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FXUS06 KWBC 231927
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE JULY 23 2024
6-10 DAY OUTLOOK FOR JUL 29 - AUG 02, 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 DEAMPLIFIES OVER
TIME, WHILE A RIDGE OVER THE NORTHEASTERN CONUS AND ASSOCIATED POSITIVE 500-HPA
HEIGHT ANOMALIES SPREAD WESTWARD TO COVER MOST OF THE CONUS. THE GEFS ENSEMBLE
MEAN PREDICTS NEGATIVE 500-HPA HEIGHT ANOMALIES OVER THE NORTHWESTERN CONUS AT
THE START OF THE PERIOD, WHILE THE ECMWF MODEL PREDICTS NEAR AVERAGE 500-HPA
HEIGHT ANOMALIES. 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. 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, UNDER MOSTLY
NORTHWESTERLY FLOW OR NEGATIVE 500-HPA HEIGHT ANOMALIES. ABOVE-NORMAL
TEMPERATURES ARE FORECAST FOR THE WESTERN ALEUTIANS UNDER POSITIVE 500-HPA
HEIGHT ANOMALIES. NEAR-NORMAL TEMPERATURES ARE FAVORED FOR MOST OF CALIFORNIA
AND NORTHWESTERN WASHINGTON, WITH A DEAMPLIFYING TROUGH AND NORTHERLY SURFACE
FLOW OVER THE REGION. NEAR-NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE
SOUTHEASTERN CONUS NOT INCLUDING THE EASTERN GULF COAST, DUE TO LESS
CONSISTENCY BETWEEN CALIBRATED AND BIAS-CORRECTED MODEL TEMPERATURE FORECAST
TOOLS. BELOW-NORMAL TEMPERATURES ARE FAVORED FOR SOUTHERN TEXAS, WHILE
ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR THE EASTERN GULF COAST, CONSISTENT
WITH THE ECMWF REFORECAST-CALIBRATED TEMPERATURE TOOL. 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 FAVORED
FOR PARTS OF THE PACIFIC NORTHWEST, AHEAD OF RELATIVE TROUGHING DURING THE
PERIOD. BELOW-NORMAL PRECIPITATION IS FAVORED OVER A LARGE AREA OF THE WESTERN
HALF OF THE CONUS INTO PARTS OF THE CENTRAL AND SOUTHERN GREAT PLAINS,
CONSISTENT WITH MOST DYNAMICAL MODEL FORECASTS. ABOVE-NORMAL PRECIPITATION IS
FAVORED OVER SOUTHERN TEXAS CONSISTENT WITH THE PRECIPITATION CONSOLIDATION
TOOL. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED OVER MUCH OF THE EASTERN
CONUS, OUTSIDE THE NORTHERN ATLANTIC COAST, 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 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: ABOVE-AVERAGE, 4 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,
SUCH AS THE WEST COAST OF THE CONUS.
8-14 DAY OUTLOOK FOR JUL 31 - AUG 06, 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. A SMALL AREA OF FAVORED NEAR-TO-BELOW-NORMAL TEMPERATURES IS FORECAST
FOR PARTS OF SOUTH TEXAS, CONSISTENT WITH THE TEMPERATURE CONSOLIDATION AND
POTENTIAL PRECIPITATION DURING THE PERIOD. BELOW-NORMAL TEMPERATURES ARE
FAVORED FOR MAINLAND AND SOUTHEAST ALASKA, UNDER PREDICTED NEGATIVE 500-HPA
HEIGHT ANOMALIES IN THE MANUAL BLEND AND MOST DYNAMICAL MODEL FORECASTS.
ABOVE-NORMAL TEMPERATURES ARE FORECAST FOR THE WESTERN ALEUTIANS UNDER POSITIVE
500-HPA HEIGHT ANOMALIES. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR WESTERN
ISLANDS OF HAWAII, UNDER WEAK POSITIVE 500-HPA HEIGHT ANOMALIES.
ABOVE-NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR THE CENTRAL ALEUTIANS,
MAINLAND ALASKA, AND SOUTHEAST ALASKA, UNDER ENHANCED ONSHORE AND CYCLONIC
FLOW. NEAR-NORMAL PRECIPITATION IS FAVORED FOR SOME AREAS OF THE PACIFIC
NORTHWEST, AHEAD OF A WEAKENING TROUGH. BELOW-NORMAL PRECIPITATION IS FAVORED
ACROSS MOST OF THE WESTERN AND CENTRAL CONUS IN WEEK-2, UNDER THE PREDICTED
BROAD RIDGE. ABOVE-NORMAL PRECIPITATION IS SLIGHTLY FAVORED OVER MOST OF THE
EASTERN CONUS AND PARTS OF SOUTH TEXAS, WHERE PRECIPITATION TOOLS ARE
RELATIVELY CONSISTENT. 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: 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: 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:
19980801 - 19740802 - 19670712 - 20030720 - 20060704
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:
19980801 - 19890715 - 19980706 - 19740802 - 19940727
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 29 - AUG 02, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF N 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 N N W TEXAS A B
MINNESOTA A A IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA N N WISCONSIN A A
ILLINOIS A A MISSISSIPPI N A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA N A NEW YORK A A
VERMONT A A NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A A NEW JERSEY A N W VIRGINIA A A
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA N N S CAROLINA N A GEORGIA N 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 JUL 31 - AUG 06, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A B 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 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 A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE B A
AK ALEUTIAN B N 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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