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FXUS06 KWBC 241902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED MAY 24 2023
6-10 DAY OUTLOOK FOR MAY 30 - JUN 03, 2023
DYNAMICAL MODEL ENSEMBLE MEAN FORECASTS ARE IN GOOD AGREEMENT ON THE PREDICTED
500-HPA CIRCULATION PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY PERIOD.
GEFS, ECMWF AND CANADIAN ENSEMBLE MEAN SOLUTIONS PREDICT AN AMPLIFIED RIDGE AND
ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE ALEUTIAN ISLANDS DURING
THE 6-10 DAY PERIOD, WITH A DOWNSTREAM TROUGH OVER THE GULF OF ALASKA. NEGATIVE
500-HPA HEIGHT ANOMALIES OVER THE GULF OF ALASKA HAVE WEAKENED IN TODAY’S MODEL
FORECASTS, RELATIVE TO YESTERDAY’S, AS THE TROUGH DE-AMPLIFIES DURING THE
PERIOD. A TROUGH AND ASSOCIATED NEGATIVE 500-HPA HEIGHT ANOMALIES CONTINUES TO
BE PREDICTED OVER SOUTHERN CALIFORNIA. AN AMPLIFIED RIDGE IS PREDICTED TO
PERSIST OVER CANADA, AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES EXTEND
ACROSS THE NORTHERN CONUS IN MODEL SOLUTIONS. ALL ENSEMBLE MEANS PREDICT A
SHORTWAVE TROUGH OVER THE SOUTHEAST DURING THE 6-10 DAY PERIOD. THE LARGE-SCALE
CIRCULATION FEATURES OVER THE CONUS ARE MORE AMPLIFIED IN TODAY’S 500-HPA
HEIGHT FORECASTS, RELATIVE TO YESTERDAY’S FORECASTS.
BELOW NORMAL TEMPERATURES ARE FAVORED FOR MOST OF ALASKA DURING THE 6-10 DAY
PERIOD, UNDER NORTHERLY FLOW, WHILE NEAR TO ABOVE NORMAL TEMPERATURES ARE
FAVORED FOR NORTHERN ALASKA, CONSISTENT WITH THE CONSOLIDATION OF CALIBRATED
DYNAMICAL MODEL TEMPERATURE FORECASTS. ABOVE NORMAL TEMPERATURES ARE VERY
LIKELY ACROSS THE NORTHERN CONUS, UNDER THE PREDICTED AMPLIFIED RIDGE AND
POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURES ARE FAVORED FROM
SOUTHERN CALIFORNIA EASTWARD THROUGH MUCH OF THE SOUTHWEST INTO THE SOUTHERN
PLAINS, AHEAD OF THE PREDICTED TROUGH AND SUPPORTED BY MOST DYNAMICAL MODEL
TEMPERATURE TOOLS. NEAR TO BELOW NORMAL TEMPERATURES ARE ALSO FAVORED FOR PARTS
OF THE SOUTHEAST ATLANTIC COAST, UNDER A PREDICTED SHORTWAVE TROUGH.
ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED ACROSS MOST OF MAINLAND ALASKA,
WHILE NEAR TO BELOW NORMAL PRECIPITATION IS FAVORED FOR SOUTHWESTERN MAINLAND
ALASKA AND SOUTHEAST ALASKA, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION OF
CALIBRATED MODEL PRECIPITATION FORECASTS. WIDESPREAD ABOVE NORMAL PRECIPITATION
IS FAVORED FOR THE INTERIOR WEST ACROSS THE ROCKY MOUNTAINS INTO MUCH OF THE
GREAT PLAINS, AHEAD OF THE PREDICTED TROUGH, WITH HIGH PROBABILITIES EXCEEDING
60 PERCENT FOR PARTS OF THE GREAT BASIN. DUE TO UNCERTAINTY IN DYNAMICAL MODEL
FORECASTS, NEAR NORMAL PRECIPITATION IS FAVORED FOR SOUTHERN CALIFORNIA AND
PARTS OF THE DESERT SOUTHWEST, WHERE ANY POTENTIAL PRECIPITATION WOULD BE NEAR
ZERO ACCUMULATION, DESPITE DYNAMICAL MODEL PRECIPITATION TOOLS THAT PRIMARILY
FAVOR ABOVE NORMAL PRECIPITATION IN THIS AREA. BELOW NORMAL PRECIPITATION IS
FAVORED FOR THE MIDWEST AND THE NORTHEAST, UNDER AND AHEAD OF THE PREDICTED
RIDGE. ABOVE NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE CENTRAL GULF
COAST REGION, CONSISTENT WITH THE PRECIPITATION CONSOLIDATION OF MODEL
PRECIPITATION FORECASTS. BELOW NORMAL PRECIPITATION IS FAVORED FOR A SMALL AREA
OF THE WASHINGTON AND OREGON COASTS, SUPPORTED BY DYNAMICAL MODEL PRECIPITATION
TOOLS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% 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: ABOVE AVERAGE, 4 ON A SCALE OF
1-5, DUE TO GENERAL AGREEMENT BETWEEN MODEL ENSEMBLE MEANS ON THE LARGE-SCALE
CIRCULATION PATTERN, OFFSET BY SMALL DIFFERENCES AMONG MODEL TEMPERATURE AND
PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR JUN 01 - 07 2023
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A SIMILAR LARGE-SCALE
CIRCULATION PATTERN TO THE 6-10 DAY PERIOD FORECASTS, WITH SOME EVOLUTION OF
THE PATTERN. AN AMPLIFIED RIDGE AND ASSOCIATED POSITIVE 500-HPA HEIGHT
ANOMALIES OVER THE ALEUTIANS ALONG WITH DOWNSTREAM TROUGHING OVER THE GULF OF
ALASKA DE-AMPLIFY DURING THE WEEK 2 PERIOD. A TROUGH IS PREDICTED TO EXTEND
SOUTHWARD DOWN THE PACIFIC COAST INTO SOUTHERN CALIFORNIA IN WEEK 2. A RIDGE
AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES PERSIST OVER THE NORTHERN
CONUS IN WEEK 2, WITH SOME AMPLIFICATION AND RETROGRESSION. A WEAK SHORTWAVE
TROUGH PERSISTS INTO WEEK 2 OVER THE SOUTHEAST, BUT DE-AMPLIFIES LATER IN THE
PERIOD AS A TROUGH DEVELOPS OVER THE NORTHEAST IN MODEL SOLUTIONS.
