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FXUS06 KWBC 181902
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 18 2023
6-10 DAY OUTLOOK FOR APR 24 - 28 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 ANOMALOUS MID-LEVEL TROUGHING
AND ASSOCIATED NEGATIVE 500-HPA HEIGHT ANOMALIES OVER ALASKA. DOWNSTREAM WEAK
ANOMALOUS RIDGING IS FORECAST OVER THE NORTHEAST PACIFIC AND WEST COAST OF THE
CONTIGUOUS U.S. (CONUS), WHILE AN ANOMALOUS TROUGH IS SITUATED OVER THE
EAST-CENTRAL CONUS DURING THE 6-10 DAY PERIOD IN MODEL SOLUTIONS.
ENHANCED CHANCES FOR BELOW-NORMAL TEMPERATURES ARE FAVORED OVER PARTS OF THE
GREAT PLAINS AND EASTERN HALF OF THE CONUS UNDER THE PREDICTED ANOMALOUS
MID-LEVEL TROUGH AND BELOW-NORMAL 500-HPA HEIGHTS. NEAR- TO ABOVE-NORMAL
TEMPERATURES ARE LIKELY OVER MUCH OF THE WESTERN CONUS, EXCEPT FOR WASHINGTON
AND NORTHERN OREGON, WHERE BELOW-NORMAL TEMPERATURES ARE INDICATED, CONSISTENT
WITH THE GEFS TEMPERATURE CALIBRATED REFORECAST TOOL. BELOW-NORMAL TEMPERATURES
ARE FAVORED FOR ALASKA UNDER BELOW NORMAL 500-HPA HEIGHTS AND NORTHWESTERLY
FLOW ALOFT, SUPPORTED BY MOST OF THE DYNAMICAL TEMPERATURE FORECAST TOOLS.
TROUGHING OVER THE CENTRAL AND EASTERN CONUS FAVORS ABOVE-NORMAL PRECIPITATION
OVER MUCH OF THE SOUTHEASTERN CONUS. ODDS ALSO TILT TOWARDS ABOVE-NORMAL
PRECIPITATION FOR THE CENTRAL CONUS, WHILE BELOW-NORMAL PRECIPITATION IS LIKELY
OVER MUCH OF THE WESTERN CONUS AND THE GREAT LAKES REGION, SUPPORTED BY MOST
PRECIPITATION FORECAST TOOLS. SURFACE LOW PRESSURE OVER THE GULF OF ALASKA IS
PREDICTED BY MODEL GUIDANCE, RESULTING IN ENHANCED PROBABILITIES FOR NEAR- TO
ABOVE-NORMAL PRECIPITATION FOR ALASKA.
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 AVERAGE, 4 OUT OF 5, DUE TO
MODEL AGREEMENT ON AN AMPLIFIED 500-HPA PATTERN ACROSS MUCH OF THE FORECAST
DOMAIN.
8-14 DAY OUTLOOK FOR APR 26 - MAY 02, 2023
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT AN EVOLVING 500-HPA
CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING REGIONS. ANOMALOUS
MID-LEVEL TROUGHING WITH BELOW-NORMAL 500-HPA HEIGHTS IS SITUATED OVER THE
BERING SEA AND ALASKA IN ENSEMBLE MEAN SOLUTIONS FROM THE GEFS, ECMWF AND
CANADIAN MODELS. AN ANOMALOUS 500-HPA TROUGH WITH BELOW NORMAL 500-HPA HEIGHTS
IS PREDICTED OVER THE EASTERN CONUS, WHILE WEAK RIDGING AND SLIGHTLY POSITIVE
500-HPA HEIGHT ANOMALIES ARE FORECAST OVER THE WESTERN CONUS.
