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FXUS06 KWBC 062054
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST MON JANUARY 06 2025
6-10 DAY OUTLOOK FOR JAN 12 - 16 2025
THERE IS GOOD AGREEMENT BETWEEN THE LATEST ECMWF, GEFS, AND CANADIAN ENSEMBLE
MEAN 500-HPA HEIGHT FORECASTS ON THE PREDICTED CIRCULATION PATTERN ACROSS NORTH
AMERICA FOR THE 6-10 DAY PERIOD. DYNAMICAL MODELS PREDICT A TROUGH OVER THE
BERING SEA AND WESTERN MAINLAND ALASKA. DOWNSTREAM, MODELS CONSISTENTLY PREDICT
A RIDGE OVER THE NORTH PACIFIC AND POSITIVE 500-HPA HEIGHT ANOMALIES EXTENDING
OVER SOUTHEAST ALASKA AND THE NORTHWESTERN CONTIGUOUS U.S. (CONUS). DYNAMICAL
MODELS CONSISTENTLY PREDICT A TROUGH AND ASSOCIATED NEGATIVE 500-HPA HEIGHT
ANOMALIES OVER THE EASTERN HALF OF THE CONUS. TO VARYING DEGREES, ENSEMBLE
MEANS PREDICT AN EXTENSION OF THE TROUGH OVER THE SOUTHWESTERN CONUS IN THE
6-10 DAY MEAN FORECASTS.
ABOVE-NORMAL TEMPERATURES ARE LIKELY OVER MOST OF MAINLAND ALASKA, EXCLUDING
PARTS OF THE WEST COAST, AND OVER SOUTHEAST ALASKA, UNDER ANOMALOUS SOUTHERLY
FLOW. NEAR-TO-BELOW-NORMAL TEMPERATURES ARE FAVORED OVER PARTS OF THE WEST
COAST OF MAINLAND ALASKA AND THE ALEUTIANS. UNDER THE PREDICTED BROAD TROUGH
AND NEGATIVE 500-HPA HEIGHT ANOMALIES, BELOW-NORMAL TEMPERATURES ARE LIKELY
ACROSS A LARGE AREA OF THE CONUS, EXCLUDING PARTS OF THE WEST AND ACROSS THE
NORTHERN TIER. NEAR-NORMAL TEMPERATURES ARE FAVORED OVER SOME AREAS OF THE
WEST, WHERE TEMPERATURE TOOLS ARE INCONSISTENT, UNDER POSITIVE 500-HPA HEIGHT
ANOMALIES AND ANOMALOUS NORTHEASTERLY FLOW. ABOVE-NORMAL TEMPERATURES ARE
SLIGHTLY FAVORED FOR PARTS OF THE NORTHERN PLAINS ALONG THE CANADIAN BORDER,
CONSISTENT WITH MOST DYNAMICAL MODEL FORECAST TOOLS.
ABOVE-NORMAL PRECIPITATION IS LIKELY ACROSS MOST OF ALASKA, INCLUDING THE
EASTERN ALEUTIANS, MAINLAND ALASKA, AND SOUTHEAST ALASKA, AHEAD OF THE
PREDICTED AMPLIFIED TROUGH. BELOW-NORMAL PRECIPITATION IS LIKELY ACROSS THE
WESTERN CONUS, UNDER AND AHEAD OF A PREDICTED RIDGE. ABOVE-NORMAL PRECIPITATION
IS FAVORED FOR PARTS OF THE NORTHERN PLAINS AND PARTS OF THE SOUTHERN PLAINS
CONSISTENT WITH MOST DYNAMICAL MODEL PRECIPITATION TOOLS AND THE PRECIPITATION
CONSOLIDATION. BELOW-NORMAL PRECIPITATION IS FAVORED OVER A LARGE AREA OF THE
EASTERN CONUS, INCLUDING PARTS OF THE CENTRAL AND SOUTHERN MISSISSIPPI VALLEY,
MOST OF THE SOUTHEAST, AND THE EASTERN SEABOARD, UNDER ANOMALOUS NORTHERLY FLOW
BEHIND THE CENTER OF NEGATIVE 500-HPA HEIGHT ANOMALIES OVER THE ATLANTIC.
