829
FXUS06 KWBC 191902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT WED JULY 19 2023
6-10 DAY OUTLOOK FOR JUL 25 - 29 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 PATTERN CHANGE ACROSS THE
EASTERN CONUS WHERE THE ENSEMBLE MEANS DEPICT A FLIP FROM BELOW TO ABOVE NORMAL
500-HPA HEIGHTS. THE ECMWF ENSEMBLE MEAN IS THE MOST BULLISH WITH THIS PATTERN
CHANGE AND FEATURES DAILY POSITIVE 500-HPA HEIGHT ANOMALIES OF MORE THAN 60
METERS EXTENDING FROM THE MIDWEST EASTWARD TO THE NORTHEAST BY DAY 8, JULY 27.
REGARDLESS OF THE STRENGTH OF THE MID-LEVEL RIDGING EXPANDING NORTH AND EAST
WITH TIME, MODEL SOLUTIONS FOR THE SECOND CONSECUTIVE DAY ARE SUPPORTING A
WARMING TREND FROM THE MISSISSIPPI VALLEY TO THE EAST COAST DURING THE 6-10 DAY
PERIOD. THE GFS, ECMWF, AND CANADIAN ENSEMBLE MEANS DEPICT POSITIVE 500-HPA
HEIGHT ANOMALIES THROUGHOUT NEARLY THE ENTIRE CONUS WITH SMALL NEGATIVE
ANOMALIES LIMITED TO WASHINGTON. THE EXPANSIVE AND ANOMALOUS 500-HPA RIDGE
FAVORS ABOVE-NORMAL TEMPERATURES FOR MOST OF THE LOWER 48 STATES WITH THE
LARGEST PROBABILITIES (MORE THAN 70 PERCENT) FORECAST ACROSS THE SOUTHWEST,
GREAT PLAINS, AND WESTERN CORN BELT UNDERNEATH THE AMPLIFIED RIDGE AXIS. A
TROUGH WITH BELOW-NORMAL HEIGHTS ON DAYS 6 AND 7 SLIGHTLY ELEVATES BELOW NORMAL
TEMPERATURE PROBABILITIES ACROSS PARTS OF THE PACIFIC NORTHWEST.
THE EXPANDING RIDGE WITH RISING 500-HEIGHTS IS LIKELY TO SUPPRESS SUMMER
CONVECTION ACROSS THE SOUTHERN TIER OF THE CENTRAL AND EASTERN CONUS. FARTHER
TO THE NORTH AND CLOSER TO THE MID-LEVEL WESTERLIES, NEAR NORMAL PRECIPITATION
AMOUNTS OR A SLIGHT LEAN TOWARDS ABOVE-NORMAL PRECIPITATION IS FORECAST FOR THE
NORTHERN GREAT PLAINS, GREAT LAKES, NORTHEAST, AND MID-ATLANTIC. A SHORTWAVE
TROUGH SLIGHTLY FAVORS ABOVE-NORMAL PRECIPITATION ACROSS PARTS OF THE PACIFIC
NORTHWEST, WHILE BELOW-NORMAL PRECIPITATION IS MORE LIKELY FARTHER TO THE SOUTH
ACROSS THE GREAT BASIN. A MODERATE MONSOON CIRCULATION WITH NEAR NORMAL
PRECIPITATION AMOUNTS FOR THIS 5-DAY PERIOD IS MOST LIKELY FOR THE SOUTHWEST AS
A FAVORABLE 500-HPA RIDGE AXIS OVER THE FOUR CORNERS REGION IS OFFSET BY THE
STRENGTH OF THE RIDGING ALOFT.
