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FXUS06 KWBC 252002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST MON DECEMBER 25 2023
6-10 DAY OUTLOOK FOR DEC 31, 2023 - JAN 04, 2024
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED AMPLIFIED
500-HPA CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS DURING
THE 6-10 DAY PERIOD. THE MANUAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY ON THE
ENSEMBLE MEANS FROM THE GFS, ECMWF, AND CANADIAN MODELS DUE TO RECENT MODEL
SKILL. THE RESULTANT MANUAL BLEND FEATURES TROUGHING OVER THE BERING SEA AND
THE ALEUTIANS. RIDGING AND POSITIVE HEIGHT ANOMALIES ARE FORECAST OVER ALASKA,
WESTERN CANADA, AND THE NORTHWESTERN CONTIGUOUS U.S. (CONUS). ANOTHER TROUGH
AND ASSOCIATED BELOW-NORMAL 500-HPA HEIGHTS ARE FORECAST OVER THE EASTERN
CONUS. ABOVE-NORMAL 500-HPA HEIGHTS ARE FORECAST ACROSS HAWAII.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE
WESTERN CONUS, PARTS OF THE SOUTHERN AND NORTHERN PLANS, THE UPPER MISSISSIPPI
VALLEY AND THE UPPER GREAT LAKES REGION, SUPPORTED BY MOST OF THE DYNAMICAL
TEMPERATURE FORECAST TOOLS. OVER THE SOUTHEASTERN QUARTER OF THE CONUS,
NEGATIVE 500-HPA HEIGHT ANOMALIES AND MID-LEVEL TROUGHING FAVOR BELOW-NORMAL
TEMPERATURES, WITH PROBABILITIES EXCEEDING 70% ACROSS SOUTHERN FLORIDA. CHANCES
FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED FOR ALASKA, DUE TO PREDICTED
RIDGING AND SOUTHWESTERLY FLOW. FOR HAWAII, FORECAST TOOLS FAVOR ABOVE-NORMAL
TEMPERATURES FOR MOST OF THE ISLANDS EXCEPT THE BIG ISLAND, WHERE THERE IS A
SLIGHT TILT TOWARDS BELOW-NORMAL TEMPERATURES.
NEAR- TO BELOW-NORMAL PRECIPITATION IS FAVORED OVER THE NORTHERN TIER OF THE
CONUS, WHILE ABOVE-NORMAL PRECIPITATION IS MORE LIKELY OVER MUCH OF THE
SOUTHERN CONUS, EXCEPT FOR SOUTHERN FLORIDA WHERE SLIGHTLY BELOW-NORMAL
PRECIPITATION IS INDICATED. IN ALASKA, BROAD ONSHORE FLOW PROMOTES ELEVATED
CHANCES OF NEAR- TO ABOVE-NORMAL PRECIPITATION FOR MUCH OF ALASKA, EXCEPT FOR
PARTS OF SOUTHEAST ALASKA WHERE BELOW-NORMAL PRECIPITATION IS FAVORED.
BELOW-NORMAL PRECIPITATION IS FAVORED FOR THE HAWAIIAN ISLANDS, CONSISTENT WITH
THE GEFS AND ECMWF PRECIPITATION REFORECAST CONSOLIDATION TOOLS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S GFS
SUPERENSEMBLE 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG MODEL SOLUTIONS AND FORECAST TEMPERATURE AND PRECIPITATION
TOOLS.
8-14 DAY OUTLOOK FOR JAN 02 - 08 2024
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY PERSISTENT
500-HPA CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS. THE
GEFS AND ECMWF ARE IN GOOD AGREEMENT REGARDING WEAKENING OF THE BERING SEA
MID-LEVEL TROUGH AND RIDGING OVER ALASKA AND WESTERN CANADA. A TROUGH IS
CONTINUED TO BE PREDICTED OVER THE EASTERN CONUS. BELOW-NORMAL 500-HPA HEIGHTS
ARE FORECASTED ACROSS MOST OF THE CONUS, WHILE POSITIVE 500-HPA HEIGHT
ANOMALIES ARE PREDICTED OVER MUCH OF ALASKA.
