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FXUS06 KWBC 301902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON SEPTEMBER 30 2024
6-10 DAY OUTLOOK FOR OCT 06 - 10 2024
TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED AMPLIFIED
500-HPA CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS DURING
THE 6-10 DAY PERIOD. THE MANUAL 500-HPA HEIGHT BLEND IS BASED PRIMARILY ON THE
ENSEMBLE MEANS FROM THE GEFS, ECMWF AND CANADIAN MODELS DUE TO RECENT MODEL
SKILL. THE RESULTANT MANUAL BLEND FEATURES POSITIVE MID-LEVEL HEIGHT ANOMALIES
AND FULL LATITUDE MID-LEVEL RIDGING OVER WESTERN NORTH AMERICA, WITH
BELOW-NORMAL MID-LEVEL HEIGHTS AND TROUGHING ACROSS EASTERN CANADA AND THE
EASTERN CONTIGUOUS U.S. (CONUS). IN ALASKA, MID-LEVEL TROUGHING AND NEGATIVE
500-HPA HEIGHT ANOMALIES ARE FORECAST, EXTENDING SOUTH TOWARDS THE GULF OF
ALASKA. IN HAWAII, NEAR-NORMAL 500-HPA HEIGHTS ARE FORECAST.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE STRONGLY FAVORED BENEATH THE
MID-LEVEL RIDGE ACROSS MUCH OF THE WESTERN AND CENTRAL U.S. DURING THE 6-10 DAY
PERIOD. CHANCES EXCEED 80% FOR ABOVE-NORMAL TEMPERATURES ACROSS MOST OF THE
WESTERN CONUS, SUPPORTED BY MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS.
NEAR-NORMAL TEMPERATURES ARE PREDICTED ACROSS MOST OF THE EASTERN CONUS DUE TO
A TROUGH PREDICTED OVER THE REGION.THE EXCEPTION IS IN PARTS OF THE GULF OF
MEXICO STATES AND FROM THE UPPER GREAT LAKES EXTENDING EASTWARD TO PARTS OF THE
NORTHEAST WHERE ABOVE-NORMAL TEMPERATURES REMAIN FAVORED. IN ALASKA, NEAR- TO
ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MAINLAND ALASKA, WHILE BELOW-NORMAL
TEMPERATURES ARE FORECAST OVER THE ALEUTIANS, SUPPORTED BY MOST OF THE
DYNAMICAL TEMPERATURE FORECAST TOOLS. IN HAWAII, NEAR- TO ABOVE-NORMAL
TEMPERATURES ARE FAVORED, CONSISTENT WITH THE TEMPERATURE AUTO BLEND AND
CONSOLIDATION TEMPERATURE FORECAST TOOLS.
THE 6-10 DAY PRECIPITATION FORECAST FAVORS BELOW-NORMAL PRECIPITATION FOR MUCH
OF THE WESTERN AND CENTRAL CONUS DUE TO THE RIDGING AND ABOVE-NORMAL 500-HPA
HEIGHTS. HOWEVER, A TILT TOWARDS ABOVE-NORMAL IS FAVORED ALONG THE SOUTHEASTERN
CONUS AND MAINE, UNDERNEATH A PREDICTED TROUGH. IN ALASKA, ABOVE-NORMAL
PRECIPITATION IS FAVORED FOR SOUTHEASTERN MAINLAND AND SOUTHEAST ALASKA, DUE TO
THE PREDICTED TROUGHING OVER THE STATE, WHILE BELOW-NORMAL PRECIPITATION IS
FORECAST OVER NORTHERN PORTIONS OF THE STATE. IN HAWAII, ABOVE-NORMAL
PRECIPITATION IS SLIGHTLY FAVORED ACROSS MOST OF THE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 6Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% 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. GOOD
AGREEMENT AMONG THE DYNAMICAL TOOLS IS OFFSET BY A MORE PROGRESSIVE PATTERN BY
THE END OF THE PERIOD.
8-14 DAY OUTLOOK FOR OCT 08 - 14 2024
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY CONSISTENT
500-HPA CIRCULATION PATTERN RELATIVE TO THE 6-10 DAY PERIOD ACROSS NORTH
AMERICA AND THE SURROUNDING REGIONS. DURING WEEK-2, ENSEMBLE MEANS FROM THE
GEFS, ECMWF AND CANADIAN MODELS DEPICT A MORE AMPLIFIED PATTERN COMPARED TO THE
6-10 DAY PERIOD, WITH A TROUGH ACROSS PORTIONS OF ALASKA AND THE GULF OF
ALASKA, AND A FULL LATITUDE RIDGE FORECAST ACROSS WESTERN AND CENTRAL NORTH
AMERICA, A TROUGH ACROSS THE EASTERN CONUS, AND A STRONG RIDGE CENTERED NEAR
GREENLAND. IN HAWAII, NEAR-NORMAL HEIGHTS ARE FORECAST.
