623
FXUS06 KWBC 301902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI JUNE 30 2023
6-10 DAY OUTLOOK FOR JUL 06 - 10 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 EASTERN ALASKA. THERE ARE ALSO
INDICATIONS, PARTICULARLY IN THE ECMWF AND CANADIAN ENSEMBLES, OF WEAK
TROUGHING DEVELOPING ALONG THE WEST COAST OF THE CONUS TOWARD THE MIDDLE OF THE
PERIOD. ACROSS THE REMAINDER OF THE CONUS, THE DOMINANT FEATURE IS FORECAST TO
BE A SHORTWAVE TROUGH MOVING FROM THE ROCKIES TOWARD THE EAST COAST, WHICH HAS
CONTINUED TO TREND MORE AMPLIFIED IN TODAY’S MODEL GUIDANCE. A TREND TOWARD
HIGHER MID-LEVEL HEIGHTS AND MORE RIDGING IS POSSIBLE ACROSS THE SOUTHWEST BY
THE END OF THE PERIOD AS THE SHORTWAVE TROUGHING MOVES FURTHER DOWNSTREAM.
TODAY’S 6-10 DAY MANUAL 500-HPA HEIGHT BLEND DEPICTS NEAR TO BELOW-NORMAL
HEIGHTS ACROSS MOST OF THE CONUS, WITH A -30 M NEGATIVE HEIGHT ANOMALY CENTER
DEPICTED ACROSS PORTIONS OF THE NORTHERN AND CENTRAL PLAINS, UPPER MISSISSIPPI
VALLEY, AND WESTERN GREAT LAKES. ABOVE-NORMAL HEIGHTS ARE FAVORED ACROSS
PORTIONS OF THE PACIFIC NORTHWEST AND NORTHEAST CLOSER TO ANOMALOUS MID-LEVEL
RIDGES OVER THE NORTHEAST PACIFIC AND THE NORTHWEST ATLANTIC RESPECTIVELY. FOR
ALASKA, BELOW-NORMAL HEIGHTS ARE FAVORED ACROSS THE EXTREME WESTERN MAINLAND
AND THE ALEUTIANS, WITH ABOVE-NORMAL HEIGHTS FORECAST OVER EASTERN ALASKA,
UNDERNEATH ANOMALOUS MID-LEVEL RIDGING.
SHORTWAVE TROUGHING AND AN ASSOCIATED FRONTAL SYSTEM IS LIKELY TO RESULT IN
COOLER TEMPERATURES SPREADING EASTWARD AND SOUTHWARD ACROSS THE CONUS. THE
UNCALIBRATED GUIDANCE CONTINUES TO DEPICT ENHANCED PROBABILITIES OF
BELOW-NORMAL TEMPERATURES REACHING INTO PARTS OF THE SOUTHEAST AND CENTRAL GULF
COAST REGIONS. HOWEVER, THE GEFS AND ECMWF REFORECAST TOOLS MAINTAIN A LARGER
WARM SIGNAL OVER THESE AREAS. PROBABILITIES FOR BELOW-NORMAL TEMPERATURES ARE
ELEVATED ACROSS MUCH OF THE NORTHERN AND CENTRAL ROCKIES, EXTENDING EASTWARD
THROUGH MUCH OF THE MIDWEST, AND THE OHIO AND TENNESSEE VALLEYS. ABOVE-NORMAL
TEMPERATURE PROBABILITIES REMAIN INCREASED ACROSS PORTIONS OF THE SOUTHEAST AND
NORTHEAST. 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 BUILDING SUBTROPICAL RIDGING
LATER IN THE PERIOD. ABOVE-NORMAL TEMPERATURE PROBABILITIES EXTEND THROUGH
NORTHERN CALIFORNIA, PARTS OF THE GREAT BASIN, AND THE PACIFIC NORTHWEST TIED
TO RIDGING OVER THE NORTHEAST PACIFIC. CONVERSELY, NEAR- TO BELOW-NORMAL
TEMPERATURES ARE FAVORED FOR MUCH OF CENTRAL AND 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 CONSOLIDATION TOOL. NEAR- TO ABOVE-NORMAL
TEMPERATURES ARE MOST FAVORED ACROSS PARTS OF EASTERN 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
PERIOD. 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,
MID-ATLANTIC, AND NORTHEAST COINCIDING WITH INCREASED ABOVE-NORMAL
PRECIPITATION PROBABILITIES. WHILE MUCH OF THE ATTENTION IS FORECAST TO BE ON
THIS INITIAL SYSTEM WHICH IS FORECAST TO REACH THE NORTHEAST TOWARD THE END OF
THE PERIOD, MODELS INDICATE THE POTENTIAL DEVELOPMENT OF A SECOND SYSTEM ACROSS