INCREASED ABOVE-NORMAL TEMPERATURE PROBABILITIES ARE FORECAST FOR NEARLY ALL OF
ALASKA DUE TO THE POSITIVE 500-HPA HEIGHT ANOMALIES, BUT NEAR NORMAL
TEMPERATURES ARE FAVORED FOR PARTS OF SOUTHEASTERN ALASKA AND THE ALEUTIANS
CLOSER TO A COUPLE OF TROUGHS. DOWNSTREAM OF A TROUGH OVER THE BERING SEA,
INCREASED CHANCES OF ABOVE-NORMAL PRECIPITATION ARE FORECAST FOR NORTHERN AND
EASTERN MAINLAND ALASKA.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
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: AVERAGE, 3 OUT OF 5, DUE TO GOOD
MODEL AGREEMENT ON THE 500-HPA HEIGHT PATTERN AND TEMPERATURE TOOLS OFFSET BY
WEAK SIGNALS AMONG THE PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR JUL 27 - AUG 02, 2023
ENSEMBLE MEANS ARE IN REASONABLY GOOD AGREEMENT THAT THE MID-LEVEL RIDGING
PEAKS IN STRENGTH ACROSS THE EASTERN CONUS EARLY IN WEEK-2, WHILE ANOMALOUS
RIDGING PERSISTS OVER MUCH OF THE WESTERN AND CENTRAL CONUS INTO THE BEGINNING
OF AUGUST. FOLLOWING A TRANSIENT SHORTWAVE TROUGH DURING THE 6-10 DAY PERIOD
ACROSS THE PACIFIC NORTHWEST, 500-HPA HEIGHTS ARE FORECAST TO INCREASE BY
WEEK-2. SINCE THE ENSEMBLE MEANS DEPICT POSITIVE 500-HPA HEIGHT ANOMALIES
THROUGHOUT NORTH AMERICA AND CONSISTENT WITH THE REFORECAST TOOLS, ABOVE-NORMAL
TEMPERATURES ARE THE LIKELY OUTCOME FOR NEARLY THE ENTIRE CONUS. THE LARGEST
PROBABILITIES (ABOVE 70 PERCENT) FOR ABOVE-NORMAL TEMPERATURES ARE FORECAST
ACROSS THE CENTRAL TO SOUTHERN GREAT PLAINS AND OZARKS REGION, PREDICTED TO BE
LOCATED ALONG THE AMPLIFIED RIDGE AXIS AND SUPPORTED BY THE TEMPERATURE TOOLS.
TYPICAL FOR MID-SUMMER, THE PRECIPITATION TOOLS OFFER WEAK SIGNALS THROUGHOUT
THE FORECAST DOMAIN. THE WEEK-2 PRECIPITATION OUTLOOK WAS PRIMARILY BASED ON
THE CONSOLIDATION TOOL (SKILL-BASED GEFS AND ECMWF REFORECASTS) AND THE ANALOG
TOOL DERIVED FROM THE 500-HPA HEIGHT BLEND. THE PREDICTED RIDGE ALOFT SUPPORTS
ELEVATED BELOW-NORMAL PRECIPITATION PROBABILITIES ACROSS THE SOUTH-CENTRAL
CONUS. NORTHWEST FLOW ALOFT ALONG WITH ENHANCED LOW-LEVEL MOISTURE (MONSOONAL
AND FROM THE GULF OF MEXICO) FAVORS NEAR TO ABOVE-NORMAL PRECIPITATION ACROSS
THE CENTRAL ROCKIES, NORTHERN TO CENTRAL GREAT PLAINS, AND MIDWEST. ALONG THE
EAST COAST, NEAR NORMAL PRECIPITATION IS MOST LIKELY WITH A WEAK TROUGH
PREDICTED ACROSS THE NORTHEAST, BUT FORECAST CONFIDENCE IS LOW. THE INCREASING
500-HPA HEIGHTS SLIGHTLY FAVOR BELOW-NORMAL PRECIPITATION ACROSS MUCH OF THE
PACIFIC NORTHWEST AND INTERMOUNTAIN WEST. THE ENSEMBLE MEANS DEPICT THE 500-HPA
RIDGE AXIS TO BE CENTERED OVER THE FOUR CORNERS REGION WHICH IS TYPICALLY A
FAVORABLE POSITION FOR AN ENHANCED MONSOON. HOWEVER, THE ANOMALOUSLY STRONG
500-HPA RIDGE MAY TEND TO SUPPRESS CONVECTION. DYNAMICAL MODEL FORECASTS ARE
SHOWING A MORE COHERENT MADDEN-JULIAN OSCILLATION (MJO) DEVELOPING BASED ON THE
200-HPA VELOCITY POTENTIAL ANOMALY FIELD WITH EASTWARD PROPAGATION OVER THE
WESTERN HEMISPHERE DURING THE NEXT FEW WEEKS. THIS WOULD PROVIDE A MORE
FAVORABLE LARGE-SCALE ENVIRONMENT FOR TROPICAL CYCLONE (TC) DEVELOPMENT ACROSS
