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FXUS06 KWBC 132046
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED NOVEMBER 13 2024
6-10 DAY OUTLOOK FOR NOV 19 - 23 2024
TODAY'S ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON PREDICTING AN
AMPLIFIED MEAN 500-HPA FLOW PATTERN ACROSS NORTH AMERICA AND SURROUNDING
REGIONS. A HIGH AMPLITUDE RIDGE IS PREDICTED OVER THE ALEUTIAN ISLANDS, WHILE A
TROUGH IS PREDICTED DOWNSTREAM OVER THE NORTHEASTERN PACIFIC OCEAN IN 6-10 DAY
MEAN FORECASTS. AS THE TROUGH PROGRESSES EASTWARD OVER THE PACIFIC DURING THE
PERIOD, APPROACHING THE WEST COAST IN THE GEFS ENSEMBLE MEAN, A SECOND TROUGH
IS PREDICTED TO MOVE ACROSS THE CONTIGUOUS U.S. (CONUS). THE GEFS MODEL
PROGRESSES THE PATTERN MORE RAPIDLY EASTWARD THAN THE ECMWF MODEL, SHIFTING
MEAN NEGATIVE 500-HPA HEIGHT ANOMALIES FROM THE CENTRAL CONUS IN THE ECWMF
FORECAST TO THE MIDWEST IN THE GEFS FORECAST. A RIDGE AND ASSOCIATED POSITIVE
500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER THE NORTHWESTERN CONUS FOR THE 6-10
DAY PERIOD, WITH PRIMARILY ANOMALOUS NORTHERLY FLOW INTO THE INTERIOR WEST. THE
500-HPA MANUAL BLEND WEIGHTS THE ECMWF GREATER THAN OTHER MODELS, DUE TO RECENT
SKILL EVALUATION.
ANOMALOUS SOUTHERLY FLOW AND POSITIVE MID-LEVEL HEIGHT ANOMALIES, ASSOCIATED
WITH THE RIDGE OVER THE ALEUTIANS, LEAD TO FAVORED ABOVE NORMAL TEMPERATURES
FOR NORTHWESTERN MAINLAND ALASKA. BELOW NORMAL TEMPERATURES ARE FAVORED FOR
SOUTHERN AND SOUTHEASTERN ALASKA, DUE TO ANOMALOUS NORTHERLY FLOW. BELOW NORMAL
TEMPERATURES ARE FAVORED FOR THE INTERIOR WEST AND THE SOUTHERN CENTRAL CONUS,
UNDER PRIMARILY NORTHERLY MID-LEVEL FLOW ASSOCIATED WITH A RIDGE TO THE
NORTHWEST AND A TROUGH TO THE EAST. ABOVE NORMAL MEAN TEMPERATURES ARE FAVORED
FOR THE MIDWEST AND THE EAST IN THE 6-10 DAY PERIOD, WITH WARMER TEMPERATURES
PRIMARILY IN THE FIRST HALF OF THE PERIOD, UNDER A PREDICTED RIDGE. NEAR NORMAL
TEMPERATURES ARE FORECAST FOR HAWAII, WHERE 500-HPA HEIGHT ANOMALIES ARE WEAK
AND TOOLS ARE INCONSISTENT.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR CENTRAL AND NORTHERN MAINLAND ALASKA,
UNDER STRONG WESTERLY MID-LEVEL FLOW. NEAR TO BELOW NORMAL PRECIPITATION IS
FAVORED FOR MOST OF THE WESTERN CONUS INTO THE SOUTHERN PLAINS, UNDER A RIDGE
AND ANOMALOUS NORTHERLY FLOW. ABOVE NORMAL PRECIPITATION IS FAVORED FOR PARTS
OF THE NORTHERN PLAINS, THE MIDWEST, AND THE EAST, WITH A TROUGH PREDICTED TO
PROGRESS ACROSS THE CONUS. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR
HAWAII, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 25% OF TODAY'S 0Z 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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
GENERAL AGREEMENT ON THE OVERALL CIRCULATION FORECAST, OFFSET BY A RAPIDLY
CHANGING PATTERN AND DIFFERENCES AMONG THE MODEL TEMPERATURE AND PRECIPITATION
TOOLS.
8-14 DAY OUTLOOK FOR NOV 21 - 27 2024
THE RAPIDLY CHANGING 500-HPA HEIGHT PATTERN FORECAST CONTINUES INTO THE WEEK-2
PERIOD, WITH INCREASING DIFFERENCES BETWEEN MODELS. THE GEFS CONTINUES TO BE
MORE PROGRESSIVE WITH AN EASTWARD SHIFT IN THE LARGE-SCALE WAVE PATTERN
RELATIVE TO THE ECWMF. THE ECMWF FORECAST WAS AGAIN GIVEN GREATER WEIGHT THAN
OTHER MODELS, DUE TO RECENT SKILL. THE MANUAL 500-HPA HEIGHT BLEND PREDICTS
POSITIVE 500-HPA HEIGHT ANOMALIES ACROSS ALASKA AND A RIDGE CENTERED OVER THE
ALEUTIANS. A PREDICTED TROUGH OVER THE NORTHEASTERN PACIFIC APPROACHES THE WEST
COAST OF THE CONUS IN WEEK 2. THE MANUAL BLEND PREDICTS MEAN POSITIVE 500-HPA
HEIGHT ANOMALIES OVER THE WESTERN CONUS AND NEGATIVE 500-HPA HEIGHT ANOMALIES
OVER MOST OF THE EASTERN CONUS, ASSOCIATED WITH AN AMPLIFIED TROUGH EARLY IN
THE PERIOD THAT DEAMPLIFIES OVER TIME.
ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR CENTRAL AND NORTHERN ALASKA
IN WEEK 2, UNDER POSITIVE MID-LEVEL HEIGHT ANOMALIES. ABOVE NORMAL TEMPERATURES
ARE FAVORED FOR THE WEST COAST OF THE CONUS, UNDER THE PREDICTED RIDGE. NEAR
NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF THE INTERIOR WEST IN WEEK 2,
WITH INCREASED UNCERTAINTY AMONG MODEL TEMPERATURE TOOLS WITH A RAPIDLY
CHANGING HEIGHT PATTERN. BELOW NORMAL TEMPERATURES ARE FAVORED FROM THE
SOUTHERN CENTRAL CONUS INTO THE SOUTHEAST, UNDER A PREDICTED MEAN TROUGH. ABOVE
NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR THE NORTHERN GREAT LAKES REGION
AND THE NORTHEAST, SUPPORTED BY MOST DYNAMICAL MODEL TEMPERATURES FORECASTS.
NEAR NORMAL TEMPERATURES ARE FAVORED FOR HAWAII WHERE TEMPERATURE TOOLS ARE
INCONSISTENT.
ABOVE NORMAL PRECIPITATION IS FAVORED ACROSS MUCH OF ALASKA, CONSISTENT WITH
MOST DYNAMICAL MODEL FORECASTS. WITH CYCLONIC FLOW PROGRESSING EASTWARD ACROSS
THE CENTRAL AND EASTERN CONUS, AREAS OF SLIGHTLY ENHANCED PROBABILITIES OF
ABOVE NORMAL PRECIPITATION ARE CONFINED TO PARTS OF THE NORTH-CENTRAL AND
NORTHEASTERN CONUS. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED FOR THE SOUTHERN
FLORIDA PENINSULA, WHERE PRECIPITATION TOOLS ARE RELATIVELY CONSISTENT. BELOW
NORMAL PRECIPITATION IS FAVORED ACROSS A LARGE AREA OF THE SOUTHERN CONUS,
UNDER A DRIER PATTERN BEHIND THE PREDICTED TROUGH. ABOVE NORMAL PRECIPITATION
IS FAVORED FOR PARTS OF THE WEST COAST OF THE CONUS AS A TROUGH IS PREDICTED TO
APPROACH THE COAST DURING THE PERIOD. PERSISTENT CYCLONIC FLOW FAVORS ABOVE
NORMAL PRECIPITATION ACROSS HAWAII.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 25% OF TODAY'S 0Z 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
MODEL FORECAST DIFFERENCES ON A RAPIDLY EVOLVING MID-LEVEL HEIGHT PATTERN.
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 21.
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:
20091104 - 20011029 - 19751104 - 19721103 - 19991119
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:
20091104 - 19751103 - 19721103 - 20011029 - 20051031
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 19 - 23 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N B NRN CALIF N B
SRN CALIF N N IDAHO B B NEVADA N B
W MONTANA B B E MONTANA N N WYOMING B N
UTAH B B ARIZONA B N COLORADO B N
NEW MEXICO B B N DAKOTA N A S DAKOTA N N
NEBRASKA B N KANSAS B N OKLAHOMA B N
N TEXAS B B S TEXAS B B W TEXAS B B
MINNESOTA A A IOWA N A MISSOURI N N
ARKANSAS B N LOUISIANA N N WISCONSIN A A
ILLINOIS A A MISSISSIPPI N N MICHIGAN A A
INDIANA A A OHIO A 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 N B AK WESTERN N A AK INT BSN N A
AK S INT B N AK SO COAST B B AK PNHDL B N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 21 - 27 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON A N NRN CALIF A A
SRN CALIF A N IDAHO N N NEVADA N N
W MONTANA N N E MONTANA N A WYOMING N N
UTAH N B ARIZONA N N COLORADO N N
NEW MEXICO N B N DAKOTA N A S DAKOTA N A
NEBRASKA B N KANSAS B B OKLAHOMA B B
N TEXAS B B S TEXAS B B W TEXAS B B
MINNESOTA A A IOWA N N MISSOURI B B
ARKANSAS B B LOUISIANA B B WISCONSIN N A
ILLINOIS N N MISSISSIPPI B B MICHIGAN A A
INDIANA N N OHIO N N KENTUCKY B N
TENNESSEE B B ALABAMA B B NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A N
MASS A N CONN A A RHODE IS A N
PENN N A NEW JERSEY A N W VIRGINIA N N
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N N S CAROLINA N N GEORGIA B B
FL PNHDL B N FL PENIN B A AK N SLOPE A A
AK ALEUTIAN N B AK WESTERN A A AK INT BSN A A
AK S INT N A AK SO COAST N N AK PNHDL N 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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