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FXUS06 KWBC 272002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI DECEMBER 27 2024
6-10 DAY OUTLOOK FOR JAN 02 - 06 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 +210 METERS) NEAR SOUTHERN
GREENLAND. TROUGHING IS PREDICTED ACROSS 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 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
MAINE, WHERE ABOVE-NORMAL TEMPERATURES ARE FAVORED) DUE THE BELOW-NORMAL 500HPA
HEIGHTS AND TROUGHING. PREDICTED TROUGHING OVER THE ALETIANS 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.
ABOVE-NORMAL PRECIPITATION IS FORECAST OVER PARTS OF SOUTHEASTERN TEXAS AND
FROM THE PACIFIC NORTHWEST EXTENDING EASTWARD TO PORTIONS OF THE NORTHERN AND
CENTRAL PLAINS, WHILE NEAR- TO 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 AND OAHU, WHILE NEAR- TO
BELOW-NORMAL PRECIPITATION IS PREDICTED OVER 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 04 - 10 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 WITH BELOW-NORMAL 500-HPA
HEIGHTS ARE FORECAST OVER THE ALEUTIANS. RIDGING AND ABOVE-NORMAL HEIGHTS ARE
PREDICTED OVER MAINLAND ALASKA AND WESTERN CONUS, WHILE BROAD LONGWAVE
TROUGHING WITH BELOW-NORMAL 500-HPA HEIGHTS ARE FORECAST OVER THE EASTERN
CONUS. NEAR-NORMAL HEIGHTS ARE FORECAST ACROSS HAWAII.
MOST DYNAMICAL TEMPERATURE FORECAST TOOLS SUPPORT NEAR- TO ABOVE-NORMAL
TEMPERATURES OVER MOST OF THE WESTERN CONUS, UNDER PREDICTED RIDGING AND
ABOVE-NORMAL 500-HPA HEIGHTS. BELOW-NORMAL TEMPERATURES ARE FAVORED OVER THE
EASTERN CONUS DUE TO PREDICTED TROUGHING AND BELOW-NORMAL 500-HPA HEIGHTS.
RIDGING AND ABOVE-NORMAL 500-HPA HEIGHTS OVER ALASKA LEAD TO INCREASED CHANCES
FOR ABOVE-NORMAL TEMPERATURES OVER THE SOUTHERN AND CENTRAL STATE, WHILE
BELOW-NORMAL TEMPERATURES ARE FORECAST OVER PARTS OF NORTHEASTERN MAINLAND
ALASKA. HAWAII CONTINUES TO TILT TOWARDS ABOVE-NORMAL TEMPERATURES, CONSISTENT
WITH THE ECENS AND GEFS REFORECAST CONSOLIDATION.
ABOVE-NORMAL PRECIPITATION IS FAVORED ALONG THE GULF COAST AND FLORIDA
ASSOCIATED WITH THE PREDICTED TROUGHING OVER THE EASTERN CONUS. BELOW-NORMAL
PRECIPITATION IS LIKELY OVER MOST OF OREGON, CALIFORNIA, AND THE SOUTHWESTERN
CONUS DUE TO THE PREDICTED RIDGING OVER THE WESTERN CONUS. PROBABILITIES ARE
ELEVATED FOR ABOVE-NORMAL PRECIPITATION OVER PARTS OF WASHINGTON EXTENDING
EASTWARD TO PORTIONS OF THE NORTHERN GREAT PLAINS , SUPPORTED BY MOST OF THE
DYNAMICAL PRECIPITATION FORECAST TOOLS. TROUGHING OVER THE ALEUTIANS FAVORS
ABOVE-NORMAL PRECIPITATION OVER MOST OF SOUTHERN AND WESTERN ALASKA, WHILE
BELOW-NORMAL PRECIPITATION REMAINS FAVORED OVER PARTS OF NORTHEASTERN 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:
20061211 - 19861224 - 19941216 - 19871208 - 19941224
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:
20061211 - 19941218 - 19861224 - 19941223 - 20061228
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 02 - 06 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 A A E MONTANA N A WYOMING A A
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA N N KANSAS N N OKLAHOMA N N
N TEXAS N A S TEXAS A A W TEXAS A B
MINNESOTA B N IOWA B N MISSOURI B N
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 N ALABAMA B N NEW YORK B N
VERMONT B N NEW HAMP B N MAINE A 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 B B
AK ALEUTIAN A A AK WESTERN N A AK INT BSN N B
AK S INT N A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 04 - 10 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A N NEVADA A B
W MONTANA A A E MONTANA N A WYOMING N A
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA N N KANSAS N N OKLAHOMA B N
N TEXAS B N S TEXAS A N W TEXAS A B
MINNESOTA B N IOWA B N MISSOURI B N
ARKANSAS B N LOUISIANA B A WISCONSIN B N
ILLINOIS B N MISSISSIPPI B N MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B N 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 A FL PENIN B A AK N SLOPE N 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 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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