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FXUS06 KWBC 021903
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED AUGUST 02 2023
6-10 DAY OUTLOOK FOR AUG 08 - 12 2023
THE GFS, ECMWF, AND CANADIAN ENSEMBLE MEAN MODEL SOLUTIONS CONTINUE TO BE IN
GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER THE FORECAST
DOMAIN FOR THE 6-10 DAY PERIOD. THE MID-LEVEL HEIGHT BLEND DEPICTS A DEEP,
ANOMALOUS TROUGH AND BELOW NORMAL 500-HPA HEIGHTS OVER MOST OF THE BERING SEA,
SOUTHERN ALASKA, AND OVER MOST OF THE GULF OF ALASKA WITH MAXIMUM HEIGHT FALLS
OF -150 METERS JUST SOUTH OF THE ALASKA PENINSULA. TO VARYING DEGREES, ALL
THREE ENSEMBLE MEAN SOLUTIONS HAVE CONSISTENTLY FORECAST THE RAPID DEEPENING OF
THIS FEATURE OVER THE LAST FEW DAYS. A MID-LEVEL RIDGE AND ABOVE NORMAL 500-HPA
HEIGHTS ARE ANTICIPATED OVER WESTERN CANADA, NORTHERN AND CENTRAL ALASKA, AND
THE ARCTIC OCEAN WITH MAXIMUM POSITIVE HEIGHT ANOMALIES NEAR +210 METERS
APPROXIMATELY HALFWAY BETWEEN PRUDHOE BAY, ALASKA, AND THE NORTH POLE. OVER THE
TEMPERATE LATITUDES, A WEAK MID-LEVEL TROUGH IS PREDICTED ALONG THE WEST COAST,
AND A MID-LEVEL RIDGE IS INDICATED OVER THE INTERIOR OF THE WESTERN CONTIGUOUS
U.S. (CONUS), WHICH CONNECTS WITH THE WELL-ESTABLISHED SUBTROPICAL RIDGE OVER
THE SOUTHERN CONUS. THE EAST-WEST ORIENTED AXIS OF THE SUBTROPICAL RIDGE IS
EXPECTED TO BE NEAR THE 30TH PARALLEL, WHICH IS SHIFTED SOUTHWARD OF ITS
SUMMERTIME FOUR CORNERS LOCATION AND THEREFORE UNFAVORABLE FOR THE SOUTHWEST
MONSOON. A MID-LEVEL TROUGH AND BELOW NORMAL 500-HPA HEIGHTS ARE DEPICTED OVER
MUCH OF THE NORTHERN AND CENTRAL CONUS EAST OF THE ROCKY MOUNTAINS.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS MOST OF MAINLAND ALASKA, SOUTHEAST
ALASKA, MANY AREAS WEST OF THE CONTINENTAL DIVIDE AND EXTENDING EASTWARD FROM
THE SOUTHERN ROCKIES ACROSS THE SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY, THE
SOUTHEAST, AND THE SOUTHERN MID-ATLANTIC REGION. THIS IS ASSOCIATED WITH
RIDGING AND/OR NEAR TO ABOVE NORMAL MID-LEVEL HEIGHTS, WITH THE EXCEPTION OF
THE MID-ATLANTIC REGION, WHICH IS ANTICIPATED TO HAVE ANOMALOUSLY WARM,
SOUTHERLY LOW-LEVEL FLOW AHEAD OF A MID-LEVEL TROUGH AXIS. THESE AREAS OF
FAVORED ABOVE NORMAL TEMPERATURES ARE CONSISTENT WITH REFORECAST-CALIBRATED
TEMPERATURE GUIDANCE, EXCEPT FOR CALIFORNIA AND NEVADA, WHERE THE GFS AND
CANADIAN ENSEMBLE MEAN REFORECASTS DEPICT AN INTERVENING CORRIDOR OF BELOW
NORMAL TEMPERATURES. THE GREATEST PROBABILITIES FOR ABOVE NORMAL TEMPERATURES
(>70%) ARE INDICATED FROM SOUTHERN NEW MEXICO EASTWARD TO SOUTHWESTERN
LOUISIANA, AND THE FLORIDA PENINSULA. BELOW NORMAL TEMPERATURE CHANCES ARE
INCREASED OVER THE ALEUTIANS AND ALASKA PENINSULA, AND FROM THE NORTHERN AND
CENTRAL ROCKIES EASTWARD ACROSS THE NORTHERN AND CENTRAL PLAINS, UPPER AND
MIDDLE MISSISSIPPI VALLEY, GREAT LAKES REGION, OHIO VALLEY, AND MUCH OF NEW
YORK AND NEW ENGLAND. THIS IS ASSOCIATED WITH MID-LEVEL TROUGHING AND BELOW
NORMAL 500-HPA HEIGHTS, AND IS ALSO SUPPORTED BY REFORECAST-CALIBRATED
TEMPERATURES FROM THE ECMWF ENSEMBLE MEAN, WHICH REPRESENTS A REASONABLE
COMPROMISE BETWEEN THE OVERALL COLDER CANADIAN ENSEMBLE MEAN AND SLIGHTLY
WARMER GEFS. MAXIMUM PROBABILITIES FOR BELOW NORMAL TEMPERATURES (>60%) ARE
DEPICTED OVER THE NORTHERN AND CENTRAL HIGH PLAINS.