THE MIDWEST WHICH COULD RESULT IN ELEVATED PRECIPITATION CHANCES PERSISTING
INTO WEEK-2. 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 EXTREME NORTHWESTERN OREGON AND WESTERN WASHINGTON, EXTENDING THROUGH
SOUTHEAST ALASKA. TROUGHING OVER WESTERN ALASKA AND ASSOCIATED ENHANCED
SOUTHERLY FLOW FAVOR INCREASED ABOVE-NORMAL PRECIPITATION CHANCES FOR MUCH OF
MAINLAND ALASKA AND THE ALEUTIANS.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF TODAY'S OPERATIONAL 0Z GFS CENTERED ON
DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF
TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 15% 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 SOME UNCERTAINTY REGARDING THE SPREAD OF BELOW-NORMAL
TEMPERATURES INTO THE EASTERN CONUS.
8-14 DAY OUTLOOK FOR JUL 08 - 14 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 NORTHWEST
ATLANTIC, WITH A MORE ZONAL FLOW PATTERN PREDICTED ACROSS THE CONUS, ALTHOUGH
THE GENERAL PATTERN IS LIKELY TO BE INCREASING SUBTROPICAL RIDGING ACROSS THE
SOUTHERN TIER, WITH WEAK TROUGHING REMAINING ACROSS THE EAST-CENTRAL CONUS
CONSISTENT WITH A FORECAST NEGATIVE PHASE OF THE NORTH ATLANTIC OSCILLATION
DURING EARLY- TO MID-JULY. TROUGHING IS FORECAST TO WEAKEN ACROSS THE BERING
SEA, ALONG WITH A RETROGRESSION OF THE RIDGING ACROSS THE NORTHEAST PACIFIC,
LEADING TO HIGHER HEIGHTS OVER WESTERN ALASKA COMPARED TO THE 6-10 DAY PERIOD.
TODAY’S WEEK-2 MANUAL 500-HPA HEIGHT BLEND DEPICTS ABOVE-NORMAL HEIGHTS ACROSS
PARTS OF THE NORTHEAST GIVEN INCREASING SOUTHERLY MID-LEVEL FLOW AHEAD OF
TROUGHING, AND NEAR-NORMAL HEIGHTS ACROSS MUCH OF THE REMAINDER OF THE CONUS.
ABOVE-NORMAL HEIGHTS ARE FORECAST ACROSS MOST OF ALASKA.
DURING WEEK-2, INCREASED PROBABILITIES FOR BELOW-NORMAL TEMPERATURES ARE
FORECAST OVER THE CENTRAL ROCKIES AND PLAINS, MIDWEST, TENNESSEE VALLEY, AND
SPREADING EASTWARD INTO PARTS OF THE INTERIOR MID-ATLANTIC AND NORTHEAST. A
TILT TOWARD INCREASED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES IS FORECAST
ACROSS NEW ENGLAND WHERE SLIGHTLY ABOVE-NORMAL MID-LEVEL HEIGHTS ARE PREDICTED
DUE TO RIDGING OVER THE NORTHWEST ATLANTIC. INCREASING SUBTROPICAL RIDGING
FAVORS ELEVATED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ALONG THE SOUTHERN
TIER, ESPECIALLY ACROSS PORTIONS OF THE DESERT SOUTHWEST AND TEXAS WHERE
RENEWED EXCESSIVE HEAT CONCERNS ARE PREDICTED DURING THE PERIOD. THERE IS A BIT
MORE UNCERTAINTY ACROSS PORTIONS OF THE SOUTHEAST, ESPECIALLY NORTHERN AREAS,
WITH THE UNCALIBRATED TOOLS CONTINUING TO FAVOR A COLDER SOLUTION COMPARED TO
THE REFORECAST TOOLS. INCREASED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES
CONTINUE TO BE FAVORED FOR THE NORTHWESTERN CONUS, EXTENDING THROUGH THE GREAT
BASIN DUE TO RIDGING OVER THE NORTHEAST PACIFIC AND SUPPORTED BY THE GEFS AND
ECMWF REFORECAST TOOLS. NEAR- TO BELOW-NORMAL TEMPERATURES ARE FAVORED FOR
PARTS OF CALIFORNIA AND WESTERN NEVADA 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 EASTERN 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 EASTERN CONUS EARLY IN THE WEEK-2 PERIOD.
