711
FXUS06 KWBC 172002
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EST FRI NOVEMBER 17 2023
6-10 DAY OUTLOOK FOR NOV 23 - 27 2023
TODAY'S MODEL SOLUTIONS ARE IN VERY GOOD AGREEMENT ON THE PREDICTED AMPLIFIED
500-HPA CIRCULATION 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 MODEL ENSEMBLES DUE TO
RECENT MODEL SKILL. THE RESULTANT MANUAL BLEND FEATURES A MEAN MID-LEVEL TROUGH
OVER THE SOUTHERN BERING SEA AND ALEUTIANS. AN AMPLIFIED RIDGE AND ASSOCIATED
POSITIVE 500-HPA HEIGHT ANOMALIES ARE PREDICTED FROM MAINLAND ALASKA
SOUTHEASTWARD ACROSS A LARGE PORTION OF THE WESTERN CONTIGUOUS U.S. (CONUS)
DURING THE PERIOD. A DEEP TROUGH AND ASSOCIATED NEGATIVE 500-HPA HEIGHT
ANOMALIES ARE FORECAST OVER THE EASTERN CONUS. ACROSS THE VICINITY OF HAWAII,
PREDICTED MID-LEVEL HEIGHTS RANGE FROM SLIGHTLY BELOW AVERAGE TO SLIGHTLY ABOVE
AVERAGE.
ENHANCED CHANCES FOR ABOVE NORMAL TEMPERATURES ARE FAVORED OVER PRACTICALLY ALL
OF ALASKA, THE FAR WESTERN CONUS, AND MUCH OF THE FLORIDA PENINSULA DURING THE
6-10 DAY PERIOD. THE FIRST TWO AREAS ARE ASSOCIATED WITH MID-LEVEL RIDGING AND
ABOVE AVERAGE 500-HPA HEIGHTS. THE FLORIDA PENINSULA IS EXPECTED TO BE IN A
WARM SECTOR AHEAD OF THE POLAR AIR MASS ANTICIPATED ACROSS MOST AREAS EAST OF
THE ROCKIES. CONVERSELY, BELOW NORMAL TEMPERATURES ARE FAVORED EAST OF THE
CONTINENTAL DIVIDE, ASSOCIATED WITH A DEEP MID-LEVEL TROUGH AND WELL
BELOW-AVERAGE 500-HPA HEIGHTS. THE HIGHEST PROBABILITIES FAVORING BELOW NORMAL
TEMPERATURES (IN EXCESS OF 70 PERCENT) ARE INDICATED OVER APPROXIMATELY THE
NORTHEASTERN QUARTER OF THE CONUS. THIS BROAD-SCALE TEMPERATURE ANOMALY PATTERN
IS GENERALLY CONSISTENT WITH THE ERF TEMPERATURE CONSOLIDATION FORECAST, AND
THE REFORECAST-CALIBRATED TEMPERATURES FROM THE GFS, ECMWF, AND CANADIAN
ENSEMBLE MEANS. THE AUTO-TEMPERATURE FORECAST FAVORS A COOLER WEST COMPARED TO
THE REFORECAST TEMPERATURES, SIGNIFICANTLY INFLUENCED BY 00Z BIAS-CORRECTED
ECMWF ENSEMBLE TEMPERATURES, WHICH LOOK TOO COOL GIVEN THE PREDICTED 500-HPA
CIRCULATION PATTERN. THE ERF-CON TEMPERATURE FORECAST FAVORS ABOVE NORMAL
TEMPERATURES FOR THE HAWAIIAN ISLANDS.