TODAY’S 6-10 DAY PRECIPITATION OUTLOOK FAVORS A TILT IN THE ODDS TOWARDS ABOVE
NORMAL PRECIPITATION FOR PRACTICALLY ALL OF ALASKA SOUTH OF THE BROOKS RANGE,
IN PROXIMITY TO THE DEEP MID-LEVEL ALEUTIAN TROUGH. MOIST FLOW AHEAD OF THE
TROUGH PREDICTED OVER THE ALEUTIANS AND GULF OF ALASKA ENHANCES THE ODDS FOR
ABOVE NORMAL PRECIPITATION FOR APPROXIMATELY THE NORTHWESTERN QUARTER OF THE
CONUS, AND MOST OF THE GREAT PLAINS AND MISSISSIPPI VALLEY. EAST OF THE
MISSISSIPPI VALLEY, DIFFERENCES BEGIN TO APPEAR BETWEEN THE CANADIAN ENSEMBLE
MEAN REFORECAST-CALIBRATED PRECIPITATION GUIDANCE AND SIMILAR GUIDANCE FROM THE
GFS AND ECMWF ENSEMBLE MEANS. THE CANADIAN REFORECAST PRECIPITATION TOOL
EXTENDS THE AREA OF FAVORED ABOVE NORMAL PRECIPITATION FROM THE MISSISSIPPI
VALLEY ACROSS THE GREAT LAKES AND MUCH OF THE EASTERN CORN BELT REGION, WHILE
THE OTHER REFORECAST SOLUTIONS INDICATE ABOVE NORMAL PRECIPITATION EXTENDING
EASTWARD FROM THE MISSISSIPPI VALLEY TO THE ATLANTIC COAST. THE ECMWF ENSEMBLE
MEAN GUIDANCE IS PREFERRED TODAY OVER THE GFS AND CANADIAN REFORECAST
PRECIPITATION TOOLS. THE OFFICIAL PRECIPITATION OUTLOOK DEPICTS PROBABILITIES
THAT EXCEED 40% FOR ABOVE NORMAL PRECIPITATION FROM THE NORTHERN ROCKIES AND
NORTHERN HIGH PLAINS SOUTHEASTWARD ACROSS THE CENTRAL AND SOUTH-CENTRAL PLAINS,
THE SOUTH-CENTRAL MISSISSIPPI VALLEY, AND CONTINUING EASTWARD TO CENTRAL
PORTIONS OF KENTUCKY AND TENNESSEE. THIS AREA IS WHERE A BAROCLINIC ZONE IS
EXPECTED TO STALL, WITH INCREASED GULF INFLOW FROM THE SOUTH. INDIVIDUAL
DISTURBANCES MOVING ACROSS PARTS OF THE NORTHEAST RESULT IN A >40% CHANCE OF
ABOVE NORMAL PRECIPITATION FOR THIS AREA. BELOW NORMAL PRECIPITATION CHANCES
ARE INCREASED FOR SOUTHERN NEVADA, FAR SOUTHEASTERN PARTS OF CALIFORNIA, MOST
OF THE FOUR CORNERS STATES, AND SOUTHERN TEXAS, AS INDICATED BY THE
CONSOLIDATION PRECIPITATION TOOL, AND ASSOCIATED WITH A WEAKENED AND
SOUTHWARD-SHIFTED MONSOON RIDGE.
