895
FXUS06 KWBC 231916
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT MON OCTOBER 23 2023
6-10 DAY OUTLOOK FOR OCT 29 - NOV 02, 2023
THE 6-10 DAY MEAN 500-HPA HEIGHT FORECASTS FROM THE LATEST ECMWF, GFS, AND
CANADIAN ENSEMBLE MEANS ARE IN FAIRLY GOOD AGREEMENT WITH REGARD TO THE
SYNOPTIC PATTERN AS DEPICTED BY 500-HPA HEIGHT ANOMALIES WITH MODERATE
TROUGHING OVER THE NORTH PACIFIC, AMPLIFIED RIDGING ALONG THE WEST COAST NORTH
OF CAPE MENDOCINO, AND A BROAD, STRONG TROUGH OVER THE NORTH-CENTRAL AND
NORTHEASTERN CONTIGUOUS U.S. (CONUS) EXTENDING NORTHWARD INTO NORTHEASTERN
CANADA. POSITIVE HEIGHT ANOMALIES OVER THE SOUTHEASTERN U.S. RESULT IN A TIGHT
PRESSURE GRADIENT OVER NEW ENGLAND.
THE SYNOPTIC PATTERN IS FAVORABLE FOR AN ARCTIC AIR SURGE MOVING SOUTHWARD,
RESULTING IN BELOW-NORMAL TEMPERATURES BEING FAVORED FOR MUCH OF THE CONUS.
PROBABILITIES ARE HIGHEST OVER THE NORTHERN PLAINS AND UPPER MIDWEST (EXCEEDING
80%) AND BELOW-NORMAL TEMPERATURES ARE FAVORED FOR ALMOST THE ENTIRE CONUS WEST
OF THE MISSISSIPPI RIVER, AS WELL AS THE GREAT LAKES REGION AND ALONG THE
CANADA-NEW ENGLAND BORDER. WITH RIDGING OVER THE WESTERN ATLANTIC EXTENDING
SOUTHWESTWARD OVER THE SOUTHEAST U.S. ABOVE-NORMAL TEMPERATURES ARE FAVORED FOR
MUCH OF THE MID-ATLANTIC, APPALACHIANS AND SOUTHEAST U.S., AS WELL AS PORTIONS
OF SOUTHERN NEW ENGLAND. AMPLIFIED RIDGING OVER THE WEST COAST AND THE GULF OF
ALASKA RESULTS IN SOUTHERLY FLOW ALOFT AND ENHANCED PROBABILITIES OF
ABOVE-NORMAL TEMPERATURES FOR THE ENTIRE STATE, WITH THE EXCEPTION OF EXTREME
SOUTHEASTERN TIP OF THE PANHANDLE. WEAKLY ABOVE-NORMAL SEA SURFACE TEMPERATURES
IN THE HAWAII REGION RESULT IN A SLIGHT TILT TOWARDS MOST OF THE ISLANDS WITH
THE EXCEPTION OF THE MAIN ISLAND OF HAWAII, WHERE NEAR-NORMAL TEMPERATURES ARE
MOST LIKELY.
BROAD TROUGHING OVER THE NORTHEASTERN CONUS ALONG WITH PLENTIFUL TROPICAL
MOISTURE AVAILABLE FROM MULTIPLE SOURCES FAVORS ABOVE-NORMAL PRECIPITATION FOR
MUCH OF THE CENTRAL AND EASTERN CONUS. PROBABILITIES ARE ENHANCED FOR THE
SOUTHERN PLAINS, MIDDLE MISSISSIPPI VALLEY AND OHIO VALLEY WITH HIGHER
POTENTIAL FOR BAROCLINIC INSTABILITY IN THE LEE OF THE ROCKIES. AMPLIFIED
RIDGING ALONG THE WEST COAST AND COLDER AIR INTRUDING INTO THE CONUS FROM
CANADA RESULTS IN A TILT TOWARDS BELOW-NORMAL PRECIPITATION FOR PORTIONS OF THE
NORTHERN AND NORTHWESTERN CONUS. THIS RIDGING ALSO MOVES STORM ACTIVITY IN THE
GULF OF ALASKA WESTWARD, RESULTING IN A TILT TOWARDS ABOVE-NORMAL PRECIPITATION
FOR MOST OF MAINLAND ALASKA, WHILE BELOW-NORMAL PRECIPITATION IS FAVORED FOR
SOUTHEASTERN ALASKA. ONGOING EL NINO CONDITIONS CONTINUE TO SUPPRESS
PRECIPITATION IN THE HAWAII REGION, FAVORING BELOW-NORMAL PRECIPITATION FOR THE
WHOLE STATE.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 34% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 33% 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: ABOVE AVERAGE, 4 OUT OF 5, DUE TO
GOOD AGREEMENT AMONG MODELS ON SYNOPTIC PATTERN, OFFSET BY HIGHER MODEL SPREAD
WITH REGARD TO THE WESTERN EXTENT OF THE BROAD TROUGHING OVER THE EAST.
