046
FXUS06 KWBC 071920
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON OCTOBER 07 2024
6-10 DAY OUTLOOK FOR OCT 13 - 17 2024
TODAY’S ENSEMBLE MEAN MODELS (GEFS, ECENS, AND CMCE) ARE IN VERY GOOD AGREEMENT
ON THE LARGE-SCALE FEATURES OF THE PREDICTED 500-HPA CIRCULATION PATTERN OVER
THE FORECAST DOMAIN DURING THE 6-10 DAY PERIOD. MID-LEVEL ANOMALOUS RIDGES AND
POSITIVE HEIGHT ANOMALIES ARE DEPICTED OVER THE KAMCHATKA PENINSULA AND MOST OF
THE BERING SEA, AND OVER THE WESTERN AND CENTRAL CONTIGUOUS U.S. (CONUS). FOR
THE LATTER AREA, A POSITIVE HEIGHT ANOMALY CENTER IS PREDICTED IN THE VICINITY
OF NORTH DAKOTA WITH MAXIMUM HEIGHT ANOMALIES DEPICTED BY THE MANUAL HEIGHT
BLEND TO BE GREATER THAN +120 METERS. MID-LEVEL TROUGHS ARE PREDICTED TO EXTEND
FROM ALASKA SOUTHWARD ACROSS THE GULF OF ALASKA, AND ALSO FROM THE SOUTHERN
CANADIAN MARITIMES SOUTHWARD ACROSS MUCH OF THE U.S. EAST COAST. THE MANUAL
HEIGHT BLEND DEPICTS MAXIMUM NEGATIVE HEIGHT ANOMALIES GREATER THAN -120 METERS
OVER THE GULF OF ALASKA AND NEAR NEWFOUNDLAND. THE ENSEMBLE MEAN MODELS SHOW
VERY GOOD CONTINUITY WITH YESTERDAY’S RESPECTIVE RUNS. CLIMATOLOGICALLY, THE
TRANSITION FROM THE WARM SEASON TO THE COLD SEASON IS USUALLY CHARACTERIZED BY
A RE-ENERGIZED ATMOSPHERE AND INCREASED WAVE AMPLITUDES. IN THE VICINITY OF
HAWAII, MID-LEVEL HEIGHTS ARE FORECAST TO BE SLIGHTLY ABOVE AVERAGE.
ABOVE NORMAL TEMPERATURE CHANCES ARE ELEVATED FROM APPROXIMATELY THE
MISSISSIPPI RIVER WESTWARD ACROSS THE ROCKIES TO THE PACIFIC COAST, ASSOCIATED
WITH A LARGE ANOMALOUS RIDGE AND STRONG POSITIVE HEIGHT ANOMALIES EXPECTED OVER
THIS AREA. THIS IS WELL SUPPORTED BY REFORECAST-CALIBRATED, BIAS-CORRECTED, AND
RAW TEMPERATURES FROM THE GEFS, ECENS, AND CMCE ENSEMBLE MEANS. CHANCES OF
ABOVE NORMAL TEMPERATURES EXCEED 80% OVER THE SOUTHERN AND CENTRAL ROCKIES AND
NORTHERN HIGH PLAINS. BELOW NORMAL TEMPERATURE CHANCES ARE ENHANCED OVER THE
EASTERN CONUS, EAST OF A LINE THAT EXTENDS FROM CENTRAL LOWER MICHIGAN TO
EASTERN ALABAMA, WITH THE EXCEPTION OF A SMALL AREA OF FAVORED ABOVE NORMAL
TEMPERATURE CHANCES OVER SOUTHERN FLORIDA. IN ALASKA, BELOW NORMAL TEMPERATURE
CHANCES ARE INCREASED OVER WESTERN PORTIONS OF THE STATE AND SOUTHEAST ALASKA,
WITH ABOVE NORMAL TEMPERATURES FAVORED OVER THE EASTERN MAINLAND. THIS IS IN
AGREEMENT WITH THE AUTO AND CONSOLIDATED TEMPERATURE TOOLS. THE ERF-CON AND
AUTOMATED TEMPERATURE TOOLS FOR HAWAII FAVOR INCREASED ODDS OF ABOVE NORMAL
TEMPERATURES, CONSISTENT WITH THE PREDICTED 500-HPA HEIGHT ANOMALY PATTERN AND
NEAR TO SLIGHTLY ABOVE NORMAL SEA-SURFACE TEMPERATURES.
