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FXUS06 KWBC 231904
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE MAY 23 2023
6-10 DAY OUTLOOK FOR MAY 29 - JUN 02, 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 AND NEGATIVE 500-HPA HEIGHT
ANOMALIES OVER THE GULF OF ALASKA. A TROUGH AND ASSOCIATED NEGATIVE 500-HPA
HEIGHT ANOMALIES ARE PREDICTED NEAR SOUTHERN CALIFORNIA. AN AMPLIFIED RIDGE IS
PREDICTED 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.
BELOW NORMAL TEMPERATURES ARE LIKELY 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 MOST DYNAMICAL MODEL TEMPERATURE
TOOLS. ABOVE NORMAL TEMPERATURES ARE LIKELY ACROSS THE NORTHERN CONUS, UNDER
THE PREDICTED RIDGE AND POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL
TEMPERATURES ARE FAVORED FROM SOUTHERN CALIFORNIA EASTWARD ALONG THE
MEXICO-U.S. BORDER INTO THE SOUTHERN PLAINS, AHEAD OF THE PREDICTED TROUGH AND
SUPPORTED BY MOST DYNAMICAL MODEL TEMPERATURE TOOLS. BELOW NORMAL TEMPERATURES
ARE ALSO FAVORED FOR PARTS OF THE SOUTHEAST, UNDER A PREDICTED TROUGH.
NEAR TO ABOVE NORMAL PRECIPITATION IS FAVORED FOR ALASKA, CONSISTENT WITH THE
PRECIPITATION CONSOLIDATION OF CALIBRATED MODEL PRECIPITATION FORECASTS, WITH
SLIGHTLY GREATER PROBABILITIES FOR THE EASTERN INTERIOR OF THE STATE.
WIDESPREAD ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE INTERIOR WEST ACROSS
THE ROCKY MOUNTAINS INTO THE CENTRAL AND SOUTHERN PLAINS, AHEAD OF THE
PREDICTED TROUGH. DUE TO UNCERTAINTY IN DYNAMICAL MODEL FORECASTS, NEAR NORMAL
PRECIPITATION IS FAVORED FOR SOUTHERN CALIFORNIA AND ALONG THE CALIFORNIA
COAST, WHERE ANY POTENTIAL PRECIPITATION WOULD BE VERY LIGHT, DESPITE DYNAMICAL
MODEL PRECIPITATION TOOLS THAT PRIMARILY FAVOR ABOVE NORMAL PRECIPITATION IN
THIS AREA. BELOW NORMAL PRECIPITATION IS FAVORED FOR THE MIDWEST AND NORTHERN
AREAS OF THE NORTHEAST, UNDER AND AHEAD OF THE PREDICTED RIDGE. ABOVE NORMAL
PRECIPITATION IS SLIGHTLY FAVORED FOR PARTS OF THE SOUTHEAST AND SOUTHERN
ATLANTIC COAST, AHEAD OF A PREDICTED SHORTWAVE TROUGH. BELOW NORMAL
PRECIPITATION IS FAVORED FOR 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 MAY 31 - JUN 06, 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 CONTINUE BUT ARE PREDICTED TO DE-AMPLIFY IN 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, ALONG WITH A WEAK TROUGH OVER THE
SOUTHEAST.
BELOW NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR MUCH OF ALASKA UNDER
NORTHERLY FLOW IN WEEK 2, WHILE ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE
NORTH SLOPE, CONSISTENT WITH THE TEMPERATURE CONSOLIDATION OF CALIBRATED MODEL
FORECASTS. ABOVE NORMAL TEMPERATURES CONTINUE TO BE LIKELY ACROSS THE NORTHERN
CONUS. ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED SOUTHWARD THROUGH THE
TENNESSEE VALLEY TO THE GULF COAST AND FOR THE FLORIDA PENINSULA, SUPPORTED BY
THE TEMPERATURE CONSOLIDATION. ENHANCED PROBABILITIES FOR BELOW NORMAL
TEMPERATURES PERSIST FROM SOUTHERN CALIFORNIA EASTWARD ALONG THE MEXICO-U.S.
BORDER, WITH INCREASING PROBABILITIES OVER 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. 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. NEAR
NORMAL PRECIPITATION IS FAVORED FOR NORTHWESTERN AND SOUTHERN ALASKA WITH
INCREASING UNCERTAINTY. BELOW NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR
THE WASHINGTON AND OREGON COASTS, SUPPORTED BY DYNAMICAL MODEL PRECIPITATION
TOOLS. ABOVE NORMAL PRECIPITATION CONTINUES TO BE FAVORED OVER A LARGE AREA OF
THE INTERIOR WEST AHEAD OF A TROUGH, SUPPORTED BY DYNAMICAL MODEL PRECIPITATION
TOOLS. PROBABILITIES OF ABOVE NORMAL PRECIPITATION ARE SLIGHTLY ENHANCED FOR
THE SOUTHERN PLAINS INTO THE SOUTHEAST, CONSISTENT WITH THE CONSOLIDATION OF
CALIBRATED MODEL PRECIPITATION FORECASTS. BELOW NORMAL PRECIPITATION IS
SLIGHTLY FAVORED FOR THE MIDWEST AND NORTHERN AREAS OF THE NORTHEAST, UNDER THE
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:
19810511 - 19780519 - 19890602 - 19510510 - 19810527
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:
19900506 - 19810511 - 20070520 - 19510512 - 19780519
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 29 - JUN 02, 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 N
NEBRASKA A A KANSAS A A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS N A LOUISIANA B A WISCONSIN A B
ILLINOIS A B MISSISSIPPI N A MICHIGAN A B
INDIANA A B OHIO A B KENTUCKY A N
TENNESSEE N N ALABAMA B A NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B 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 N N
N CAROLINA N N S CAROLINA B N GEORGIA B A
FL PNHDL B A FL PENIN A A 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 N AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR MAY 31 - JUN 06, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A 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 B A
NEW MEXICO B A N DAKOTA A N S DAKOTA A N
NEBRASKA A A KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS N A LOUISIANA N 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 N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A B NEW JERSEY A N W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA N A S CAROLINA N A GEORGIA N A
FL PNHDL N A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN B N AK WESTERN B N AK INT BSN B A
AK S INT B N 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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