648
FXUS06 KWBC 221937
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU AUGUST 22 2024
6-10 DAY OUTLOOK FOR AUG 28 - SEP 01, 2024
THE GEFS, ECENS, AND CMCE ENSEMBLE MEANS ARE IN GOOD AGREEMENT ON THE MEAN
500-HPA CIRCULATION PATTERN OVER THE FORECAST DOMAIN DURING THE 6-10 DAY
FORECAST PERIOD. TWO ANOMALOUS RIDGES ARE PREDICTED OVER THE VICINITY OF NORTH
AMERICA; ONE CENTERED JUST WEST OF VANCOUVER ISLAND, CANADA, AND THE OTHER NEAR
THE EASTERN SHORE OF HUDSON BAY. IN BOTH CASES, MAXIMUM POSITIVE HEIGHT
DEPARTURES EXCEED 120 METERS. OVER MOST OF THE CONTIGUOUS U.S. (CONUS),
FORECASTED POSITIVE HEIGHT ANOMALIES ARE SMALL. THE MANUAL HEIGHT BLEND DEPICTS
A MEAN TROUGH IN THE FULL 500-HPA HEIGHT FIELD OVER THE CANADIAN PRAIRIES,
WHICH IS PREDICTED TO DIG SOUTHEASTWARD WITH TIME ACROSS THE NORTH-CENTRAL AND
NORTHEASTERN CONUS. A WEAK MID-LEVEL TROUGH IS FORECASTED OVER THE EASTERN
BERING SEA AND WESTERN ALASKA, ACCOMPANIED BY NEAR TO SLIGHTLY BELOW NORMAL
500-HPA HEIGHTS ACROSS APPROXIMATELY THE WESTERN HALF OF THE STATE. ABOVE
NORMAL HEIGHTS ARE DEPICTED ACROSS SOUTHEAST ALASKA, WITH NEAR- TO SLIGHTLY
ABOVE-NORMAL HEIGHTS INDICATED OVER MOST OF THE EASTERN MAINLAND. OVER THE
HAWAIIAN ARCHIPELAGO, MID-LEVEL HEIGHTS ARE PREDICTED TO BE NEAR OR SLIGHTLY
ABOVE NORMAL.
THE 6-10 DAY TEMPERATURE OUTLOOK FAVORS BELOW NORMAL TEMPERATURES FROM THE
NORTHERN AND CENTRAL ROCKIES EASTWARD INTO THE ADJACENT PLAINS AS DEPICTED BY
THE AUTO-TEMPERATURE FORECAST. THIS FORECAST REPRESENTS A REASONABLE COMPROMISE
BETWEEN THE VARIOUS MODELS WHICH DIFFER ON THE SPATIAL EXTENT OF THE FAVORED
COOLER-THAN-NORMAL TEMPERATURES. THE RAW AND BIAS-CORRECTED TEMPERATURE TOOLS
DEPICT A SOMEWHAT BROADER COVERAGE OF FAVORED BELOW NORMAL TEMPERATURES
COMPARED TO THE REFORECAST TEMPERATURE TOOLS. FOR MOST OF THE REMAINDER OF THE
CONUS, ABOVE NORMAL TEMPERATURES ARE FAVORED, SUPPORTED BY MOST TEMPERATURE
TOOLS AND CONSISTENT WITH A BROAD MID-LEVEL RIDGE AND ASSOCIATED POSITIVE
HEIGHT ANOMALIES. MAXIMUM PROBABILITIES FAVORING ABOVE NORMAL TEMPERATURES
EXCEED 60% OVER THE SOUTHEAST. FOR ALASKA, MOST TOOLS AGREE ON FAVORED BELOW
NORMAL TEMPERATURES FOR SOUTHWESTERN AND NORTHWARD ALONG THE EXTREME WESTERN
PARTS OF THE MAINLAND, THE ALASKA PENINSULA, AND THE ALEUTIANS, CONSISTENT WITH
THE MID-LEVEL TROUGH AND ASSOCIATED NEGATIVE HEIGHT ANOMALIES OVER THAT REGION.
ABOVE NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE NORTHERN AND EASTERN
MAINLAND. ABOVE NORMAL TEMPERATURES ARE INDICATED OVER THE HAWAIIAN ISLANDS,
BASED ON THE ERF-CON AND AUTOMATED TEMPERATURE TOOLS.
