637
FXUS06 KWBC 032002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI JANUARY 03 2025
6-10 DAY OUTLOOK FOR JAN 09 - 13 2025
THE GEFS, ECENS, AND CMCE ARE IN GOOD AGREEMENT AND REMAIN CONSISTENT THAT HIGH
LATITUDE BLOCKING OVER GREENLAND AND THE DAVIS STRAIT PERSISTS THROUGH EARLY TO
MID JANUARY WITH A DEEP ANOMALOUS 500-HPA TROUGH OVER THE EASTERN CONTIGUOUS
U.S. (CONUS). THIS ANOMALOUS MID-LEVEL TROUGH AND NORTHERLY FLOW FAVOR
COLDER-THAN-NORMAL TEMPERATURES ACROSS MUCH OF THE EASTERN AND SOUTH-CENTRAL
CONUS. LARGE BELOW-NORMAL TEMPERATURE PROBABILITIES (MORE THAN 80 PERCENT) ARE
FORECAST FOR THE SOUTHEAST WHERE THE ENSEMBLE MEAN SOLUTIONS HAVE 5-DAY
TEMPERATURES AVERAGING MORE THAN 10 DEGREES F BELOW NORMAL. PRIOR TO THE 6-10
DAY PERIOD, A SWATH OF SNOWFALL IS FORECAST FROM THE MIDDLE MISSISSIPPI VALLEY
EAST TO THE OHIO VALLEY AND MID-ATLANTIC WHICH WILL FURTHER SUPPORT THE
INCREASED CHANCES FOR ANOMALOUS COLD ACROSS THESE AREAS. A WARMING TREND IS
FORECAST FOR THE NORTH-CENTRAL CONUS DUE TO RISING 500-HPA HEIGHTS. TEMPERATURE
TOOLS ARE IN BETTER AGREEMENT TODAY AND DEPICT INCREASED ABOVE-NORMAL
TEMPERATURE PROBABILITIES ACROSS THE NORTHERN GREAT PLAINS. A NORTHERN STREAM
SHORTWAVE TROUGH IS FORECAST TO TRACK WELL SOUTH INTO THE SOUTHWESTERN CONUS,
WHICH FAVORS BELOW-NORMAL TEMPERATURES FOR NEW MEXICO AND MUCH OF ARIZONA. A
500-HPA RIDGE AND POSITIVE HEIGHT DEPARTURES SUPPORT INCREASED ABOVE-NORMAL
TEMPERATURES ACROSS THE PACIFIC NORTHWEST, CALIFORNIA, AND GREAT BASIN. NEAR
NORMAL TEMPERATURES ARE MORE LIKELY FOR SOUTHEASTERN IDAHO AND NORTHERN UTAH
WHERE SURFACE HIGH PRESSURE IS EXPECTED TO PROMOTE LOW-LEVEL INVERSIONS.
A MAJOR FACTOR IN THE 6-10 AND 8-14 DAY PRECIPITATION OUTLOOKS IS THE
SIGNIFICANT MODEL TREND TOWARDS A SHORTWAVE TROUGH BECOMING SEPARATED FROM THE
MID-LATITUDE FLOW AND TRACKING INTO THE SOUTHWESTERN CONUS AND NORTHERN MEXICO.
