130
FXUS06 KWBC 292001
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI NOVEMBER 29 2024
6-10 DAY OUTLOOK FOR DEC 05 - 09 2024
MODEL SOLUTIONS FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS FOR 500-HPA
HEIGHTS AND ANOMALIES HAVE BEEN VERY CONSISTENT ALL WEEK AND CONTINUE TO DEPICT
A LOW FREQUENCY WAVE TRAIN PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY
PERIOD AVERAGE, WITH RIDGING FORECAST OVER THE WEST COAST AND TROUGHING OVER
THE EASTERN CONTIGUOUS U.S. (CONUS). CONSISTENCY IN MODEL SOLUTIONS FROM RUN TO
RUN CONTINUES AT LEAST DURING THE 6-10 DAY PERIOD, SO FORECAST CONFIDENCE
REMAINS HIGH.
A STRONG COLD FRONT AND AN ASSOCIATED COLD AIRMASS ARE FAVORED TO MOVE OVER THE
CONUS EAST OF THE ROCKIES DURING THE WEEK-1 PERIOD, BRINGING A REINFORCING SHOT
OF COLD AIR RESULTING IN A STRONG TILT TOWARDS BELOW-NORMAL TEMPERATURES FOR
MUCH OF THE EASTERN CONUS, ESPECIALLY THE NORTHEAST U.S. WHERE PROBABILITIES
EXCEED 80% IN SOME LOCATIONS. MEANWHILE, AMPLIFIED RIDGING OVER THE WEST COAST
FAVORS ABOVE-NORMAL TEMPERATURES ROUGHLY FOR THE WEST COAST AND DESERT
SOUTHWEST WHERE PROBABILITIES GENERALLY EXCEED 70%. PROBABILITIES ARE LOWER
OVER THE NORTHERN GREAT BASIN WHICH IS PRONE TO COLD NIGHTTIME SURFACE
INVERSIONS, PUSHING DOWN THE AVERAGE TEMPERATURE ANOMALY OVER THE FORECAST
PERIOD. WIDESPREAD POSITIVE HEIGHT ANOMALIES OVER EASTERN SIBERIA AND THE
BERING SEA FAVOR BELOW-NORMAL TEMPERATURES FOR THE NORTHWESTERN COAST OF
ALASKA, WHILE STRONG ONSHORE FLOW OFF THE GULF OF ALASKA FAVORS ABOVE-NORMAL
TEMPERATURES FOR MUCH OF SOUTHERN AND CENTRAL ALASKA, PARTICULARLY THE
PANHANDLE WHERE PROBABILITIES EXCEED 70%. ABOVE-NORMAL TEMPERATURES ARE ALSO
FAVORED FOR HAWAII, CONSISTENT WITH MODEL GUIDANCE.
MODEL SOLUTIONS OF THE RIDGE OVER THE WEST COAST DEPICT A VERY HIGH AMPLITUDE
FEATURE WITH POSITIVE HEIGHT ANOMALIES EXTENDING WELL NORTH OF THE U.S.-CANADA
BORDER, LIMITING PACIFIC MOISTURE FLUXES INTO THE CONTINENT AND FAVORING
BELOW-NORMAL PRECIPITATION FOR MUCH OF THE WESTERN CONUS. ODDS ARE HIGHEST FOR
NORTHERN CALIFORNIA AND NORTHERN GREAT BASIN WHERE PROBABILITIES EXCEED 50%.
EASTERLY RETURN FLOW IS DEPICTED OVER THE GULF OF MEXICO, TILTING THE ODDS
TOWARD ABOVE-NORMAL PRECIPITATION FOR PORTIONS OF THE SOUTHERN PLAINS. ALTHOUGH
A STRONG RIDGE IS FAVORED OVER THE WEST COAST, TODAY’S MODEL SOLUTIONS INDICATE
A SLIGHT SOUTHWARD SHIFT IN THE MAIN STORM TRACK, WHICH FAVORS ABOVE-NORMAL
PRECIPITATION FOR MUCH OF THE U.S.-CANADA BORDER. STRONG ONSHORE FLOW INTO
SOUTHEASTERN ALASKA CONTINUES TO FAVOR ABOVE-NORMAL PRECIPITATION FOR MUCH OF
THE STATE, WHILE PORTIONS OF THE NORTH SLOPE REMAIN AT NEAR- TO BELOW-NORMAL
PRECIPITATION UNDER POSITIVE 500-HPA HEIGHT ANOMALIES. MODEL GUIDANCE HAS BEEN
MIXED OVER THE COURSE OF THE WEEK WITH REGARDS TO PRECIPITATION FOR HAWAII, SO
NEAR-NORMAL PRECIPITATION IS PREFERRED FOR THE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 33% 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, WITH
STRONG AGREEMENT AMONG FORECAST MODELS ACROSS VARIABLES, OFFSET BY DIVERGING
MODEL SOLUTIONS TOWARDS THE END OF THE FORECAST PERIOD.
