VERY WEAK
OVER THE CONUS IN THE MANUAL BLEND OF MODEL FORECASTS, AS THE GEFS, ECMWF AND
CANADIAN ENSEMBLE MEAN FORECASTS SHOW SOME DIFFERENCES DUE TO A VARIABLE
PATTERN. THE ECMWF ENSEMBLE MEAN PREDICTS A TROUGH OVER THE WEST COAST OF THE
CONUS IN THE 8-14 DAY PERIOD MEAN, WHILE THE GEFS PREDICTS A WEAK TROUGH OVER
THE NORTH-CENTRAL CONUS.
ABOVE NORMAL TEMPERATURES ARE LIKELY FOR MOST OF ALASKA, OUTSIDE OF SOUTHEAST
ALASKA, UNDER THE PREDICTED AMPLIFIED RIDGE. NEAR TO BELOW NORMAL TEMPERATURES
ARE FAVORED FOR SOUTHEAST ALASKA, UNDER ANOMALOUS NORTHERLY FLOW ALOFT. THE
AMPLIFYING RIDGE OVER ALASKA IS ASSOCIATED WITH DOWNSTREAM TROUGHING AND
INCREASED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ACROSS MOST OF THE
WESTERN AND CENTRAL CONUS DURING WEEK 2, WITH THE GREATEST PROBABILITIES FOR
BELOW NORMAL TEMPERATURES FOR THE NORTHERN HIGH PLAINS. DIFFERENCES BETWEEN
MODEL TEMPERATURE FORECASTS BETWEEN THE GEFS AND ECMWF ENSEMBLES LEAD TO WEAKER
PROBABILITIES FOR BELOW NORMAL TEMPERATURES AND SOME AREAS FAVORING NEAR NORMAL
TEMPERATURES IN THE SOUTHWESTERN CONUS. ABOVE NORMAL TEMPERATURES ARE FAVORED
WITH GENERALLY WEAK PROBABILITIES FOR MUCH OF THE EAST, SUPPORTED BY THE
TEMPERATURE CONSOLIDATION. ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE
HAWAIIAN ISLANDS IN THE 8-14 DAY PERIOD, FOLLOWING THE TEMPERATURE
CONSOLIDATION.
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR MUCH OF WESTERN AND NORTHERN
ALASKA, UNDER SOUTHWESTERLY ONSHORE FLOW ALOFT. BELOW NORMAL PRECIPITATION IS
FAVORED FOR SOUTHEASTERN ALASKA, UNDER ANOMALOUS NORTHERLY OFFSHORE FLOW. ABOVE
NORMAL PRECIPITATION IS GENERALLY SLIGHTLY FAVORED ACROSS MOST OF THE CONUS,
EXCLUDING PARTS OF THE SOUTH-CENTRAL AND NORTHWESTERN CONUS, UNDER VARIABLE
TROUGHING DURING THE PERIOD. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR
MOST OF HAWAII EXCEPT FOR SOUTHEASTERN AREAS OF THE BIG ISLAND IN THE 8-14 DAY
PERIOD, FOLLOWING THE PRECIPITATION CONSOLIDATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% 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, WITH
ONLY FAIR OVERALL AGREEMENT AMONG DYNAMICAL MODELS ON A VARIABLE 500-HPA
CIRCULATION PATTERN, AND INCREASING UNCERTAINTY WITH DIFFERENCES AMONG FORECAST
TOOLS.
FORECASTER: D COLLINS
NOTES:
AUTOMATED FORECASTS ARE ISSUED ON SATURDAY AND SUNDAY. OCCASIONALLY MANUAL
INTERVENTION IS NECESSARY TO ADDRESS QUALITY CONTROL AND CONSISTENCY ISSUES. IN
THESE CASES, FORECASTS ARE MANUALLY DRAWN BUT A FULL DISCUSSION IS NOT ISSUED.
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
NOVEMBER 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:
20051030 - 20031117 - 20051104 - 20091109 - 19611124
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:
20051103 - 20051029 - 20031116 - 19611124 - 19891023
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 19 - 23 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF A N
SRN CALIF N N IDAHO B A NEVADA N A
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B A ARIZONA N N COLORADO N A
NEW MEXICO N A N DAKOTA A A S DAKOTA A A
NEBRASKA N A KANSAS N 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 A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A 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 A A NEW JERSEY N A W VIRGINIA A A
MARYLAND A A DELAWARE A 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 A A
AK ALEUTIAN A N AK WESTERN A A AK INT BSN A A
AK S INT B B AK SO COAST B B AK PNHDL B B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 21 - 27 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B A NRN CALIF B A
SRN CALIF B A IDAHO B A NEVADA B A
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B A ARIZONA N A COLORADO B A
NEW MEXICO N A N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS B N S TEXAS N N W TEXAS B N
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A N WISCONSIN B A
ILLINOIS B A MISSISSIPPI A A MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN A 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 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 B AK PNHDL B B
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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