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FXUS06 KWBC 211924
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT FRI JULY 21 2023
6-10 DAY OUTLOOK FOR JUL 27 - 31 2023
MODEL SOLUTIONS REMAIN IN GOOD AGREEMENT AND CONSISTENT THAT THE PERSISTENT
ANOMALOUS 500-HPA RIDGE, INITIALLY OVER THE WESTERN AND SOUTHERN CONUS, EXPANDS
NORTHEASTWARD DURING LATE JULY. THIS WOULD LEAD TO A WARMING TREND ACROSS THE
MIDWEST, NORTHEAST, AND MID-ATLANTIC NEXT WEEK. FOR THESE AREAS, THE ENSEMBLE
MEANS HAVE CONVERGED ON A COMMON SOLUTION WITH POSITIVE 500-HPA HEIGHT
DEPARTURES PEAKING TO MORE THAN 60 METERS FOR THE FIRST HALF OF THE 6-10 DAY
PERIOD. HOWEVER, BY JULY 30TH, THE ENSEMBLE MEANS DEPICT AN AMPLIFYING TROUGH
OVER SOUTHEASTERN CANADA WITH DECREASING 500-HPA HEIGHTS ACROSS THE GREAT LAKES
AND NORTHEAST. ELSEWHERE, A 500-HPA TROUGH IS FORECAST OVER EASTERN SIBERIA AND
THE BERING SEA, WITH SHORTWAVE ENERGY PIVOTING THROUGH THE BASE OF THE TROUGH,
AND A RIDGE IS PREDICTED OVER THE VICINITY OF THE CANADIAN YUKON. A WEAK
MID-LEVEL TROUGH IS ANTICIPATED NEAR THE PACIFIC NORTHWEST COAST.
THE EXPANSIVE AND ANOMALOUS 500-HPA RIDGE FAVORS ABOVE-NORMAL TEMPERATURES FOR
MOST OF THE LOWER 48 STATES WITH A LARGE SPATIAL EXTENT OF 70 PERCENT
PROBABILITIES AND EVEN A 80 PERCENT CHANCE ACROSS THE CENTRAL GREAT PLAINS AND
MIDDLE MISSISSIPPI VALLEY. REFORECAST TEMPERATURES FROM THE VARIOUS ENSEMBLE
MEANS AGREE ON NEAR TO BELOW-NORMAL TEMPERATURES BEING FAVORED FOR MOST OF
WASHINGTON AND OREGON, AND AT LEAST PORTIONS OF NORTHERN CALIFORNIA. THESE
SURFACE TEMPERATURE ANOMALIES ARE ALSO CONSISTENT WITH THE PROXIMITY OF A
MID-LEVEL TROUGH AND NEAR-NORMAL 500-HPA HEIGHTS. THE LAST TWO RUNS (0Z TODAY
AND 12Z YESTERDAY) OF THE EUROPEAN ENSEMBLE MEAN CALIBRATED 2-METER
TEMPERATURES ALSO CONCUR WITH THE REFORECAST TEMPERATURES ON THE EXPECTED
NATIONAL TEMPERATURE PATTERN. MOST OF ALASKA IS FAVORED TO HAVE ABOVE-NORMAL
TEMPERATURES DURING THE 6-10 DAY PERIOD DUE TO MID-LEVEL RIDGING AND WELL
ABOVE-NORMAL 500-HPA HEIGHTS. THE EXCEPTION IS SOUTHWESTERN ALASKA, WHERE A
NEARBY MID-LEVEL TROUGH, RELATIVELY COOL SEA SURFACE TEMPERATURES OFFSHORE AND
REFORECAST TEMPERATURE TOOLS FAVOR NEAR- TO BELOW-NORMAL TEMPERATURES.
