984
FXUS06 KWBC 291902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU JUNE 29 2023
6-10 DAY OUTLOOK FOR JUL 05 - 09 2023
THE GEFS, ECMWF, AND CANADIAN ENSEMBLES REMAIN IN GOOD AGREEMENT REGARDING AN
AMPLIFIED MID-LEVEL HEIGHT PATTERN ACROSS THE NORTH PACIFIC. TROUGHING IS
FORECAST ACROSS THE EASTERN BERING SEA AND WESTERN ALASKA WITH RIDGING
DOWNSTREAM OVER THE NORTHEAST PACIFIC, INCLUDING SOUTHEAST ALASKA. THE
MID-LEVEL HEIGHT PATTERN IS GENERALLY LESS AMPLIFIED OVER THE CONUS AND MORE
TRANSIENT, WITH SHORTWAVE TROUGHING PREDICTED TO DIG ACROSS THE INTERIOR WEST
AND HIGH PLAINS, EVENTUALLY SHIFTING TOWARD THE EASTERN CONUS. A TREND TOWARD
HIGHER MID-LEVEL HEIGHTS AND MORE RIDGING IS POSSIBLE ACROSS THE SOUTHWEST BY
THE END OF THE PERIOD. TODAY’S 6-10 DAY MANUAL 500-HPA HEIGHT BLEND DEPICTS
NEAR TO BELOW-NORMAL HEIGHTS ACROSS MOST OF THE CONUS. THE EXCEPTIONS ARE
ACROSS PARTS OF THE PACIFIC NORTHWEST AND NORTHEAST WHERE NEAR- TO ABOVE-NORMAL
HEIGHTS ARE FAVORED. FOR ALASKA, BELOW-NORMAL HEIGHTS ARE FAVORED ACROSS MUCH
OF THE WESTERN MAINLAND AND THE ALEUTIANS, WITH ABOVE-NORMAL HEIGHTS FORECAST
OVER EASTERN ALASKA, UNDERNEATH ANOMALOUS MID-LEVEL RIDGING.
TODAY’S GUIDANCE HAS TRENDED COOLER ACROSS PORTIONS OF THE EAST-CENTRAL CONUS
DURING THE 6-10 DAY PERIOD DUE TO SHORTWAVE TROUGHING FORECAST TO MOVE ACROSS
THE REGION ALONG WITH AN ASSOCIATED FRONTAL SYSTEM. THE UNCALIBRATED GUIDANCE
IS QUITE ROBUST IN SHOWING ENHANCED PROBABILITIES OF BELOW-NORMAL TEMPERATURES
REACHING INTO PARTS OF THE SOUTHEAST AND CENTRAL GULF COAST REGIONS. HOWEVER,
THE REFORECAST TOOLS, PARTICULARLY THE ECMWF, STILL MAINTAIN A LARGER WARM
SIGNAL OVER THESE AREAS. GIVEN THE TRENDS, A LARGER AREA OF NEAR-NORMAL
TEMPERATURES IS FORECAST COMPARED TO YESTERDAY ACROSS THE MIDDLE MISSISSIPPI
AND TENNESSEE VALLEYS INTO PARTS OF THE SOUTHEAST. PROBABILITIES FOR
BELOW-NORMAL TEMPERATURES ARE ELEVATED ACROSS MUCH OF THE NORTHERN AND CENTRAL
ROCKIES, NORTHERN AND CENTRAL PLAINS, AND UPPER AND MIDDLE MISSISSIPPI VALLEY.
