602
FXUS06 KWBC 242006
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 24 2023
6-10 DAY OUTLOOK FOR NOV 30 - DEC 04, 2023
TODAY’S GEFS, CMCE, AND ECMWF SOLUTIONS OF THE 500-HPA ANOMALY FIELD DEPICTS AN
EXTENDED TROUGH EXTENDING FROM THE GULF OF ALASKA DOWN TO BAJA CALIFORNIA.
WEAKER NEGATIVE HEIGHT ANOMALIES ARE ALSO PRESENT OVER THE NORTH ATLANTIC,
WHILE WEAK POSITIVE HEIGHT ANOMALIES ARE DEPICTED OVER THE OHIO VALLEY. AT THE
SURFACE, BROAD HIGH PRESSURE FROM THE GREAT BASIN TO THE NORTHERN PLAINS HELPS
TO CONFINE COLDER AIR TO HIGHER LATITUDES AND ALSO HELPS TO FOCUS MOISTURE
TRANSPORT FROM THE PACIFIC INTO A NORTHERN STREAM FOCUSED OVER THE PACIFIC
NORTHWEST AND A SUBTROPICAL STREAM MOVING OVER THE SOUTHERN TIER. THIS PATTERN
GENERALLY FAVORS WARMING TEMPERATURES AND INCREASED PRECIPITATION FOR MUCH OF
THE CONTIGUOUS U.S. (CONUS).
SOUTHERLY RETURN FLOW AROUND A SURFACE HIGH PRESSURE OVER THE EASTERN CONUS
FAVORS MODERATING TEMPERATURES AND A LARGE SHIFT IN THE 6-10 DAY TEMPERATURE
OUTLOOK RELATIVE TO YESTERDAY. ABOVE-NORMAL TEMPERATURES ARE NOW FAVORED FOR
MUCH OF THE CENTRAL AND SOUTHEAST CONUS, ALSO INCLUDING THE MID-ATLANTIC AND
OHIO VALLEY. PROBABILITIES ARE HIGHEST (>60%) OVER THE LOWER MISSISSIPPI
VALLEY. BELOW-NORMAL TEMPERATURES REMAIN SLIGHTLY FAVORED FOR PORTIONS OF
NORTHERN NEW ENGLAND AS LINGERING COLDER AIR IS SLOWER TO EXIT THAN FURTHER
SOUTH, AND MUCH OF THE WESTERN CONUS WHERE INCREASED CLOUDINESS AND SURFACE
HIGH PRESSURE OVER THE MOUNTAINS HELPS TO MAINTAIN COOLER TEMPERATURES. MUCH OF
ALASKA TILTS TOWARDS ABOVE-NORMAL TEMPERATURES WITH SOUTHERLY FLOW MAINTAINED
BY A STRONG SURFACE LOW OVER THE GULF OF ALASKA, EXCEPT FOR THE MOST OF THE
SOUTHERN COAST, WHERE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY. THE HAWAII
CONSOLIDATION TOOL FAVORS ABOVE-NORMAL TEMPERATURES FOR THE ISLANDS.
THE STRONG LOW PRESSURE OVER THE NORTH PACIFIC, ABUNDANT AVAILABLE SUBTROPICAL
MOISTURE, AND GOOD RETURN FLOW AROUND SURFACE HIGH PRESSURE OVER THE EASTERN
CONUS COMBINE TO FAVOR ABOVE-NORMAL PRECIPITATION FOR MOST OF THE CONUS. FOR
THE 6-10 DAY PERIOD THE HIGHEST PROBABILITIES EXTEND ALONG THE SOUTHERN TIER
WITH THE STRONGEST RETURN FLOW AROUND THE EASTERN HIGH AND BEST SOURCING OF
PACIFIC MOISTURE FROM THE SUBTROPICAL BRANCH OF THE JET STREAM. SURFACE HIGH
PRESSURE OVER THE GREAT BASIN RESULTS IN A TILT TOWARD BELOW-NORMAL
PRECIPITATION DOWNSTREAM OVER PORTIONS OF THE NORTHERN PLAINS AND UPPER
MIDWEST, AND NEAR-NORMAL PRECIPITATION FURTHER DOWNSTREAM OVER NORTHERN NEW
ENGLAND. CONTINUED STORMINESS OVER THE GULF OF ALASKA FAVORS ABOVE-NORMAL
PRECIPITATION FOR THE PANHANDLE AND SOUTHERN MAINLAND ALASKA, WHILE NEAR-NORMAL
PRECIPITATION IS MOST LIKELY FOR THE REST OF THE STATE. PROBABILITIES OF
ABOVE-NORMAL PRECIPITATION ARE ALSO ENHANCED FOR THE HAWAIIAN ISLANDS,
SUPPORTED BY THE HAWAII CONSOLIDATION TOOL.
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, DUE TO
GOOD AGREEMENT AMONG ENSEMBLE MODELS AND FORECAST TOOLS, OFFSET BY QUESTIONS
REGARDING TIMING OF ONGOING PATTERN SHIFT.
8-14 DAY OUTLOOK FOR DEC 02 - 08 2023
THE WEEK-2 FORECAST PERIOD FEATURES A SIMILAR SYNOPTIC PICTURE TO WHAT IS SEEN
IN THE 6-10 DAY PERIOD. MODEL 500-HPA HEIGHT ANOMALIES ARE QUITE DIMINISHED
RELATIVE TO THE EARLY PERIOD, BUT TROUGHING OVER THE WEST COAST REMAINS EVEN AS
THE PREVAILING SYNOPTIC PATTERN TENDS TOWARDS ZONAL FLOW. WITH CONTINUED
TROUGHING OVER THE WEST COAST AND A ZONAL PATTERN OVER THE REST OF THE CONUS,
THE 8-14 DAY OUTLOOKS CONTINUE TO FAVOR ABOVE-NORMAL TEMPERATURES AND
PRECIPITATION.