BELOW NORMAL PRECIPITATION IS FAVORED FOR MOST AREAS WEST OF THE CONTINENTAL
DIVIDE, UNDER THE GRADUALLY DIMINISHING INFLUENCE OF MID-LEVEL RIDGING AND
ABOVE AVERAGE HEIGHTS. BELOW NORMAL PRECIPITATION IS ALSO FAVORED OVER MUCH OF
THE EASTERN CONUS, FROM THE VICINITY OF THE DAKOTAS EASTWARD ACROSS THE GREAT
LAKES AND NORTHEAST, EXTENDING SOUTHWARD ACROSS MOST OF THE MISSISSIPPI VALLEY,
THE OHIO AND TENNESSEE VALLEYS, MOST OF THE APPALACHIANS, AND INTERIOR SECTIONS
OF THE MID-ATLANTIC REGION. THIS RELATIVE DRYNESS IS ATTRIBUTED TO THE COOLER,
DRIER POLAR AIR MASS PREDICTED TO BE OVER THIS REGION. ON THE EDGES OF THIS
POLAR AIR MASS, ABOVE NORMAL PRECIPITATION IS FAVORED OVER MUCH OF THE NORTHERN
AND CENTRAL ROCKIES AND ADJACENT GREAT PLAINS, APPROXIMATELY THE SOUTHERN HALF
OF TEXAS, AND NEAR THE GULF AND SOUTHEAST COASTS (INCLUDING ALL OF FLORIDA).
THIS BROAD-SCALE PRECIPITATION PATTERN IS GENERALLY CONSISTENT WITH THE ERF
PRECIPITATION CONSOLIDATION FORECAST AND THE AUTO-PRECIPITATION FORECAST.
ACROSS THE ALASKA SECTOR, SOUTHERLY AND SOUTHWESTERLY ANOMALOUS FLOW ACROSS
SOUTHERN ALASKA ENHANCES THE LIKELIHOOD OF WET WEATHER FOR THAT REGION. ODDS
ARE TILTED TOWARDS NEAR AND BELOW NORMAL PRECIPITATION ACROSS NORTHERN ALASKA,
WHERE THE MID-LEVEL RIDGE AND ACCOMPANYING POSITIVE 500-HPA HEIGHT ANOMALIES
ARE THE STRONGEST, AND IS SUPPORTED BY THE REFORECAST-CALIBRATED PRECIPITATION
TOOLS. THE ERF-CON AND AUTO PRECIPITATION TOOLS DEPICT A SLIGHT TILT TOWARDS
WETTER-THAN-NORMAL CONDITIONS FOR MOST OF THE HAWAIIAN ISLANDS, WITH THE
EXCEPTION OF THE BIG ISLAND, WHERE NEAR TO BELOW NORMAL PRECIPITATION IS
FAVORED. IT WAS DECIDED TO GO WITH NEAR NORMAL PRECIPITATION FOR THE BIG
ISLAND, WHICH OFFERS A SMOOTHER OVERALL TRANSITION ACROSS THE ISLANDS.
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, OFFSET BY THE INCREASING UNCERTAINTY ASSOCIATED WITH THE EXPECTED
DECREASE IN AMPLITUDE OF THE WESTERN CONUS RIDGE.
8-14 DAY OUTLOOK FOR NOV 25 - DEC 01, 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 THE WESTERN NORTH AMERICA RIDGE IS STILL IN PLACE, THE SOUTHERN
PORTION OF IT (MEANING THE WESTERN CONUS) IS FORECAST TO TRANSITION TO A
QUASI-ZONAL FLOW PATTERN LATER IN THE PERIOD. THE EASTERN CONUS TROUGH
PREDICTED DURING THE EARLIER 6-10 DAY PERIOD IS FORECAST TO WEAKEN AS IT
PROGRESSES EASTWARD DURING WEEK-2.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS A SOMEWHAT LARGER PORTION OF THE
WESTERN CONUS DURING WEEK-2 RELATIVE TO THE EARLIER 6-10 DAY PERIOD, BASED ON
REFORECAST-CALIBRATED TEMPERATURES FROM THE ECMWF AND CANADIAN ENSEMBLE MEANS.
