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FXUS06 KWBC 231903
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE APRIL 23 2024
6-10 DAY OUTLOOK FOR APR 29 - MAY 03, 2024
DYNAMICAL MODELS AGREE ON THE OVERALL 500-HPA CIRCULATION PATTERN FORECAST OVER
THE REGION OF NORTH AMERICA DURING THE 6-10 DAY PERIOD. AT THE START OF THE
PERIOD A TROUGH IS FORECAST NEAR THE COAST OF THE ALASKA PANHANDLE AND BRITISH
COLUMBIA, AND WEAK 500-HPA HEIGHT ANOMALIES ARE FORECAST OVER THE CENTRAL
CONTIGUOUS U.S. (CONUS) IN THE ECMWF AND NCEP GEFS ENSEMBLE MEANS. A BROAD
TROUGH IS FORECAST TO THE WEST OF MAINLAND ALASKA DURING THE PERIOD. A RIDGE IS
PREDICTED OVER THE EAST COAST OF THE CONTIGUOUS U.S. (CONUS) BY ENSEMBLE MEAN
FORECASTS AT THE START OF THE PERIOD, WHILE A RIDGE DEVELOPS OVER THE CENTRAL
CONUS AND A TROUGH MOVES INTO THE WEST COAST LATER IN THE PERIOD.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE ALEUTIANS AND MOST OF SOUTHERN
MAINLAND ALASKA DURING THE 6-10 DAY PERIOD UNDER SOUTHERLY MID-LEVEL FLOW AND
POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURES ARE FAVORED FOR
THE NORTH SLOPE, UNDER SLIGHTLY NEGATIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL
TEMPERATURES ARE FAVORED FOR THE NORTHWESTERN CONUS, UNDER A PREDICTED TROUGH
DURING THE PERIOD. ABOVE NORMAL TEMPERATURES ARE LIKELY ACROSS MOST OF THE
REMAINDER OF THE CONUS WITH A RIDGE PREDICTED OVER THE CENTRAL AND EASTERN
CONUS. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR NORTHWESTERN ISLANDS
OF HAWAII SUPPORTED BY THE AUTO FORECAST.
NEAR TO ABOVE NORMAL PRECIPITATION IS FAVORED FOR ALASKA, CONSISTENT WITH MOST
DYNAMICAL MODEL FORECASTS, AND AHEAD OF A PREDICTED TROUGH. NEAR TO BELOW
NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTHWESTERN CONUS INTO THE
CENTRAL HIGH PLAINS, WHERE LITTLE OR NO PRECIPITATION IS EXPECTED DURING THE
PERIOD FOR CLIMATOLOGICALLY RELATIVELY DRY REGIONS. ABOVE NORMAL PRECIPITATION
IS FAVORED FROM THE PACIFIC NORTHWEST ACROSS THE NORTHERN CONUS INTO THE
NORTHERN PLAINS, AHEAD OF A PREDICTED TROUGH, AND FOR THE SOUTHERN PLAINS AND
MISSISSIPPI VALLEY WITH SOUTHERLY SURFACE MOISTURE TRANSPORT, AS WELL AS FAR
NORTHERN AREAS OF THE NORTHEAST, AS PREDICTED BY THE CONSOLIDATION OF
CALIBRATED DYNAMICAL MODEL PRECIPITATION FORECASTS. ABOVE NORMAL PRECIPITATION
IS SLIGHTLY FAVORED ACROSS HAWAII SUPPORTED BY THE AUTO FORECAST.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 20% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, WITH
GOOD AGREEMENT AMONG MODEL FORECASTS FOR THE CIRCULATION PATTERN DURING THE
PERIOD, OFFSET BY WEAKER SIGNALS AND SOME DISAGREEMENT AMONG PRECIPITATION
TOOLS.
8-14 DAY OUTLOOK FOR MAY 01 - 07 2024
THE 500-HPA CIRCULATION PATTERN PREDICTED FOR THE 6-10 DAY PERIOD GENERALLY
PERSISTS INTO THE 8-14 DAY PERIOD. A TROUGH IS FORECAST TO THE WEST OF MAINLAND
ALASKA WITH SOUTHERLY FLOW INTO THE STATE. A PREDICTED TROUGH NEAR THE WEST
COAST OF THE CONUS AMPLIFIES FROM THE 6-10 DAY TO THE 8-14 DAY FORECAST IN
MODEL SOLUTIONS. POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER THE
EASTERN TWO-THIRDS OF THE CONUS.
ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MOST OF MAINLAND ALASKA AND THE
ALASKA PANHANDLE, WHILE NEAR TO BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE
NORTH SLOPE, SUPPORTED BY CALIBRATED GEFS MODEL FORECASTS. NEAR TO BELOW NORMAL
TEMPERATURES ARE FAVORED FOR THE WEST, UNDER A WEAK TROUGH. ABOVE NORMAL
TEMPERATURES CONTINUE TO BE LIKELY OVER THE REMAINDER OF THE CONUS, UNDER
PREDICTED POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURES ARE
SLIGHTLY FAVORED FOR HAWAII, SUPPORTED BY THE CONSOLIDATION OF CALIBRATED MODEL
FORECASTS.
A PREDICTED TROUGH TO THE WEST OF ALASKA INCREASES CHANCES OF ABOVE NORMAL
PRECIPITATION ACROSS MOST OF THE STATE, EXCLUDING THE ALASKA PANHANDLE. ABOVE
NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE WEST ACROSS THE NORTHERN
ROCKIES INTO THE NORTHERN HIGH PLAINS, AHEAD OF THE PREDICTED TROUGH. ABOVE
NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE GREAT PLAINS AND UPPER
MISSISSIPPI VALLEY, AS MOISTURE STREAMS NORTHWARD INTO THE REGION EARLY IN THE
PERIOD. BELOW NORMAL PRECIPITATION IS FAVORED FOR MUCH OF THE EASTERN CONUS,
UNDER A PREDICTED RIDGE. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED ACROSS
HAWAII SUPPORTED BY THE AUTO FORECAST.
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: SLIGHTLY BELOW AVERAGE, 2 OUT OF
5, WITH GENERAL AGREEMENT AMONG DYNAMICAL MODELS FOR THE OVERALL CIRCULATION
PATTERN DURING THE PERIOD, OFFSET BY WEAKER SIGNALS AND SOME DISAGREEMENT AMONG
PRECIPITATION AND TEMPERATURE 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 MAY
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:
19510403 - 19520403 - 19530403 - 19540403 - 19550403
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:
19510402 - 19520402 - 19530402 - 19540402 - 19550402
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 29 - MAY 03, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B N
SRN CALIF N N IDAHO B A NEVADA A B
W MONTANA B A E MONTANA A A WYOMING A B
UTAH A B ARIZONA A N COLORADO A B
NEW MEXICO A N N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A N MISSISSIPPI A A MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK A N
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A N NEW JERSEY A N W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE B A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 01 - 07 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B A
SRN CALIF B A IDAHO N A NEVADA N A
W MONTANA N A E MONTANA A A WYOMING A N
UTAH A N ARIZONA N N COLORADO A B
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A A
ILLINOIS A N MISSISSIPPI A N MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A B NEW YORK A N
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A B NEW JERSEY A B W VIRGINIA A B
MARYLAND A B DELAWARE A B VIRGINIA A B
N CAROLINA A B S CAROLINA A B GEORGIA A B
FL PNHDL A N FL PENIN A B AK N SLOPE N A
AK ALEUTIAN N A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A 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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