896
FXUS06 KWBC 211925
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 21 2024
6-10 DAY OUTLOOK FOR OCT 27 - 31 2024
TODAY’S MODEL SOLUTIONS FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS FOR
500-HPA HEIGHTS AND ANOMALIES ARE IN GOOD AGREEMENT AND ALL DEPICT A WAVE TRAIN
PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA. RIDGING IS FORECAST OVER THE
NORTH PACIFIC NEAR THE ALEUTIANS AND THE EASTERN CONTIGUOUS U.S. (CONUS) AND
TROUGHING AND NEGATIVE HEIGHT ANOMALIES ARE DEPICTED OVER THE CHUKCHI SEA AND
THE WESTERN CONUS. MODEL SOLUTIONS ARE SHIFTING A BIT FROM RUN TO RUN AND THE
DAILY EVOLUTION OF THE SYNOPTIC PATTERN SUGGESTS A MINOR REALIGNMENT OF THE
DOMINANT FEATURES DURING THE EARLY PART OF THE 6-10 DAY PERIOD.
EXPANSIVE POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE CENTRAL AND EASTERN CONUS
RESULT IN ABOVE-NORMAL TEMPERATURES BEING FAVORED FOR MUCH OF THE LOWER 48,
ESPECIALLY THE GREAT PLAINS AND MUCH OF THE MISSISSIPPI VALLEY WHERE
PROBABILITIES EXCEED 70%. CHANCES WEAKEN TOWARDS THE NORTHEAST, WITH
NEAR-NORMAL TEMPERATURES MOST LIKELY FOR PORTIONS OF NEW ENGLAND. NEAR-NORMAL
TEMPERATURES ARE ALSO FAVORED AS A PERIOD-AVERAGE FOR PORTIONS OF THE
INTERMOUNTAIN WEST AS COOLER AIR MOVES INTO THE WESTERN CONUS LATER IN THE
PERIOD ASSOCIATED WITH THE AMPLIFIED TROUGH OVER THE NORTHWESTERN CONUS. THIS
SHIFT TO COOLER TEMPERATURES HAPPENS EARLIER FOR THE PACIFIC NORTHWEST, TILTING
THE ODDS TOWARDS BELOW-NORMAL TEMPERATURES FOR THAT REGION. UPPER-LEVEL
TROUGHING OVER THE CHUKCHI SEA BRINGS WESTERLY TO NORTHWESTERLY FLOW OVER
ALASKA, GENERALLY FAVORING BELOW-NORMAL TEMPERATURES, EXCEPT FOR THE NORTHERN
AND SOUTHWESTERN COASTAL AREAS WHERE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY.
TROUGHING OVER THE NORTHWESTERN CONUS ALONG WITH FAVORABLE POSITIONING OF THE
MJO OVER THE AMERICAS STACKS THE ODDS TOWARDS ABOVE-NORMAL PRECIPITATION FOR
MUCH OF THE NORTHERN CONUS, ESPECIALLY OVER THE PACIFIC NORTHWEST WHERE ODDS
EXCEED 50%. MUCH OF THE MID-ATLANTIC AND NORTHEAST U.S. TILTS TOWARDS
BELOW-NORMAL PRECIPITATION WITH POSITIVE 500-HPA HEIGHT ANOMALIES OVERLYING THE
REGION. BELOW-NORMAL PRECIPITATION IS ALSO FAVORED FOR PORTIONS OF THE DESERT
SOUTHWEST, TOO FAR SOUTH TO BENEFIT FROM THE ENHANCED PACIFIC MOIST FLOW. THE
SYNOPTIC PATTERN OVER THE ALASKA REGION TENDS TO FAVOR STORMIER CONDITIONS OVER
THE GULF OF ALASKA AND ABOVE-NORMAL PRECIPITATION FOR MUCH OF THE STATE,
ESPECIALLY ALONG THE SOUTHERN COAST. PREVAILING WINDS OVER THE NORTH PACIFIC
CROSS A LONG FETCH OF WARM WATERS, WEAKLY FAVORING ABOVE-NORMAL PRECIPITATION
AND STRONGLY FAVORING ABOVE-NORMAL TEMPERATURES FOR HAWAII.
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: ABOUT AVERAGE, 3 OUT OF 5, WITH
GOOD AGREEMENT AMONG FORECAST MODELS ON THE OVERALL SYNOPTIC PATTERN, OFFSET BY
A LARGE SPREAD AMONG INDIVIDUAL MODELS AND AN ANTICIPATED REALIGNMENT OF
SYNOPTIC FEATURES LATE IN THE FORECAST PERIOD.
8-14 DAY OUTLOOK FOR OCT 29 - NOV 04, 2024
MODEL ENSEMBLES DEPICT A SLIGHT PROGRESSION OF THE SYNOPTIC PATTERN FROM THE
6-10 DAY PERIOD. THE TROUGH OVER THE WESTERN CONUS IS FAVORED TO MOVE SLIGHTLY
EASTWARD AND DEVELOP AN EASTWARD TILT. MEANWHILE, POSITIVE HEIGHT ANOMALIES
REMAIN ENTRENCHED OVER THE EASTERN CONUS AND AMPLIFY RELATIVE TO THE 6-10 DAY
PERIOD. POSITIVE HEIGHT ANOMALIES OVER THE NORTH PACIFIC ARE FAVORED TO REDUCE
IN MAGNITUDE, SLOWING BUT NOT ELIMINATING NORTHWESTERLY FLOW ALOFT OVER ALASKA.
