646
FXUS06 KWBC 242001
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST TUE DECEMBER 24 2024
6-10 DAY OUTLOOK FOR DEC 30, 2024 - JAN 03, 2025
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 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 GEFS, ECMWF AND CANADIAN MODELS DUE TO RECENT MODEL
SKILL. THE RESULTANT MANUAL BLEND FEATURES BROAD RIDGING WITH A LARGE POSITIVE
500-HPA HEIGHT ANOMALY CENTER (GREATER THAN +360 METERS) OVER EASTERN CANADIAN
EXTENDING SOUTHWARD TO THE NORTHEASTERN CONTIGUOUS U.S. (CONUS). TROUGHING IS
PREDICTED ACROSS THE BERING SEA AND THE ALEUTIANS. ANOMALOUS RIDGING AND
POSITIVE 500-HPA HEIGHT ANOMALIES ARE FORECAST OVER MAINLAND ALASKA AND ALONG
THE WEST COAST OF NORTH AMERICA, WHILE A TROUGH IS PREDICTED OVER THE CENTRAL
AND EASTERN CONUS. NEAR-NORMAL HEIGHTS ARE PREDICTED ACROSS HAWAII.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE STRONGLY FAVORED ACROSS MOST
OF THE SOUTHERN AND EASTERN CONUS DURING THE 6-10 DAY PERIOD, SUPPORTED BY MOST
OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS.CHANCES EXCEED 80% FOR ABOVE-NORMAL
TEMPERATURES ACROSS THE NORTHEASTERN CONUS. NEAR-NORMAL TEMPERATURES ARE LIKE
OVER THE NORTHWESTERN CONUS. PREDICTED TROUGHING OVER THE BERING SEA FAVORS
INCREASED SOUTHERLY FLOW DEVELOPING ACROSS PARTS OF SOUTHERN MAINLAND ALASKA
LEADING TO ELEVATED ODDS OF ABOVE-NORMAL TEMPERATURES. MOST DYNAMICAL
TEMPERATURE FORECAST TOOLS FAVOR BELOW-NORMAL TEMPERATURES OVER PARTS OF
NORTHERN MAINLAND ALASKA. ABOVE-NORMAL TEMPERATURES ARE FORECAST ACROSS HAWAII,
CONSISTENT WITH THE GEFS AND ECENS REFORECAST TEMPERATURE CONSOLIDATION.
THE 6-10 DAY PRECIPITATION FORECAST FAVORS BELOW-NORMAL PRECIPITATION FROM
CALIFORNIA EXTENDING EASTWARD TO PARTS OF SOUTHWESTERN NEW MEXICO AND
SOUTHWESTERN TEXAS DUE TO THE RIDGING AND ABOVE-NORMAL 500-HPA HEIGHTS.
ABOVE-NORMAL PRECIPITATION IS FORECAST OVER MUCH OF THE NORTHERN CONUS AND
PORTIONS OF SOUTHERN TEXAS, SUPPORTED BY MOST OF THE DYNAMICAL PRECIPITATION
FORECAST TOOLS. ABOVE-NORMAL PRECIPITATION IS FORECAST FOR SOUTHERN ALASKA
UNDERNEATH THE ONSHORE FLOW, WHILE MOST DYNAMICAL PRECIPITATION FORECAST TOOLS
FAVOR BELOW-NORMAL PRECIPITATION OVER NORTHERN MAINLAND ALASKA. ABOVE-NORMAL
PRECIPITATION IS FAVORED ACROSS HAWAII CONSISTENT WITH THE CONSOLIDATED
PRECIPITATION FORECAST TOOL.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 30% 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. GOOD
AGREEMENT AMONG THE DYNAMICAL TOOLS IS OFFSET BY A MORE PROGRESSIVE PATTERN BY
THE END OF THE PERIOD.
8-14 DAY OUTLOOK FOR JAN 01 - 07 2025
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY CONSISTENT
500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY PERIOD ACROSS NORTH
AMERICA AND THE SURROUNDING REGIONS. TROUGHING INITIALLY OVER THE NORTHEAST
PACIFIC IS FORECAST TO RETREAT, WITH THE 0Z GEFS, ECENS, AND CMCE DEPICTING
RIDGING DEVELOPING ALONG THE WEST COAST OF NORTH AMERICA BY THE END OF WEEK-2,
AND EVIDENCE OF MORE BROAD LONGWAVE TROUGHING BECOMING ESTABLISHED OVER THE
CENTRAL AND EASTERN CONUS. ABOVE-NORMAL HEIGHTS ARE FAVORED OVER MOST OF
MAINLAND ALASKA TIED TO THE AFOREMENTIONED RIDGING PREDICTED TO DEVELOP, WITH
BELOW-NORMAL HEIGHTS REMAINING FORECAST ACROSS THE ALEUTIANS. NEAR TO
BELOW-NORMAL HEIGHTS ARE FORECAST ACROSS HAWAII TIED TO TROUGHING DEVELOPING TO
THE EAST OF THE ISLANDS.
