861
FXUS06 KWBC 202002
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 20 2024
6-10 DAY OUTLOOK FOR NOV 26 - 30 2024
DURING THE 6-10 DAY PERIOD MODELS REMAIN IN FAIRLY GOOD AGREEMENT RELATIVE TO
YESTERDAY ON AN AMPLIFIED AND PROGRESSIVE MID-LEVEL HEIGHT PATTERN ACROSS NORTH
AMERICA AND THE SURROUNDING REGIONS. STRONG POSITIVE 500-HPA HEIGHT ANOMALIES
ARE FORECAST TO BE CENTERED OVER THE GULF OF ALASKA CONSISTENT WITH YESTERDAY.
MEANWHILE, A FAST MOVING MID-LEVEL TROUGH IS FORECAST TO PROGRESS FROM THE
INTERIOR WEST ACROSS MUCH OF THE CONTIGUOUS U.S. (CONUS) DURING THE 6-10 DAY
PERIOD. THIS TROUGH WILL DISPLACE POSITIVE MID-LEVEL HEIGHT ANOMALIES ACROSS
THE SOUTHEASTERN CONUS AS THE PERIOD PROGRESSES LEAVING THE POSITIVE 6-10 DAY
MEAN HEIGHT ANOMALIES ONLY IN THE SOUTHEASTERN AND SOUTH-CENTRAL CONUS.
ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS MUCH OF THE SOUTHERN AND
SOUTHEASTERN CONUS DURING THE 6-10 DAY PERIOD BENEATH POSITIVE 500-HPA HEIGHT
ANOMALIES AHEAD OF AN APPROACHING MID-LEVEL TROUGH. THERE IS GOOD AGREEMENT
BETWEEN THE RAW, SHORT-TERM BIAS-CORRECTED, AND REFORECAST TOOLS FROM THE GEFS
AND ECENS ACROSS THESE REGIONS. BELOW-NORMAL TEMPERATURE CHANCES ARE ENHANCED
ACROSS MUCH OF THE WESTERN CONUS AND INTO THE NORTHERN AND CENTRAL PLAINS. THIS
IS CONSISTENT WITH DYNAMICAL AND STATISTICAL GUIDANCE. NEAR-NORMAL TEMPERATURES
ARE FAVORED AS A PERIOD AVERAGE IN THE EASTERN GREAT LAKES AND NORTHEAST AS
BELOW-NORMAL TEMPERATURES MOVE INTO THE REGION DURING THE PERIOD. IN ALASKA, A
MID-LEVEL RIDGE OVER THE GULF OF ALASKA BRINGS SOUTHWESTERLY FLOW INTO PORTIONS
OF SOUTHERN MAINLAND ALASKA. NEAR- TO BELOW-NORMAL TEMPERATURES ARE FAVORED FOR
NORTHWEST MAINLAND AND SOUTHEAST ALASKA. IN HAWAII, TOOLS ARE IN VERY STRONG
AGREEMENT FOR ABOVE-NORMAL TEMPERATURES.
