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FXUS06 KWBC 251914
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU JULY 25 2024
6-10 DAY OUTLOOK FOR JUL 31 - AUG 04, 2024
THERE IS GOOD AGREEMENT ON THE 500-HPA HEIGHT FORECAST ACROSS NORTH AMERICA
BETWEEN THE 0Z ENSEMBLE MEAN SOLUTIONS OF THE ECMWF, GEFS AND CANADIAN MODELS.
MODEL SOLUTIONS PREDICT CYCLONIC FLOW OVER MOST OF ALASKA AHEAD OF A TROUGH
CENTERED TO THE WEST OF THE STATE. NEGATIVE 500-HPA HEIGHT ANOMALIES ARE
FORECAST OVER MAINLAND ALASKA AND POSITIVE ANOMALIES ARE PREDICTED OVER AND
SOUTH OF THE ALEUTIANS. A SHORTWAVE TROUGH AND NEGATIVE 500-HPA HEIGHT
ANOMALIES ARE PREDICTED TO EXTEND SOUTHWARD INTO THE NORTH PACIFIC TO THE WEST
OF NORTH AMERICA. A RIDGE AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES
COVER MOST OF THE CONUS, WITH A WEAKNESS IN POSITIVE 500-HPA HEIGHT ANOMALIES
OVER THE SOUTHEAST. WEAK POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER
HAWAII BY THE ECMWF ENSEMBLE MEAN, WHILE NEAR AVERAGE 500-HPA HEIGHTS ARE
PREDICTED OVER HAWAII BY THE GEFS.
BELOW-NORMAL TEMPERATURES ARE LIKELY OVER MOST OF ALASKA, INCLUDING THE EASTERN
ALEUTIANS, MAINLAND ALASKA, AND SOUTHEAST ALASKA, UNDER MOSTLY NORTHWESTERLY
FLOW OR NEGATIVE 500-HPA HEIGHT ANOMALIES. NEAR-NORMAL TEMPERATURES ARE FAVORED
FOR NORTHWESTERN WASHINGTON AND THE CENTRAL CALIFORNIA COAST, AHEAD OF A WEAK
TROUGH AND UNDER NORTHERLY SURFACE FLOW. NEAR-NORMAL TEMPERATURES ARE FAVORED
FOR SOUTHERN TEXAS, CONSISTENT WITH THE CONSOLIDATION OF GEFS AND ECMWF
REFORECAST-CALIBRATED TEMPERATURE FORECASTS. ABOVE-NORMAL TEMPERATURES ARE
LIKELY ACROSS THE REMAINDER OF THE CONUS, AS POSITIVE 500-HPA HEIGHT ANOMALIES
SPREAD WESTWARD OVER THE ENTIRE CONUS DURING THE PERIOD. NEAR-NORMAL
TEMPERATURES ARE FAVORED FOR HAWAII, UNDER WEAK MID-LEVEL HEIGHT ANOMALIES.
ABOVE-NORMAL PRECIPITATION IS FAVORED ACROSS ALASKA, UNDER ENHANCED ONSHORE
FLOW OR CYCLONIC FLOW AHEAD OF A TROUGH. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY
FAVORED FOR PARTS OF THE PACIFIC NORTHWEST, AHEAD OF TROUGHING DURING THE
PERIOD. BELOW-NORMAL PRECIPITATION IS FAVORED OVER A LARGE AREA OF THE WESTERN
AND CENTRAL CONUS, CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS. ABOVE-NORMAL
PRECIPITATION IS FAVORED OVER MUCH OF THE EASTERN CONUS, CONSISTENT WITH MOST
DYNAMICAL MODEL PRECIPITATION TOOLS. BELOW-NORMAL PRECIPITATION IS FAVORED FOR
THE NORTHWESTERN ISLANDS OF HAWAII, AS PREDICTED BY THE AUTO PRECIPITATION
FORECAST TOOL AND CONSISTENT WITH THE CONSOLIDATION.
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 OUT OF 5, DUE TO
GOOD GENERAL AGREEMENT AMONG THE DYNAMICAL MODEL HEIGHT FORECASTS AND TOOLS AND
DAY-TO-DAY RUN CONSISTENCY, OFFSET BY DIFFERENCES IN TEMPERATURE AND
PRECIPITATION TOOLS FOR SOME AREAS, SUCH AS THE WEST COAST OF THE CONUS AND THE
SOUTHEAST.
