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FXUS06 KWBC 262003
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST THU DECEMBER 26 2024
6-10 DAY OUTLOOK FOR JAN 01 - 05 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 +240 METERS) NEAR SOUTHERN
GREENLAND. TROUGHING IS PREDICTED ACROSS THE BERING SEA AND THE ALEUTIANS.
ANOMALOUS RIDGING AND POSITIVE 500-HPA HEIGHT ANOMALIES ARE FORECAST OVER
MAINLAND ALASKA AND THE WESTERN CONTIGUOUS U.S. (CONUS), WHILE A TROUGH IS
PREDICTED OVER THE EASTERN CONUS. NEAR-NORMAL HEIGHTS ARE PREDICTED ACROSS
HAWAII.
ENHANCED CHANCES FOR NEAR- TO ABOVE-NORMAL TEMPERATURES ARE FAVORED BENEATH THE
MID-LEVEL RIDGE ACROSS MUCH OF THE WESTERN AND CENTRAL U.S. DURING THE 6-10 DAY
PERIOD, SUPPORTED BY MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS.
BELOW-NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE EASTERN CONUS (EXCEPT
FOR PARTS OF THE NORTHEAST, WHERE ABOVE-NORMAL TEMPERATURES ARE FAVORED) DUE
THE BELOW-NORMAL 500HPA HEIGHTS AND TROUGHING. 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.
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. ABOVE-NORMAL PRECIPITATION IS ALSO FORECAST OVER PARTS OF SOUTHERN TEXAS
AND FROM THE PACIFIC NORTHWEST EXTENDING EASTWARD TO PORTIONS OF THE NORTHERN
PLAINS AND THE UPPER MISSISSIPPI VALLEY, WHILE BELOW-NORMAL PRECIPITATION IS
EXPECTED OVER THE REMAINDER OF THE CONUS, SUPPORTED BY MOST OF THE DYNAMICAL
PRECIPITATION FORECAST TOOLS. INCREASED CHANCES OF ABOVE-NORMAL PRECIPITATION
ARE FORECAST FOR SOUTHERN ALASKA DUE TO THE ONSHORE FLOW, WHILE MOST DYNAMICAL
PRECIPITATION FORECAST TOOLS FAVOR BELOW-NORMAL PRECIPITATION OVER NORTHERN
MAINLAND ALASKA. ABOVE-NORMAL PRECIPITATION IS FAVORED OVER KAUAI, WHILE NEAR-
TO BELOW-NORMAL PRECIPITATION IS PREDICTED OVER OAHU, MAUI AND THE BIG ISLAND,
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 03 - 09 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 EITHER NEAR OR INLAND OF THE WEST COAST DURING WEEK-2, AND
EVIDENCE OF MORE BROAD LONGWAVE TROUGHING BECOMING ESTABLISHED OVER THE EASTERN
CONUS. THE 0Z GEFS DEPICTS A 500-HPA RIDGE AXIS OFFSHORE OF THE WEST COAST,
WHILE THE 0Z ECENS PREDICTS THIS RIDGE AXIS TO SHIFT INLAND OVER THE WESTERN
CONUS. ABOVE-NORMAL HEIGHTS ARE FAVORED OVER MOST OF MAINLAND ALASKA, WITH
BELOW-NORMAL HEIGHTS REMAINING FORECAST ACROSS THE ALEUTIANS. NEAR-NORMAL
HEIGHTS ARE FORECAST ACROSS HAWAII
MOST DYNAMICAL TEMPERATURE FORECAST TOOLS SUPPORT ABOVE-NORMAL TEMPERATURES
OVER MOST OF THE WESTERN AND CENTRAL CONUS (EXCEPT FOR PARTS OF NORTHEASTERN
MONTANA, NORTHERN NORTH DAKOTA AND NORTHWESTERN MINNESOTA, WHERE BELOW-NORMAL
TEMPERATURES ARE FAVORED), UNDER PREDICTED RIDGING AND ABOVE-NORMAL 500-HPA
HEIGHTS. BELOW-NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE EASTERN CONUS
(EXCEPT FOR PARTS OF NORTHERN MAINE, WHERE ABOVE-NORMAL TEMPERATURES ARE
FAVORED) DUE TO PREDICTED TROUGHING AND BELOW-NORMAL 500-HPA HEIGHTS. RIDGING
AND ABOVE-NORMAL 500-HPA HEIGHTS OVER ALASKA LEAD TO INCREASED CHANCES FOR
NEAR- TO ABOVE-NORMAL TEMPERATURES OVER MOST OF THE STATE, EXCEPT FOR PARTS OF
NORTHEASTERN MAINLAND ALASKA, WHERE BELOW-NORMAL TEMPERATURES ARE FAVORED.
HAWAII CONTINUES TO TILT TOWARDS ABOVE-NORMAL TEMPERATURES, CONSISTENT WITH THE
ECENS AND GEFS REFORECAST CONSOLIDATION.
PROBABILITIES ARE ELEVATED FOR ABOVE-NORMAL PRECIPITATION OVER PARTS OF THE
PACIFIC NORTHWEST EXTENDING EASTERWARD TO PORTIONS OF THE UPPER MISSISSIPPI
VALLEY, WHILE NEAR- TO BELOW-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.
ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS NORTHEASTERN HAWAIIAN ISLANDS, AND
NEAR- TO BELOW-NORMAL PRECIPITATION IS FORECAST OVER SOUTHEASTERN HAWAIIAN
ISLANDS, 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:
20061210 - 19941218 - 20051226 - 19861223 - 20030101
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:
19941218 - 20061210 - 19861224 - 19941223 - 20051227
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 01 - 05 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 B NEVADA A B
W MONTANA A A E MONTANA N A WYOMING A N
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA N A S DAKOTA N N
NEBRASKA N B KANSAS N B OKLAHOMA N B
N TEXAS N B S TEXAS N B W TEXAS A B
MINNESOTA N N IOWA N B MISSOURI B B
ARKANSAS B B LOUISIANA B B WISCONSIN N B
ILLINOIS B B MISSISSIPPI B B MICHIGAN N N
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B B NEW YORK N N
VERMONT A A NEW HAMP A A MAINE A A
MASS A N CONN N N RHODE IS N N
PENN B N NEW JERSEY N B W VIRGINIA B B
MARYLAND B B DELAWARE B B VIRGINIA B B
N CAROLINA B B S CAROLINA B B GEORGIA B B
FL PNHDL B B FL PENIN B B AK N SLOPE B B
AK ALEUTIAN A A AK WESTERN N N AK INT BSN N B
AK S INT A N AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 03 - 09 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 N NEVADA A B
W MONTANA N A E MONTANA N A WYOMING N A
UTAH A B ARIZONA A B COLORADO N N
NEW MEXICO A B N DAKOTA N A S DAKOTA N A
NEBRASKA N N KANSAS N B OKLAHOMA N B
N TEXAS A B S TEXAS A N W TEXAS A B
MINNESOTA N N IOWA N N MISSOURI B B
ARKANSAS B N LOUISIANA B N WISCONSIN B N
ILLINOIS B N MISSISSIPPI B N MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B B ALABAMA B N 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 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 N AK INT BSN N B
AK S INT A A AK SO COAST A A AK PNHDL A A
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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