ABOVE-NORMAL TEMPERATURES AND ABOVE-NORMAL PRECIPITATION ARE FAVORED FOR THE
HAWAIIAN ISLANDS, LARGELY DUE TO THE INFLUENCE OF POSITIVE SEA SURFACE
TEMPERATURE ANOMALIES AROUND THE ISLANDS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 8, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, AND 10%
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE DYNAMICAL MODEL HEIGHT FORECASTS AND AN AMPLIFIED
PATTERN, OFFSET BY DIFFERENCES IN TEMPERATURE AND PRECIPITATION TOOLS AND A
CHANGING PATTERN.
8-14 DAY OUTLOOK FOR JAN 14 - 20 2025
DYNAMICAL MODEL FORECASTS FROM THE ECMWF, GEFS AND CANADIAN ENSEMBLE MEANS ARE
IN GENERAL OVERALL AGREEMENT ON THE AVERAGE LARGE SCALE 500-HPA HEIGHT PATTERN
IN THE WEEK-2 PERIOD. THE GEFS, ECMWF AND CANADIAN ENSEMBLE MEANS FOR THE 8-14
DAY PERIOD PREDICT A WESTWARD RETROGRESSION OF THE RIDGE AND ASSOCIATED
POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE NORTH PACIFIC, TO BE CENTERED OVER
THE EASTERN ALEUTIAN ISLANDS. DOWNSTREAM, A TROUGH AND NEGATIVE 500-HPA HEIGHT
ANOMALIES DEVELOP OVER THE WESTERN CONUS LATE IN THE WEEK-2 PERIOD. IN THE 8-14
DAY MEAN MANUAL BLEND, NEGATIVE 500-HPA HEIGHT ANOMALIES PERSIST OVER THE
EASTERN CONUS, WHILE NEAR-ZERO ANOMALIES ARE PREDICTED OVER THE WEST.
UNDER A CHANGING HEIGHT PATTERN, TEMPERATURE PROBABILITY FORECASTS FOR ALASKA
DECREASE IN CONFIDENCE FOR THE 8-14 DAY PERIOD FORECAST, RELATIVE TO THE 6-10
DAY PERIOD FORECAST. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE ALEUTIANS
AND PARTS OF THE SOUTHWEST COAST OF MAINLAND ALASKA, UNDER THE PREDICTED RIDGE.
ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR NORTHEASTERN MAINLAND
ALASKA, CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS TOOLS. BELOW-NORMAL
TEMPERATURES ARE FAVORED FOR PARTS OF THE SOUTHEAST COAST OF MAINLAND ALASKA
AND SOUTHEAST ALASKA. BELOW-NORMAL TEMPERATURES CONTINUE TO BE FAVORED ACROSS A
LARGE PART OF THE CONUS IN WEEK 2, UNDER A TROUGH AND ANOMALOUS NORTHERLY FLOW,
WITH INCREASED PROBABILITIES OF BELOW-NORMAL TEMPERATURES FOR MUCH OF THE
WESTERN CONUS, AS A TROUGH DEVELOPS OVER THE REGION.