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 OUT OF 5, BASED
ON GOOD AGREEMENT AMONG THE DYNAMICAL MODEL 500-HPA HEIGHT FORECASTS AND MOST
SURFACE TEMPERATURE TOOLS, OFFSET BY SOME AREAS OF DISAGREEMENT AMONG
PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR AUG 10 - 16 2023
ENSEMBLE MEAN SOLUTIONS FOR THE WEEK-2 500-HPA HEIGHT FORECAST ARE GENERALLY IN
GOOD AGREEMENT TODAY OVER THE FORECAST DOMAIN. THE LARGE MID-LEVEL ALEUTIAN
TROUGH IS EXPECTED TO SHIFT A BIT WEST COMPARED TO ITS PREDICTED 6-10 DAY
LOCATION, WITH MAXIMUM MID-LEVEL HEIGHT FALLS TO -150 METERS BELOW NORMAL.
ANOMALOUS RIDGING IS INDICATED OVER NORTHERN ALASKA, WESTERN CANADA, AND THE
ARCTIC OCEAN, WITH MAXIMUM POSITIVE 500-HPA HEIGHT ANOMALIES IN EXCESS OF +180
METERS APPROXIMATELY HALFWAY BETWEEN UTQIAGVIK (BARROW) AND THE NORTH POLE.
THIS ANOMALOUS RIDGE EXTENDS SOUTHWARD ACROSS MUCH OF THE WESTERN CONUS AND
CONNECTS WITH THE SUBTROPICAL RIDGE LOCATED OVER THE SOUTHERN CONUS. A
MID-LEVEL TROUGH ACCOMPANIED BY MOSTLY NEAR NORMAL 500-HPA HEIGHTS IS FORECAST
FROM THE NORTHERN AND CENTRAL GREAT PLAINS EASTWARD ACROSS THE GREAT LAKES AND
OHIO VALLEY TO THE NORTHERN HALF OF THE ATLANTIC COAST.
REFORECAST-CALIBRATED TEMPERATURE TOOLS FAVOR ABOVE NORMAL TEMPERATURES OVER
MOST OF MAINLAND AND SOUTHEAST ALASKA IN THE WEEK-2 PERIOD, UNDER MOSTLY
RIDGING AND/OR POSITIVE 500-HPA HEIGHT ANOMALIES. BELOW NORMAL TEMPERATURE
CHANCES ARE INCREASED OVER THE ALEUTIANS AND ALASKA PENINSULA, IN PROXIMITY TO
A DEEP MID-LEVEL TROUGH. FOR THE CONUS, ABOVE NORMAL TEMPERATURE CHANCES ARE
INCREASED OVER MOST AREAS WEST OF THE CONTINENTAL DIVIDE, UNDER RISING 500-HPA
HEIGHTS AND/OR RIDGING. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FROM THE
SOUTHERN ROCKIES EASTWARD ACROSS THE SOUTHERN PLAINS, LOWER MISSISSIPPI VALLEY,
THE SOUTHEAST, AND MUCH OF THE MID-ATLANTIC REGION. MAXIMUM PROBABILITIES FOR
ABOVE NORMAL TEMPERATURES EXCEED 60% FROM SOUTHERN NEW MEXICO TO SOUTHERN
LOUISIANA, AND OVER FLORIDA. THIS IS SUPPORTED BY REFORECAST-CALIBRATED
TEMPERATURES FROM THE ECMWF ENSEMBLE MEAN MODEL, WHICH REPRESENTS A REASONABLE
COMPROMISE BETWEEN THE WARMER GEFS SOLUTION AND COOLER CANADIAN ENSEMBLE MEAN
SOLUTION. BELOW NORMAL TEMPERATURES ARE FAVORED FROM THE NORTHERN AND CENTRAL
PLAINS EASTWARD ACROSS THE UPPER AND MIDDLE MISSISSIPPI VALLEY, GREAT LAKES
REGION, AND OHIO VALLEY, ASSOCIATED WITH A MID-LEVEL TROUGH.