A GENERALLY WET PATTERN IS PREDICTED ACROSS THE CONUS DURING THE 6-10 DAY
PERIOD. THE STRONGEST CHANCES ARE ACROSS PORTIONS OF THE CENTRAL ROCKIES WITH
THE MID-LEVEL TROUGH FORECAST TO BE FURTHER INLAND RELATIVE TO YESTERDAY. THE
MORE EASTERLY PROGRESSION OF THE MID-LEVEL TROUGH REDUCES CHANCES FOR
ABOVE-NORMAL PRECIPITATION ALONG THE IMMEDIATE WEST COAST AND INTO THE GREAT
BASIN RELATIVE TO YESTERDAY. IN THE EAST ABOVE-NORMAL PRECIPITATION CHANCES ARE
FORECAST ACROSS PORTIONS OF THE OHIO AND TENNESSEE VALLEY. RETURN FLOW OFF THE
GULF OF MEXICO IS FORECAST TO INTERACT WITH THE PROGRESSIVE MID-LEVEL TROUGH
BRINGING INCREASED CHANCES FOR PRECIPITATION. NEAR-NORMAL PRECIPITATION IS
FAVORED ACROSS PORTIONS OF FLORIDA AND THE RIO GRANDE VALLEY, IN AREAS FURTHER
REMOVED FROM THE MEAN STORM TRACK. IN ALASKA, A RELATIVELY WET PATTERN IS
FORECAST WITH SOUTHWESTERLY FLOW INTO MAINLAND ALASKA. NEAR- TO BELOW-NORMAL
PRECIPITATION IS FAVORED IN SOUTHEAST ALASKA WITH MID-LEVEL HIGH PRESSURE TO
THE WEST. IN HAWAII, BELOW-NORMAL PRECIPITATION IS FAVORED CONSISTENT WITH
REFORECAST AND BIAS-CORRECTED TOOLS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5. GOOD
AGREEMENT AMONG THE DYNAMICAL AND STATISTICAL TOOLS IS OFFSET BY A PROGRESSIVE
AND SHIFTING PATTERN.
8-14 DAY OUTLOOK FOR NOV 28 - DEC 04, 2024
THE PROGRESSIVE MID-LEVEL TROUGH IS FORECAST TO MOVE EAST ACROSS THE CONUS
EARLY IN WEEK-2 AND THEN STALL ACROSS PORTIONS OF THE NORTHEASTERN CONUS BY THE
END OF THE WEEK. POSITIVE MID-LEVEL HEIGHTS ARE FORECAST OFF THE WEST COAST AND
ACROSS MUCH OF ALASKA BRINGING NORTHWESTERLY FLOW ACROSS THE EASTERN CONUS FOR
MUCH OF WEEK-2. THE ENHANCED POSITIVE MID-LEVEL ANOMALIES ACROSS THE GULF OF
ALASKA BRINGS SOUTHWESTERLY FLOW OVER MAINLAND ALASKA.
BELOW-NORMAL TEMPERATURE CHANCES ARE FORECAST FOR MUCH OF THE CONUS DURING
WEEK-2 BENEATH MID-LEVEL TROUGHING AND NORTHWESTERLY FLOW ALOFT. ABOVE-NORMAL
TEMPERATURE CHANCES FOR THE CONUS ARE LIMITED TO PORTIONS OF FLORIDA. THE
STRONGEST PROBABILITIES FOR BELOW-NORMAL TEMPERATURES ARE FAVORED ACROSS
PORTIONS OF THE NORTHERN PLAINS. WEAKENING AGREEMENT AMONG THE TOOLS HAS
REDUCED CONFIDENCE IN THE BELOW-NORMAL TEMPERATURES ACROSS THE SOUTHWESTERN
CONUS RELATIVE TO YESTERDAY. IN ALASKA, THE SOUTHWESTERLY FLOW PATTERN ALOFT
BRINGS CHANCES FOR ABOVE-NORMAL TEMPERATURES. A COMPLICATING FACTOR IN THE
FORECAST IS THE POTENTIAL FOR LOW-LEVEL INVERSIONS TO DEVELOP DUE TO THE LOW
SOLAR HEATING AT THIS TIME OF YEAR, REDUCING THE CONFIDENCE IN ABOVE-NORMAL
TEMPERATURE CHANCES. NEAR-NORMAL TO BELOW-NORMAL TEMPERATURES ARE FAVORED
ACROSS NORTHWESTERN MAINLAND ALASKA AND IN SOUTHEAST. IN HAWAII, ABOVE-NORMAL
TEMPERATURES REMAIN FORECAST CONSISTENT WITH THE AVAILABLE GUIDANCE.
