090
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 WED DECEMBER 25 2024
6-10 DAY OUTLOOK FOR DEC 31, 2024 - JAN 04, 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 +300 METERS) OVER EASTERN CANADAN
EXTENDING SOUTHWARD TO THE NORTHEAST. 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 EASTERN CONTIGUOUS U.S. (CONUS).
NEAR-NORMAL HEIGHTS ARE PREDICTED ACROSS HAWAII.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE STRONGLY FAVORED ACROSS MOST
OF THE WESTERN AND PARTS OF THE NORTHEASTERN CONUS DURING THE 6-10 DAY PERIOD,
SUPPORTED BY MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS. CHANCES EXCEED
80% FOR ABOVE-NORMAL TEMPERATURES ACROSS MAINE. BELOW-NORMAL TEMPERATURES ARE
FAVORED OVER FLORIDA DUE THE BELOW-NORMAL 500HPA HEIGHTS. 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 OVER MOST
OF THE SOUTHERN CONUS (EXCEPT FOR PARTS OF SOUTHERN TEXAS, WHERE ABOVE-NORMAL
PRECIPITATION IS FAVORED) AND ABOVE-NORMAL PRECIPITATION FROM THE PACIFIC
NORTHWEST EXTENDING EASTWARD TO THE NORTHERN AND CENTRAL PLAINS, SUPPORTED BY
MOST OF THE DYNAMICAL PRECIPITATION FORECAST TOOLS. PREDICTED MID-LEVEL
TROUGHING OVER THE EASTERN CONUS AND AN ACTIVE STORM TRACK INCREASE CHANCES OF
ABOVE NORMAL PRECIPITATION OVER PARTS OF THE NORTHEASTERN CONUS. INCREASED
CHANCES OF ABOVE-NORMAL PRECIPITATION ARE 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 02 - 08 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
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.
MOST DYNAMICAL TEMPERATURE FORECAST TOOLS SUPPORT ABOVE-NORMAL TEMPERATURES
OVER MOST OF THE WESTERN AND SOUTHWESTERN CONUS, WHILE BELOW-NORMAL
TEMPERATURES ARE SLIGHTLY MORE LIKELY OVER PARTS OF NORTHEASTERN MONTANA AND
NORTHWESTERN NORTH DAKOTA. NEAR- TO BELOW-NORMAL TEMPERATURES ARE FAVORED OVER
MOST OF THE EASTERN CONUS (EXCEPT FOR THE NORTHEAST, WHERE ABOVE-NORMAL
TEMPERATURES ARE FAVORED) DUE TO A PREDICTED TROUGH OVER THE EASTERN CONUS.
RIDGING AND ABOVE-NORMAL 500-HPA HEIGHTS OVER ALASKA LEAD TO INCREASED CHANCES
FOR NEAR- TO 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 GEFS AND ECENS CALIBRATED REFORECAST PRECIPITATION TOOLS. 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
SOUTHERN ALASKA, WHILE BELOW-NORMAL PRECIPITATION REMAINS FAVORED OVER PARTS OF
NORTHERN MAINLAND ALASKA. NEAR TO ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS
HAWAII, CONSISTENT WITH THE OPERATIONAL AUTOBLEND PRECIPITATION FORECAST TOOL.
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:
20051226 - 20061209 - 19941218 - 19861223 - 20021213
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:
20061209 - 20051225 - 19941218 - 19861223 - 19941223
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 31, 2024 - JAN 04, 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A B
SRN CALIF A B IDAHO A A NEVADA A B
W MONTANA N A E MONTANA N A WYOMING N A
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A B N DAKOTA N A S DAKOTA N A
NEBRASKA N A KANSAS N N OKLAHOMA N B
N TEXAS N B S TEXAS A N W TEXAS A B
MINNESOTA N N IOWA N N MISSOURI N B
ARKANSAS N B LOUISIANA N B WISCONSIN A N
ILLINOIS N B MISSISSIPPI N B MICHIGAN A A
INDIANA N N OHIO N N KENTUCKY N B
TENNESSEE N B ALABAMA N B 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 A A DELAWARE A A VIRGINIA N N
N CAROLINA N N S CAROLINA N N GEORGIA N B
FL PNHDL N B FL PENIN N B AK N SLOPE B B
AK ALEUTIAN A A AK WESTERN N N AK INT BSN B B
AK S INT N A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 02 - 08 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF A B
SRN CALIF A B IDAHO A A NEVADA A B
W MONTANA N A E MONTANA N A WYOMING N A
UTAH A N ARIZONA A B COLORADO A A
NEW MEXICO A B N DAKOTA N A S DAKOTA N A
NEBRASKA N A KANSAS N A OKLAHOMA N A
N TEXAS N A S TEXAS A A W TEXAS A N
MINNESOTA N A IOWA N A MISSOURI B N
ARKANSAS B N LOUISIANA B N WISCONSIN N N
ILLINOIS B N MISSISSIPPI B N MICHIGAN N N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B N ALABAMA B N NEW YORK N N
VERMONT A N NEW HAMP A A MAINE A A
MASS N N CONN N N RHODE IS N N
PENN B N NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B N S CAROLINA B N GEORGIA B N
FL PNHDL B N FL PENIN B N AK N SLOPE N 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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