THE WEEK-2 PRECIPITATION OUTLOOK IS SIMILAR TO THE 6-10 DAY PRECIPITATION
OUTLOOK, THOUGH WITH SOME ADJUSTMENTS. THERE ARE INCREASED CHANCES FOR ABOVE
NORMAL PRECIPITATION FOR MOST OF THE NORTHWESTERN QUARTER OF THE CONUS, AND
MOST OF THE GREAT PLAINS AND MISSISSIPPI VALLEY. EAST OF THE MISSISSIPPI
VALLEY, THE REFORECAST-CALIBRATED SOLUTIONS BEGIN TO DIVERGE, IN THE SAME
MANNER AS THEY DID DURING THE EARLIER 6-10 DAY PERIOD. THE PRECIPITATION
CONSOLIDATION TOOL, WHICH SKILL-WEIGHTS THE GEFS AND ECMWF
REFORECAST-CALIBRATED ENSEMBLE MEAN PRECIPITATION PROJECTIONS FAVORS A
RELATIVELY WET SOLUTION FROM THE MISSISSIPPI VALLEY EASTWARD TO THE EAST COAST.
THE GREATEST PROBABILITIES (>40%) FOR ABOVE NORMAL PRECIPITATION ARE INDICATED
FOR THE SOUTH-CENTRAL MISSISSIPPI VALLEY AND PARTS OF ADJACENT STATES. THIS
AREA IS THE FOCUS REGION FOR STALLED FRONTS AND THUNDERSTORM CLUSTERS. BELOW
NORMAL PRECIPITATION CHANCES ARE ELEVATED OVER PORTIONS OF THE FOUR CORNERS
REGION, SUPPORTED BY THE CONSOLIDATION PRECIPITATION TOOL, AND CONSISTENT WITH
A WEAKENED AND SOUTHWARD-SHIFTED MONSOON. ABOVE NORMAL PRECIPITATION IS FAVORED
FOR MOST OF ALASKA ASSOCIATED WITH A WIDESPREAD ONSHORE FLOW REGIME AHEAD OF A
DEEP ALEUTIAN TROUGH.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 33% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: NEAR AVERAGE, 3 OUT OF 5, BASED ON
GOOD AGREEMENT AMONG THE DYNAMICAL MODEL 500-HPA HEIGHT AND SURFACE TEMPERATURE
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:
19540807 - 19940813 - 19570815 - 19970727 - 19630813
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:
20040806 - 19940813 - 19540808 - 19570813 - 19960720
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 08 - 12 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A N
SRN CALIF N N IDAHO B A NEVADA N B
W MONTANA B A E MONTANA B A WYOMING B A
UTAH N B ARIZONA A B COLORADO B B
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA A A
N TEXAS A A S TEXAS A B W TEXAS A N
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS A A LOUISIANA A A WISCONSIN B A
ILLINOIS B A MISSISSIPPI A A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY N A
TENNESSEE N A ALABAMA A A NEW YORK B A
VERMONT B A NEW HAMP B A MAINE B A
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA N 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 N AK N SLOPE A N
AK ALEUTIAN B A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 10 - 16 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A N OREGON A N NRN CALIF A N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA N N E MONTANA B A WYOMING B N
UTAH A N ARIZONA A N COLORADO B A
NEW MEXICO A N N DAKOTA B N S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA A A
N TEXAS A A S TEXAS A N W TEXAS A N
MINNESOTA B N IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A A WISCONSIN B A
ILLINOIS B A MISSISSIPPI A A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE N A ALABAMA A A NEW YORK N A
VERMONT N N NEW HAMP N A MAINE N N
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY A A W VIRGINIA N A
MARYLAND A A DELAWARE A A VIRGINIA A A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A N FL PENIN A N AK N SLOPE A N
AK ALEUTIAN B N AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A 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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