THE 6-10 DAY PRECIPITATION OUTLOOK FAVORS ABOVE NORMAL PRECIPITATION WITHIN A
HORSESHOE-SHAPED PATTERN THAT INCLUDES THE NORTHEAST, GREAT LAKES, NORTHERN
OHIO VALLEY, THE UPPER HALF OF THE MISSISSIPPI VALLEY, PORTIONS OF THE NORTHERN
AND CENTRAL GREAT PLAINS, THE FOUR CORNER STATES, SOUTHERN AND SOUTHWESTERN
TEXAS, AND SOUTHERN FLORIDA. THE NORTHERN PORTION OF THIS AREA OF FAVORED ABOVE
NORMAL PRECIPITATION IS RELATED TO THE EXPECTED PASSAGE OF A LOW PRESSURE
SYSTEM. THE FOUR CORNERS REGION PRECIPITATION IS MOST LIKELY ASSOCIATED WITH
THE SUMMER MONSOON. SOUTHERN TEXAS AND SOUTHERN FLORIDA ARE FORECASTED TO
REMAIN SOUTH OF THE BERMUDA HIGH SURFACE RIDGE AXIS, WHICH FAVORS ABOVE NORMAL
PRECIPITATION. BELOW NORMAL PRECIPITATION IS FAVORED FROM THE NORTHERN HALF OF
THE PACIFIC COAST EASTWARD TO THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS,
WHICH COINCIDES WITH THE BROAD MID-LEVEL RIDGE AND POSITIVE HEIGHT DEPARTURES
PREDICTED OVER THAT REGION. BELOW NORMAL PRECIPITATION IS ALSO FAVORED FOR
INTERIOR PORTIONS OF THE GULF COAST REGION. ELSEWHERE, WHICH INCLUDES A
SIGNIFICANT PORTION OF THE CONUS, NEAR NORMAL PRECIPITATION IS FAVORED. IN
ALASKA, THERE IS EXCELLENT AGREEMENT AMONG THE PRECIPITATION TOOLS FOR ABOVE
NORMAL PRECIPITATION ACROSS MOST OF THE STATE, ASSOCIATED WITH WIDESPREAD
ONSHORE FLOW AT LOW-LEVELS AND MID-LEVELS ACCOMPANYING AND AHEAD OF THE TROUGH
PREDICTED OVER THE EASTERN BERING SEA AND WESTERN ALASKA.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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, ON A SCALE OF
1-5, DUE TO GOOD AGREEMENT AMONG THE VARIOUS HEIGHT FORECASTS AND SURFACE
TEMPERATURE FIELDS, OFFSET SOMEWHAT BY GREATER DIFFERENCES AMONG THE
PRECIPITATION GUIDANCE.
8-14 DAY OUTLOOK FOR AUG 30 - SEP 05, 2024
DURING WEEK-2, THE ENSEMBLE MEANS ARE IN FAIRLY GOOD AGREEMENT ON THE MEAN
CIRCULATION PATTERN ACROSS THE FORECAST DOMAIN. IN THE FULL 500-HPA HEIGHT
FIELDS, A WEAK TROUGH IS DEPICTED NEAR THE WEST COAST OF THE CONUS AND A
LOW-AMPLITUDE RIDGE IS INDICATED OVER THE WESTERN CONUS. A LOW-AMPLITUDE TROUGH
IS PREDICTED OVER THE EAST. IN THE HEIGHT ANOMALY FIELDS, MOST OF THE CONUS IS
EXPECTED TO BE UNDER WEAKLY ABOVE NORMAL 500-HPA HEIGHTS, WITH THE TWO LARGER
POSITIVE HEIGHT ANOMALY CENTERS (>60 M AND >90M, RESPECTIVELY) LOCATED OVER
ATLANTIC CANADA AND BRITISH COLUMBIA. IN ALASKA, A WEAK TROUGH IS PREDICTED
OVER THE EASTERN BERING SEA AND WESTERN ALASKA WITH PREDICTED HEIGHT DEPARTURES
ABOUT -30 METERS OVER THE ALEUTIANS ON THE MANUAL HEIGHT BLEND. THIS BLEND ALSO
DEPICTS POSITIVE HEIGHT ANOMALIES AND ASSOCIATED MID-LEVEL RIDGING ACROSS MOST
OF THE REMAINDER OF THE STATE. WELL TO THE SOUTH, HEIGHTS ARE FORECAST TO BE
NEAR OR SLIGHTLY ABOVE NORMAL IN THE VICINITY OF THE HAWAIIAN ISLANDS.
THE 8-14 DAY TEMPERATURE OUTLOOK FAVORS ABOVE NORMAL TEMPERATURES OVER MUCH OF
THE LOWER 48 STATES, SUPPORTED BY THE REFORECAST AND RAW TEMPERATURE GUIDANCE.
