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FXUS06 KWBC 311907
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI MAY 31 2024
6-10 DAY OUTLOOK FOR JUN 06 - 10 2024
WHILE TODAY'S MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON AN AMPLIFIED 500-HPA
CIRCULATION PATTERN ACROSS NORTH AMERICA DURING THE 6-10 DAY PERIOD, ENSEMBLE
MEANS FROM THE GEFS AND ECMWF ARE SHOWING SOME DIFFERENCES IN THE EVOLUTION OF
THE PATTERN AND RESULTING SURFACE TEMPERATURE AND PRECIPITATION FORECASTS. THE
MANUAL 500-HPA HEIGHT BLEND IS BASED ON THE 0Z ENSEMBLE MEANS FROM THE GEFS,
ECMWF, AND CANADIAN ENSEMBLE MODELS. AT THE START OF THE PERIOD A TROUGH IS
PREDICTED TO THE WEST OF MAINLAND ALASKA THAT EXTENDS SOUTHWARD ACROSS THE
ALEUTIANS INTO THE NORTH PACIFIC BY BOTH THE GEFS AND ECMWF ENSEMBLE MEANS.
DURING THE PERIOD, THE CENTER OF NEGATIVE 500-HPA HEIGHT ANOMALIES IN THE GEFS
MOVES SOUTHEASTWARD INTO THE NORTH PACIFIC, AS MID-LEVEL HEIGHTS RISE OVER
MAINLAND ALASKA IN BOTH MODELS. THE MANUAL BLEND PREDICTS A TROUGH AND NEGATIVE
500-HPA HEIGHT ANOMALIES OVER THE ALEUTIANS AND NORTH PACIFIC. A RIDGE AND
POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER THE WESTERN CONTIGUOUS
U.S. (CONUS) IN THE MANUAL BLEND. ENSEMBLE MEAN FORECASTS FROM THE GEFS AND
ECMWF MODELS BOTH PREDICT THE AMPLIFICATION OF A TROUGH AND NEGATIVE 500-HPA
HEIGHT ANOMALIES OVER THE EASTERN CONUS DURING THE 6-10 DAY PERIOD, WHILE THE
TROUGH AXIS IN THE ECMWF ENSEMBLE MEAN IS SLIGHTLY WEST OF THE TROUGH AXIS IN
THE GEFS ENSEMBLE MEAN. NEGATIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER
THE ENTIRE EASTERN CONUS IN THE 6-10 DAY MEAN MANUAL BLEND, WITH THE EXCEPTION
OF NORTHERN MAINE.
ENHANCED CHANCES FOR ABOVE-NORMAL TEMPERATURES ARE PREDICTED OVER THE WESTERN
CONUS DUE TO THE PREDICTED MID-LEVEL RIDGE AND POSITIVE 500-HPA HEIGHT
ANOMALIES, AND SUPPORTED BY MOST DYNAMICAL MODEL TEMPERATURE FORECAST TOOLS.
PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES EXCEED 70 PERCENT AND IN SOME AREAS
80 PERCENT FOR MUCH OF THE GREAT BASIN AND CENTRAL ROCKIES. ABOVE-NORMAL
TEMPERATURES ARE ALSO FAVORED FOR THE GULF AND SOUTHERN ATLANTIC COASTS AND
SLIGHTLY FAVORED FOR PARTS OF THE NORTHEAST, SUPPORTED BY THE TEMPERATURE
CONSOLIDATION. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR MOST REMAINING AREAS
OF THE EASTERN CONUS, UNDER THE PREDICTED TROUGH. PROBABILITIES FOR
BELOW-NORMAL TEMPERATURES ARE ENHANCED OVER SOUTHERN ALASKA, INCLUDING THE
ALEUTIANS AND SOUTHEAST ALASKA, UNDER THE PREDICTED TROUGH AND ENHANCED
PRECIPITATION, WHILE ABOVE-NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR
NORTHERN MAINLAND ALASKA, AS A RIDGE PUSHES INTO THE REGION LATER IN THE
PERIOD. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR HAWAII, WHERE TEMPERATURE
FORECAST TOOLS ARE IN DISAGREEMENT.
