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FXUS06 KWBC 012001
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST WED JANUARY 01 2025
6-10 DAY OUTLOOK FOR JAN 07 - 11 2025
THE GEFS, ECENS, AND CMCE ARE IN GOOD AGREEMENT AND REMAIN CONSISTENT THAT HIGH
LATITUDE BLOCKING DEVELOPS DURING EARLY JANUARY AS A PAIR OF STRONG 500-HPA
RIDGES OVER GREENLAND AND NEAR THE WEST COAST OF NORTH AMERICA MERGE. THE GEFS
DEPICTS A NEGATIVE ARCTIC OSCILLATION (AO) PEAKING IN STRENGTH AT NEAR -4
STANDARD DEVIATIONS AT THE BEGINNING OF THIS PERIOD. THE HIGH LATITUDE BLOCKING
IS LIKELY TO PROMOTE ARCTIC HIGH PRESSURE SHIFTING SOUTH PRIOR TO THIS PERIOD.
ANOMALOUSLY COLD TEMPERATURES, ASSOCIATED WITH THE ARCTIC HIGH, SUPPORT
BELOW-NORMAL TEMPERATURES ACROSS THE EASTERN TWO-THIRDS OF THE CONTIGUOUS U.S.
(CONUS). LARGE BELOW-NORMAL TEMPERATURE PROBABILITIES (MORE THAN 80 PERCENT)
ARE FORECAST FROM THE LOWER AND MIDDLE MISSISSIPPI VALLEY EASTWARD TO THE
SOUTHEAST AND MID-ATLANTIC WHERE THE ENSEMBLE MEAN SOLUTIONS HAVE 5-DAY
TEMPERATURES AVERAGING 10 TO 20 DEGREES F BELOW NORMAL. AN AMPLIFIED 500-HPA
RIDGE AND POSITIVE HEIGHT DEPARTURES SUPPORT INCREASED ABOVE-NORMAL
TEMPERATURES ACROSS THE PACIFIC NORTHWEST, CALIFORNIA, GREAT BASIN, AND DESERT
SOUTHWEST.
FOLLOWING A LOW PRESSURE SYSTEM EXITING THE EASTERN CONUS BY DAY 6, ANOMALOUS
NORTHERLY FLOW FAVORS NEAR TO BELOW-NORMAL PRECIPITATION FOR MOST AREAS FROM
THE MISSISSIPPI VALLEY TO THE EAST COAST. LAKE-EFFECT SNOW IS EXPECTED TO
PERSIST THROUGH JANUARY 7 OR 8. CLOSER TO THE GULF COAST AND ACROSS FLORIDA,
ABOVE-NORMAL PRECIPITATION PROBABILITIES INCREASE DUE TO THE POTENTIAL FOR LOW
PRESSURE DEVELOPMENT NEAR THE GULF COAST. THE DETERMINISTIC 12Z GFS AND SEVERAL
OF ITS ENSEMBLE MEMBERS FAVOR SURFACE LOW DEVELOPMENT ACROSS THE WESTERN GULF
OF MEXICO ON DAY 8 WITH A SUBSEQUENT TRACK EASTWARD TO THE CAROLINAS. THIS LOW
PRESSURE SYSTEM AND ITS PRECIPITATION COULD BE HIGHLY IMPACTFUL WITH WINTER
WEATHER HAZARDS FOR THE SOUTH. UPSLOPE FLOW ALONG WITH SHORTWAVE TROUGHS WITHIN
THE NORTHWEST FLOW ALOFT INCREASE ABOVE-NORMAL PRECIPITATION CHANCES FOR THE
GREAT PLAINS WEST TO THE ROCKIES. AN AMPLIFIED 500-HPA RIDGE NEAR THE WEST
COAST LEADS TO AN INCREASED CHANCE OF BELOW-NORMAL PRECIPITATION ACROSS THE
PACIFIC NORTHWEST, GREAT BASIN, CALIFORNIA, AND THE SOUTHWEST.
