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FXUS06 KWBC 031914
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU AUGUST 03 2023
6-10 DAY OUTLOOK FOR AUG 09 - 13 2023
THE GFS, ECMWF, AND CANADIAN ENSEMBLE MEANS REMAIN IN GOOD AGREEMENT ON THE
PREDICTED LONGWAVE PATTERN DURING THE 6-10 DAY PERIOD. THE MANUAL 500-HPA
HEIGHT BLEND FEATURES A DEEP, ANOMALOUS TROUGH EXTENDING FROM THE BERING SEA
SOUTH TO THE ALEUTIANS, A MODERATELY STRONG RIDGE ACROSS WESTERN NORTH AMERICA,
AND AN AMPLIFIED TROUGH OVER EASTERN NORTH AMERICA. THE 0Z ECMWF ENSEMBLE
DEPICTS THE ANOMALOUS TROUGH TO THE SOUTH OF THE ALEUATIANS PEAKING IN STRENGTH
ON DAY 8 (AUGUST 11) WITH 500-HPA HEIGHT DEPARTURES OF MORE THAN -240 METERS.
THIS AMPLIFIED TROUGH FAVORS BELOW NORMAL TEMPERATURES FOR THE ALEUTIANS,
ALASKA PENINSULA, AND SOUTHWESTERN MAINLAND ALASKA, WHILE SOUTHERLY SURFACE
FLOW SUPPORTS INCREASED ABOVE NORMAL TEMPERATURE PROBABILITIES FOR THE
REMAINDER OF MAINLAND ALASKA. ANOMALOUS RIDGING SUPPORTS INCREASED ABOVE NORMAL
TEMPERATURE PROBABILITIES THROUGHOUT MOST OF THE WESTERN AND SOUTHERN CONUS.
PROBABILITIES FOR ABOVE NORMAL TEMPERATURES EXCEED 80 PERCENT ACROSS
SOUTHEASTERN NEW MEXICO AND WESTERN TEXAS WHERE THE GEFS AND ECMWF ENSEMBLE
MEANS DEPICT 5-DAY TEMPERATURE ANOMALIES OF NEAR +10 DEGREES F.
THE AMPLIFIED TROUGH OVER EASTERN NORTH AMERICA LEADS TO INCREASED ABOVE NORMAL
PRECIPITATION PROBABILITIES ACROSS MUCH OF THE CENTRAL AND EASTERN CONUS.
HOWEVER, THESE PROBABILITIES ARE TEMPERED DUE TO THE LIMITED PREDICTABILITY
ASSOCIATED WITH CONVECTIVE RAINFALL DURING EARLY TO MID-AUGUST. THE ENSEMBLE
MEANS DEPICT A 500-HPA RIDGE AXIS OVER NORTHERN MEXICO AND THE RIO GRANDE
VALLEY WHICH IS LIKELY TO SUPPRESS THE MONSOON, WHICH FAVORS BELOW NORMAL
PRECIPITATION ACROSS THE SOUTHWEST. THIS FAVORED DRYNESS ALSO INCLUDES THE RIO
GRANDE VALLEY AND SOUTHERN TEXAS DUE TO THE PROMINENT RIDGING ALOFT. FARTHER TO
THE NORTH, A SHORTWAVE TROUGH MAY TRACK EASTWARD ACROSS THE INTERMOUNTAIN WEST
AND NORTHERN ROCKIES ON DAYS 6 AND 7, SUPPORTING ELEVATED ABOVE NORMAL
PRECIPITATION PROBABILITIES FOR THESE AREAS.
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
UNCERTAINTY IN THE PRECIPITATION OUTLOOK ACROSS THE CENTRAL AND EASTERN CONUS.