THE PRECIPITATION OUTLOOK FOR THE CONUS IS QUITE UNCERTAIN AT THIS TIME WITH
THE ECENS AND GEFS FORECASTING VERY DIFFERENT OUTCOMES ACROSS MUCH OF THE
CONUS. THE GEFS IS QUITE A BIT DRIER WITH BELOW-NORMAL PRECIPITATION IN MUCH OF
THE NORTHWESTERN CONUS AND NORTH-CENTRAL CONUS. HOWEVER, IN THESE LOCATIONS THE
ECENS REFORECAST AND RAW MODEL GUIDANCE BRING INCREASED PROBABILITIES FOR
ABOVE-NORMAL PRECIPITATION. AS SUCH, ONLY LOW PROBABILITIES ARE FORECAST ACROSS
MOST OF THE CONUS TODAY. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED IN
PARTS OF THE ROCKIES AND NORTHERN AND CENTRAL PLAINS. A SECOND AREA FOR
ABOVE-NORMAL PRECIPITATION IS OVER PARTS OF THE GREAT LAKES, EXTENDING SOUTH
THROUGH THE EASTERN CONUS TOWARDS THE GULF COAST. THE MID-LEVEL TROUGH
PROGRESSING THROUGH THE AREA AT THE ONSET OF THE PERIOD MAY BRING SOME FORCING
FOR PRECIPITATION TO THESE AREAS. BELOW-NORMAL PRECIPITATION IS FORECAST FOR
PARTS OF CALIFORNIA AND THE FOUR CORNERS WHERE THE RAW MODEL GUIDANCE IS IN
AGREEMENT. ELSEWHERE, NEAR-NORMAL IS FORECAST WITH DISAGREEMENTS AMONG THE
TOOLS LIMITING CONFIDENCE. IN ALASKA, ABOVE-NORMAL IS SLIGHTLY FAVORED ACROSS
SOUTH-CENTRAL AND SOUTHEAST MAINLAND ALASKA WHERE THERE IS THE BEST MODEL
AGREEMENT AMONG THE TOOLS. IN HAWAII, NEAR-NORMAL PRECIPITATION IS FORECAST.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 10% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 30% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 20%
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
DIVERGENT SOLUTIONS AMONG THE MODEL GUIDANCE FOR TEMPERATURE AND PRECIPITATION
REDUCING CONFIDENCE.
FORECASTER: RYAN BOLT
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:
19731126 - 19941112 - 19731119 - 19731114 - 20031117
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:
19731126 - 19731118 - 19611124 - 19631114 - 19731201
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 26 - 30 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B B OREGON B B NRN CALIF B N
SRN CALIF B N IDAHO B N NEVADA B A
W MONTANA B N E MONTANA B A WYOMING B A
UTAH B A ARIZONA N A COLORADO B A
NEW MEXICO A A N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA N A
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS A A LOUISIANA A A WISCONSIN B N
ILLINOIS B A MISSISSIPPI A A MICHIGAN N N
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE N A ALABAMA A A NEW YORK N N
VERMONT N N NEW HAMP N N MAINE N N
MASS N N CONN N N RHODE IS N N
PENN N A NEW JERSEY N N W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A N AK N SLOPE N A
AK ALEUTIAN A A AK WESTERN N A AK INT BSN N A
AK S INT A A AK SO COAST A A AK PNHDL N N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 28 - DEC 04, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B N NRN CALIF B B
SRN CALIF B B IDAHO B N NEVADA B N
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B N ARIZONA B N COLORADO B A
NEW MEXICO B N N DAKOTA B A S DAKOTA B A
NEBRASKA B N KANSAS B N OKLAHOMA B N
N TEXAS B N S TEXAS N A W TEXAS B N
MINNESOTA B N IOWA B N MISSOURI B N
ARKANSAS B N LOUISIANA N A WISCONSIN B N
ILLINOIS B N MISSISSIPPI B A MICHIGAN B A
INDIANA B N OHIO B A KENTUCKY B A
TENNESSEE B A ALABAMA N A NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B A NEW JERSEY B N W VIRGINIA B A
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA B A S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A A AK N SLOPE N N
AK ALEUTIAN A N AK WESTERN N N AK INT BSN A N
AK S INT A A AK SO COAST A N AK PNHDL N 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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