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FXUS06 KWBC 301916
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 30 2023
6-10 DAY OUTLOOK FOR NOV 05 - 09 2023
THE LATEST GEFS, CANADIAN, AND ECMWF ENSEMBLE MEANS ARE IN GOOD AGREEMENT
PREDICTING AN AMPLIFIED 500-HPA RIDGE OVER THE ALEUTIAN ISLANDS AND AN
AMPLIFIED TROUGH DOWNSTREAM OVER THE NORTH ATLANTIC. OVER THE CONTIGUOUS U.S.
(CONUS), THE PREDICTED 500-HPA FLOW PATTERN IS LESS AMPLIFIED, BUT THE GEFS,
ECMWF AND CANADIAN ENSEMBLE MEAN FORECASTS ARE IN GOOD AGREEMENT. ENSEMBLE MEAN
SOLUTIONS PREDICT A RIDGE OVER WESTERN CANADA AND THE WESTERN CONUS AND A
TROUGH OVER EASTERN NORTH AMERICA. THE GEFS ENSEMBLE PREDICTS A MORE AMPLIFIED
TROUGH, RELATIVE TO THE ECMWF ENSEMBLE MEAN, EXTENDING SOUTHWARD INTO THE
SOUTHEAST. THE OVERALL 500-HPA ANOMALY PATTERN FOR THE NORTH AMERICAN REGION IN
THE MANUAL BLEND IS MORE AMPLIFIED THAN YESTERDAY’S 6-10 DAY PERIOD MODEL
FORECAST BLEND.
BELOW NORMAL TEMPERATURES ARE FAVORED FOR WEST-CENTRAL AREAS OF MAINLAND
ALASKA, AS MID-LEVEL HEIGHTS DROP IN THE 6-10 DAY FORECAST PERIOD. ABOVE NORMAL
TEMPERATURES CONTINUE TO BE FAVORED FOR THE NORTH SLOPE, EASTERN MAINLAND
ALASKA, AND SOUTHEAST ALASKA, WITH PREDICTED SOUTHERLY FLOW AND POSITIVE
500-HPA HEIGHT ANOMALIES EARLY IN THE PERIOD. ABOVE NORMAL TEMPERATURES ARE
LIKELY FOR THE WESTERN CONUS, UNDER A PREDICTED RIDGE. LIKELY ABOVE NORMAL
TEMPERATURES ARE FORECAST ACROSS THE CENTRAL MISSISSIPPI VALLEY, OHIO VALLEY,
AND THE SOUTHEAST, CONSISTENT WITH THE CONSOLIDATION OF GEFS AND ECMWF
REFORECAST-CALIBRATED TEMPERATURES. SOME TEMPERATURE TOOLS FORECAST THE
POTENTIAL FOR COOLER TEMPERATURES IN THE EAST, AS A TROUGH BEGINS TO RELOAD IN
DYNAMICAL MODEL FORECASTS LATE IN THE PERIOD. BELOW NORMAL TEMPERATURES ARE
FAVORED FOR NORTHERN AREAS OF THE GREAT LAKES REGION AND NORTHEAST, UNDER A
PREDICTED MEAN TROUGH. ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE
HAWAIIAN ISLANDS, AS INDICATED BY THE CONSOLIDATION OF MODEL TEMPERATURE TOOLS.
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR MAINLAND ALASKA, CONSISTENT
WITH MOST DYNAMICAL MODEL PRECIPITATION TOOLS. ABOVE NORMAL PRECIPITATION IS
LIKELY FOR THE PACIFIC NORTHWEST, AHEAD OF A PREDICTED AMPLIFIED TROUGH OVER
THE NORTHEAST PACIFIC. ABOVE NORMAL PRECIPITATION IS FAVORED ACROSS THE
NORTHERN TIER OF THE CONUS, CONSISTENT WITH DYNAMICAL MODEL PRECIPITATION
TOOLS. ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE EASTERN SEABOARD, WITH
PREDICTED SOUTHERLY MOISTURE FLOW FROM THE TROPICS, UNDER THE PREDICTED
MID-LEVEL TROUGH. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR
NORTHWESTERN ISLANDS OF HAWAII, WHILE BELOW NORMAL PRECIPITATION IS SLIGHTLY
FAVORED FOR SOUTHEASTERN AREAS OF THE BIG ISLAND, CONSISTENT WITH THE
PRECIPITATION CONSOLIDATION.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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, DUE TO
GOOD AGREEMENT ON AN AMPLIFIED MID-LEVEL HEIGHT PATTERN OVER NORTH AMERICA,
OFFSET BY A VARIABLE PATTERN OVER THE EASTERN CONUS.