8-14 DAY OUTLOOK FOR AUG 11 - 17 2023
ENSEMBLE MEANS ARE IN GOOD AGREEMENT THAT THE ANOMALOUS TROUGH OVER THE BERING
SEA AND ALEUTIANS PERSISTS THROUGH MID-AUGUST WHICH LEADS TO AN AMPLIFYING
RIDGE ACROSS THE WESTERN CONUS. THE MANUAL 500-HPA BLEND DEPICTS 7-DAY HEIGHT
DEPARTURES OF MORE THAN 90 METERS ACROSS WASHINGTON AND SOUTHERN BRITISH
COLUMBIA. THE AMPLIFIED TROUGH, THAT IS FORECAST OVER EASTERN NORTH AMERICA
DURING THE 6-10 DAY PERIOD, WEAKENS WITH SLIGHTLY NEGATIVE 500-HPA HEIGHTS
CONFINED TO THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES DURING WEEK-2. THE
PREDICTED LONGWAVE PATTERN ALONG WITH THE GEFS AND ECMWF REFORECAST TOOLS
SUPPORT INCREASED ABOVE NORMAL TEMPERATURE PROBABILITIES ACROSS THE WESTERN AND
SOUTHERN CONUS ALONG WITH THE EAST COAST WITH BELOW NORMAL TEMPERATURES
SLIGHTLY FAVORED FOR THE NORTHERN TO CENTRAL GREAT PLAINS AND UPPER MISSISSIPPI
VALLEY. THE TEMPERATURE OUTLOOK IS GENERALLY CONSISTENT WITH A TELECONNECTION
UPON THE LARGE NEGATIVE 500-HPA HEIGHT ANOMALY CENTER OVER THE ALEUTIANS. THE
LOWEST FORECAST CONFIDENCE EXISTS ACROSS THE MIDWEST WHERE TEMPERATURES ARE
EXPECTED TO VARY DURING THIS 7-DAY PERIOD. WITH A PERSISTENT PATTERN FORECAST
AT THE SURFACE AND ALOFT, THE 6-10 AND 8-14 DAY TEMPERATURE OUTLOOKS FOR ALASKA
ARE VERY SIMILAR.
FORECAST CONFIDENCE IN THE PRECIPITATION OUTLOOK IS HIGHEST ACROSS SOUTHEASTERN
ALASKA DUE TO THE PERSISTENT, ANOMALOUS TROUGH UPSTREAM WITH STRONG ONSHORE
FLOW INCREASING CHANCES FOR ABOVE NORMAL PRECIPITATION. ALSO, CONFIDENCE IS
RELATIVELY HIGH IN THE PRECIPITATION OUTLOOK ACROSS EASTERN ARIZONA, WESTERN
NEW MEXICO, AND SOUTHERN UTAH WHERE THE MONSOON IS FORECAST TO BE SUPPRESSED.
AN AMPLIFIED TROUGH, LINGERING THROUGH THE BEGINNING OF WEEK-2, SLIGHTLY
ELEVATES PROBABILITIES FOR ABOVE NORMAL PRECIPITATION THROUGHOUT MUCH OF THE
CENTRAL AND EASTERN CONUS. MODEL SOLUTIONS ARE FEATURING AN INCREASED POTENTIAL
FOR EASTERLY WAVES TO EMERGE FROM THE CARIBBEAN AND TRACK NORTHWESTWARD TO THE
GULF OF MEXICO, WHICH SLIGHTLY FAVORS ABOVE NORMAL PRECIPITATION ACROSS FLORIDA
AND PARTS OF THE GULF COAST.
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
CONTINUED GOOD AGREEMENT AMONG THE TEMPERATURE TOOLS OFFSET BY WEAK OR
CONFLICTING SIGNALS IN THE PRECIPITATION TOOLS, ESPECIALLY ACROSS THE GREAT
PLAINS.
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
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:
19540807 - 19970727 - 19940814 - 19570815 - 19630813
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:
19540807 - 19970726 - 20040806 - 19960720 - 19940813
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 09 - 13 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A N
SRN CALIF N N IDAHO B A NEVADA N B
W MONTANA B A E MONTANA B A WYOMING B A
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A B N DAKOTA B A S DAKOTA B A
NEBRASKA B A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA B A IOWA B A MISSOURI N A
ARKANSAS A A LOUISIANA A N WISCONSIN B A
ILLINOIS N A MISSISSIPPI A A MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY N A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT N 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 N FL PENIN A A AK N SLOPE A N
AK ALEUTIAN B A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST B A AK PNHDL N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR AUG 11 - 17 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 B N WYOMING B N
UTAH A B ARIZONA A B COLORADO A N
NEW MEXICO A N N DAKOTA B N S DAKOTA B N
NEBRASKA B A KANSAS N A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA B N IOWA B A MISSOURI N A
ARKANSAS A A LOUISIANA A A WISCONSIN B N
ILLINOIS N A MISSISSIPPI A A MICHIGAN N A
INDIANA N A OHIO N A KENTUCKY N 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 A AK N SLOPE A N
AK ALEUTIAN B N AK WESTERN A A AK INT BSN A A
AK S INT B A AK SO COAST B A AK PNHDL A A
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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