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FXUS06 KWBC 202002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST MON NOVEMBER 20 2023
6-10 DAY OUTLOOK FOR NOV 26 - 30 2023
TODAY'S MODEL SOLUTIONS ARE IN VERY GOOD AGREEMENT ON THE PREDICTED LARGE-SCALE
MID-LEVEL FLOW PATTERN ACROSS NORTH AMERICA AND SURROUNDING OCEANIC REGIONS
DURING THE 6-10 DAY PERIOD. THE MANUAL 500-HPA HEIGHT BLEND IS BASED ON THE
ENSEMBLE MEANS FROM THE GFS, ECMWF, AND CANADIAN MODELS DUE TO RECENT MODEL
SKILL. THE RESULTANT MANUAL BLEND FEATURES A ZONALLY-ORIENTED MID-LEVEL TROUGH
OVER THE BERING SEA AND ALEUTIANS. AN AMPLIFIED RIDGE AND ASSOCIATED POSITIVE
500-HPA HEIGHT ANOMALIES ARE PREDICTED FROM MAINLAND ALASKA SOUTHEASTWARD
ACROSS THE NORTHWESTERN CONTIGUOUS U.S. (CONUS) DURING THE PERIOD. A DEEP
TROUGH AND ASSOCIATED NEGATIVE 500-HPA HEIGHT ANOMALIES ARE FORECAST OVER THE
EASTERN CONUS, WITH A PORTION OF THE TROUGH LAGGING BACK OVER THE SOUTHWESTERN
STATES. IN GENERAL, 500-HPA HEIGHTS ARE PREDICTED TO BE SLIGHTLY BELOW NORMAL
ACROSS THE HAWAIIAN ISLANDS.
REFORECAST-CALIBRATED TEMPERATURES FROM THE GFS AND ECMWF ENSEMBLES FAVOR ABOVE
NORMAL TEMPERATURES OVER PORTIONS OF THE NORTHERN GREAT PLAINS, FLORIDA, AND IN
THE CASE OF THE GEFS NORTHERN CALIFORNIA AND THE PACIFIC NORTHWEST. THE
CANADIAN REFORECAST-CALIBRATED TEMPERATURES ARE GENERALLY SIMILAR TO THE OTHER
TWO MODELS, BUT PREDICT MORE EXTENSIVE COVERAGE OF FAVORED BELOW NORMAL
TEMPERATURES OVER THE SOUTHEAST. TEMPERATURES ACROSS MOST OF THE REMAINDER OF
THE CONUS ARE FAVORED TO BE BELOW NORMAL. CHANCES FOR ABOVE NORMAL TEMPERATURES
ARE ELEVATED OVER ALASKA, IN PROXIMITY TO A MID-LEVEL RIDGE AND POSITIVE HEIGHT
ANOMALIES. IN HAWAII, BELOW NORMAL TEMPERATURES ARE FAVORED FOR KAUAI IN THE
VICINITY OF THE LARGER NEGATIVE HEIGHT ANOMALIES, AND ABOVE NORMAL TEMPERATURES
ARE FAVORED FOR MUCH OF THE BIG ISLAND WHERE THE PREDICTED HEIGHTS ARE CLOSE TO
NORMAL.
ABOVE NORMAL PRECIPITATION IS FAVORED FOR THE SOUTHERN TIER OF THE CONUS,
GENERALLY ALONG THE BROAD SOUTHERN FLANK OF MID-LEVEL TROUGHING EXPECTED OVER
THE SOUTHEASTERN, SOUTH-CENTRAL, AND SOUTHWESTERN CONUS. ODDS FAVORING ABOVE
NORMAL PRECIPITATION EXCEED 50% OVER MOST OF FLORIDA. REFORECAST-CALIBRATED
PRECIPITATION TOOLS DEPICT A SLIGHT TILT TOWARDS ABOVE NORMAL PRECIPITATION
OVER THE NORTHERN PLAINS REGION. MOST OF THE REMAINDER OF THE LOWER 48 STATES
ARE FAVORED TO HAVE BELOW NORMAL PRECIPITATION, EITHER ASSOCIATED WITH
MID-LEVEL RIDGING AND POSITIVE HEIGHT ANOMALIES ACROSS THE NORTHWESTERN CONUS,
OR IN THE COOLER AND DRIER POLAR AIR MASS SITUATED ACROSS MOST OF THE EASTERN
HALF OF THE CONUS. AT HIGHER LATITUDES, THE APPROACH OF THE BERING SEA TROUGH
FAVORS WIDESPREAD ONSHORE FLOW ACROSS ALASKA, INCREASING THE LIKELIHOOD OF
ANOMALOUSLY WET WEATHER ACROSS THE STATE. THE ERF-CON PRECIPITATION TOOL
INDICATES A SLIGHT TILT TOWARDS WETTER-THAN-NORMAL CONDITIONS FOR THE HAWAIIAN
ISLANDS, IN PROXIMITY TO A MID-LEVEL TROUGH.
THE OFFICIAL 6-10 DAY 500-HPA HEIGHT BLEND CONSISTS OF 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 40% 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: ABOVE NORMAL, 4 OUT OF 5, DUE TO
VERY GOOD MODEL AGREEMENT ON A PERSISTENT 500-HPA FLOW PATTERN ACROSS NORTH
AMERICA, AND GENERALLY GOOD AGREEMENT AMONG THE SURFACE TEMPERATURE AND
PRECIPITATION TOOLS.