8-14 DAY OUTLOOK FOR DEC 07 - 13 2024
MODEL ENSEMBLES FAVOR A PERSISTENCE OF THE SYNOPTIC PATTERN FROM THE 6-10 DAY
PERIOD. LIKE THE EARLY PERIOD, THE WEEK-2 500-HPA MANUAL HEIGHT BLEND FEATURES
AMPLIFIED RIDGING OVER THE WEST COAST AND A BROAD TROUGH OVER THE EASTERN CONUS
AND NORTH ATLANTIC. THE WEEK-2 TEMPERATURE AND PRECIPITATION OUTLOOKS ARE ALSO
VERY SIMILAR TO THE 6-10 PERIOD, ONCE AGAIN WITH HIGH FORECAST CONFIDENCE DUE
TO BOTH THE PERSISTENT PATTERN AS WELL AS GOOD MODEL AGREEMENT.
CONTINUED POSITIVE 500-HPA HEIGHT ANOMALIES OVER WESTERN NORTH AMERICA CONTINUE
TO FAVOR ABOVE-NORMAL TEMPERATURES FOR THE WESTERN HALF OF THE CONUS. CHANCES
OF ABOVE-NORMAL TEMPERATURES ARE BROADLY SIMILAR FROM THE EARLIER FORECAST
PERIOD, WITH A SLIGHT REDUCTION IN PROBABILITIES AS RIDGING OVER THE WESTERN
CONUS IS FAVORED TO FLATTEN SLIGHTLY DURING THE WEEK-2 PERIOD. THE TROUGH
DEPICTED OVER THE EASTERN CONUS DURING THE 6-10 DAY PERIOD IS FAVORED TO WEAKEN
SOMEWHAT, AND CHANCES OF BELOW-NORMAL TEMPERATURES FOR THE EASTERN HALF OF THE
COUNTRY ARE CONCURRENTLY REDUCED RELATIVE TO TODAY’S 6-10 DAY OUTLOOK.
PROBABILITIES REMAIN ABOVE 70% FOR PORTIONS OF THE NORTHEAST WHERE COLD AIR IS
FAVORED TO LINGER THROUGHOUT THE PERIOD. WITH CONTINUED ONSHORE FLOW OFF THE
GULF OF ALASKA, ELEVATED CHANCES OF ABOVE-NORMAL TEMPERATURES ARE FAVORED TO
SPREAD OVER MOST OF THE STATE. NORTHWESTERN ALASKA CONTINUES TO TILT TOWARDS
NEAR-NORMAL TEMPERATURES UNDER THE CONTINUED INFLUENCE OF RIDGING OVER EASTERN
SIBERIA. PERSISTENCE IS ALSO THE PREFERRED SOLUTION FOR THE HAWAIIAN ISLANDS,
WITH THE WHOLE STATE FAVORED FOR ABOVE-NORMAL TEMPERATURES.
CONTINUED AMPLIFIED RIDGING OVER THE WESTERN CONUS FAVORS BELOW-NORMAL
PRECIPITATION TO PERSIST FOR MUCH OF THE WESTERN CONUS THROUGH WEEK-2. CHANCES
ARE SLIGHTLY REDUCED OVER THE PORTIONS OF THE GREAT BASIN BUT REMAIN ABOVE 50%
FOR PORTIONS OF CENTRAL CALIFORNIA. CONTINUED RETURN FLOW OFF THE GULF OF
MEXICO KEEPS PORTIONS OF THE SOUTHERN PLAINS AND GULF COAST TILTING TOWARDS
ABOVE-NORMAL PRECIPITATION, WHILE ALBERTA CLIPPERS REMAIN A POSSIBILITY ALONG
THE U.S.-CANADA BORDER, TILTING THE ODDS SLIGHTLY TOWARD ABOVE-NORMAL
PRECIPITATION FOR PORTIONS OF THE PACIFIC NORTHWEST AND NORTHERN PLAINS. AS
ONSHORE FLOW CONTINUES OFF THE GULF OF ALASKA, ABOVE-NORMAL PRECIPITATION IS
FAVORED TO SPREAD TO COVER THE ENTIRE STATE. NEAR-NORMAL PRECIPITATION IS
FAVORED ACROSS HAWAII, DUE TO CONTINUED MIXED GUIDANCE FROM FORECAST TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 20% 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, WITH
GOOD AGREEMENT AMONG FORECAST MODELS ACROSS VARIABLES, OFFSET BY DIFFERENCES IN
DEPICTED AMPLITUDE OF SYNOPTIC FEATURES AND WEAKER ANOMALIES DURING THE
FORECAST PERIOD.
FORECASTER: DANIEL BARANDIARAN
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
DECEMBER 19.
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:
19551213 - 20051203 - 19631114 - 19591110 - 19611208
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:
19551212 - 20051203 - 19631114 - 20091208 - 19591111
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 05 - 09 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N 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 A A
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA B A S DAKOTA A A
NEBRASKA A N KANSAS A N OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B A IOWA B N MISSOURI B N
ARKANSAS B A LOUISIANA N A WISCONSIN B N
ILLINOIS B N MISSISSIPPI B A MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B B
TENNESSEE B N ALABAMA B N NEW YORK B N
VERMONT B B NEW HAMP B N MAINE B N
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 N AK N SLOPE A N
AK ALEUTIAN A N 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 DEC 07 - 13 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N 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 A N
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A N N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA N A IOWA N 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 N FL PENIN B A AK N SLOPE A A
AK ALEUTIAN A N 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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page