NEAR- TO ABOVE-NORMAL PRECIPITATION IS FAVORED FOR MOST OF MAINLAND ALASKA AND
NORTHERN AREAS OF SOUTHEAST ALASKA, WITH SOUTHERLY FLOW AHEAD OF A PREDICTED
TROUGH OVER THE NORTH PACIFIC. A PREDICTED ANOMALOUS MID-LEVEL RIDGE FAVORS
BELOW-NORMAL PRECIPITATION FROM MUCH OF THE PACIFIC NORTHWEST ACROSS THE
NORTHERN PLAINS INTO PARTS OF THE UPPER MISSISSIPPI VALLEY. ABOVE-NORMAL
PRECIPITATION IS SLIGHTLY FAVORED FROM EASTERN NEW MEXICO AND CENTRAL TEXAS
INTO PARTS OF THE SOUTHERN PLAINS, CONSISTENT WITH MOST DYNAMICAL MODEL
PRECIPITATION FORECASTS. MEDIAN PRECIPITATION ACCUMULATION PREDICTIONS BY THE
CONSOLIDATION TOOL ARE AS LITTLE AS ONE OR TWO MILLIMETERS DURING THE 6-10 DAY
PERIOD IN SEMI-ARID REGIONS OF THE SOUTHWEST. HOWEVER, ANY PRECIPITATION IN
ARID REGIONS WOULD BE CONSIDERED ABOVE-NORMAL. ABOVE-NORMAL PRECIPITATION IS
ALSO FAVORED FOR THE NORTHEASTERN CONUS, CONSISTENT WITH THE CONSOLIDATION.
NEAR-NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHEAST, WHERE DYNAMICAL MODEL
PRECIPITATION FORECASTS ARE INCONSISTENT. PROBABILITIES OF BELOW-NORMAL
PRECIPITATION ARE ENHANCED ACROSS HAWAII, CONSISTENT WITH THE CONSOLIDATION
PRECIPITATION FORECAST TOOL.
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, DUE TO
GOOD AGREEMENT AMONG MODEL SOLUTIONS ON THE MEAN CIRCULATION PATTERN, OFFSET BY
AN EVOLVING PATTERN AND SOME DIFFERENCES AMONG FORECAST TEMPERATURE AND
PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR JUN 08 - 14 2024
WHILE GEFS AND ECMWF ENSEMBLE MEANS FOR THE 8-14 DAY PERIOD 500-HPA HEIGHT
FORECAST ARE CONSISTENT WITH THE OVERALL MID-LEVEL CIRCULATION PATTERN ACROSS
NORTH AMERICA AND WITH THE 6-10 DAY PERIOD FORECAST, LARGER DIFFERENCES BETWEEN
MODELS ARE APPARENT IN WEEK 2, AS UNCERTAINTY INCREASES. LARGER POSITIVE
500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER MAINLAND ALASKA DURING THE 8-14 DAY
PERIOD BY THE ECMWF FORECAST, WITH THE CENTER OF NEGATIVE 500-HPA HEIGHT
ANOMALIES SHIFTING SOUTHWARD INTO THE NORTH PACIFIC. A MORE AMPLIFIED RIDGE AND
ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES IS PREDICTED OVER THE WESTERN HALF
OF THE CONUS IN THE ECMWF ENSEMBLE MEAN THAN IN THE GEFS ENSEMBLE MEAN, WHILE
AN AMPLIFIED TROUGH AND NEGATIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER
THE EASTERN CONUS DURING WEEK 2 BY BOTH THE ECMWF AND GEFS.
BELOW-NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR THE SOUTHWESTERN COAST OF
MAINLAND ALASKA AND THE ALEUTIANS, ASSOCIATED WITH THE PREDICTED TROUGH OVER
THE REGION, WHILE NEAR-NORMAL IS FAVORED FOR MOST OF SOUTHERN MAINLAND ALASKA.
ABOVE NORMAL TEMPERATURES ARE SLIGHTLY FAVORED FOR NORTHERN MAINLAND ALASKA,
CONSISTENT WITH MOST TEMPERATURE TOOLS INCLUDING THE CONSOLIDATION. A PREDICTED
RIDGE OVER THE WESTERN CONUS AND POSITIVE 500-HPA HEIGHT ANOMALIES FAVOR
ABOVE-NORMAL TEMPERATURES, WITH PROBABILITIES EXCEEDING 70 PERCENT OVER PARTS
OF THE NORTHWEST. BELOW-NORMAL TEMPERATURES ARE FAVORED OVER MOST OF THE
EASTERN CONUS, UNDER A PREDICTED TROUGH DURING THE PERIOD. ABOVE-NORMAL
TEMPERATURES CONTINUE TO BE LIKELY FOR MUCH OF THE GULF COAST AND SOUTHERN
ATLANTIC COAST, CONSISTENT WITH DYNAMICAL MODEL FORECAST TOOLS. NEAR-NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED FOR NEW ENGLAND, WHERE TEMPERATURE FORECAST
TOOLS ARE INCONSISTENT. NEAR-NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR
HAWAII, WHERE TEMPERATURE FORECAST TOOLS ARE IN DISAGREEMENT.