THE AMPLIFYING RIDGE OVER THE EASTERN CONUS CONTINUES TO FAVOR ABOVE-NORMAL
TEMPERATURES FOR MOST OF THE CONUS EAST OF THE ROCKIES. CHANCES OF ABOVE-NORMAL
TEMPERATURES ARE EVEN HIGHER THAN THE 6-10 DAY PERIOD FOR PORTIONS OF THE GREAT
LAKES, EXCEEDING 80% IN SOME LOCATIONS. AS THE WEST COAST TROUGH IS FAVORED TO
MOVE INTO THE INTERMOUNTAIN WEST DURING WEEK-2, CHANCES FOR BELOW-NORMAL
TEMPERATURES EXPAND FARTHER INTO THE WEST RELATIVE TO THE 6-10 DAY PERIOD. THE
SYNOPTIC PICTURE OVER THE ALASKA REGION IS QUALITATIVELY UNCHANGED, RESULTING
IN A CONTINUED TILT TOWARDS BELOW-NORMAL TEMPERATURES FOR MOST OF THE STATE
WHILE NEAR-NORMAL TEMPERATURES ARE FAVORED ALONG THE NORTHERN COAST. HAWAII
CONTINUES TO TILT STRONGLY TOWARDS ABOVE-NORMAL TEMPERATURES, CONSISTENT WITH
THE ERF CONSOLIDATION AND HAWAII FORECAST TOOLS.
MUCH OF THE NORTHERN CONUS CONTINUES TO TILT TOWARDS ABOVE-NORMAL PRECIPITATION
FOR WEEK-2. ODDS ARE WEAKER FOR THE PACIFIC NORTHWEST AS THE TROUGH SHIFTS
EASTWARD, WHICH ALSO SETS UP THE POTENTIAL FOR A BAROCLINIC ZONE OVER THE GREAT
PLAINS, ENHANCING ABOVE-NORMAL PRECIPITATION ODDS FOR PORTIONS OF THE CENTRAL
CONUS, ESPECIALLY OVER PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY WHERE
PROBABILITIES EXCEED 50%. NEAR- TO BELOW-NORMAL PRECIPITATION REMAINS FAVORED
FOR MUCH OF THE EASTERN CONUS UNDER THE CONTINUED INFLUENCE OF POSITIVE 500-HPA
HEIGHT ANOMALIES. NEAR-NORMAL PRECIPITATION IS ALSO FAVORED ALONG THE SOUTHERN
U.S. BORDER REGION, ONCE AGAIN TOO FAR SOUTH TO BENEFIT FROM PRECIPITATION
ENHANCING FACTORS AT PLAY FURTHER NORTH. WITH THE OVERALL SYNOPTIC PICTURE
LITTLE CHANGED FOR BOTH ALASKA AND HAWAII, THEIR WEEK-2 PRECIPITATION OUTLOOK
IS SIMILAR TO THE 6-10 DAY PERIOD. IN ALASKA THE HIGHEST ODDS OF ABOVE-NORMAL
PRECIPITATION ARE SHIFTED SOUTHWARD TO THE SOUTHERN COAST RELATIVE TO THE EARLY
PERIOD. FOR HAWAII, DRIER AIR IS DEPICTED MOVING IN FROM THE WEST, PUSHING
KAUAI INTO NEAR-NORMAL PRECIPITATION WHILE THE REST OF THE ISLANDS CONTINUE TO
LEAN TOWARDS ABOVE-NORMAL PRECIPITATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 34% 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
CONTINUED GOOD AGREEMENT AMONG MODELS REGARDING THE SYNOPTIC PATTERN, OFFSET BY
DIFFERENCES BETWEEN MODELS REGARDING STRENGTH AND POSITION OF VARIOUS SYNOPTIC
FEATURES AND WEAKER ANOMALIES IN SOME FORECAST FIELDS.
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 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:
19511012 - 19561023 - 19631003 - 19981007 - 19901101
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:
19561022 - 19730930 - 19901031 - 19511013 - 19981007
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 27 - 31 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B A
SRN CALIF N N IDAHO B A NEVADA N A
W MONTANA N A E MONTANA A A WYOMING N A
UTAH N A ARIZONA A N COLORADO A A
NEW MEXICO A B N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A N S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A N LOUISIANA A N WISCONSIN A A
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A N OHIO A B KENTUCKY A B
TENNESSEE A B ALABAMA A N NEW YORK A B
VERMONT A B NEW HAMP N B MAINE N B
MASS N B CONN N B RHODE IS N B
PENN A B NEW JERSEY A B W VIRGINIA A B
MARYLAND A B DELAWARE N B VIRGINIA A B
N CAROLINA A B S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A N AK N SLOPE B A
AK ALEUTIAN N A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B N
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 29 - NOV 04, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B A
SRN CALIF B N IDAHO B A NEVADA B A
W MONTANA B A E MONTANA N A WYOMING N A
UTAH B A ARIZONA B N COLORADO N A
NEW MEXICO A N N DAKOTA A A S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A N W TEXAS A N
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A A WISCONSIN A A
ILLINOIS A A MISSISSIPPI A A MICHIGAN A A
INDIANA A A OHIO A N KENTUCKY A A
TENNESSEE A A ALABAMA A N NEW YORK A B
VERMONT A B NEW HAMP A B MAINE A B
MASS A B CONN A B RHODE IS A B
PENN A B NEW JERSEY A B W VIRGINIA A N
MARYLAND A B DELAWARE A B VIRGINIA A B
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE N A
AK ALEUTIAN B A AK WESTERN B A AK INT BSN B A
AK S INT B A AK SO COAST B A AK PNHDL B 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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