ABOVE-NORMAL TEMPERATURES REMAIN FAVORED FOR THE WESTERN AND CENTRAL CONUS
DURING WEEK-2 BENEATH THE FORECAST RIDGE AND ABOVE-NORMAL 500-HPA HEIGHTS
ACROSS THE REGION WITH GOOD AGREEMENT AMONG THE TOOLS. NEAR-NORMAL TEMPERATURES
ARE FORECAST OVER MOST OF THE EASTERN CONUS (EXCEPT FOR PARTS OF GREAT LAKES,
MAINE AND FLORIDA, WHERE ABOVE-NORMAL TEMPERATURES ARE FORECAST), IN
ASSOCIATION WITH A TROUGH PREDICTED ALONG THE REGION. IN ALASKA, ABOVE-NORMAL
TEMPERATURES ARE FORECAST FOR THE EASTERN MAINLAND WITH BELOW-NORMAL
TEMPERATURES FAVORED OVER THE ALEUTIANS, SUPPORTED BY MOST OF THE DYNAMICAL
TEMPERATURE FORECAST TOOLS. IN HAWAII, ABOVE-NORMAL TEMPERATURES ARE FORECAST,
CONSISTENT WITH A BLEND OF TOOLS AND FORECAST CONSOLIDATION.
BELOW-NORMAL PRECIPITATION IS FAVORED ACROSS MOST OF THE CONUS DURING THE
WEEK-2 PERIOD BENEATH AN EXPANDING MID-LEVEL RIDGE AND ABOVE-NORMAL 500-HPA
HEIGHTS, EXCEPT FOR MAINE AND PARTS OF THE SOUTHEASTERN CONUS, WHERE
ABOVE-NORMAL PRECIPITATION IS FAVORED, DUE TO A TROUGH PREDICTED OVER THE
EASTERN CONUS, SUPPORTED BY MOST OF THE DYNAMICAL PRECIPITATION FORECAST TOOLS.
MEANWHILE, THE TROUGH ACROSS ALASKA IS FORECAST TO BRING ABOVE-NORMAL
PRECIPITATION TO SOUTHEASTERN MAINLAND ALASKA AND SOUTHEAST ALASKA, WHILE
BELOW-NORMAL PRECIPITATION IS PREDICTED OVER NORTHERN ALASKA. IN HAWAII,
ABOVE-NORMAL PRECIPITATION IS FORECAST CONSISTENT WITH THE MAJORITY OF
AVAILABLE TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 35% OF TODAY'S GFS
SUPERENSEMBLE 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: ABOVE-AVERAGE, 4 OUT OF 5. DUE TO
GOOD MODEL AGREEMENT ON A PERSISTENT 500-HPA FLOW PATTERN ACROSS NORTH AMERICA.
FORECASTER: LUKE H
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:
20051013 - 19841011 - 20041009 - 19710910 - 20031009
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:
20051013 - 19841011 - 20041008 - 19710910 - 19551012
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 06 - 10 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B 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 A B MISSISSIPPI A B MICHIGAN A B
INDIANA A B OHIO N B KENTUCKY N B
TENNESSEE N B ALABAMA N A NEW YORK A N
VERMONT A N NEW HAMP N N MAINE A A
MASS N N CONN N N RHODE IS N N
PENN N B NEW JERSEY N N W VIRGINIA N B
MARYLAND N N DELAWARE N N VIRGINIA N N
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A A AK N SLOPE A N
AK ALEUTIAN B N AK WESTERN N N AK INT BSN A N
AK S INT A N AK SO COAST A A AK PNHDL N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 08 - 14 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B 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 A B MISSISSIPPI A B MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY N B
TENNESSEE N B ALABAMA N B NEW YORK N N
VERMONT N N NEW HAMP N N MAINE A N
MASS N N CONN N N RHODE IS N N
PENN N B NEW JERSEY N N W VIRGINIA N B
MARYLAND N N DELAWARE N N VIRGINIA N B
N CAROLINA N N S CAROLINA N N GEORGIA N N
FL PNHDL N N FL PENIN A N AK N SLOPE A N
AK ALEUTIAN B N AK WESTERN N N AK INT BSN A N
AK S INT A N AK SO COAST N A AK PNHDL N 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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