GUIDANCE FROM THE DYNAMICAL MODELS, REFORECAST TOOLS, AND OTHER TOOLS INDICATE
ENHANCED CHANCES FOR BELOW-NORMAL TEMPERATURES OVER PARTS OF THE NORTHERN AND
THE CENTRAL ROCKIES, THE GREAT PLAINS, AND MUCH OF THE EASTERN HALF OF THE
CONUS (EXCEPT FOR MAINE, SOUTHERN FLORIDA AND SOUTHERN TEXAS WHERE ABOVE-NORMAL
TEMPERATURES ARE INDICATED) DUE TO A PREDICTED ANOMALOUS TROUGH WITH BELOW
NORMAL 500-HPA HEIGHTS OVER THE REGION. MEANWHILE, ENHANCED PROBABILITIES OF
NEAR- TO ABOVE-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE WESTERN CONUS
UNDER PREDICTED WEAK ANOMALOUS RIDGING. BELOW-NORMAL TEMPERATURES ARE FAVORED
FOR MUCH OF ALASKA UNDER BELOW NORMAL 500-HPA HEIGHTS AND NORTHWESTERLY FLOW
ALOFT, WITH THE EXCEPTION OF THE ALASKA PANHANDLE WHERE NEAR-NORMAL
TEMPERATURES ARE MOST LIKELY UNDER ANOMALOUS SOUTHERLY FLOW.
ANOMALOUS TROUGHING IS FORECAST TO BUILD OVER THE EASTERN CONUS DURING THE 8-14
DAY PERIOD, RESULTING IN A TILT TOWARDS ABOVE-NORMAL PRECIPITATION OVER MOST OF
THE EASTERN CONUS AND THE SOUTHERN PLAINS. ABOVE-NORMAL PRECIPITATION IS
FAVORED OVER PARTS OF CALIFORNIA, WHILE BELOW-NORMAL PRECIPITATION IS LIKELY
OVER THE PACIFIC NORTHWEST, THE NORTHERN GREAT BASIN, THE NORTHERN ROCKIES, THE
UPPER AND MIDDLE MISSISSIPPI VALLEY, AND UPPER GREAT LAKES REGION, CONSISTENT
WITH THE GEFS AND ECMWF PRECIPITATION REFORECAST TOOLS. CONTINUED SURFACE LOW
PRESSURE OVER THE GULF OF ALASKA IS FAVORED BY MODEL GUIDANCE, RESULTING IN
ELEVATED PROBABILITIES FOR NEAR- TO ABOVE-NORMAL PRECIPITATION FOR MUCH OF
ALASKA.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S GFS
SUPERENSEMBLE MEAN CENTERED ON DAY 11, 30% 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
MODEL AGREEMENT ON AN AMPLIFIED 500-HPA PATTERN ACROSS MUCH OF THE FORECAST
DOMAIN.
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
APRIL 20.
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:
19620430 - 19520401 - 19610418 - 19860415 - 19550413
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:
19620501 - 19520331 - 19610418 - 19790412 - 19550412
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR APR 24 - 28 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B B OREGON N B NRN CALIF A B
SRN CALIF A B IDAHO N B NEVADA A B
W MONTANA N N E MONTANA B A WYOMING B A
UTAH N B ARIZONA A B COLORADO N A
NEW MEXICO A N N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS N A W TEXAS N N
MINNESOTA B N IOWA B N MISSOURI B A
ARKANSAS B A LOUISIANA B A WISCONSIN B N
ILLINOIS B N MISSISSIPPI B A MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B A
TENNESSEE B A ALABAMA B A NEW YORK B N
VERMONT B N NEW HAMP N N MAINE N N
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B A
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN B A AK N SLOPE B N
AK ALEUTIAN B A AK WESTERN B N AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR APR 26 - MAY 02, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF N N IDAHO A N NEVADA A N
W MONTANA B N E MONTANA B N WYOMING B N
UTAH A N ARIZONA A N COLORADO B N
NEW MEXICO N N N DAKOTA B N S DAKOTA B N
NEBRASKA B N KANSAS B N OKLAHOMA B N
N TEXAS B A S TEXAS N A W TEXAS N N
MINNESOTA B N IOWA B N MISSOURI B N
ARKANSAS B N LOUISIANA B A WISCONSIN B N
ILLINOIS B N MISSISSIPPI B A MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B A ALABAMA B A NEW YORK N A
VERMONT N N NEW HAMP N N MAINE N N
MASS N N CONN N A RHODE IS N N
PENN B A NEW JERSEY B A W VIRGINIA B A
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN N A AK N SLOPE B A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B 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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