8-14 DAY OUTLOOK FOR NOV 07 - 13 2023
THE PREDICTED 500-HPA CIRCULATION PATTERN FOR THE WEEK-2 PERIOD IS SIMILAR TO
THE FORECAST FOR THE 6-10 DAY PERIOD, WITH SOME EVOLUTION OF THE PATTERN. AN
AMPLIFIED RIDGE PERSISTS OVER THE ALEUTIANS AND A TROUGH CONTINUES TO BE
FORECAST OVER THE NORTHEASTERN PACIFIC, WITH A SLIGHT EASTWARD PROGRESSION
DURING THE PERIOD. THE 500-HPA RIDGE-TROUGH PATTERN OVER THE CONUS PERSISTS
INTO WEEK 2, WITH A RELOADING AND AMPLIFICATION OF THE TROUGH OVER THE EASTERN
CONUS DURING WEEK 2. THE GEFS ENSEMBLE MEAN PREDICTS A MORE AMPLIFIED TROUGH
OVER THE EAST COMPARED TO THE ECMWF ENSEMBLE MEAN.
BELOW NORMAL TEMPERATURES CONTINUE TO BE FAVORED IN WEEK 2 FOR THE WEST-CENTRAL
COAST OF MAINLAND ALASKA, WHILE ABOVE NORMAL TEMPERATURES ARE FAVORED FOR
EASTERN ALASKA, CONSISTENT WITH MOST DYNAMICAL MODEL TEMPERATURE TOOLS. ABOVE
NORMAL TEMPERATURES ARE LIKELY FOR THE WESTERN AND CENTRAL CONUS FOR WEEK 2,
UNDER A PERSISTENT RIDGE AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES.
BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE NORTHEAST, UNDER A PREDICTED
TROUGH, WHILE NEAR NORMAL TEMPERATURES ARE PREDICTED FOR THE SOUTHEAST, WITH A
VARIABLE MID-LEVEL HEIGHT PATTERN. ABOVE NORMAL TEMPERATURES CONTINUE TO BE
FAVORED FOR THE HAWAIIAN ISLANDS, AS PREDICTED BY DYNAMICAL MODEL TEMPERATURE
TOOLS.
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR WESTERN MAINLAND ALASKA,
CONSISTENT WITH PRECIPITATION FORECAST TOOLS. ABOVE NORMAL PRECIPITATION IS
FAVORED FOR SOUTHEAST ALASKA INCLUDING THE ALASKA PANHANDLE, AND FOR THE
PACIFIC COAST OF THE CONUS, AHEAD OF THE PREDICTED AMPLIFIED TROUGH. BELOW
NORMAL PRECIPITATION IS FAVORED FOR THE SOUTH-CENTRAL CONUS, FROM THE SOUTHEAST
TO THE SOUTHERN PLAINS AND WESTERN GULF STATES, AHEAD OF THE PREDICTED RIDGE.
ABOVE NORMAL PRECIPITATION IS PREDICTED FOR THE EASTERN CONUS, AS THE TROUGH IS
FORECAST TO AMPLIFY OVER THE EASTERN CONUS IN THE MIDDLE OF WEEK 2. ABOVE
NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR NORTHWESTERN ISLANDS OF HAWAII, AS
PREDICTED BY MOST DYNAMICAL MODEL PRECIPITATION TOOLS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE 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: AVERAGE, 3 OUT OF 5, DUE TO GOOD
OVERALL AGREEMENT ON THE 500-HPA HEIGHT PATTERN IN WEEK-2, OFFSET BY INCREASING
UNCERTAINTY IN TEMPERATURE AND PRECIPITATION TOOLS.
FORECASTER: D COLLINS
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
NOVEMBER 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:
20031105 - 19861109 - 19811022 - 19861030 - 19781112
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:
20031104 - 19861109 - 19861104 - 19811021 - 19781112
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 05 - 09 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 A NEVADA A A
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A B ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA N A S DAKOTA A A
NEBRASKA A A KANSAS A N OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA N A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A B WISCONSIN N A
ILLINOIS A A MISSISSIPPI A B MICHIGAN N A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A N NEW YORK N A
VERMONT B A NEW HAMP N A MAINE B A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN N N AK WESTERN B A AK INT BSN N A
AK S INT A A AK SO COAST A A AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 07 - 13 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 A NEVADA A N
W MONTANA A N E MONTANA A N WYOMING A N
UTAH A N ARIZONA A B COLORADO A B
NEW MEXICO A B N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA N N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A B WISCONSIN N N
ILLINOIS N N MISSISSIPPI A B MICHIGAN B N
INDIANA N N OHIO B A KENTUCKY N N
TENNESSEE N N ALABAMA N B NEW YORK B A
VERMONT B A NEW HAMP B A MAINE B A
MASS B A CONN B A RHODE IS B A
PENN B A NEW JERSEY B A W VIRGINIA B A
MARYLAND B A DELAWARE B A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA N N
FL PNHDL N N FL PENIN N A AK N SLOPE A N
AK ALEUTIAN N N AK WESTERN N A AK INT BSN A N
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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