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR NORTHERN CALIFORNIA DURING WEEK-2
BENEATH THE FORECAST RIDGE AND ABOVE-NORMAL 500-HPA HEIGHTS ACROSS THE REGION.
BELOW-NORMAL TEMPERATURES ARE FORECAST OVER SOUTHEASTERN CONUS DUE TO A
PREDICTED TROUGH OVER THE CENTRAL AND EASTERN CONUS. MOST DYNAMICAL TEMPERATURE
FORECAST TOOLS SUPPORT ABOVE-NORMAL TEMPERATURES OVER PARTS OF THE NORTHEASTERN
CONUS AND SOUTHERN TEXAS, WHILE BELOW-NORMAL TEMPERATURES OVER MOST OF THE
NORTHERN AND CENTRAL ROCKIES, AND THE NORTHERN AND THE CENTRAL PLAINS. RIDGING
AND ABOVE-NORMAL 500-HPA HEIGHT OVER ALASKA LEAD TO INCREASED CHANCES FOR
ABOVE-NORMAL TEMPERATURES OVER THE STATE. HAWAII CONTINUES TO TILT TOWARDS
ABOVE-NORMAL TEMPERATURES, CONSISTENT WITH THE ECENS AND GEFS REFORECAST
CONSOLIDATION.
PROBABILITIES ARE ELEVATED FOR BELOW-NORMAL PRECIPITATION OVER PARTS OF THE
SOUTHWESTERN CONUS, DUE TO AN INFLUENCE FROM MID-LEVEL RIDGING, CONSISTENT WITH
THE ECENS CALIBRATED REFORECAST PRECIPITATION TOOL. NEAR- TO ABOVE-NORMAL
PRECIPITATION IS MORE LIKELY OVER THE REMAINDER OF THE CONUS, SUPPORTED BY MOST
OF THE DYNAMICAL PRECIPITATION FORECAST TOOLS. TROUGHING OVER THE BERING SEA
AND THE ALEUTIANS FAVORS ABOVE-NORMAL PRECIPITATION OVER MOST OF WESTERN AND
SOUTHERN ALASKA, WHILE BELOW-NORMAL PRECIPITATION REMAINS FAVORED OVER PARTS OF
NORTHERN MAINLAND ALASKA. ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS HAWAII,
CONSISTENT WITH THE ECENS AND GEFS REFORECAST CONSOLIDATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 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 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: ABOVE-AVERAGE, 4 OUT OF 5. GOOD
AGREEMENT AMONG THE DYNAMICAL TOOLS IS OFFSET BY A MORE PROGRESSIVE PATTERN BY
THE END OF THE PERIOD.
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 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:
20051225 - 20061208 - 19691218 - 20051220 - 19941218
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:
20051224 - 20061208 - 20021212 - 19751223 - 19691219
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 30, 2024 - JAN 03, 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N N NRN CALIF A B
SRN CALIF A B IDAHO N N NEVADA N B
W MONTANA N A E MONTANA N A WYOMING N A
UTAH N N ARIZONA A B COLORADO N A
NEW MEXICO A N N DAKOTA N A S DAKOTA N A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN A A
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A N
TENNESSEE A N ALABAMA A N 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 N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE B B
AK ALEUTIAN A A AK WESTERN N N AK INT BSN N B
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 01 - 07 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N N NRN CALIF N B
SRN CALIF N B IDAHO B A NEVADA N N
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B N ARIZONA N B COLORADO B A
NEW MEXICO N A N DAKOTA B A S DAKOTA B A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS N A S TEXAS N A W TEXAS N A
MINNESOTA N A IOWA N A MISSOURI N A
ARKANSAS N A LOUISIANA N A WISCONSIN N A
ILLINOIS N A MISSISSIPPI N A MICHIGAN A A
INDIANA N N OHIO N N KENTUCKY N N
TENNESSEE N A ALABAMA N 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 N N
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N N S CAROLINA N N GEORGIA N N
FL PNHDL N N FL PENIN N N AK N SLOPE A B
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A N
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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