8-14 DAY OUTLOOK FOR OCT 31 - NOV 06, 2023
THE SYNOPTIC PATTERN FOR THE WEEK-2 PERIOD IS SIMILAR TO THE 6-10 PERIOD, WITH
SOME NOTABLE DIFFERENCES. MODELS FAVOR THE RIDGE OVER THE PACIFIC NORTHWEST TO
DEAMPLIFY, RESULTING IN ONSHORE FLOW FOR THE WEST COAST OF THE CONUS.
OTHERWISE, BROAD TROUGHING IS FAVORED TO CONTINUE OVER THE NORTHEASTERN CONUS,
WITH THE SYNOPTIC PATTERN APPROACHING ZONAL FLOW OVER THE CONUS BY THE END OF
THE FORECAST PERIOD.
BELOW-NORMAL TEMPERATURES CONTINUE TO BE FAVORED FOR MUCH OF THE CONUS DURING
THE 8-14 DAY PERIOD. PROBABILITIES OVER THE NORTHERN PLAINS ARE LOWER RELATIVE
TO THE 6-10 DAY PERIOD, AND BELOW-NORMAL TEMPERATURES BECOME FAVORED FOR MUCH
OF THE NORTHEASTERN U.S. AS WELL AS COLD AIR FROM THE PLAINS SPREADS EASTWARD.
ABOVE-NORMAL TEMPERATURES CONTINUE TO BE FAVORED OVER THE SOUTHEAST U.S. WITH
PERSISTENT RIDGING REMAINING IN PLACE. ANOMALOUS POSITIVE HEIGHT ANOMALIES ARE
REDUCED BUT REMAIN OVER THE GULF OF ALASKA, RESULTING IN CONTINUED CHANCES FOR
ABOVE-NORMAL TEMPERATURES FOR MUCH OF THE STATE. HAWAII ALSO CONTINUES TO TILT
TOWARD ABOVE-NORMAL TEMPERATURES WITH SLIGHTLY ELEVATED SSTS IN THE REGION.
WIDESPREAD BAROCLINIC INSTABILITY EAST OF THE ROCKIES IS FAVORED TO CONTINUE
INTO THE WEEK-2 PERIOD, RESULTING IN A TILT TOWARDS ABOVE-NORMAL PRECIPITATION
FOR MUCH OF THE SOUTH-CENTRAL AND SOUTHEASTERN CONUS. AS SYNOPTIC FLOW BECOMES
MORE ZONAL OVER THE NORTH PACIFIC, ABOVE-NORMAL PRECIPITATION BECOMES FAVORED
FOR THE NORTHWESTERN CONUS. RIDGING OVER THE GULF OF ALASKA WEAKENS BUT
PERSISTS, RESULTING IN CONTINUED BELOW-NORMAL PRECIPITATION FAVORED FOR THE
PANHANDLE, WHILE SOUTHERLY FLOW ALOFT OVER THE MAINLAND RESULTS IN A TILT
TOWARDS ABOVE-NORMAL PRECIPITATION. ONGOING EL NINO CONDITIONS CONTINUE TO TILT
THE HAWAIIAN ISLANDS TOWARDS BELOW-NORMAL PRECIPITATION.
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: ABOUT AVERAGE, 3 OUT OF 5, WITH
GOOD AGREEMENT ON SYNOPTIC PATTERN AMONG DYNAMICAL MODELS, OFFSET BY WEAKER
ANOMALIES AND ONSET OF ZONAL FLOW LATER IN THE FORECAST PERIOD.
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
NOVEMBER 16.
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:
20061103 - 19821018 - 20061029 - 19861029 - 19601017
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:
20061102 - 19961002 - 20031026 - 19821018 - 19881012
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 29 - NOV 02, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B B OREGON B B NRN CALIF B N
SRN CALIF B N IDAHO B B NEVADA B N
W MONTANA B B E MONTANA B B WYOMING B B
UTAH B N ARIZONA B N COLORADO B A
NEW MEXICO B A N DAKOTA B B S DAKOTA B B
NEBRASKA B A KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA B B IOWA B A MISSOURI B A
ARKANSAS B A LOUISIANA N A WISCONSIN B N
ILLINOIS B A MISSISSIPPI A A MICHIGAN B A
INDIANA B A OHIO B A KENTUCKY N A
TENNESSEE A A ALABAMA A N NEW YORK N A
VERMONT N A NEW HAMP N A MAINE B 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 A
AK ALEUTIAN A N AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A B
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 31 - NOV 06, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON A A NRN CALIF A A
SRN CALIF N N IDAHO B A NEVADA N A
W MONTANA B A E MONTANA B N WYOMING B N
UTAH B A ARIZONA N N COLORADO B A
NEW MEXICO B A N DAKOTA B N S DAKOTA B N
NEBRASKA B N KANSAS B A OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA B N IOWA B N MISSOURI B N
ARKANSAS B A LOUISIANA B A WISCONSIN B N
ILLINOIS B N MISSISSIPPI N A MICHIGAN B N
INDIANA B N OHIO B N KENTUCKY B A
TENNESSEE B A ALABAMA N A NEW YORK B N
VERMONT B N NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B N NEW JERSEY B N W VIRGINIA B A
MARYLAND B A DELAWARE B A VIRGINIA B A
N CAROLINA N A S CAROLINA N A GEORGIA A A
FL PNHDL A A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A N AK WESTERN A N AK INT BSN A A
AK S INT A A 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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page