905
FXUS06 KWBC 261938
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 26 2023
6-10 DAY OUTLOOK FOR AUG 01 - 05 2023
THERE IS GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER THE
NORTH AMERICAN REGION FOR THE 6-10 DAY PERIOD AMONG THE GFS, ECMWF AND CANADIAN
ENSEMBLE MEAN MODEL SOLUTIONS. MODEL SOLUTIONS PREDICT POSITIVE 500-HPA HEIGHT
ANOMALIES OVER THE ALEUTIANS AND BERING SEA THAT EXTEND ACROSS ALASKA. A
MID-LEVEL TROUGH AND GENERALLY NEAR NORMAL 500-HPA HEIGHTS ARE PREDICTED OVER
THE GULF OF ALASKA. A RIDGE AND ASSOCIATED POSITIVE 500-HPA HEIGHT ANOMALIES
ARE FORECAST OVER THE WESTERN, CENTRAL, AND SOUTHERN CONTIGUOUS U.S. (CONUS).
DOWNSTREAM, A TROUGH AND ASSOCIATED NEGATIVE MID-LEVEL HEIGHT ANOMALIES ARE
FORECAST OVER THE NORTHEASTERN CONUS.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS ALASKA IN THE 6-10 DAY PERIOD
UNDER PREDICTED POSITIVE MID-LEVEL HEIGHT ANOMALIES, CONSISTENT WITH DYNAMICAL
MODEL FORECAST TOOLS. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED ACROSS MUCH OF
THE WESTERN, CENTRAL, AND SOUTHERN CONUS, UNDER POSITIVE 500-HPA HEIGHT
ANOMALIES AND IS CONSISTENT WITH THE ECMWF AND GEFS REFORECAST-CALIBRATED
TEMPERATURE FORECASTS. THE GREATEST PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
(>80%) ARE INDICATED OVER THE LOWER MISSISSIPPI VALLEY. THE EXCEPTION TO THIS
IS AN AREA OF PREDICTED NEAR NORMAL TEMPERATURES FROM MUCH OF CALIFORNIA
EASTWARD AND NORTHEASTWARD TO WYOMING AND COLORADO. WITHIN THIS REGION OF
PREDICTED NEAR NORMAL TEMPERATURES, A RELATIVELY SMALL AREA OF BELOW NORMAL
TEMPERATURES IS FAVORED FOR PARTS OF THE CALIFORNIA COAST, IN PROXIMITY TO
NEGATIVE SEA SURFACE TEMPERATURE ANOMALIES. BELOW NORMAL TEMPERATURES ARE
LIKELY FOR THE NORTHEAST, EASTERN GREAT LAKES REGION, AND NORTHERN MID-ATLANTIC
REGION UNDER THE PREDICTED TROUGH.
BELOW NORMAL PRECIPITATION IS FAVORED NEAR THE SOUTHERN COAST OF ALASKA, AND
ABOVE NORMAL PRECIPITATION PROBABILITIES ARE ENHANCED OVER NORTHERN ALASKA.
THESE PREDICTED PRECIPITATION ANOMALIES ARE CONSISTENT WITH THE CONSOLIDATION
AND AUTO PRECIPITATION TOOLS. ABOVE NORMAL PRECIPITATION IS FAVORED FROM MUCH
OF THE WESTERN HALF OF THE CONUS ACROSS THE MIDDLE MISSISSIPPI AND OHIO VALLEYS
INTO THE NORTHEAST AND MID-ATLANTIC REGION, CONSISTENT WITH THE CONSOLIDATION
AND AUTO PRECIPITATION TOOLS. THE SOUTHWEST MONSOON IS EXPECTED TO BRING ABOUT
PRECIPITATION AMOUNTS CLOSE TO THE 30-YEAR CLIMATOLOGICAL AVERAGE DURING THE
6-10 DAY PERIOD. THE BAND OF FAVORED ABOVE NORMAL PRECIPITATION OVER THE
EASTERN HALF OF THE CONUS (FROM ABOUT THE MIDDLE MISSISSIPPI AND OHIO VALLEYS
NORTHEASTWARD AS NOTED EARLIER) IS ASSOCIATED WITH THE MID-LEVEL TROUGH
FORECAST OVER THE GREAT LAKES AND NORTHEAST. BELOW NORMAL PRECIPITATION IS
FAVORED OVER THE UPPER MISSISSIPPI VALLEY, AND MUCH OF THE GULF COAST REGION,
ON THE BACK-SIDE OF THE TROUGH AND NEAR THE SUBTROPICAL RIDGE AXIS,
RESPECTIVELY.