THE EXPANDING RIDGE WITH RISING 500-HPA HEIGHTS IS LIKELY TO SUPPRESS SUMMER
CONVECTION ACROSS THE SOUTHERN TIER OF THE CENTRAL AND EASTERN CONUS. THE
EXCEPTION IS THE FLORIDA PENINSULA, WHICH IS FORECAST TO REMAIN NEAR OR SOUTH
OF A SURFACE RIDGE AXIS. FARTHER TO THE NORTH AND CLOSER TO THE MID-LEVEL
WESTERLIES AND ASSOCIATED FRONTAL ACTIVITY, NEAR NORMAL PRECIPITATION AMOUNTS
OR A SLIGHT LEAN TOWARDS ABOVE-NORMAL PRECIPITATION IS FORECAST FROM THE
NORTHERN GREAT PLAINS AND NEBRASKA EASTWARD ACROSS THE UPPER MISSISSIPPI
VALLEY, GREAT LAKES REGION, NORTHERN OHIO VALLEY, NORTHERN HALF OF THE
APPALACHIANS AND THE INTERIOR NORTHEAST. THUNDERSTORM CLUSTERS (KNOWN AS MCS’S)
HAVE BEEN OBSERVED IN THE PAST WEEK TO MOVE SOUTHEASTWARD NEAR THE SOUTHERN
EDGE OF THE WESTERLIES. THIS INCLUDES AREAS FROM SOUTHERN MISSOURI TO
TENNESSEE, AND MCS ACTIVITY IS EXPECTED TO SHIFT A BIT NORTHWARD DURING THE
6-10 DAY FORECAST PERIOD. IN THE SOUTHWEST, THE WESTERN FLANK OF THE
SUBTROPICAL RIDGE IS PREDICTED TO BE CENTERED NEAR THE FOUR CORNERS REGION, A
FAVORABLE LOCATION FOR AN ENHANCED MONSOON. HOWEVER, THE STRENGTH OF THE
RIDGING ALOFT MAY OFFSET THE FAVORABLE MONSOON CIRCULATION PATTERN. NEAR NORMAL
PRECIPITATION AMOUNTS ARE FORECAST FOR MUCH OF THE SOUTHWEST WITH SLIGHTLY
ELEVATED ABOVE-NORMAL PRECIPITATION PROBABILITIES LIMITED TO SOUTHWESTERN
ARIZONA AND SOUTHEASTERN CALIFORNIA. FARTHER TO THE NORTH ACROSS MUCH OF THE
INTERMOUNTAIN WEST, TOOLS ARE LEANING TOWARDS BELOW-NORMAL PRECIPITATION. THE
EXCEPTIONS INCLUDE WASHINGTON, NORTHERN IDAHO AND MONTANA, WHERE NEAR TO
ABOVE-NORMAL PRECIPITATION AMOUNTS ARE FAVORED IN ADVANCE OF A MID-LEVEL
TROUGH. ABOVE-NORMAL PRECIPITATION IS FAVORED OVER ALL BUT SOUTHERNMOST
PORTIONS OF ALASKA, DUE TO AN APPROACHING MID-LEVEL TROUGH AND ONSHORE FLOW.
NEAR TO BELOW-NORMAL PRECIPITATION IS FAVORED OVER SOUTHERNMOST PORTIONS OF
ALASKA, IN AN AREA MORE DOMINATED BY MID-LEVEL RIDGING AND POSITIVE 500-HPA
HEIGHT ANOMALIES.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 34% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 33% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON DAY
8
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO GOOD
MODEL AGREEMENT ON THE 500-HPA HEIGHT PATTERN AND TEMPERATURE TOOLS OFFSET BY
CONTINUED WEAK SIGNALS AMONG THE PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR JUL 29 - AUG 04, 2023
ENSEMBLE MEANS ARE IN GOOD AGREEMENT THAT THE MID-LEVEL RIDGING PEAKS IN
STRENGTH ACROSS THE EASTERN AND NORTH-CENTRAL CONUS AT THE BEGINNING OF WEEK-2,
WHILE A TROUGH AMPLIFIES OVER SOUTHEASTERN CANADA AND EXPANDS SOUTHWARD ACROSS
THE GREAT LAKES AND NORTHEAST. OTHER MEAN CIRCULATION FEATURES AT 500-HPA
INCLUDE TROUGHS OVER EASTERN SIBERIA/BERING SEA AND NEAR THE PACIFIC NORTHWEST
COAST, AND RIDGING OVER THE VICINITY OF THE CANADIAN YUKON.
ANOMALOUS HEAT EARLY IN WEEK-2 ACROSS THE GREAT LAKES, NORTHEAST, AND NORTHERN
MID-ATLANTIC REGION IS FAVORED TO GIVE WAY TO NEAR- AND BELOW-NORMAL
TEMPERATURES LATER IN WEEK-2, AS A MID-LEVEL TROUGH ADVANCES SOUTHWARD ACROSS
THE REGION. INCREASED CLOUDINESS AND LIGHT PRECIPITATION AHEAD OF THE MID-LEVEL
TROUGH OFF THE PACIFIC NORTHWEST COAST IS EXPECTED TO BRING NEAR-NORMAL SURFACE
TEMPERATURES FOR THE LOWLANDS OF WESTERN WASHINGTON. ELSEWHERE ACROSS THE
CONUS, THERE ARE ELEVATED PROBABILITIES FAVORING ABOVE-NORMAL TEMPERATURES,
WITH 70% OR GREATER ODDS FOR ANOMALOUS HEAT ACROSS THE GULF COAST REGION, LOWER
MISSISSIPPI VALLEY, AND EASTERN SECTIONS OF THE SOUTHERN PLAINS. THESE MAXIMUM
PROBABILITIES FAVORING ABOVE-NORMAL TEMPERATURES ARE PREDICTED TO BE LOCATED
ALONG THE AMPLIFIED RIDGE AXIS AND ARE SUPPORTED BY THE VARIOUS TEMPERATURE
TOOLS. THE WEEK-2 ALASKA TEMPERATURE OUTLOOK IS SIMILAR TO ITS EARLIER 6-10 DAY
TEMPERATURE OUTLOOK, FAVORING ABOVE-NORMAL TEMPERATURES OVER MOST OF EASTERN
AND CENTRAL ALASKA, AND NEAR- TO BELOW-NORMAL TEMPERATURES OVER THE WESTERN
MAINLAND, ALASKA PENINSULA, AND THE ALEUTIANS.
