102
FXUS06 KWBC 091902
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 09 2023
6-10 DAY OUTLOOK FOR OCT 15 - 19 2023
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 GFS, ECMWF, AND CANADIAN MODEL ENSEMBLES DUE TO RECENT
MODEL SKILL. THE RESULTANT MANUAL BLEND FEATURES A STRONG MID-LEVEL TROUGH,
ASSOCIATED WITH NEGATIVE 500-HPA GEOPOTENTIAL HEIGHT ANOMALIES, OVER THE
ALEUTIANS AND THE EASTERN NORTH PACIFIC, WHILE AN ANOMALOUS RIDGE IS FORECAST
OVER THE WESTERN CONTIGUOUS UNITED STATES (CONUS). TROUGHING AND NEGATIVE
500-HPA HEIGHT ANOMALIES ARE FORECAST ACROSS THE CENTRAL AND EASTERN CONUS.
ABOVE NORMAL 500-HPA HEIGHTS ARE FORECAST OVER HAWAII.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE
WESTERN CONUS, AND PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY,
ASSOCIATED WITH MID-LEVEL RIDGING AND/OR ABOVE-AVERAGE 500-HPA HEIGHTS.
CONVERSELY, A TILT TOWARD NEAR- TO BELOW-NORMAL TEMPERATURES IS INDICATED
ACROSS MOST OF THE CENTRAL AND EASTERN CONUS NEAR AND BEHIND THE STRONG
MID-LEVEL TROUGH. THE HIGHEST PROBABILITIES FOR BELOW-NORMAL TEMPERATURES (IN
EXCESS OF 80 PERCENT) ARE INDICATED OVER PORTIONS OF THE SOUTHEAST. COOLER THAN
NORMAL WEATHER FAVORS PARTS OF WESTERN MAINLAND ALASKA, WHILE ABOVE
NORMAL-TEMPERATURES ARE FORECAST OVER CENTRAL AND WESTERN ALASKA, SUPPORTED BY
MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS. FARTHER SOUTH, WARMER SEA
SURFACE TEMPERATURES AND MID-LEVEL RIDGE ENHANCE THE CHANCES FOR NEAR- TO
ABOVE-TEMPERATURES OVER HAWAII, CONSISTENT WITH THE GEFS AND ECMWF TEMPERATURE
REFORECAST CONSOLIDATION TOOLS.
THE TROUGH PREDICTED ACROSS THE NORTH PACIFIC ENHANCES THE LIKELIHOOD OF
NEAR-NORMAL PRECIPITATION IN THE WESTERN CONUS. THE TROUGH SHOULD ALSO BRING
MORE PRECIPITATION THAN NORMAL TO NORTHERN AND EASTERN ALASKA. THE TROUGH
PREDICTED OVER THE EASTERN CONUS FAVORS ABOVE-NORMAL PRECIPITATION OVER
PORTIONS OVER THE NORTHERN ATLANTIC COAST. NEAR- TO BELOW-NORMAL PRECIPITATION
IS FAVORED ACROSS THE REMAINDER OF CONUS, EXCEPT FOR PARTS OF THE SOUTHERN
PLAINS WHERE ABOVE-NORMAL PRECIPITATION IS EXPECTED, CONSISTENT WITH THE GEFS
AND ECMWF PRECIPITATION REFORECAST CONSOLIDATION TOOLS. FARTHER SOUTH AND WEST,
THE MID-LEVEL RIDGE COVERING HAWAII SHOULD FAVOR BELOW-NORMAL PRECIPITATION
ACROSS MOST OF THE ISLAND CHAIN.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 8, 30% 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 NORMAL, 4 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT ON A PERSISTENT 500-HPA FLOW PATTERN ACROSS NORTH AMERICA.
8-14 DAY OUTLOOK FOR OCT 17 - 23 2023
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY PERSISTENT
500-HPA CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS.
STRONG TROUGHING AND BELOW-NORMAL 500-HPA HEIGHTS ARE FORECASTED OVER THE
EASTERN NORTH PACIFIC IN THE MANUAL BLEND OF MODELS. WEAK RIDGING AND POSITIVE
500-HPA GEOPOTENTIAL HEIGHT ANOMALIES ARE PREDICTED ACROSS THE WESTERN CONUS,
AND A TROUGH AND BELOW-NORMAL 500-HPA HEIGHTS ARE EXPECTED OVER THE EASTERN
CONUS. POSITIVE 500-HPA GEOPOTENTIAL HEIGHT ANOMALIES ARE FAVORED ACROSS MUCH
OF ALASKA. A WEAK MID-LEVEL RIDGE IS FORECAST OVER THE HAWAII ISLANDS.