BELOW NORMAL PRECIPITATION CHANCES ARE INCREASED OVER THE MAJORITY OF THE
CONUS, WITH MAXIMUM CHANCES EXCEEDING 50% OVER THE CENTRAL AND EAST-CENTRAL
CONUS. THIS IS WELL SUPPORTED BY THE VARIOUS ENSEMBLE MEAN MODELS AND TOOLS,
AND BY THE FORECAST OF A LARGE MID-LEVEL RIDGE WITH WELL ABOVE-NORMAL HEIGHTS
OVER MOST OF THE LOWER 48 STATES. THERE IS A SLIGHT TILT IN THE ODDS FAVORING
ANOMALOUS DRYNESS OVER SOUTHWESTERN ALASKA, WEST OF A MEAN TROUGH AXIS
PREDICTED OVER THE STATE. ABOVE NORMAL PRECIPITATION CHANCES ARE ELEVATED OVER
MOST OF THE REMAINDER OF ALASKA, ASSOCIATED WITH ONSHORE FLOW AT LOW AND MID
LEVELS. THIS BROAD REGION OF FAVORED ABOVE NORMAL PRECIPITATION CHANCES EXTENDS
SOUTHWARD INTO THE NORTHWESTERN CONUS. OTHER AREAS OF FAVORED ABOVE NORMAL
PRECIPITATION INCLUDE THE NORTHEAST CONUS (RELATED TO THE PASSAGE OF WEAK
DISTURBANCES), AND FLORIDA (IN THE EASTERLY FLOW SOUTH OF A SURFACE HIGH
FORECAST OVER THE SOUTHERN APPALACHIANS). FOR HAWAII, A SUBJECTIVE CONSENSUS
BETWEEN THE ERF-CON AND AUTOMATED PRECIPITATION TOOLS FAVORS ABOVE NORMAL
PRECIPITATION FOR THE BIG ISLAND, AND NEAR NORMAL PRECIPITATION FOR MAUI, OAHU,
AND KAUAI.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 25% 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
VERY GOOD AGREEMENT AMONG THE PREDICTED MODEL HEIGHT FIELDS, AND SURFACE
TEMPERATURE AND PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR OCT 15 - 21 2024
THE WEEK-2 MEAN CIRCULATION PATTERN ACROSS THE FORECAST DOMAIN IS PREDICTED TO
SIGNIFICANTLY DEAMPLIFY, ACCOMPANIED BY EASTWARD PROGRESSION. THE ANOMALOUS
RIDGE OVER THE WESTERN AND CENTRAL CONUS IS FORECAST TO ADVANCE INTO THE UPPER
MISSISSIPPI VALLEY AND GREAT LAKES REGION, AS THE EAST COAST TROUGH RAPIDLY
COLLAPSES AND LIFTS NORTHEASTWARD. THE TROUGH PREDICTED OVER THE GULF OF ALASKA
DURING THE EARLIER 6-10 DAY PERIOD IS ALSO EXPECTED TO WEAKEN RAPIDLY DURING
WEEK-2. IN ADDITION, A SHALLOW TROUGH OVER FAR EASTERN SIBERIA IS FORECAST TO
ADVECT EASTWARD ACROSS THE NORTHERN BERING SEA AND NORTHERN ALASKA DURING THE
OUTLOOK PERIOD.