THE PRECIPITATION TOOLS CONTINUE TO OFFER WEAK OR CONFLICTING SIGNALS
THROUGHOUT THE FORECAST DOMAIN, WHICH IS TYPICAL FOR MID-SUMMER. THE WEEK-2
PRECIPITATION OUTLOOK WAS PRIMARILY BASED ON THE CONSOLIDATION TOOL
(SKILL-BASED GEFS AND ECMWF REFORECASTS) AND THE AUTOMATED PRECIPITATION TOOL.
NEAR THE WESTERN AND NORTHERN FLANKS OF THE STRONG CONUS RIDGE, THERE ARE
MODEST TILTS IN THE ODDS FOR ABOVE-NORMAL PRECIPITATION FROM CALIFORNIA AND
WESTERN ARIZONA NORTHEASTWARD ACROSS MOST OF THE INTERMOUNTAIN REGION AND
ROCKIES, AND MOST OF THE NORTHERN HALF OF THE GREAT PLAINS REGION. THE MOISTURE
SOURCES FOR THIS BROAD REGION INCLUDE THE SOUTHWEST MONSOON, THE WEST COAST
TROUGH, AND INDIVIDUAL DISTURBANCES ASSOCIATED WITH THE WESTERLIES AND
ACCOMPANYING FRONTAL SYSTEMS. ABOVE NORMAL PRECIPITATION IS ALSO FAVORED OVER
MUCH OF THE NORTHEASTERN QUARTER OF THE CONUS, ATTRIBUTED TO AN AMPLIFYING
500-HPA TROUGH, ONE OR MORE WEATHER FRONTS, AND MCS ACTIVITY (THE LAST BEING
FOCUSED MORE TOWARDS THE SOUTHERN EDGE OF THE PREVAILING WESTERLIES).
ABOVE-NORMAL PRECIPITATION IS ALSO ANTICIPATED OVER THE NORTHERN AND CENTRAL
ALASKA MAINLAND, IN THE ONSHORE FLOW ASSOCIATED WITH AN APPROACHING MID-LEVEL
TROUGH. ODDS FAVOR BELOW-NORMAL PRECIPITATION FROM NEW MEXICO GENERALLY
EASTWARD ACROSS THE SOUTH-CENTRAL PLAINS, LOWER MISSISSIPPI VALLEY, AND
PORTIONS OF THE EAST-CENTRAL GULF COAST. THIS AREA CORRESPONDS TO THE VICINITY
OF THE SUBTROPICAL RIDGE AXIS ACROSS THE SOUTHERN CONUS. BELOW-NORMAL
PRECIPITATION IS ALSO FAVORED OVER THE ALASKA PENINSULA AND PORTIONS OF
SOUTHEAST ALASKA, SUPPORTED BY THE AUTOMATED TEMPERATURE TOOL, AND CONSISTENT
WITH SOME RIDGING/POSITIVE 500-HPA HEIGHT ANOMALIES IN THE REGION.
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 HIGH
CONFIDENCE IN THE TEMPERATURE OUTLOOK OFFSET BY LOWER CONFIDENCE IN THE
PRECIPITATION OUTLOOK.
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:
19980731 - 19670713 - 19790716 - 19960723 - 19930730
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:
19980731 - 19790715 - 19930730 - 19670713 - 20030710
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 27 - 31 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N N OREGON N B NRN CALIF N N
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A N E MONTANA A A WYOMING A N
UTAH A B ARIZONA A N COLORADO A N
NEW MEXICO A B N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A N OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A A IOWA A A MISSOURI A N
ARKANSAS A B LOUISIANA A B WISCONSIN A A
ILLINOIS A N MISSISSIPPI A B MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A N
TENNESSEE A N ALABAMA A B NEW YORK A A
VERMONT A A NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A A NEW JERSEY A N W VIRGINIA A A
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA A B S CAROLINA A B GEORGIA A B
FL PNHDL A B FL PENIN A N AK N SLOPE A A
AK ALEUTIAN N N AK WESTERN N A AK INT BSN A A
AK S INT A N AK SO COAST A N AK PNHDL A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 29 - AUG 04, 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 A N E MONTANA A A WYOMING A N
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A N N DAKOTA A N S DAKOTA A N
NEBRASKA A N KANSAS A N OKLAHOMA A N
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A N LOUISIANA A N WISCONSIN A N
ILLINOIS A N MISSISSIPPI A N MICHIGAN N N
INDIANA A N OHIO A N KENTUCKY A N
TENNESSEE A N ALABAMA A N NEW YORK N N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN N N RHODE IS N N
PENN N N NEW JERSEY N N W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A 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 N N AK WESTERN N A AK INT BSN A A
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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