972
FXUS06 KWBC 121915
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON AUGUST 12 2024
6-10 DAY OUTLOOK FOR AUG 18 - 22 2024
TODAY’S MODEL SOLUTIONS FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS FOR
500-HPA HEIGHT ANOMALIES ARE IN REASONABLE AGREEMENT AND ALL DEPICT AN
OMEGA-LIKE PATTERN OVER NORTH AMERICA, WITH TROUGHING AND NEGATIVE HEIGHT
ANOMALIES OVER THE NORTHWEST AND NORTHEASTERN CONTIGUOUS U.S. (CONUS) AND AN
EXPANSIVE RIDGE OVER THE CENTER OF THE CONTINENT AND STRONG POSITIVE HEIGHT
ANOMALIES OVER NORTHERN CANADA. AN AMPLIFIED TROUGH OVER THE BERING SEA AND
POSITIVE HEIGHT ANOMALIES OVER THE NORTH PACIFIC RESULT IN A TIGHT PRESSURE
GRADIENT AND MORE ACTIVE WEATHER FOR THE ALASKA REGION.
THE OMEGA PATTERN DESCRIBED ABOVE BRINGS AN INCREASED CHANCE FOR BELOW-NORMAL
TEMPERATURES TO THE WEST COAST AND THE GREAT LAKES, WHILE THE REST OF THE CONUS
IS FAVORED FOR ABOVE-NORMAL TEMPERATURES, ESPECIALLY THE SOUTHERN TIER WITH
PROBABILITIES EXCEEDING 80% FOR PORTIONS OF TEXAS. NEW ENGLAND ALSO TILTS
TOWARDS ABOVE-NORMAL TEMPERATURES, CONSISTENT WITH THE LARGE-SCALE PATTERN AND
MOST FORECAST TOOLS. WITH TROUGHING OVER THE BERING SEA, MUCH OF THE ALASKAN
MAINLAND LEANS TOWARDS BELOW-NORMAL TEMPERATURES, WHILE ABOVE-NORMAL
TEMPERATURES ARE SLIGHTLY FAVORED ALONG THE ALASKA-CANADA BORDER AND FOR THE
PANHANDLE. ABOVE-NORMAL TEMPERATURES ARE THE MOST LIKELY FOR HAWAII, WITH
PROBABILITIES INCREASING FROM SOUTHEAST TO NORTHWEST, CONSISTENT WITH THE
HAWAII CON TOOL.
TROUGHING OVER BOTH COASTS RESULTS IN A TILT TOWARDS ABOVE-NORMAL PRECIPITATION
FOR THE NORTHWESTERN AND NORTHEASTERN CONUS, CONSISTENT WITH MODEL GUIDANCE.
MODELS ALSO DEPICT INCREASED MONSOON ACTIVITY DURING THE 6-10 DAY PERIOD,
INCREASING THE PROBABILITY OF ABOVE-NORMAL PRECIPITATION FOR PORTIONS OF THE
DESERT SOUTHWEST AS WELL. ONSHORE FLOW BOTH AT THE SURFACE AND ALOFT FAVORS
ABOVE-NORMAL PRECIPITATION FOR THE ALASKAN MAINLAND, WHILE POSITIVE HEIGHT
ANOMALIES OVER THE NORTH PACIFIC RESULT IN A TILT TOWARDS BELOW-NORMAL
PRECIPITATION FOR THE PANHANDLE. MODEL GUIDANCE INDICATES NEAR-NORMAL
PRECIPITATION FOR HAWAII.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 40% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 8, AND 20% 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, WITH
GOOD RUN-TO-RUN CONTINUITY AMONG FORECAST MODELS, OFFSET BY DIFFERENCES BETWEEN
MODELS REGARDING STRENGTH AND POSITION OF VARIOUS SYNOPTIC FEATURES.
8-14 DAY OUTLOOK FOR AUG 20 - 26 2024
MODEL ENSEMBLES DEPICT A GENERAL PERSISTENCE OF THE SYNOPTIC PATTERN FROM THE
6-10 DAY PERIOD. THE MOST NOTABLE DIFFERENCE IS A WEAKENING OF THE TROUGH OVER
THE BERING SEA, RELAXING THE PRESSURE GRADIENT OVER ALASKA. ENSEMBLE SOLUTIONS
ALSO TEND TO FAVOR A WEAKER TROUGH OVER THE WEST COAST, AND SMALLER HEIGHT
ANOMALIES OVERALL. THIS GENERAL PERSISTENCE OF SYNOPTIC FEATURES RESULTS IN
VERY SIMILAR OUTLOOKS FOR THE 6-10 AND 8-14 DAY PERIODS.