ABOVE-NORMAL PRECIPITATION CONTINUES TO BE VERY SLIGHTLY FAVORED FOR INTERIOR
MAINLAND ALASKA AND SOUTHERN ALASKA, CONSISTENT WITH MOST DYNAMICAL MODEL
FORECAST TOOLS, AND UNDER SOUTHERLY FLOW. BELOW-NORMAL PRECIPITATION IS
SLIGHTLY FAVORED FOR WESTERN WASHINGTON AND THE NORTHERN TIER OF THE CONUS FROM
MONTANA TO THE UPPER MISSISSIPPI VALLEY, UNDER A PREDICTED RIDGE. ABOVE NORMAL
PRECIPITATION CONTINUES TO BE SLIGHTLY FAVORED FROM NORTHEASTERN NEW MEXICO AND
MUCH OF TEXAS INTO PARTS OF THE CENTRAL PLAINS, CONSISTENT WITH MOST DYNAMICAL
MODEL PRECIPITATION FORECASTS. ABOVE-NORMAL PRECIPITATION IS FAVORED FOR MUCH
OF THE NORTHEASTERN CONUS, AHEAD OF A PREDICTED TROUGH. ABOVE-NORMAL
PRECIPITATION IS FAVORED FOR THE FLORIDA PENINSULA, CONSISTENT WITH MOST
PRECIPITATION TOOLS. NEAR-NORMAL PRECIPITATION IS FAVORED ACROSS REMAINING
AREAS OF THE CONUS, WHERE THERE IS GREATER UNCERTAINTY AND PRECIPITATION TOOLS
ARE INCONSISTENT. NEAR-NORMAL PRECIPITATION IS FAVORED ACROSS HAWAII, AS
PRECIPITATION TOOLS ARE INCONSISTENT.
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: BELOW AVERAGE, 2 OUT OF 5, DUE TO
GENERAL CONSISTENCY IN THE FORECAST PATTERN AMONG ENSEMBLE MEAN MODEL
FORECASTS, OFFSET BY INCREASING DIFFERENCES AMONG MODELS AND ESPECIALLY
PRECIPITATION FORECAST 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 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:
19660514 - 20030515 - 20040530 - 20010601 - 19890518
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:
20030514 - 20040531 - 19660515 - 20010601 - 19840530
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 06 - 10 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A N
UTAH A N ARIZONA A N COLORADO A A
NEW MEXICO A N N DAKOTA A B S DAKOTA B B
NEBRASKA B N KANSAS B A OKLAHOMA B A
N TEXAS A A S TEXAS A N W TEXAS A A
MINNESOTA B B IOWA B B MISSOURI B N
ARKANSAS B N LOUISIANA A N WISCONSIN B B
ILLINOIS B N MISSISSIPPI B N MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B N ALABAMA B N NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS N A CONN N A RHODE IS N A
PENN B A NEW JERSEY N A W VIRGINIA B A
MARYLAND N A DELAWARE N A VIRGINIA B A
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN A A
AK S INT B A AK SO COAST B A AK PNHDL B N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUN 08 - 14 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A N
UTAH A N ARIZONA A N COLORADO A A
NEW MEXICO A N N DAKOTA B B S DAKOTA B B
NEBRASKA B N KANSAS B A OKLAHOMA B A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B B IOWA B N MISSOURI B N
ARKANSAS B A LOUISIANA A N WISCONSIN B N
ILLINOIS B N MISSISSIPPI B N MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE B N ALABAMA B N NEW YORK B A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN N A RHODE IS N A
PENN B N NEW JERSEY B A W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA N N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE A N
AK ALEUTIAN B N AK WESTERN A N AK INT BSN A N
AK S INT N A AK SO COAST N A AK PNHDL N 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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