990
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 JULY 24 2024
6-10 DAY OUTLOOK FOR JUL 30 - AUG 03, 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
WITH ONLY SMALL DIFFERENCES AMONG THE HEIGHT FORECASTS. A MID-LEVEL TROUGH OVER
THE WESTERN CONTIGUOUS U.S. (CONUS) AT THE START OF THE PERIOD DE-AMPLIFIES
OVER TIME, WHILE A RIDGE OVER THE SOUTH-CENTRAL AND NORTHEASTERN CONUS AND
ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES SPREAD WESTWARD TO COVER MOST OF
THE CONUS. MODEL SOLUTIONS PREDICT CYCLONIC FLOW OVER MOST OF ALASKA AHEAD OF A
BROAD 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. DURING THE PERIOD, NEGATIVE 500-HPA
HEIGHT ANOMALIES EXTEND SOUTHEASTWARD ACROSS SOUTHEAST ALASKA. WEAK POSITIVE
500-HPA HEIGHT ANOMALIES ARE PREDICTED OVER SOUTHEASTERN 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 WASHINGTON AND THE CENTRAL AND SOUTHERN CALIFORNIA COAST, UNDER A WEAK
TROUGH AND 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
HALF OF THE CONUS INTO MUCH OF THE CENTRAL AND SOUTHERN GREAT PLAINS AND PARTS
OF THE NORTHERN PLAINS, CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS.
ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED OVER MUCH OF THE EASTERN CONUS,
CONSISTENT WITH MOST DYNAMICAL MODEL PRECIPITATION TOOLS. NEAR-NORMAL
PRECIPITATION IS FAVORED ACROSS HAWAII, AS PREDICTED BY THE AUTO PRECIPITATION
FORECAST TOOL.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 25% 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 01 - 07 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. CYCLONIC FLOW AHEAD OF A TROUGH CONTINUES
OVER MOST OF ALASKA, WHILE A RIDGE IS PREDICTED OVER THE CONUS IN EACH ENSEMBLE
MEAN.
NEARLY COAST-TO-COAST LIKELY ABOVE-NORMAL TEMPERATURES ARE PREDICTED ACROSS THE
CONUS, UNDER A RIDGE AND CONSISTENT WITH MOST DYNAMICAL MODEL TEMPERATURE
TOOLS. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF SOUTH TEXAS,
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 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 PACIFIC NORTHWEST,
AHEAD OF A WEAKENING TROUGH. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR
PARTS OF SOUTHERN CALIFORNIA AND SOUTHWESTERN ARIZONA, WITH A POSSIBLE SURGE OF
MOISTURE FROM DEVELOPMENT OF A TROPICAL SYSTEM IN THE EASTERN PACIFIC.
BELOW-NORMAL PRECIPITATION IS FAVORED ACROSS MOST OF THE WESTERN AND CENTRAL
CONUS IN WEEK-2, UNDER THE PREDICTED RIDGE. NEAR-NORMAL PRECIPITATION IS
FAVORED OVER MOST OF THE GULF COAST REGION AND EASTERN CONUS, AS PRECIPITATION
TOOLS ARE INCONSISTENT. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED FOR THE
SOUTHERN FLORIDA PENINSULA AND A SMALL AREA OF SOUTHERN TEXAS, CONSISTENT WITH
MOST PRECIPITATION TOOLS. NEAR-NORMAL PRECIPITATION IS FAVORED ACROSS HAWAII,
AS PREDICTED BY THE AUTO PRECIPITATION FORECAST TOOL.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 45% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 25% 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.
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 30 - AUG 03, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON A A 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 B COLORADO A B
NEW MEXICO A B N DAKOTA A N S DAKOTA A B
NEBRASKA A B KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A N W TEXAS A B
MINNESOTA A N IOWA A B MISSOURI A B
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A N 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 01 - 07 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 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 B
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK A N
VERMONT A N 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 A N VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N 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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