ABOVE-NORMAL TEMPERATURE PROBABILITIES REMAIN INCREASED ALONG THE EASTERN
SEABOARD EXTENDING INTO PARTS OF THE OHIO VALLEY AND GREAT LAKES. CHANCES FOR
ABOVE-NORMAL TEMPERATURES ARE ALSO INCREASED ACROSS PORTIONS OF THE SOUTHERN
PLAINS AND DESERT SOUTHWEST FURTHER DISPLACED FROM THE FRONTAL SYSTEM TO THE
NORTH, AS WELL AS DUE TO A DELAYED START TO THE MONSOON AND DRIER THAN USUAL
CONDITIONS OVER THE SOUTHWEST. ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE ALSO
INCREASED ACROSS NORTHERN CALIFORNIA, PARTS OF THE GREAT BASIN, AND THE PACIFIC
NORTHWEST ASSOCIATED WITH RIDGING OVER THE NORTHEAST PACIFIC. CONVERSELY, NEAR-
TO BELOW-NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF SOUTHERN CALIFORNIA DUE TO
POTENTIAL CUT-OFF TROUGHING DEVELOPING UNDERNEATH THE RIDGE AND BELOW-NORMAL
SEA SURFACE TEMPERATURES ALONG THE COAST. INCREASED TROUGHING OVER THE BERING
SEA AND WESTERN ALASKA FAVORS LARGER PROBABILITIES FOR BELOW-NORMAL
TEMPERATURES ACROSS WESTERN AND SOUTHERN PORTIONS OF ALASKA, CONSISTENT WITH
THE GEFS AND ECMWF REFORECAST TOOLS. NEAR- TO ABOVE-NORMAL TEMPERATURES ARE
MOST FAVORED ACROSS PARTS OF SOUTHEASTERN AND NORTHERN ALASKA GIVEN CLOSER
PROXIMITY TO THE RIDGE AND SUPPORTED BY THE ECMWF GUIDANCE.
MODELS CONTINUE TO DEPICT SHORTWAVE TROUGHING AND AN ASSOCIATED FRONTAL
DISTURBANCE MOVING ACROSS THE EASTERN TWO-THIRDS OF THE CONUS DURING THE 6-10
DAY PERIOD, LEADING TO ENHANCED PRECIPITATION CHANCES OVER MANY AREAS.
PRECIPITATION TOTALS CONTINUE TO BE ELEVATED IN THE UNCALIBRATED 0Z ECMWF,
GEFS, AND CANADIAN ENSEMBLES FROM THE NORTHERN AND CENTRAL ROCKIES THROUGH THE
GREAT PLAINS, MISSISSIPPI, TENNESSEE, AND OHIO VALLEYS, AND NORTHEAST. THE
HIGHEST ABOVE-NORMAL PRECIPITATION PROBABILITIES IN TODAY’S FORECAST (GREATER
THAN 60 PERCENT) ARE FOCUSED ACROSS THE CENTRAL ROCKIES AND PLAINS GIVEN THE
LOWER PRECIPITATION CLIMATOLOGIES IN THESE AREAS. HOWEVER, A LARGER COVERAGE OF
PROBABILITIES GREATER THAN 50 PERCENT COVERS A BROAD SWATH OF THE MIDWEST INTO
THE INTERIOR NORTHEAST. BELOW-NORMAL PRECIPITATION PROBABILITIES ARE INCREASED
ACROSS THE DESERT SOUTHWEST DUE TO A SLOW START TO THE MONSOON. RIDGING ACROSS
THE NORTHEAST PACIFIC FAVORS INCREASED BELOW-NORMAL PRECIPITATION PROBABILITIES
ACROSS THE PACIFIC NORTHWEST, EXTENDING THROUGH SOUTHEAST ALASKA. TROUGHING
OVER WESTERN ALASKA AND ASSOCIATED ENHANCED SOUTHERLY FLOW FAVOR INCREASED
ABOVE-NORMAL PRECIPITATION CHANCES FOR MAINLAND ALASKA AND THE ALEUTIANS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON
DAY 8, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF
TODAY'S OPERATIONAL 0Z ECMWF 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 MODEL AGREEMENT REGARDING THE 500-HPA HEIGHT PATTERN EVOLUTION ACROSS
NORTH AMERICA, OFFSET BY A GENERALLY WEAKER FLOW PATTERN ACROSS THE CONUS.