ABOVE NORMAL TEMPERATURE CHANCES ARE ELEVATED ACROSS MOST OF THE CONTIGUOUS
U.S. AND THE EASTERN QUARTER OF THE ALASKA MAINLAND, ASSOCIATED WITH A LARGE
ANOMALOUS RIDGE AND POSITIVE HEIGHT ANOMALIES EXPECTED OVER MUCH OF NORTH
AMERICA. MAXIMUM PROBABILITIES ARE FAVORED TO EXCEED 70% FROM THE SOUTHERN
ROCKIES NORTHEASTWARD TO THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY
REGION. ENSEMBLE MEAN MODELS AND MOST TEMPERATURE TOOLS CONTINUE TO BE IN VERY
GOOD AGREEMENT ON THIS WIDESPREAD ANOMALOUS WARMTH. FROM ABOUT THE SPINE OF THE
APPALACHIANS EASTWARD TO THE ATLANTIC COAST, A MIX OF BELOW, ABOVE, AND MOSTLY
NEAR NORMAL TEMPERATURES ARE FAVORED. NEAR NORMAL TEMPERATURES ARE FAVORED FOR
MOST OF THE REMAINDER OF ALASKA, WITH RELATIVELY SMALL-SCALE AREAS OF FAVORED
BELOW NORMAL TEMPERATURES FOR PORTIONS OF SOUTHEAST ALASKA, THE ALASKA
PENINSULA/ALEUTIANS, AND NEAR-COASTAL AREAS OF WESTERN ALASKA. ABOVE NORMAL
TEMPERATURE CHANCES ARE ELEVATED ACROSS HAWAII.
DURING WEEK-2 BELOW NORMAL PRECIPITATION CHANCES ARE INCREASED OVER THE
MAJORITY OF THE CONUS, AS WAS THE CASE WITH THE EARLIER 6-10 DAY PERIOD, BASED
ON THE SAME REASONING. RELATIVELY SMALL-SCALE REGIONS OF ABOVE NORMAL
PRECIPITATION ARE FAVORED OVER FLORIDA AND THE NORTHWEST, SUPPORTED BY MOST OF
THE TEMPERATURE TOOLS. MOST OF ALASKA IS FAVORED TO HAVE ABOVE NORMAL
PRECIPITATION DURING WEEK-2 AS AN ELONGATED MID-LEVEL TROUGH MOVES OVER THE
STATE FROM THE WEST. NEAR NORMAL PRECIPITATION IS FAVORED OVER THE HAWAIIAN
ISLANDS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 33% 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
CONTINUING VERY GOOD AGREEMENT BETWEEN THE VARIOUS MID-LEVEL HEIGHT
FORECASTS,AND TEMPERATURE AND PRECIPITATION TOOLS.
FORECASTER: ANTHONY A
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
OCTOBER 17.
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:
19920927 - 19551011 - 20010921 - 20041004 - 19551006
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:
19551010 - 19920925 - 19951011 - 20041006 - 20010921
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 13 - 17 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A N E MONTANA A B WYOMING A B
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A B IOWA A B MISSOURI A B
ARKANSAS A B LOUISIANA A B WISCONSIN A B
ILLINOIS N B MISSISSIPPI N B MICHIGAN N B
INDIANA N B OHIO B B KENTUCKY B B
TENNESSEE N B ALABAMA N B 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 B NEW JERSEY B N 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 A AK N SLOPE N A
AK ALEUTIAN B B AK WESTERN B B AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 15 - 21 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF A B
SRN CALIF A N IDAHO A N NEVADA A B
W MONTANA A N E MONTANA A N WYOMING A B
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A B IOWA A B MISSOURI A B
ARKANSAS A B LOUISIANA A B WISCONSIN A B
ILLINOIS A B MISSISSIPPI A B MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A B
TENNESSEE A B ALABAMA A B NEW YORK N B
VERMONT N B NEW HAMP N B MAINE N B
MASS N B CONN N B RHODE IS N B
PENN N B NEW JERSEY N B W VIRGINIA N B
MARYLAND N B DELAWARE N B VIRGINIA N B
N CAROLINA B B S CAROLINA N B GEORGIA N B
FL PNHDL N N FL PENIN A A AK N SLOPE N A
AK ALEUTIAN B N AK WESTERN N A AK INT BSN N 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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