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: ABOUT AVERAGE, 3 OUT OF 5, BASED
ON GOOD AGREEMENT AMONG THE DYNAMICAL MODEL 500-HPA HEIGHT FORECASTS, OFFSET BY
SOME AREAS OF DISAGREEMENT AMONG SURFACE TEMPERATURE AND PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR AUG 03 - 09 2023
ENSEMBLE MEAN SOLUTIONS FOR THE WEEK-2 500-HPA HEIGHT FORECAST REMAIN IN GOOD
AGREEMENT. MODELS CONTINUE TO FORECAST POSITIVE 500-HPA HEIGHT ANOMALIES ACROSS
ALASKA WITH ANOTHER MID-LEVEL TROUGH CENTERED OVER THE GULF OF ALASKA, WHILE A
MID-LEVEL TROUGH IS ANTICIPATED TO APPROACH ALASKA FROM THE WEST. POSITIVE
500-HPA HEIGHT ANOMALIES ARE FORECAST BY THE MANUAL BLEND ACROSS MOST OF THE
CONUS, EXCEPT UNDER A TROUGH OVER THE NORTHEAST, WHERE MODESTLY NEGATIVE
500-HPA ANOMALIES ARE PREDICTED. ALTHOUGH THE MID-LEVEL CIRCULATION PATTERN
FORECAST FOR WEEK-2 IS OVERALL SIMILAR TO THE PATTERN FORECAST FOR THE 6-10 DAY
PERIOD, THE WEEK-2 MANUAL BLEND DISPLAYS SMALLER ANOMALIES AND GREATER
UNCERTAINTY, RELATIVE TO THE 6-10 DAY PERIOD MANUAL BLEND. WHERE THE TWO MANUAL
BLENDS DIFFER SIGNIFICANTLY, HOWEVER, IS OVER THE SOUTHEASTERN CONUS. AFTER A
RELATIVELY BRIEF EASTWARD EXTENSION AND STRENGTHENING OF THE MID-LEVEL RIDGE
PREDICTED BY RECENT MODEL SOLUTIONS, TODAY’S WEEK-2 HEIGHT BLEND RETRACTS THE
RIDGE BACK TO THE SOUTHWESTERN CONUS. THIS SCENARIO ALLOWS MID-LEVEL HEIGHTS TO
DECREASE SOMEWHAT ACROSS THE SOUTHEAST, ACCOMPANIED BY SLIGHTLY COOLER SURFACE
TEMPERATURES.
BIAS-CORRECTED AND REFORECAST-CALIBRATED TEMPERATURES FAVOR ABOVE NORMAL
TEMPERATURES OVER ALASKA IN THE WEEK-2 PERIOD, UNDER POSITIVE 500-HPA HEIGHTS
ANOMALIES. THE PROJECTED RETRACTION OF THE RIDGE BACK TOWARDS THE SOUTHWESTERN
CONUS FAVORS AN INCREASE IN COVERAGE OF FAVORED ABOVE NORMAL TEMPERATURES OVER
THE WEST, RELATIVE TO THE 6-10 DAY PERIOD. MUCH OF THE SOUTHERN HALF OF THE
CONUS HAS INCREASED CHANCES OF ABOVE NORMAL TEMPERATURES, WITH ODDS IN EXCESS
OF 70% DEPICTED OVER THE FLORIDA PENINSULA. THIS IS CONSISTENT WITH THE
PROXIMITY OF THE SUBTROPICAL RIDGE AND REFORECAST-CALIBRATED TEMPERATURES FROM
THE GFS AND ECMWF ENSEMBLE MEAN MODELS. THERE ARE ELEVATED ODDS OF BELOW NORMAL
TEMPERATURES ACROSS THE GREAT LAKES REGION, OHIO VALLEY, NORTHEAST, AND
NORTHERN MID-ATLANTIC REGION, ASSOCIATED WITH A MID-LEVEL TROUGH, WITH A >50%
CHANCE OF BELOW-NORMAL TEMPERATURES FOR MUCH OF NEW ENGLAND AND NEW YORK. BELOW
NORMAL TEMPERATURES ARE ALSO FAVORED, ALBEIT MODESTLY, OVER PORTIONS OF THE
NORTHERN AND CENTRAL HIGH PLAINS, CONSISTENT WITH REFORECAST-CALIBRATED AND
BIAS-CORRECTED TEMPERATURE GUIDANCE.