ABOVE-NORMAL PRECIPITATION CONTINUES TO BE FAVORED OVER MOST OF MAINLAND
ALASKA, EXCLUDING THE SOUTH COAST, CONSISTENT WITH MOST DYNAMICAL MODEL
FORECASTS AND THE PRECIPITATION CONSOLIDATION. BELOW-NORMAL PRECIPITATION IS
FAVORED FOR THE CENTRAL PACIFIC COAST OF THE WESTERN CONUS TO THE CENTRAL
ROCKIES, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION. ABOVE-NORMAL
PRECIPITATION IS SLIGHTLY FAVORED FROM THE ROCKY MOUNTAINS EASTWARD ACROSS MOST
OF THE GREAT PLAINS, AS THE TROUGH DEVELOPS OVER THE WEST, INCREASING THE
CHANCES OF PRECIPITATION TO THE REGION. ABOVE-NORMAL PRECIPITATION IS FAVORED
ALONG THE GULF COAST IN WEEK 2, CONSISTENT WITH MOST PRECIPITATION TOOLS. A
LARGE AREA OF FAVORED NEAR-NORMAL PRECIPITATION IS FORECAST FOR THE EASTERN
CONUS, WITH DIFFERENCES AMONG THE VARIOUS MODEL PRECIPITATION FORECASTS. BELOW
NORMAL PRECIPITATION IS FAVORED FOR PARTS OF THE NORTHEAST AND MID-ATLANTIC,
WHERE MODEL PRECIPITATION FORECASTS ARE CONSISTENT.
ABOVE-NORMAL TEMPERATURES AND ABOVE-NORMAL PRECIPITATION CONTINUES TO BE
FAVORED FOR THE HAWAIIAN ISLANDS, DUE TO THE INFLUENCE OF POSITIVE SEA SURFACE
TEMPERATURE ANOMALIES AROUND THE ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 15% OF TODAY'S 6Z GFS ENSEMBLE MEAN CENTERED
ON DAY 11, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 11, AND 10%
OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE DYNAMICAL MODEL HEIGHT FORECASTS, OFFSET BY
DIFFERENCES IN TEMPERATURE AND PRECIPITATION TOOLS AND A RAPIDLY EVOLVING
MID-LEVEL HEIGHT PATTERN FORECAST.
FORECASTER: D COLLINS
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:
20001226 - 19770116 - 19850119 - 19951220 - 20091221
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:
20001226 - 19770115 - 19850118 - 19951219 - 19951224
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 12 - 16 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON N B NRN CALIF N B
SRN CALIF B B IDAHO B B NEVADA B B
W MONTANA N B E MONTANA N A WYOMING B B
UTAH B B ARIZONA B B COLORADO B N
NEW MEXICO B A N DAKOTA A A S DAKOTA N A
NEBRASKA B N KANSAS B B OKLAHOMA B B
N TEXAS B N S TEXAS B A W TEXAS B A
MINNESOTA N N IOWA N N MISSOURI B B
ARKANSAS B B LOUISIANA B B WISCONSIN N N
ILLINOIS B N MISSISSIPPI B B MICHIGAN N N
INDIANA B N OHIO B N KENTUCKY B B
TENNESSEE B B ALABAMA B B NEW YORK B B
VERMONT B B NEW HAMP B B MAINE N B
MASS B B CONN B B RHODE IS B B
PENN B B NEW JERSEY B 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 N AK N SLOPE A A
AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 14 - 20 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B N OREGON B B NRN CALIF N B
SRN CALIF B N IDAHO B B NEVADA N B
W MONTANA B N E MONTANA B A WYOMING B A
UTAH B N ARIZONA B N COLORADO B A
NEW MEXICO B A N DAKOTA N A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B N
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA N N IOWA B N MISSOURI B N
ARKANSAS B N LOUISIANA B A 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 B B
VERMONT N B NEW HAMP B B MAINE N B
MASS B B CONN B B RHODE IS B B
PENN B B NEW JERSEY B B W VIRGINIA B N
MARYLAND B B DELAWARE B B VIRGINIA B B
N CAROLINA B N S CAROLINA B N GEORGIA B N
FL PNHDL B A FL PENIN B A AK N SLOPE A A
AK ALEUTIAN A N AK WESTERN N A AK INT BSN A A
AK S INT N A AK SO COAST N N AK PNHDL B 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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