MODELS ALSO INDICATE INCREASED POTENTIAL FOR ANOTHER SYSTEM LATER IN THE PERIOD
WHICH COULD FURTHER ENHANCE PRECIPITATION TOTALS. AS A RESULT, INCREASED
PROBABILITIES OF ABOVE-NORMAL PRECIPITATION ARE FORECAST OVER PARTS OF THE
NORTHWEST CONUS AND EXTENDING THROUGH THROUGH MUCH OF THE EAST, WITH THE
HIGHEST PROBABILITIES (GREATER THAN 50-PERCENT) ACROSS PORTIONS OF THE
NORTHEAST WHERE THE HIGHEST WEEK-2 PRECIPITATION TOTALS ARE DEPICTED IN THE 0Z
ECMWF, GEFS, AND CANADIAN ENSEMBLES. THIS IS ALSO CONSISTENT WITH SUMMERTIME EL
NINO CLIMATOLOGY, AND ALSO SUPPORTED BY STATISTICAL ANALOG GUIDANCE.
NEAR-TO-BELOW NORMAL PRECIPITATION CONTINUES TO BE SLIGHTLY FAVORED FOR
SOUTHEAST ALASKA, UNDERNEATH THE RIDGE OVER THE NORTHEAST PACIFIC. ENHANCED
PROBABILITIES FOR BELOW-NORMAL PRECIPITATION ARE ALSO FAVORED FOR PARTS OF THE
SOUTHWEST, FOUR CORNERS, AND SOUTHERN HIGH PLAINS DUE TO A LATE START TO THE
MONSOON. NEAR- TO 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: 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG THE MODELS REGARDING A TREND TOWARD MORE SUBTROPICAL
RIDGING, OFFSET BY UNCERTAINTY REGARDING ITS NORTHWARD EXTENT, ESPECIALLY
ACROSS THE SOUTHEAST.
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:
19550626 - 19520706 - 19920617 - 19550710 - 19700704
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 - 19550710 - 19520704 - 19700703 - 19920618
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 06 - 10 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF B A
SRN CALIF B N IDAHO A A NEVADA A B
W MONTANA A A E MONTANA B A WYOMING B A
UTAH A 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 B A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA B N IOWA B A MISSOURI B A
ARKANSAS N A LOUISIANA A A WISCONSIN B N
ILLINOIS B A MISSISSIPPI N A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE B 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 N A
MARYLAND A A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A A GEORGIA A A
FL PNHDL A A 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 N AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 08 - 14 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF N B
SRN CALIF N N IDAHO A A NEVADA A B
W MONTANA A A E MONTANA B A WYOMING B A
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A B N DAKOTA N A S DAKOTA B A
NEBRASKA B A KANSAS N A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA N A IOWA B A MISSOURI B A
ARKANSAS A A LOUISIANA A N WISCONSIN B A
ILLINOIS B A MISSISSIPPI A N MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY B A
TENNESSEE B A ALABAMA N A NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS N A CONN N A RHODE IS N A
PENN B A NEW JERSEY N A W VIRGINIA B A
MARYLAND B A DELAWARE N A VIRGINIA B A
N CAROLINA B A S CAROLINA N A GEORGIA N A
FL PNHDL A N FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B N AK INT BSN A A
AK S INT B N AK SO COAST B N 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.
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