THE EAST PACIFIC HEADING INTO EARLY AUGUST. RECENT GFS MODEL RUNS ARE SHOWING A
TC TRACKING WEST OR NORTHWEST ACROSS THE EAST PACIFIC DURING EARLY WEEK-2 WITH
THE POTENTIAL FOR A TRACK CLOSER TO THE SOUTHERN BAJA PENINSULA. IF THIS WERE
TO OCCUR, THEN A SURGE OF LOW TO MID-LEVEL MOISTURE COULD SPREAD NORTHWARD FROM
THE GULF OF CALIFORNIA INTO THE DESERT SOUTHWEST. NEAR NORMAL PRECIPITATION IS
FAVORED FOR MUCH OF THE SOUTHWEST WITH SLIGHTLY ELEVATED PROBABILITIES FOR
ABOVE-NORMAL PRECIPITATION LIMITED TO SOUTHWEST ARIZONA AND SOUTHERN
CALIFORNIA.
NEAR TO ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR ALASKA, CONSISTENT WITH A
WEAK 500-HPA RIDGE OVER MAINLAND ALASKA. DUE TO A WEAK TROUGH UPSTREAM OVER THE
EASTERN BERING SEA, ABOVE-NORMAL PRECIPITATION PROBABILITIES ARE SLIGHTLY
ELEVATED FOR MOST OF MAINLAND ALASKA.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 35% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 35% 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 HIGH
CONFIDENCE IN THE TEMPERATURE OUTLOOK OFFSET BY LOWER CONFIDENCE IN THE
PRECIPITATION OUTLOOK.
FORECASTER: BRAD PUGH
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:
19930731 - 19960723 - 19670712 - 20030722 - 19940724
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:
19930730 - 19960722 - 19670712 - 19790713 - 20030723
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 25 - 29 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON N B NRN CALIF A B
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A N E MONTANA A N WYOMING A N
UTAH A N ARIZONA A N COLORADO A N
NEW MEXICO A B N DAKOTA A A S DAKOTA A N
NEBRASKA A N KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A A IOWA A N MISSOURI A B
ARKANSAS A B LOUISIANA A B WISCONSIN A N
ILLINOIS A B MISSISSIPPI A B MICHIGAN A N
INDIANA A N OHIO A N KENTUCKY A B
TENNESSEE A B ALABAMA A B NEW YORK A A
VERMONT A A NEW HAMP A A MAINE A A
MASS A N CONN A N RHODE IS A N
PENN A A NEW JERSEY A N W VIRGINIA A N
MARYLAND A N DELAWARE A N VIRGINIA A N
N CAROLINA A N 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 A N AK INT BSN A A
AK S INT A N AK SO COAST A N AK PNHDL N N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR JUL 27 - AUG 02, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A N
SRN CALIF A N IDAHO A B NEVADA A B
W MONTANA A B E MONTANA A N WYOMING A N
UTAH A N ARIZONA A N COLORADO A A
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A N KANSAS A B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A N IOWA A N MISSOURI A N
ARKANSAS A B LOUISIANA A B WISCONSIN A N
ILLINOIS A N MISSISSIPPI A B MICHIGAN A N
INDIANA A A OHIO A A KENTUCKY A N
TENNESSEE A N ALABAMA A B NEW YORK A N
VERMONT N N NEW HAMP A N MAINE N 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 N S CAROLINA A N GEORGIA A N
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 A AK SO COAST N N AK PNHDL N 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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