FOR THE CONUS AND ALASKA, THE WEEK-2 TEMPERATURE OUTLOOK LOOKS VERY SIMILAR TO
THE TEMPERATURE OUTLOOK VALID FOR THE 6-10 DAY PERIOD, BASED ON REFORECAST
TEMPERATURE GUIDANCE FROM THE GEFS AND ECMWF ENSEMBLES, AND THE SHORT-TERM
BIAS-CORRECTED NAEFS TEMPERATURE FORECAST. ABOVE-NORMAL TEMPERATURES ARE ALSO
FAVORED ACROSS KAUAI, OAHU, AND MAUI, WHILE BELOW-NORMAL TEMPERATURES ARE
LIKELY OVER THE BIG ISLAND IN THE 8-14 DAY PERIOD, FOLLOWING THE TEMPERATURE
CONSOLIDATION TOOL.
THE WEEK-2 PRECIPITATION OUTLOOK TILTS THE ODDS TOWARDS BELOW-NORMAL
PRECIPITATION OVER MUCH OF THE NORTHEASTERN CONUS, SUPPORTED BY A MAJORITY OF
PRECIPITATION TOOLS. IN CONTRAST, NEAR- TO ABOVE-NORMAL PRECIPITATION IS
FAVORED OVER THE REMAINDER OF THE CONUS. THIS IS CONSISTENT WITH GEFS
REFORECAST PRECIPITATION. AT HIGHER LATITUDES, A TROUGH ANTICIPATED NEAR THE
ALEUTIANS FAVORS SOUTHERLY ONSHORE FLOW OVER MOST OF ALASKA. THE ERF-CON TOOL
INDICATES NEAR-NORMAL PRECIPITATION FOR MOST OF THE HAWAIIAN ISLANDS, EXCEPT
FOR THE SOUTHERN BIG ISLAND WHERE BELOW-NORMAL PRECIPITATION IS FAVORED.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S GFS
SUPERENSEMBLE 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: NEAR AVERAGE, 3 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG MODEL SOLUTIONS, OFFSET BY FAIR AGREEMENT ON THE FORECAST
TEMPERATURE AND PRECIPITATION TOOLS.
FORECASTER: LUKE H
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
JANUARY 18.
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:
19920101 - 19941224 - 19941215 - 20070101 - 20061211
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:
19941225 - 19911231 - 20070101 - 19941216 - 19791224
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 31, 2023 - JAN 04, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A A
SRN CALIF A A IDAHO A B NEVADA A A
W MONTANA A B E MONTANA A N WYOMING N N
UTAH A A ARIZONA A A COLORADO N A
NEW MEXICO A A N DAKOTA A B S DAKOTA N B
NEBRASKA N N KANSAS N A OKLAHOMA N A
N TEXAS N A S TEXAS A A W TEXAS A A
MINNESOTA A B IOWA N B MISSOURI N N
ARKANSAS N A LOUISIANA N A WISCONSIN A B
ILLINOIS N B MISSISSIPPI B A MICHIGAN N B
INDIANA N B OHIO N B KENTUCKY N B
TENNESSEE B N ALABAMA B N NEW YORK N B
VERMONT N B NEW HAMP N B MAINE N B
MASS N B CONN N B RHODE IS N B
PENN N B NEW JERSEY N B W VIRGINIA N B
MARYLAND N B DELAWARE B B VIRGINIA B B
N CAROLINA B B S CAROLINA B N GEORGIA B N
FL PNHDL B N FL PENIN B N AK N SLOPE A N
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 02 - 08 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON N N NRN CALIF N A
SRN CALIF N A IDAHO N N NEVADA N A
W MONTANA A N E MONTANA A A WYOMING N A
UTAH N A ARIZONA N A COLORADO N A
NEW MEXICO N A N DAKOTA A N S DAKOTA N N
NEBRASKA N N KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS N A W TEXAS N A
MINNESOTA A N IOWA N N MISSOURI N N
ARKANSAS B A LOUISIANA B A WISCONSIN A B
ILLINOIS N N MISSISSIPPI B A MICHIGAN N B
INDIANA N N OHIO N B KENTUCKY N N
TENNESSEE B N ALABAMA B A NEW YORK N B
VERMONT N B NEW HAMP N B MAINE N B
MASS N B CONN N B RHODE IS N N
PENN N B NEW JERSEY N N W VIRGINIA N N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN B 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 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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