894
FXUS06 KWBC 281903
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED JUNE 28 2023
6-10 DAY OUTLOOK FOR JUL 04 - 08 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 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 SLIGHTLY BELOW-NORMAL
HEIGHTS ACROSS MOST OF THE CONUS. THE EXCEPTIONS ARE ACROSS PARTS OF THE
PACIFIC NORTHWEST, GREAT LAKES, 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.
ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE INCREASED ACROSS MUCH OF THE EASTERN
HALF OF THE CONUS DUE TO ENHANCED SOUTHERLY SURFACE FLOW, ALTHOUGH THE WEAK
MID-LEVEL FLOW PATTERN GENERALLY FAVORS SMALL POSITIVE ANOMALIES IN MOST
PLACES, GENERALLY LESS THAN +5 DEG F. DRY SOILS ACROSS PARTS OF TEXAS AND THE
LOWER MISSISSIPPI VALLEY COULD LEAD TO RELATIVELY HOTTER TEMPERATURES OVER
THESE AREAS COMPARED TO SURROUNDING REGIONS. CHANCES FOR ABOVE-NORMAL
TEMPERATURES ARE ALSO INCREASED ACROSS PORTIONS OF THE DESERT SOUTHWEST AS A
RESULT OF THE DELAYED MONSOON. INCREASED PROBABILITIES FOR BELOW-NORMAL
TEMPERATURES ARE INDICATED OVER PORTIONS OF THE INTERIOR WEST AND NORTHERN AND
CENTRAL PLAINS DUE TO PREDICTED TROUGHING, AND IS ALSO SUPPORTED WITH
TELECONNECTION ANALYSIS WITH THE RIDGING FORECAST ACROSS THE NORTHEAST PACIFIC.
NEAR- TO BELOW-NORMAL TEMPERATURES ARE ALSO FAVORED FOR MUCH OF SOUTHERN
CALIFORNIA DUE TO THIS TROUGHING ALONG WITH BELOW-NORMAL SEA SURFACE
TEMPERATURES ALONG THE COAST. ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE
INCREASED ACROSS NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST UNDERNEATH THE
AFOREMENTIONED RIDGING OVER THE NORTHWEST PACIFIC. CONVERSELY, 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-NORMAL TEMPERATURES
ARE MOST FAVORED ACROSS SOUTHEASTERN ALASKA GIVEN CLOSER PROXIMITY TO THE RIDGE
AND SUPPORTED BY THE ECMWF GUIDANCE.
THE WEAK, TRANSIENT FLOW PATTERN ACROSS THE CONUS GENERALLY FAVORS INCREASED
ABOVE-NORMAL PRECIPITATION PROBABILITIES OVER MOST AREAS, WITH THE LARGEST
PROBABILITIES (GREATER THAN 50-PERCENT) ACROSS PARTS OF THE NORTHERN AND
CENTRAL ROCKIES AND PLAINS, CONSISTENT WITH PREDICTED TROUGHING, ALONG WITH THE
RELATIVELY DRIER CLIMATOLOGY COMPARED WITH FURTHER EAST. TOWARD THE END OF THE
PERIOD, PRECIPITATION CHANCES ARE PREDICTED TO INCREASE ACROSS THE EAST AS THE
SHORTWAVE TROUGHING SHIFTS EASTWARD, WITH A POTENTIAL SURFACE LOW DEVELOPING
AHEAD OF THE TROUGH, FURTHER ENHANCING PRECIPITATION. BELOW-NORMAL
PRECIPITATION PROBABILITIES ARE SLIGHTLY INCREASED ACROSS THE DESERT SOUTHWEST
DUE TO A SLOW START TO THE MONSOON, ALTHOUGH INCREASING TROPICAL ACTIVITY IN
THE EAST PACIFIC COULD TRIGGER ISOLATED CONVECTION EARLY IN THE PERIOD,
ALTHOUGH CONFIDENCE REMAINS LOW. 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, 30% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN CENTERED ON DAY 8, 5% OF
TODAY'S OPERATIONAL 0Z ECMWF CENTERED ON DAY 8, AND 30% 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 06 - 12 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 NORTHWESTERN MAINLAND ALASKA.
INCREASED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED
FOR NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST DUE TO RIDGING OVER THE
NORTHEAST PACIFIC. NEAR- TO BELOW-NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF
CALIFORNIA, EXTENDING THROUGH MUCH OF THE INTERIOR WEST AND NORTHERN AND
CENTRAL PLAINS DUE TO STRONGER INFLUENCE FROM TROUGHING AND CONTINUED
BELOW-NORMAL SEA SURFACE TEMPERATURES ALONG THE CALIFORNIA COAST. PROBABILITIES
FOR ABOVE-NORMAL TEMPERATURES REMAIN ELEVATED ACROSS MUCH OF THE EASTERN CONUS
UNDERNEATH A WEAK MID-LEVEL FLOW PATTERN. HOWEVER, PROBABILITIES ARE REDUCED
COMPARED TO THE 6-10 DAY PERIOD DUE TO A TREND TOWARD MORE TROUGHING AND A
POTENTIAL FRONTAL SYSTEM WHICH MAY LOWER TEMPERATURES BY THE MIDDLE OF THE
PERIOD. THIS IS ALSO CONSISTENT WITH THE PREDICTED DEVELOPMENT OF A NEGATIVE
PHASE OF THE NORTH ATLANTIC OSCILLATION IN EARLY-JULY. SUBTROPICAL RIDGING IS
FORECAST TO AGAIN INCREASE IN THE WAKE OF THE SHORTWAVE DISTURBANCE MOVING
THROUGH THE EAST, FAVORING ENHANCED PROBABILITIES OF ABOVE-NORMAL TEMPERATURES
ACROSS THE SOUTHERN TIER OF THE CONUS. 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 SOUTHEASTERN AND NORTHERN PORTIONS OF THE STATE.
SHORTWAVE TROUGHING IS FORECAST TO MOVE FROM THE NORTHERN ROCKIES AND PLAINS
INTO THE EASTERN CONUS, LEADING TO A POTENTIAL AREA OF SURFACE LOW PRESSURE AND
ASSOCIATED FRONTAL SYSTEM. THIS FAVORS INCREASED PROBABILITIES OF ABOVE-NORMAL
PRECIPITATION OVER MUCH OF THE NORTHERN ROCKIES AND GREAT BASIN THROUGH THE
EAST, WITH THE HIGHEST PROBABILITIES (GREATER THAN 50-PERCENT) ACROSS PORTIONS
OF THE MIDDLE MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS, CONSISTENT WITH THE
LARGEST POSITIVE WEEK-2 TOTAL PRECIPITATION ANOMALIES IN THE GEFS AND ECMWF
ENSEMBLES. 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. ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE INCREASED ACROSS MOST
OF ALASKA, 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: 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: 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:
19920616 - 19550626 - 19960711 - 19520707 - 19580708
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:
19920616 - 19550625 - 19520707 - 19650630 - 19580708
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 04 - 08 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 A
W MONTANA N A E MONTANA B A WYOMING B A
UTAH N A ARIZONA A B COLORADO B A
NEW MEXICO A N N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS N A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A 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 A FL PENIN A N AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL N B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 06 - 12 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A N NRN CALIF N N
SRN CALIF B N IDAHO A A NEVADA N B
W MONTANA N A E MONTANA B A WYOMING B A
UTAH N B ARIZONA N B COLORADO B A
NEW MEXICO A B N DAKOTA N A S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA N A IOWA N A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN N A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY N A
TENNESSEE N A ALABAMA A A NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS N 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 N 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.
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