WITH CONTINUED SURFACE HIGH PRESSURE OVER THE GREAT BASIN AND NORTHERN PLAINS,
SOUTHERLY FLOW REMAINS OVER THE CENTRAL AND EASTERN CONUS, WHILE ONSHORE FLOW
CONTINUES OVER THE WEST COAST. THESE COMBINE TO FAVOR ABOVE-NORMAL TEMPERATURES
FOR MOST OF THE CONUS DURING WEEK-2, EXCEPT FOR PORTIONS OF THE GREAT BASIN AND
DESERT SOUTHWEST, AND NORTHERN NEW ENGLAND, WHERE NEAR-NORMAL TEMPERATURES ARE
MOST LIKELY. THIS DEPICTION OF THE WEEK-2 TEMPERATURES IS GENERALLY
WELL-SUPPORTED BY MOST FORECAST TOOLS, EXCEPT FOR THE WEST WHERE DYNAMICAL
MODELS FAVOR BELOW-NORMAL TEMPERATURES WHILE THE ENSEMBLE REFORECASTS INDICATE
ABOVE-NORMAL. DURING THE FORECAST PERIOD SURFACE LOW PRESSURE IS FAVORED TO
SHIFT SOUTHWARD OUT OF THE GULF OF ALASKA, REDUCING SOUTHERLY FLOW OVER THE
STATE. ABOVE-NORMAL TEMPERATURES ARE STILL FAVORED FOR THE PANHANDLE AND THE
EASTERN MAINLAND, WHILE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY FOR THE
WESTERN HALF OF THE STATE. LIKE THE 6-10 DAY PERIOD, HAWAII TILTS TOWARD
ABOVE-NORMAL TEMPERATURES DURING WEEK-2, SUPPORTED BY THE HAWAII CONSOLIDATION.
ABOVE-NORMAL PRECIPITATION CONTINUES TO BE FAVORED FOR MUCH OF THE CONUS DURING
WEEK-2. MODEL SOLUTIONS FAVOR THE SURFACE LOW OVER THE NORTH PACIFIC TO SHIFT
SOUTHWARD AND THE SUBTROPICAL BRANCH OF THE JET STREAM TO BECOME LESS ACTIVE,
SHIFTING THE HIGHEST PROBABILITIES OF ABOVE-NORMAL PRECIPITATION FROM THE
SOUTHERN TIER TO THE NORTHWEST CONUS. PORTIONS OF THE NORTHERN PLAINS CONTINUE
TO TILT TOWARDS BELOW-NORMAL PRECIPITATION DOWNSTREAM OF SURFACE HIGH PRESSURE
OVER THE GREAT BASIN. THE MOVING SURFACE LOW PRESSURE ALSO REDUCES THE
ENHANCEMENT OF PRECIPITATION FOR THE ALASKAN REGION. SOUTHEAST ALASKA CONTINUES
TO TILT TOWARD ABOVE-NORMAL PRECIPITATION, BUT NEAR-NORMAL PRECIPITATION IS NOW
FAVORED FOR THE REST OF THE STATE. HAWAII CONTINUES TO TILT TOWARDS
ABOVE-NORMAL TEMPERATURES, BUT PROBABILITIES ARE MUCH REDUCED RELATIVE TO THE
6-10 DAY PERIOD AS THE SUBTROPICAL BRANCH OF THE JET STREAM IS FAVORED TO
BECOME LESS ACTIVE DURING WEEK-2.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 40% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 40% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 20% 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
REASONABLE AGREEMENT ON SYNOPTIC PATTERN AMONG DYNAMICAL MODELS, OFFSET BY
WEAKER ANOMALIES AND PROBABILITIES FROM FORECAST TOOLS.
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
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:
20071122 - 19561122 - 19561127 - 19861208 - 19881208
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:
20071122 - 19561121 - 19861207 - 20051118 - 19761129
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 30 - DEC 04, 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N A NRN CALIF B A
SRN CALIF B A IDAHO N A NEVADA B A
W MONTANA N A E MONTANA N B WYOMING N B
UTAH B A ARIZONA B A COLORADO B A
NEW MEXICO B A N DAKOTA A B S DAKOTA A B
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A N IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A N
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK N A
VERMONT N N NEW HAMP N N MAINE B N
MASS N A CONN N A RHODE IS N A
PENN N A NEW JERSEY N A W VIRGINIA A A
MARYLAND N A DELAWARE N 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 A A AK WESTERN A N AK INT BSN A N
AK S INT N A AK SO COAST N A AK PNHDL N A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR DEC 02 - 08 2023
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON A A OREGON A A NRN CALIF A A
SRN CALIF N A IDAHO A A NEVADA N A
W MONTANA A A E MONTANA A N WYOMING A A
UTAH N A ARIZONA N A COLORADO N A
NEW MEXICO N A N DAKOTA A B S DAKOTA A B
NEBRASKA A N KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A N IOWA A N MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A N
ILLINOIS A A MISSISSIPPI A A MICHIGAN A N
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A A
VERMONT N A NEW HAMP N A MAINE N A
MASS N A CONN A A RHODE IS N 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 N N
AK ALEUTIAN N N AK WESTERN N N AK INT BSN A N
AK S INT A N AK SO COAST A N 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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