WITH INCREASING ENSEMBLE SPREAD AND WEAK 500-HPA HEIGHT ANOMALIES IN THE MANUAL
BLEND OF DYNAMICAL MODEL FORECASTS, THE WEEK-2 PRECIPITATION OUTLOOK IS
SOMEWHAT UNCERTAIN ACROSS MOST OF THE DOMAIN. ABOVE NORMAL PRECIPITATION IS
FAVORED ACROSS WESTERN ALASKA, WHERE DYNAMICAL MODEL RAW PRECIPITATION AMOUNTS
AND REFORECAST-CALIBRATED PRECIPITATION ARE GENERALLY CONSISTENT, IN ADVANCE OF
A MID-LEVEL TROUGH. ABOVE NORMAL PRECIPITATION IS FAVORED FROM MOST OF THE
NORTHWESTERN CONUS (INCLUDING NORTHERN CALIFORNIA) ACROSS MUCH OF THE GREAT
PLAINS, SOUTH-CENTRAL MISSISSIPPI VALLEY, THE TENNESSEE VALLEY, AND THE EAST
COAST STATES FROM GEORGIA TO MAINE. THIS IS GENERALLY CONSISTENT WITH THE
PRECIPITATION OUTLOOK FOR THE EARLIER 6-10 DAY PERIOD. THE EXPECTED SOUTHWARD
PUSH OF THE NORTHEAST CONUS TROUGH INTO THE SOUTHEAST IS CONSISTENT WITH THE
INCREASED CHANCES FOR ABOVE NORMAL PRECIPITATION ACROSS THE CAROLINAS, GEORGIA,
AND THE SOUTHERN APPALACHIANS, RELATIVE TO THE 6-10 DAY PERIOD. MODESTLY
ENHANCED CHANCES OF BELOW NORMAL PRECIPITATION ARE FORECAST OVER THE WESTERN
AND CENTRAL GREAT LAKES, FOR PORTIONS OF THE SOUTHWEST, AND SOUTHEAST ALASKA.
THIS IS CONSISTENT WITH REFORECAST-CALIBRATED PRECIPITATION GUIDANCE, AND
HIGHLIGHTS REGIONS THAT ARE EXPECTED TO BE WELL REMOVED FROM STORM TRACKS.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% 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, BASED
ON GOOD AGREEMENT AMONG THE DYNAMICAL MODEL 500-HPA HEIGHT FORECASTS, OFFSET BY
FORECASTS OF WEAK 500-HPA HEIGHT ANOMALIES AND WEAK SIGNALS IN 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
AUGUST 17.
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:
19530724 - 20030722 - 19940726 - 19880711 - 19670712
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:
19530723 - 20030722 - 19970725 - 19880711 - 19940807
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 01 - 05 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A A NRN CALIF N A
SRN CALIF N N IDAHO A A NEVADA A A
W MONTANA A A E MONTANA A A WYOMING N A
UTAH N A ARIZONA A N COLORADO A A
NEW MEXICO A A N DAKOTA A N S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA A N OHIO N N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA N A
MARYLAND B A DELAWARE B A VIRGINIA N N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE A N
AK ALEUTIAN A N AK WESTERN A N AK INT BSN A N
AK S INT A N AK SO COAST A N AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 03 - 09 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF A N IDAHO A A NEVADA A N
W MONTANA A A E MONTANA A A WYOMING N A
UTAH A A ARIZONA A N COLORADO N A
NEW MEXICO A N N DAKOTA N A S DAKOTA N A
NEBRASKA N A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA N N IOWA N N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN N N
ILLINOIS N N MISSISSIPPI A N MICHIGAN B N
INDIANA N N OHIO B N KENTUCKY N N
TENNESSEE A N ALABAMA A N NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA N 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 A N AK WESTERN A A AK INT BSN A N
AK S INT A N AK SO COAST A N AK PNHDL A 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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