MAXIMUM PROBABILITIES FAVORING ABOVE NORMAL TEMPERATURES EXCEED 60% OVER THE
PACIFIC NORTHWEST AND ADJACENT PARTS OF THE NORTHERN INTERMOUNTAIN REGION. A
SUBSTANTIAL AREA OF FAVORED BELOW NORMAL TEMPERATURES IS INDICATED OVER THE
DAKOTAS, NEBRASKA, AND THE UPPER MISSISSIPPI VALLEY, BASED ON THE PREDICTED
PASSAGE OF A MID-LEVEL TROUGH AND ACCOMPANYING COLD FRONT. FOR REMAINING AREAS
OF THE CONUS, WHICH INCLUDES SOUTHWESTERN PARTS OF CALIFORNIA, NEAR NORMAL
TEMPERATURES ARE FAVORED. IN ALASKA, COVERAGE OF FAVORED BELOW NORMAL
TEMPERATURES IS RESTRICTED TO FAR WESTERN PARTS OF THE STATE. ABOVE NORMAL
TEMPERATURES ARE FAVORED FOR MOST OF THE REMAINDER OF ALASKA, EXCLUDING THE
SOUTHERN MAINLAND COAST AND SOUTHEAST ALASKA WHERE NEAR NORMAL TEMPERATURES ARE
FAVORED. THE ERF-CON AND AUTOMATED TEMPERATURE TOOLS SUPPORT ABOVE NORMAL
TEMPERATURES ACROSS HAWAII, SIMILAR TO THE EARLIER 6-10 DAY TEMPERATURE OUTLOOK.
THE 8-14 DAY PRECIPITATION OUTLOOK CONTINUES TO BE CHARACTERIZED BY SIGNIFICANT
UNCERTAINTY, AS INDICATED BY THE BROAD EXPANSE OF FAVORED NEAR NORMAL
PRECIPITATION ACROSS THE LOWER 48 STATES, AND THE RELATIVELY WEAK TILTS TOWARD
ABOVE OR BELOW NORMAL PRECIPITATION. ABOVE NORMAL PRECIPITATION CHANCES ARE
ELEVATED ACROSS MUCH OF THE FOUR CORNERS REGION AND CENTRAL PLAINS,
SOUTHWESTERN AND SOUTHERN TEXAS, FLORIDA, AND ALONG THE NORTHERN COAST OF
CALIFORNIA. THIS IS SUPPORTED BY THE AUTO-PRECIPITATION AND CONSOLIDATION
TOOLS. ABOVE NORMAL PRECIPITATION CHANCES ARE ALSO ELEVATED ACROSS THE
NORTHEAST, ASSOCIATED WITH THE PASSAGE OF A MID-LEVEL TROUGH AND COLD FRONT.
ODDS FAVOR BELOW NORMAL PRECIPITATION FROM WASHINGTON AND NORTHERN OREGON
EASTWARD ACROSS THE NORTHERN PLAINS, IN PROXIMITY TO A MODERATELY STRONG
ANOMALOUS RIDGE. BELOW NORMAL PRECIPITATION IS ALSO FAVORED OVER PARTS OF THE
INTERIOR PORTIONS OF THE GULF COAST REGION. MOST TOOLS CONTINUE TO FAVOR
ANOMALOUS WETNESS FOR MOST OF ALASKA AND HAWAII.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 30% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: NEAR AVERAGE, 3, ON A SCALE OF
1-5, DUE TO REASONABLE AGREEMENT AMONG THE VARIOUS HEIGHT FORECASTS AND SURFACE
TEMPERATURE FORECASTS, BUT SUBSTANTIALLY OFFSET BY POOR AGREEMENT AMONG THE
PRECIPITATION TOOLS.
FORECASTER: ANTHONY A
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
SEPTEMBER 19.
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:
19540828 - 19830831 - 19900825 - 19530824 - 20050827
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:
20050825 - 19830831 - 19540828 - 19530825 - 19820813
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 28 - SEP 01, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF N N IDAHO B B NEVADA A N
W MONTANA B B E MONTANA B B WYOMING B N
UTAH N N ARIZONA A A COLORADO N A
NEW MEXICO A A N DAKOTA N N S DAKOTA B A
NEBRASKA N A KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A A W TEXAS A N
MINNESOTA N A IOWA N A MISSOURI A N
ARKANSAS A B LOUISIANA A B WISCONSIN A A
ILLINOIS A A MISSISSIPPI A B MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A N
TENNESSEE A B ALABAMA A B 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 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 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 N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 30 - SEP 05, 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 N NEVADA A N
W MONTANA A B E MONTANA N B WYOMING N A
UTAH A A ARIZONA A N COLORADO N A
NEW MEXICO A A N DAKOTA B N S DAKOTA B N
NEBRASKA B A KANSAS N A OKLAHOMA N N
N TEXAS A N S TEXAS A A W TEXAS A N
MINNESOTA B N IOWA B N MISSOURI N N
ARKANSAS A N LOUISIANA A N WISCONSIN B N
ILLINOIS N N MISSISSIPPI A B MICHIGAN N N
INDIANA N N OHIO N N KENTUCKY A N
TENNESSEE A N ALABAMA A B 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 N NEW JERSEY A A 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 A A
AK ALEUTIAN B N AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST N A AK PNHDL N 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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