8-14 DAY OUTLOOK FOR JUL 07 - 13 2023
THE 500-HPA HEIGHT PATTERN DURING WEEK-2 IS PREDICTED TO BE SIMILAR TO THE 6-10
DAY PERIOD. RIDGING REMAINS FAVORED ACROSS THE NORTHEAST PACIFIC AND EASTERN
CANADA, WITH A MORE ZONAL FLOW PATTERN PREDICTED ACROSS THE CONUS. THE ECMWF,
GEFS, AND CANADIAN ENSEMBLES ALL SHOW A TREND TOWARD MORE SUBTROPICAL RIDGING
TOWARD THE END OF THE PERIOD. TROUGHING IS FORECAST TO WEAKEN ACROSS THE BERING
SEA, LEADING TO HIGHER HEIGHTS OVER WESTERN ALASKA COMPARED TO THE 6-10 DAY
PERIOD. TODAY’S WEEK-2 MANUAL 500-HPA HEIGHT BLEND DEPICTS WEAKLY ABOVE-NORMAL
HEIGHTS ACROSS PARTS OF THE PACIFIC NORTHWEST AND NORTHEAST, WITH NEAR- TO
SLIGHTLY BELOW-NORMAL HEIGHTS PREDICTED ACROSS THE REMAINDER OF THE CONUS.
ABOVE-NORMAL HEIGHTS ARE FORECAST ACROSS MUCH OF EASTERN AND SOUTHERN ALASKA,
WITH NEAR-NORMAL HEIGHTS PREDICTED ACROSS PARTS OF WESTERN MAINLAND ALASKA.
MUCH LIKE IN THE 6-10 DAY PERIOD, THERE HAS BEEN A NOTICEABLE SHIFT IN THE
UNCALIBRATED GUIDANCE TOWARD RELATIVELY COOLER TEMPERATURES ACROSS MUCH OF THE
EASTERN CONUS, IN RESPONSE TO SHORTWAVE TROUGHING PREDICTED TO MOVE THROUGH
EARLY IN THE PERIOD AND ALSO CONSISTENT WITH A DEVELOPING NEGATIVE PHASE OF THE
NORTH ATLANTIC OSCILLATION IN EARLY JULY. THEREFORE, A SLIGHT TILT TOWARD
ELEVATED BELOW-NORMAL TEMPERATURE PROBABILITIES EXTENDS THROUGH MUCH OF THE
MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS, WITH LARGER PROBABILITIES FOR
BELOW-NORMAL TEMPERATURES REMAINING ACROSS THE NORTHERN AND CENTRAL ROCKIES AND
PLAINS. SLIGHTLY ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ARE
FORECAST ACROSS THE NORTHEAST. INCREASING SUBTROPICAL RIDGING LATER IN THE
PERIOD FAVORS ELEVATED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ALONG THE
SOUTHERN TIER. INCREASED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES CONTINUE TO
BE FAVORED FOR NORTHERN CALIFORNIA, PARTS OF THE GREAT BASIN, AND THE PACIFIC
NORTHWEST DUE TO RIDGING OVER THE NORTHEAST PACIFIC. NEAR- TO BELOW-NORMAL
TEMPERATURES ARE FAVORED FOR PARTS OF CALIFORNIA DUE TO POSSIBLE CUT-OFF
TROUGHING AND CONTINUED BELOW-NORMAL SEA SURFACE TEMPERATURES ALONG THE
CALIFORNIA COAST. ENHANCED ONSHORE FLOW FAVORS A PERSISTENCE OF ELEVATED
BELOW-NORMAL TEMPERATURE PROBABILITIES ACROSS MUCH OF SOUTHWESTERN ALASKA, WITH
A STRONGER INFLUENCE FROM RIDGING AND HIGHER MID-LEVEL HEIGHTS FAVORING
INCREASED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES ACROSS PARTS OF THE
SOUTHEASTERN AND NORTHERN PORTIONS OF THE STATE.