BELOW NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR MUCH OF ALASKA UNDER
PRIMARILY NORTHERLY FLOW IN WEEK 2, WHILE ABOVE NORMAL TEMPERATURES ARE FAVORED
FOR THE NORTH SLOPE, CONSISTENT WITH THE TEMPERATURE CONSOLIDATION OF
CALIBRATED MODEL FORECASTS. ENHANCED PROBABILITIES FOR ABOVE NORMAL
TEMPERATURES CONTINUE ACROSS THE NORTHERN CONUS IN WEEK 2, WITH SLIGHTLY WEAKER
PROBABILITIES FOR THE MIDWEST AND NORTHEAST, AS A TROUGH DEVELOPS LATE IN THE
PERIOD. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED SOUTHWARD THROUGH THE
MISSISSIPPI AND TENNESSEE VALLEYS TO THE GULF COAST INCLUDING FLORIDA,
SUPPORTED BY THE TEMPERATURE CONSOLIDATION. ENHANCED PROBABILITIES FOR BELOW
NORMAL TEMPERATURES PERSIST FROM CENTRAL AND SOUTHERN CALIFORNIA EASTWARD
ACROSS THE SOUTHWEST INTO THE SOUTHERN PLAINS IN WEEK 2, SUPPORTED BY DYNAMICAL
MODEL TEMPERATURE TOOLS.
ABOVE NORMAL PRECIPITATION CONTINUES TO BE SLIGHTLY FAVORED FOR MUCH OF ALASKA
IN WEEK 2, SUPPORTED BY DYNAMICAL MODEL PRECIPITATION TOOLS. NEAR TO BELOW
NORMAL PRECIPITATION IS FAVORED FOR SOUTHEAST ALASKA, AS THE PREDICTED TROUGH
OVER THE GULF OF ALASKA DE-AMPLIFIES AND MID-LEVEL HEIGHTS ARE PREDICTED TO
RISE. ABOVE NORMAL PRECIPITATION CONTINUES TO BE LIKELY OVER A LARGE AREA OF
THE INTERIOR WEST EXTENDING INTO THE SOUTHERN PLAINS, AHEAD OF A TROUGH.
PROBABILITIES OF ABOVE NORMAL PRECIPITATION ARE SLIGHTLY ENHANCED FOR THE
SOUTHEAST, CONSISTENT WITH THE CONSOLIDATION OF CALIBRATED MODEL PRECIPITATION
FORECASTS. BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE MIDWEST AND
PARTS OF THE NORTHEAST, UNDER THE PREDICTED RIDGE.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% 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: ABOUT AVERAGE, 3 ON A SCALE OF
1-5, DUE TO GENERAL AGREEMENT ON THE MEAN LARGE-SCALE CIRCULATION PATTERN,
OFFSET BY INCREASING UNCERTAINTY AMONG MODEL 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
JUNE 15.
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:
19780519 - 19910518 - 19890602 - 20020607 - 19810511
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:
19910518 - 19890605 - 19780519 - 20080526 - 20070523
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 30 - JUN 03, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A A NRN CALIF N A
SRN CALIF B N IDAHO A A NEVADA A A
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A A ARIZONA B N COLORADO A A
NEW MEXICO B A N DAKOTA A N S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA N A
N TEXAS N A S TEXAS B A W TEXAS B A
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A A LOUISIANA A A WISCONSIN A B
ILLINOIS A B MISSISSIPPI A A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE A N ALABAMA A A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA N N S CAROLINA N N GEORGIA N N
FL PNHDL N N FL PENIN N N AK N SLOPE N A
AK ALEUTIAN B N AK WESTERN B N AK INT BSN B A
AK S INT B A AK SO COAST B B AK PNHDL B N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 01 - 07 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF B A
SRN CALIF B N IDAHO A A NEVADA N A
W MONTANA A A E MONTANA A A WYOMING A A
UTAH N A ARIZONA B N COLORADO N A
NEW MEXICO B A N DAKOTA A N S DAKOTA A N
NEBRASKA A A KANSAS N A OKLAHOMA N A
N TEXAS B A S TEXAS N A W TEXAS B A
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS A A LOUISIANA A A WISCONSIN A B
ILLINOIS A N MISSISSIPPI A A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE A N ALABAMA A A NEW YORK A B
VERMONT A B 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 N N VIRGINIA A N
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL A A FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A
AK S INT B A AK SO COAST B N AK PNHDL N B
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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