8-14 DAY OUTLOOK FOR AUG 02 - 08 2024
THE WEEK-2 MANUAL BLEND AND THE ECMWF, GEFS AND CANADIAN ENSEMBLE MEAN
FORECASTS PREDICT POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE ALEUTIAN ISLANDS
AND ACROSS THE ENTIRE CONUS, WITH NEGATIVE 500-HPA HEIGHT ANOMALIES PREDICTED
OVER MAINLAND AND SOUTHEAST ALASKA. TROUGHS CONTINUE TO BE PREDICTED TO THE
WEST AND SOUTH OF ALASKA, WHILE A RIDGE IS PREDICTED OVER MOST OF THE CONUS BY
EACH ENSEMBLE MEAN.
ABOVE-NORMAL TEMPERATURES ARE PREDICTED ACROSS MOST OF THE CONUS, UNDER A RIDGE
AND CONSISTENT WITH MOST DYNAMICAL MODEL TEMPERATURE TOOLS.
NEAR-TO-BELOW-NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF SOUTH TEXAS AND THE
WESTERN GULF COAST STATES, CONSISTENT WITH THE TEMPERATURE CONSOLIDATION.
BELOW-NORMAL TEMPERATURES ARE FAVORED FOR THE EASTERN ALEUTIANS, MAINLAND
ALASKA, AND SOUTHEAST ALASKA, UNDER PREDICTED NEGATIVE 500-HPA HEIGHT ANOMALIES
IN THE MANUAL BLEND AND MOST DYNAMICAL MODEL FORECASTS. ABOVE-NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED FOR HAWAII, UNDER WEAK POSITIVE 500-HPA
HEIGHT ANOMALIES.
ABOVE-NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR THE EASTERN ALEUTIANS,
MAINLAND ALASKA, AND SOUTHEAST ALASKA, UNDER ENHANCED ONSHORE AND CYCLONIC
FLOW. NEAR-NORMAL PRECIPITATION IS FAVORED FOR MOST OF THE WEST FROM THE
PACIFIC COAST TO THE ROCKY MOUNTAINS, WHERE PRECIPITATION TOOLS ARE SOMEWHAT
INCONSISTENT. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR PARTS OF
SOUTHERN CALIFORNIA, SOUTHERN NEVADA, AND WESTERN ARIZONA, WITH A POSSIBLE
SURGE OF MOISTURE FROM DEVELOPMENT OF A TROPICAL SYSTEM IN THE EASTERN PACIFIC.
BELOW-NORMAL PRECIPITATION IS LIKELY FOR MOST OF THE CENTRAL CONUS IN WEEK-2,
UNDER THE PREDICTED PERSISTENT RIDGE. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY
FAVORED OVER MOST OF THE GULF COAST REGION AND EASTERN CONUS, CONSISTENT WITH
MOST PRECIPITATION TOOLS AND THE CONSOLIDATION. NEAR-NORMAL PRECIPITATION IS
FAVORED ACROSS HAWAII, WHERE PRECIPITATION TOOLS ARE INCONSISTENT.
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 OUT OF 5, DUE TO
GOOD GENERAL AGREEMENT AMONG THE DYNAMICAL MODEL HEIGHT FORECASTS AND TOOLS,
OFFSET BY DIFFERENCES IN TEMPERATURE AND PRECIPITATION TOOLS FOR SOME AREAS, AN
EVOLVING CIRCULATION PATTERN, AND WEAK PRECIPITATION SIGNALS.
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
AUGUST 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:
19510705 - 19520705 - 19530705 - 19540705 - 19550705
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:
19510704 - 19520704 - 19530704 - 19540704 - 19550704
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 31 - AUG 04, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A B ARIZONA A N COLORADO A B
NEW MEXICO A B N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A B
N TEXAS A N S TEXAS N N W TEXAS A B
MINNESOTA A B IOWA A B MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A 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 B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 02 - 08 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A A IDAHO A N NEVADA A N
W MONTANA A B E MONTANA A B WYOMING A B
UTAH A N ARIZONA A N COLORADO A B
NEW MEXICO A B N DAKOTA A B S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A N
N TEXAS A N S TEXAS N A W TEXAS A B
MINNESOTA A B IOWA A B MISSOURI A B
ARKANSAS A N LOUISIANA N A WISCONSIN A B
ILLINOIS A N MISSISSIPPI N A MICHIGAN A N
INDIANA A N OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A FL PENIN A 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 B 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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