8-14 DAY OUTLOOK FOR NOV 28 - DEC 04, 2023
ENSEMBLE MEAN SOLUTIONS FOR THE 8-14 DAY PERIOD PREDICT A FAIRLY PERSISTENT
500-HPA CIRCULATION PATTERN ACROSS NORTH AMERICA AND SURROUNDING OCEANIC
REGIONS, THOUGH LESS AMPLIFIED OVERALL. THE MANUAL HEIGHT BLEND DEPICTS A MEAN
TROUGH ACROSS THE BERING SEA, ALEUTIANS, AND FAR WESTERN ALASKA, AND ANOTHER
TROUGH THAT EXTENDS FROM THE EASTERN CONUS SOUTHWESTWARD TO THE FOUR CORNERS
REGION.
THE WEEK-2 TEMPERATURE OUTLOOK IS BASED ON THE REFORECAST-CALIBRATED
TEMPERATURE TOOLS AND THE AUTO-TEMPERATURE FORECAST. ODDS FAVOR BELOW NORMAL
TEMPERATURES FOR MOST OF THE FOUR CORNERS STATES AND SOUTHERN WYOMING, THE
CENTRAL HIGH PLAINS AND SOUTHERN PLAINS, AND THE LOWER MISSISSIPPI VALLEY. FROM
THERE, THE AREA OF FAVORED BELOW NORMAL TEMPERATURES CONTINUES EASTWARD FOR
MOST AREAS EAST OF THE MISSISSIPPI RIVER TO THE EAST COAST, EXCLUDING AREAS
NEAR THE GULF COAST. REFORECAST-CALIBRATED TEMPERATURES FAVOR ABOVE NORMAL
TEMPERATURES ACROSS THE FAR WESTERN CONUS, EXTENDING EASTWARD ACROSS MONTANA
AND MOST OF THE DAKOTAS TO THE UPPER MISSISSIPPI VALLEY. MANY OF THE TOOLS
WARRANT WARMER-THAN-NORMAL TEMPERATURES BEING FAVORED FOR THE FLORIDA PENINSULA
DURING WEEK-2. MID-LEVEL RIDGING OVER MOST OF ALASKA SUPPORTS ABOVE NORMAL
TEMPERATURES ACROSS THE ENTIRE STATE EXCLUDING THE FAR WESTERN ALEUTIANS. FOR
HAWAII, THE OUTLOOK FAVORS BELOW NORMAL TEMPERATURES ACROSS KAUAI, NEAR NORMAL
TEMPERATURES FOR OAHU, AND ABOVE NORMAL TEMPERATURES OVER MOST OF THE REMAINING
ISLANDS TO THE SOUTHEAST.
THERE IS A TILT IN THE ODDS TOWARDS BELOW NORMAL PRECIPITATION FOR
APPROXIMATELY THE NORTHERN HALF OF THE LOWER 48 STATES, AND A TILT TOWARDS
ABOVE NORMAL TEMPERATURES FOR MOST OF THE SOUTHERN TIER OF THE CONUS. THIS IS
CONSISTENT WITH THE AUTO-PRECIPITATION AND CONSOLIDATED PRECIPITATION TOOLS,
AND GENERALLY FOLLOWS THE SAME LINE OF REASONING AS THAT FOR THE EARLIER 6-10
DAY PRECIPITATION OUTLOOK. WIDESPREAD ONSHORE FLOW SUPPORTS INCREASED CHANCES
OF ABOVE NORMAL PRECIPITATION FOR ALASKA. IN HAWAII, THE PROXIMITY OF A
MID-LEVEL TROUGH AND SLIGHTLY BELOW NORMAL 500-HPA HEIGHTS LEADS TO A TILT IN
THE ODDS TOWARDS ABOVE NORMAL PRECIPITATION ACROSS THE STATE.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 30% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% 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: ABOVE NORMAL, 4 OUT OF 5, DUE TO
GOOD MODEL AGREEMENT ON THE 500-HPA FLOW PATTERN ACROSS NORTH AMERICA, OFFSET
BY THE EXPECTATION OF DECREASING AMPLITUDE OF LONGWAVE FEATURES.
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
DECEMBER 21.
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:
20031201 - 19871105 - 20041106 - 19791115 - 19811104
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:
19891127 - 19801105 - 19871107 - 19761030 - 19651030
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 26 - 30 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N B OREGON N B NRN CALIF N B
SRN CALIF N B IDAHO N B NEVADA N B
W MONTANA N B E MONTANA A N WYOMING B B
UTAH B B ARIZONA B N COLORADO B B
NEW MEXICO B A N DAKOTA N N S DAKOTA N B
NEBRASKA B B KANSAS B B OKLAHOMA B N
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA N N IOWA B B MISSOURI B B
ARKANSAS B B LOUISIANA B A WISCONSIN B B
ILLINOIS B B MISSISSIPPI B A MICHIGAN B B
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B 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 N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL N A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 28 - DEC 04, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A B OREGON A B NRN CALIF A B
SRN CALIF A B IDAHO N B NEVADA N B
W MONTANA A B E MONTANA A N WYOMING N B
UTAH N B ARIZONA B N COLORADO B N
NEW MEXICO B A N DAKOTA A N S DAKOTA A B
NEBRASKA N B KANSAS N N OKLAHOMA B A
N TEXAS B A S TEXAS B A W TEXAS B A
MINNESOTA A B IOWA N B MISSOURI N N
ARKANSAS B N LOUISIANA B A WISCONSIN N B
ILLINOIS N B MISSISSIPPI B A MICHIGAN B B
INDIANA B B OHIO B B KENTUCKY B N
TENNESSEE B N ALABAMA B A NEW YORK B B
VERMONT B B NEW HAMP B N MAINE B N
MASS B N CONN B N RHODE IS B N
PENN B B NEW JERSEY B N W VIRGINIA B N
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL N A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN A A AK WESTERN A A AK INT BSN A A
AK S INT A A AK SO COAST A 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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