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT FEATURING AN AMPLIFIED 500-HPA
TROUGH (RIDGE) OVER THE ALEUTIANS (EASTERN MAINLAND ALASKA). THIS LONGWAVE
PATTERN YIELDS INCREASED ABOVE-NORMAL TEMPERATURE PROBABILITIES FOR CENTRAL AND
SOUTHERN ALASKA. TO THE NORTH OF THE BROOKS RANGE, NEAR TO BELOW-NORMAL
TEMPERATURES ARE FAVORED DUE TO NEARBY ARCTIC HIGH PRESSURE NEAR BANKS ISLAND.
ENHANCED ONSHORE FLOW FAVORS ABOVE-NORMAL PRECIPITATION FOR THE MAJORITY OF
ALASKA WITH THE HIGHEST FORECAST CONFIDENCE ACROSS SOUTHEASTERN ALASKA.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES ARE STRONGLY FAVORED FOR
HAWAII. THE CONSOLIDATION SUPPORTS RELATIVELY LARGE ABOVE-NORMAL PRECIPITATION
PROBABILITIES FOR THE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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, DUE TO
A HIGHLY AMPLIFIED LONGWAVE PATTERN AND GOOD AGREEMENT AMONG THE TEMPERATURE
AND PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR JAN 09 - 15 2025
A HIGHLY AMPLIFIED 500-HPA TROUGH IS FORECAST TO PERSIST OVER THE EASTERN CONUS
AND WESTERN ATLANTIC, WHILE THE HIGH LATITUDE BLOCK ACROSS SOUTHERN GREENLAND
AND THE DAVIS STRAIT GRADUALLY WEAKENS. THE ANOMALOUS MID-LEVEL TROUGH AND
LIKELIHOOD OF MUCH BELOW-NORMAL TEMPERATURES EARLY IN WEEK-2 FAVOR
COLDER-THAN-NORMAL TEMPERATURES ACROSS MUCH OF THE EASTERN AND SOUTH-CENTRAL
CONUS. THE LARGEST PROBABILITIES (MORE THAN 80 PERCENT) ARE FORECAST FROM THE
OHIO VALLEY SOUTHEASTWARD TO THE CAROLINAS, GEORGIA, AND NORTHEASTERN FLORIDA
WHERE THE GEFS AND ECENS FEATURE 7-DAY TEMPERATURES AVERAGING NEAR 15 DEGREES F
BELOW NORMAL. LATER IN WEEK-2, THE MODEL SOLUTIONS HAVE TRENDED TOWARDS A
FASTER MODERATION OF TEMPERATURES ACROSS THE HIGH PLAINS AND THE PREFERRED
CONSOLIDATION TOOL (SKILL-WEIGHTED GEFS AND ECENS REFORECASTS) DEPICTS A LARGER
EASTWARD EXTENT OF FAVORED ABOVE-NORMAL TEMPERATURES COMPARED TO PREVIOUS DAYS.
ANOTHER CHANGE FROM PRIOR 8-14 TEMPERATURE OUTLOOKS IS A DECREASE IN THE
BELOW-NORMAL TEMPERATURE PROBABILITIES ACROSS THE UPPER MISSISSIPPI VALLEY AS
THE MOST ANOMALOUS COLD BECOMES CENTERED WELL SOUTH OF THIS REGION. IN
ADDITION, THE UNCALIBRATED ECENS DEPICTS A FLIP TO ABOVE-NORMAL TEMPERATURES
ACROSS THE NORTH-CENTRAL CONUS BY DAY 11. THE WARMER OUTCOME FORECAST FOR THIS
REGION IS RELATED TO A WEAKENING OF THE UPSTREAM RIDGE OVER WESTERN NORTH
AMERICA AND DIMINISHING COLD AIR ADVECTION WITH TIME. DUE TO POSITIVE 500-HPA
HEIGHT DEPARTURES, ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE WESTERN THIRD
OF THE CONUS WITH INCREASING PROBABILITIES CLOSER TO THE WEST COAST.