AS DISCUSSED IN THE 6-10 DAY OUTLOOK, SHORTWAVE TROUGHING IS FORECAST TO LEAD
TO A FRONTAL SYSTEM MOVING ACROSS THE CONUS EARLY IN THE WEEK-2 PERIOD. MODELS
ALSO INDICATE INCREASED POTENTIAL FOR ANOTHER SYSTEM LATER IN THE PERIOD, BUT
WITH MORE UNCERTAINTY. AS A RESULT, INCREASED PROBABILITIES OF ABOVE-NORMAL
PRECIPITATION ARE FORECAST OVER MUCH OF THE NORTHERN ROCKIES AND NORTHERN GREAT
BASIN THROUGH THE EAST, WITH THE HIGHEST PROBABILITIES (GREATER THAN
50-PERCENT) ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI, OHIO, AND TENNESSEE
VALLEYS AND INTERIOR NORTHEAST CONSISTENT WITH THE UNCALIBRATED GEFS, ECMWF,
AND CANADIAN MODELS. NEAR-TO-BELOW NORMAL PRECIPITATION CONTINUES TO BE
SLIGHTLY FAVORED FOR SOUTHEAST ALASKA AND THE PACIFIC NORTHWEST, UNDERNEATH THE
RIDGE OVER THE NORTHEAST PACIFIC. ENHANCED PROBABILITIES FOR BELOW-NORMAL
PRECIPITATION ARE ALSO FAVORED FOR PARTS OF THE SOUTHWEST AND FOUR CORNERS DUE
TO A LATE START TO THE MONSOON, AS WELL AS PARTS OF THE FLORIDA PENINSULA DUE
TO FURTHER DISPLACEMENT FROM THE FRONTAL ACTIVITY TO THE NORTH. ABOVE-NORMAL
PRECIPITATION PROBABILITIES ARE INCREASED ACROSS MOST OF MAINLAND ALASKA AND
THE ALEUTIANS, DUE TO WEST TO SOUTHWESTERLY SURFACE FLOW AND SUPPORTED BY MOST
DYNAMICAL MODEL PRECIPITATION TOOLS.
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: AVERAGE, 3 OUT OF 5, DUE TO GOOD
AGREEMENT AMONG THE MODELS, OFFSET BY A WEAK MID-LEVEL FLOW PATTERN FORECAST
ACROSS THE CONUS.
FORECASTER: THOMAS COLLOW
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
JULY 20.
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:
19920617 - 19550626 - 19520706 - 19650701 - 19550709
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:
19550626 - 19920617 - 19550708 - 19520705 - 19650630
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 05 - 09 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A A NRN CALIF A A
SRN CALIF B N IDAHO A A NEVADA A B
W MONTANA B A E MONTANA B A WYOMING B A
UTAH B B ARIZONA A B COLORADO B A
NEW MEXICO A A N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B A IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A A WISCONSIN N A
ILLINOIS N A MISSISSIPPI N A MICHIGAN A A
INDIANA N A OHIO A A KENTUCKY N A
TENNESSEE N A ALABAMA N A 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 N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A
AK S INT B A AK SO COAST B A AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 07 - 13 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF N N
SRN CALIF N N IDAHO A A NEVADA A B
W MONTANA B A E MONTANA B A WYOMING B A
UTAH N B ARIZONA A B COLORADO B A
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA N A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA N A IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A A WISCONSIN B A
ILLINOIS B A MISSISSIPPI A A MICHIGAN N A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE N A ALABAMA N A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA N A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA N A S CAROLINA N A GEORGIA A N
FL PNHDL A N FL PENIN A B AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN N A
AK S INT B A AK SO COAST B A AK PNHDL A B
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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page