THIS SHORTWAVE TROUGH FAVORS ABOVE-NORMAL PRECIPITATION FOR MUCH OF THE
SOUTHWEST AND TEXAS. THE MID-LEVEL TROUGH WOULD ALSO LEAD TO A MORE ACTIVE
SOUTHERN STREAM AND FAVOR SURFACE LOW DEVELOPMENT EITHER OVER THE GULF OF
MEXICO OR NEAR THE GULF COAST. DESPITE AN INCREASED CHANCE OF MULTIPLE WAVES OF
LOW PRESSURE IN THE SOUTHERN STREAM, THERE IS HIGH UNCERTAINTY ON HOW
SUPPRESSED THE STORM TRACK IS. INITIALLY, THE STORM TRACK IS EXPECTED TO BE
ALONG OR SOUTH OF THE GULF COAST BUT IT MAY SHIFT NORTHWARD WITH TIME AS THE
GREENLAND BLOCK WEAKENS. THE MODEL CONSENSUS FAVORS ELEVATED ABOVE-NORMAL
PRECIPITATION PROBABILITIES ALONG THE GULF COAST AND MUCH OF FLORIDA. FARTHER
TO THE NORTH, ANOMALOUS NORTHERLY FLOW FAVORS BELOW-NORMAL PRECIPITATION ACROSS
THE OHIO AND TENNESSEE VALLEYS, MID-ATLANTIC, AND NORTHEAST. INCREASED
ABOVE-NORMAL PROBABILITIES FOR THE NORTHERN TO CENTRAL ROCKIES, NORTHERN TO
CENTRAL GREAT PLAINS, AND UPPER MISSISSIPPI VALLEY ARE RELATED TO A SHORTWAVE
TROUGH IN THE NORTHERN STREAM. A 500-HPA RIDGE NEAR THE WEST COAST LEADS TO AN
INCREASED CHANCE OF BELOW-NORMAL PRECIPITATION ACROSS THE PACIFIC NORTHWEST,
GREAT BASIN, AND CALIFORNIA.
ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT FEATURING AN AMPLIFIED 500-HPA
TROUGH OVER THE BERING SEA AND ENHANCED ONSHORE FLOW. THIS PREVAILING SURFACE
FLOW AND PATTERN ALOFT LEAD TO RELATIVELY LARGE ABOVE-NORMAL PRECIPITATION
PROBABILITIES THROUGHOUT ALASKA. INCREASED ABOVE-NORMAL TEMPERATURE
PROBABILITIES ARE ALSO FORECAST FOR A MAJORITY OF THE STATE EXCEPT FOR
NORTHWESTERN ALASKA WHERE NEAR TO BELOW-NORMAL TEMPERATURES ARE FAVORED CLOSER
TO THE 500-HPA TROUGH AXIS.
BASED ON THE GEFS AND ECENS, ABOVE-NORMAL TEMPERATURES AND ABOVE-NORMAL
PRECIPITATION ARE STRONGLY FAVORED FOR HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 20% 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 11 - 17 2025
THE GEFS, ECENS, AND CMCE DEPICT A BROAD ANOMALOUS 500-HPA TROUGH OVER THE
WESTERN ATLANTIC AND EASTERN CONUS THROUGH WEEK-2. THEREFORE, BELOW-NORMAL
TEMPERATURES ARE FAVORED TO PERSIST FROM THE MIDDLE AND LOWER MISSISSIPPI
VALLEY EASTWARD TO THE EAST COAST. THE ELEVATED BELOW-NORMAL TEMPERATURE
PROBABILITIES ACROSS PORTIONS OF THE SOUTHWEST ARE RELATED TO THE SHORTWAVE
TROUGH CENTERED OVER THE SOUTHWESTERN CONUS AND NORTHERN MEXICO. FOLLOWING A
PEAK IN STRENGTH OF THE NEGATIVE ARCTIC OSCILLATION (AO) OF NEAR -4 STANDARD
DEVIATIONS DURING EARLY JANUARY, THE GEFS INDICATES THE AO BECOMING NEUTRAL
WITH MANY ENSEMBLE MEMBERS HAVING A POSITIVE AO LATER IN WEEK-2 AFTER THE HIGH
LATITUDE BLOCKING WEAKENS. CONSISTENT WITH THIS TRANSITION TO A NEUTRAL OR EVEN
POSITIVE AO LATER IN WEEK-2 AND WITH SUPPORT FROM THE TEMPERATURE TOOLS,
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHERN GREAT PLAINS AND UPPER
MISSISSIPPI VALLEY. FOR THE THIRD CONSECUTIVE DAY, ENSEMBLE SPREAD INCREASES
DURING WEEK-2 WITH THE AMPLITUDE AND PLACEMENT OF A 500-HPA RIDGE EITHER NEAR
THE WEST COAST OR OVER THE NORTH PACIFIC. THE CMCE FAVORS A MORE PERSISTENT
LONGWAVE PATTERN WITH A HIGH AMPLITUDE RIDGE REMAINING ALONG THE WEST COAST,
WHILE THE GEFS AND ECENS DEPICT A RETROGRESSION OF THE MID-LEVEL RIDGE TO THE
WEST AND CLOSER TO THE ALEUTIANS LATER IN WEEK-2. DUE TO THESE DIVERGING MODEL
SOLUTIONS AND CONFLICTING REFORECAST TOOLS (WARMER) AND UNCALIBRATED MODEL
OUTPUT (COLDER), NEAR NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE WESTERN
CONUS. ANOMALOUS WARMTH EARLY IN WEEK-2 TILTS THE OUTLOOK TO ABOVE-NORMAL
TEMPERATURES FOR NORTHERN TO CENTRAL CALIFORNIA.