IN CONTRAST, THE GEFS MAINTAINS FAVORED ABOVE NORMAL TEMPERATURES OVER A
SIGNIFICANTLY SMALLER PORTION OF THE WEST. TEMPERATURE CHANCES TILT
SUBSTANTIALLY TOWARDS ABOVE NORMAL IN ALASKA, UNDER THE PREDICTED INFLUENCE OF
MID-LEVEL RIDGING AND WELL ABOVE-AVERAGE 500-HPA HEIGHTS. A SMALL AREA OF ABOVE
NORMAL TEMPERATURES CONTINUES TO BE FAVORED OVER SOUTHERN FLORIDA, SOUTH OF A
MEAN BAROCLINIC ZONE. BELOW NORMAL TEMPERATURE CHANCES ARE ELEVATED FOR MOST
AREAS EAST OF THE CONTINENTAL DIVIDE, CONSISTENT WITH A PREDICTED MID-LEVEL
TROUGH AND BELOW AVERAGE 500-HPA HEIGHTS. THIS IS SUPPORTED BY
REFORECAST-CALIBRATED TEMPERATURES FROM THE GEFS AND ECMWF ENSEMBLE MEAN MODEL
SOLUTIONS. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED ACROSS THE HAWAIIAN
ISLANDS IN THE 8-14 DAY PERIOD, CONSISTENT WITH THE ERF-CON TEMPERATURE TOOL.
BELOW NORMAL PRECIPITATION IS SLIGHTLY FAVORED OVER MUCH OF THE WESTERN CONUS,
EXTENDING EASTWARD ACROSS APPROXIMATELY THE NORTHEASTERN QUARTER OF THE CONUS.
THIS IS IN REASONABLE AGREEMENT WITH BOTH THE AUTO-PRECIPITATION FORECAST AND
THE CONSOLIDATED PRECIPITATION TOOL. THESE SAME TOOLS ALSO LEND SUPPORT TO THE
INCREASED LIKELIHOOD OF WET WEATHER ACROSS MUCH OF TEXAS, THE GULF COAST
STATES, AND THE ATLANTIC COAST FROM THE DELMARVA PENINSULA TO FLORIDA. AT
HIGHER LATITUDES, ABOVE NORMAL PRECIPITATION CHANCES CONTINUE TO BE ELEVATED
FOR MOST OF ALASKA SOUTH OF THE BROOKS RANGE, AND NEAR NORMAL PRECIPITATION IS
FAVORED FOR FAR NORTHERN ALASKA. FOR THE HAWAIIAN ISLANDS, ABOVE NORMAL
PRECIPITATION IS FAVORED BY THE ERF-CON PRECIPITATION TOOL.
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 INCREASING ONSHORE FLOW EXPECTED ACROSS THE PACIFIC COAST STATES.
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:
19901116 - 20031110 - 20091111 - 19611201 - 19941108
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:
19901117 - 20031112 - 19941113 - 19941108 - 19941118
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 23 - 27 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 N N E MONTANA N A WYOMING B A
UTAH N B ARIZONA N B COLORADO B A
NEW MEXICO B N N DAKOTA B B S DAKOTA B A
NEBRASKA B A KANSAS B A OKLAHOMA B N
N TEXAS B N S TEXAS B A W TEXAS B N
MINNESOTA B B IOWA B B MISSOURI B B
ARKANSAS B B LOUISIANA B N WISCONSIN B B
ILLINOIS B B MISSISSIPPI B N MICHIGAN B B
INDIANA B B OHIO B B KENTUCKY B B
TENNESSEE B B ALABAMA B N NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
MASS B B CONN B B RHODE IS B N
PENN B B NEW JERSEY B B W VIRGINIA B B
MARYLAND B N DELAWARE B N VIRGINIA B N
N CAROLINA B A S CAROLINA B A GEORGIA B A
FL PNHDL B A FL PENIN A A AK N SLOPE A B
AK ALEUTIAN A N AK WESTERN A A AK INT BSN A N
AK S INT A A AK SO COAST A A AK PNHDL A A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 25 - DEC 01, 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 B NEVADA A N
W MONTANA A N E MONTANA N N WYOMING N B
UTAH N N ARIZONA N N COLORADO B N
NEW MEXICO B N N DAKOTA N B S DAKOTA N B
NEBRASKA B B KANSAS B B OKLAHOMA B N
N TEXAS B A S TEXAS B A W TEXAS B N
MINNESOTA B B IOWA B B MISSOURI B B
ARKANSAS B N 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 N ALABAMA B N NEW YORK B B
VERMONT B B NEW HAMP B B MAINE B B
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 B A FL PENIN N A AK N SLOPE A N
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 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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