EARLY IN WEEK-2, MODEL SOLUTIONS MAY BE CONVERGING ON SURFACE LOW DEVELOPMENT
ACROSS THE WESTERN GULF OF MEXICO WITH A SUBSEQUENT TRACK EASTWARD TO THE
CAROLINAS. THEREFORE, NEAR TO ABOVE-NORMAL PRECIPITATION IS FAVORED FOR THE
GULF COAST ALONG WITH PORTIONS OF THE SOUTHEAST. PLEASE REFER TO THE CLIMATE
PREDICTION CENTER’S WEEK-2 HAZARDS FOR ADDITIONAL INFO ON POTENTIAL WINTER
WEATHER HAZARDS ASSOCIATED WITH THIS LOW PRESSURE SYSTEM. AWAY FROM THE MODELED
SURFACE LOW TRACK, BELOW-NORMAL PRECIPITATION IS MORE LIKELY ACROSS THE
SOUTHERN GREAT PLAINS, OHIO AND TENNESSEE VALLEY, AND NORTHEAST. SHORTWAVE
TROUGHS, WITHIN NORTHWEST FLOW ALOFT, INCREASE THE CHANCE OF ABOVE-NORMAL
PRECIPITATION ACROSS THE NORTHERN TO CENTRAL ROCKIES, NORTHERN TO CENTRAL GREAT
PLAINS, WESTERN IOWA, AND WESTERN MINNESOTA. THE BROAD AND AMPLIFIED 500-HPA
RIDGE AND LACK OF PACIFIC FLOW FAVOR BELOW-NORMAL PRECIPITATION ACROSS THE
PACIFIC NORTHWEST, CALIFORNIA, GREAT BASIN, AND SOUTHWEST.
DOWNSTREAM OF THE AMPLIFIED TROUGH OVER THE ALEUTIANS AND BERING SEA,
ABOVE-NORMAL PRECIPITATION IS FAVORED FOR ALASKA. CONSISTENT WITH THIS WETNESS
AND ENHANCED ONSHORE FLOW, INCREASED ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE
FORECAST ACROSS SOUTHERN TO CENTRAL ALASKA. SIMILAR TO THE 6-10 DAY OUTLOOK,
NEARBY ARCTIC HIGH PRESSURE NEAR BANKS ISLAND FAVORS NEAR TO BELOW NORMAL
TEMPERATURES FOR THE NORTH SLOPE.
BASED ON THE GEFS AND ECENS, INCREASED CHANCES OF ABOVE-NORMAL TEMPERATURES AND
ABOVE-NORMAL PRECIPITATION ARE FORECAST FOR HAWAII.
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, DUE TO
A HIGHLY AMPLIFIED LONGWAVE PATTERN THROUGH MOST OF WEEK-2 AND GOOD AGREEMENT
AMONG THE TEMPERATURE AND PRECIPITATION TOOLS. FORECAST CONFIDENCE BEGINS TO
DECREASE LATER IN WEEK-2 AS HIGH LATITUDE BLOCKING IS PREDICTED TO WEAKEN.
FORECASTER: BRAD PUGH
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:
20091224 - 19591226 - 19961212 - 20021220 - 19950115
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:
20091223 - 20001224 - 19661223 - 19521211 - 19811212
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 07 - 11 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA A A E MONTANA A A WYOMING N A
UTAH A B ARIZONA A B COLORADO N A
NEW MEXICO B A N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B N OKLAHOMA B B
N TEXAS B B S TEXAS B A W TEXAS B A
MINNESOTA B N IOWA B N MISSOURI B B
ARKANSAS B B LOUISIANA B B WISCONSIN B N
ILLINOIS B B MISSISSIPPI B B MICHIGAN B N
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B B NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
MASS B B CONN B B RHODE IS B B
PENN B N NEW JERSEY B B W VIRGINIA B N
MARYLAND B B DELAWARE B B VIRGINIA B B
N CAROLINA B B S CAROLINA B B GEORGIA B B
FL PNHDL B A FL PENIN B A AK N SLOPE N A
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
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 09 - 15 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO A B NEVADA A B
W MONTANA A N E MONTANA A A WYOMING A A
UTAH A B ARIZONA A B COLORADO A A
NEW MEXICO N N N DAKOTA N A S DAKOTA N A
NEBRASKA B A KANSAS B N OKLAHOMA B B
N TEXAS B B S TEXAS B N W TEXAS B N
MINNESOTA B A IOWA B N MISSOURI B B
ARKANSAS B B LOUISIANA B N WISCONSIN B N
ILLINOIS B B MISSISSIPPI B N MICHIGAN B N
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B N NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
MASS B B CONN B B RHODE IS B B
PENN B N NEW JERSEY B B W VIRGINIA B B
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 N A
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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