THE TEMPERATURE PATTERN FORECAST FOR THE WEEK 2 PERIOD IS SIMILAR TO THE 6-10
DAY OUTLOOK PERIOD. THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL
TEMPERATURES ACROSS MUCH OF THE WESTERN HALF OF THE CONUS, THE UPPER
MISSISSIPPI VALLEY, AND PARTS OF THE MIDDLE MISSISSIPPI VALLEY AND THE UPPER
GREAT LAKES, ASSOCIATED WITH MID-LEVEL RIDGING PREDICTED OVER THE WESTERN
CONUS. A TILT TOWARD BELOW-NORMAL TEMPERATURES IS INDICATED FOR MOST OF THE
EASTERN CONUS (EXCEPT FOR PARTS OF NEW ENGLAND WHERE ABOVE-NORMAL TEMPERATURES
ARE FAVORED) UNDERNEATH A TROUGH PREDICTED OVER THE EASTERN CONUS. IN ALASKA,
CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE INCREASED ACROSS CENTRAL AND EASTERN
PORTIONS OF THE STATE DUE TO MEAN SOUTHERLY FLOW OVER THE REGION, WHILE NEAR-
TO BELOW-NORMAL TEMPERATURES ARE FAVORED OVER PARTS OF WESTERN ALASKA,
SUPPORTED BY MOST DYNAMICAL MODEL FORECAST TOOLS. IN HAWAII, NEAR- TO
ABOVE-NORMAL TEMPERATURES ARE FAVORED ACROSS HAWAII UNDER A WEAK MID-LEVEL
RIDGE OVER THE REGION.
THE TROUGH PREDICTED ACROSS THE NORTH PACIFIC ENHANCES THE LIKELIHOOD OF WET
WEATHER OVER PARTS OF THE PACIFIC NORTHWEST AND THE NORTHERN GREAT BASIN. THE
TROUGH SHOULD ALSO BRING MORE PRECIPITATION THAN NORMAL TO CENTRAL AND EASTERN
ALASKA. THE TROUGH OVER THE EASTERN CONUS FAVORS ABOVE-NORMAL PRECIPITATION
OVER SOUTHERN FLORIDA. NEAR- TO BELOW-NORMAL PRECIPITATION IS FAVORED OVER THE
REMAINDER OF THE CONUS (EXCEPT FOR PARTS OF THE SOUTHERN PLAINS AND THE
SOUTHERN ROCKIES WHERE ABOVE-NORMAL PRECIPITATION IS EXPECTED) AND PARTS OF
WESTERN ALASKA, CONSISTENT WITH THE GEFS AND ECMWF PRECIPITATION REFORECAST
CONSOLIDATION TOOLS. MEANWHILE, THE PERSISTENCE OF ABOVE-NORMAL 500-HPA HEIGHTS
AROUND HAWAI’I CONTINUES TO FAVOR LESS PRECIPITATION OVER THE BIG ISLAND OF
HAWAII, WHILE ABOVE-NORMAL PRECIPITATION IS FORECAST OVER THE NORTHWESTERN
ISLANDS, SUPPORTED BY THE GEFS AND ECMWF PRECIPITATION REFORECAST CONSOLIDATION
TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S GFS
SUPERENSEMBLE 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 NORMAL, 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 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:
19781005 - 20080930 - 19870920 - 19551015 - 19660921
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:
20080930 - 19781005 - 19870920 - 19660920 - 20010923
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 15 - 19 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A B S DAKOTA N B
NEBRASKA B B KANSAS B B OKLAHOMA B B
N TEXAS B B S TEXAS B B W TEXAS B A
MINNESOTA N B IOWA B B MISSOURI B B
ARKANSAS B B LOUISIANA B B WISCONSIN N B
ILLINOIS B B MISSISSIPPI B B MICHIGAN N B
INDIANA B N OHIO B N KENTUCKY B B
TENNESSEE B B ALABAMA B B NEW YORK B N
VERMONT B N NEW HAMP B N MAINE N N
MASS B A CONN B A RHODE IS B A
PENN B N NEW JERSEY B A W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B N S CAROLINA B B GEORGIA B B
FL PNHDL B B FL PENIN B B AK N SLOPE N A
AK ALEUTIAN B B AK WESTERN B N 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 OCT 17 - 23 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A B
W MONTANA A N E MONTANA A N WYOMING A N
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA N N
N TEXAS N N S TEXAS N A W TEXAS A A
MINNESOTA A B IOWA N B MISSOURI N B
ARKANSAS B N LOUISIANA B N WISCONSIN A B
ILLINOIS N B MISSISSIPPI B B MICHIGAN A B
INDIANA N B OHIO B N KENTUCKY B N
TENNESSEE B B ALABAMA B N 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 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 B
FL PNHDL B N FL PENIN B N AK N SLOPE A A
AK ALEUTIAN B N AK WESTERN N N 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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