A MID-LEVEL TROUGH OVER THE SOUTHWEST AND NORTHERN MEXICO IS EXPECTED TO RESULT
IN THE DEVELOPMENT OF MULTIPLE WAVES OF LOW PRESSURE, FAVORING NEAR TO
ABOVE-NORMAL PRECIPITATION ACROSS THE SOUTHERN TIER OF THE CONUS. FORECAST
UNCERTAINTY IS HIGH ON HOW FAR NORTH FROM THE GULF COAST THESE LOW PRESSURE
SYSTEMS TRACK, BUT THE MODEL CONSENSUS SLIGHTLY FAVORS BELOW-NORMAL
PRECIPITATION ACROSS THE OHIO AND TENNESSEE VALLEYS, MID-ATLANTIC, AND
NORTHEAST. SHORTWAVE TROUGHS WITHIN THE NORTHERN STREAM ELEVATE ABOVE-NORMAL
PRECIPITATION PROBABILITIES ACROSS THE NORTHERN AND CENTRAL ROCKIES EAST TO THE
NORTHERN AND CENTRAL GREAT PLAINS AND UPPER MISSISSIPPI VALLEY. BELOW-NORMAL
PRECIPITATION REMAINS MOST LIKELY FOR THE WESTERN CONUS WITH THE ABSENCE OF ANY
ONSHORE FLOW.
DOWNSTREAM OF A BROAD TROUGH OVER THE 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 MUCH OF
ALASKA. SIMILAR TO THE 6-10 DAY OUTLOOK, NEARBY ARCTIC HIGH PRESSURE FAVORS
NEAR TO BELOW-NORMAL TEMPERATURES FOR NORTHWESTERN ALASKA.
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: 35% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 35% 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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
UNCERTAINTY ON FAR NORTH LOW PRESSURE SYSTEMS, ORIGINATING IN THE SOUTHERN
STREAM, TRACK ALONG WITH LARGE ENSEMBLE SPREAD ON THE LOCATION OF A 500-HPA
RIDGE AXIS EITHER NEAR THE WEST COAST OR OVER THE NORTH PACIFIC.
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:
20001223 - 19661223 - 20001228 - 20091222 - 20091231
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:
20001224 - 20091230 - 20091223 - 19811213 - 19661223
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JAN 09 - 13 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 B E MONTANA A A WYOMING A A
UTAH A B ARIZONA B A COLORADO N A
NEW MEXICO B A N DAKOTA A A S DAKOTA A A
NEBRASKA N A KANSAS B N OKLAHOMA B N
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA N A IOWA B N MISSOURI B B
ARKANSAS B B LOUISIANA B A WISCONSIN N 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 A 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 N
FL PNHDL B A FL PENIN B A AK N SLOPE A 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 11 - 17 2025
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON N B NRN CALIF A B
SRN CALIF N B IDAHO N B NEVADA N B
W MONTANA N N E MONTANA A A WYOMING N A
UTAH N B ARIZONA N A COLORADO N A
NEW MEXICO B A N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS N N OKLAHOMA B N
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A A IOWA N N MISSOURI B B
ARKANSAS B B LOUISIANA B N WISCONSIN A N
ILLINOIS B B MISSISSIPPI B N MICHIGAN N 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 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 N
FL PNHDL B N FL PENIN B N AK N SLOPE B 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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