THE OMEGA PATTERN FROM THE 6-10 DAY PERIOD REMAINS, ALTHOUGH DEPICTED AS WEAKER
IN WEEK-2, THEREFORE THE WEEK-2 TEMPERATURE OUTLOOK IS LITTLE-CHANGED FROM THE
EARLIER PERIOD. CHANCES FOR ABOVE-NORMAL TEMPERATURES OVER THE CENTRAL AND
SOUTHERN CONUS ARE SLIGHTLY REDUCED BUT STILL EXCEED 70% FOR PORTIONS OF TEXAS.
A WEAKENING TROUGH OVER THE WEST COAST CONFINES THE CHANCES FOR BELOW-NORMAL
TEMPERATURES LARGELY TO COASTAL AREAS NORTH OF MONTEREY, CA. NEW ENGLAND IS
FAVORED FOR ABOVE-NORMAL TEMPERATURES, CONSISTENT WITH THE PERSISTENT PATTERN
AND MOST FORECAST TOOLS. WITH WEAKER BUT PERSISTENT TROUGHING OVER THE BERING
SEA,THE WESTERN ALASKAN MAINLAND LEANS TOWARDS BELOW-NORMAL TEMPERATURES, WHILE
ABOVE-NORMAL TEMPERATURES ARE SLIGHTLY FAVORED ALONG THE ALASKA-CANADA BORDER,
NORTH SLOPE AND FOR THE PANHANDLE. ABOVE-NORMAL TEMPERATURES ARE THE MOST
LIKELY FOR HAWAII, WITH PROBABILITIES INCREASING FROM SOUTHEAST TO NORTHWEST,
CONSISTENT WITH THE HAWAII CON TOOL.
THE WEEK-2 PRECIPITATION OUTLOOK IS ALSO QUITE SIMILAR TO THE 6-10 DAY PERIOD.
PORTIONS OF THE NORTHWESTERN AND NORTHEASTERN CONUS TILT TOWARDS ABOVE-NORMAL
PRECIPITATION UNDER THE INFLUENCE OF THE TROUGH PORTIONS OF THE OMEGA PATTERN.
CONTINUED MONSOON ACTIVITY FAVORS ABOVE-NORMAL PRECIPITATION FOR PORTIONS OF
THE DESERT SOUTHWEST. BROAD POSITIVE HEIGHT ANOMALIES OVER CENTRAL NORTH
AMERICA RESULTS IN CHANCES FOR BELOW-NORMAL PRECIPITATION FOR THE CENTRAL
CONUS. MUCH OF ALASKA CONTINUES TO TILT TOWARD ABOVE-NORMAL PRECIPITATION, BUT
THE WEAKENING NEGATIVE HEIGHT ANOMALIES OVER THE BERING SEA FAVOR NEAR-NORMAL
PRECIPITATION FOR THE SOUTHERN ALASKAN COAST AND BELOW-NORMAL PRECIPITATION FOR
THE PANHANDLE.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 34% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 33% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 33% 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, WITH A
PERSISTENT SYNOPTIC PATTERN, OFFSET BY DIFFERENCES BETWEEN MODELS REGARDING
STRENGTH AND POSITION OF VARIOUS SYNOPTIC FEATURES.
FORECASTER: DANIEL BARANDIARAN
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 15.
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:
19600805 - 19960729 - 19540802 - 20060823 - 20000804
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:
19530807 - 19960729 - 20000804 - 19540802 - 19600805
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 18 - 22 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B N
SRN CALIF A N IDAHO A A NEVADA A N
W MONTANA A A E MONTANA A A WYOMING A A
UTAH A A ARIZONA A A COLORADO A A
NEW MEXICO A B N DAKOTA A A S DAKOTA A A
NEBRASKA A N KANSAS A N OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A B IOWA B B MISSOURI N B
ARKANSAS A B LOUISIANA A B WISCONSIN N B
ILLINOIS B N MISSISSIPPI A B MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B N
TENNESSEE N N ALABAMA A B NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN N A NEW JERSEY N A W VIRGINIA B A
MARYLAND N A DELAWARE N A VIRGINIA N A
N CAROLINA A A S CAROLINA A N GEORGIA A N
FL PNHDL A N 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 A N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 20 - 26 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N A NRN CALIF N N
SRN CALIF A N IDAHO A N NEVADA A N
W MONTANA A N E MONTANA A N 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 B OKLAHOMA A B
N TEXAS A B S TEXAS A B W TEXAS A B
MINNESOTA A B IOWA N B MISSOURI N B
ARKANSAS A B LOUISIANA A B WISCONSIN N B
ILLINOIS B B MISSISSIPPI A B MICHIGAN A B
INDIANA B B OHIO B N KENTUCKY B N
TENNESSEE N N ALABAMA A B NEW YORK N A
VERMONT A A NEW HAMP A A MAINE A A
MASS A A CONN A A RHODE IS A A
PENN N N NEW JERSEY N A W VIRGINIA B N
MARYLAND N N DELAWARE N A VIRGINIA N 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 B N AK WESTERN B A AK INT BSN N A
AK S INT B N AK SO COAST B 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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