562
FXUS06 KWBC 241929
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT THU OCTOBER 24 2024
6-10 DAY OUTLOOK FOR OCT 30 - NOV 03, 2024
TODAY’S MODEL SOLUTIONS FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS FOR
500-HPA HEIGHTS AND ANOMALIES ALL DEPICT A LOW FREQUENCY WAVE TRAIN PATTERN
OVER THE NORTH PACIFIC AND NORTH AMERICA ON DAY-6, BUT AFTER THIS POINT THE
MODELS DIVERGE QUICKLY AND DEPICT WIDELY VARYING SYNOPTIC PATTERNS. LOOKING AT
THE 6-10 DAY PERIOD AVERAGE, RIDGING IS FORECAST OVER THE NORTH PACIFIC AND THE
EASTERN CONTIGUOUS U.S. (CONUS) AND TROUGHING AND NEGATIVE HEIGHT ANOMALIES ARE
DEPICTED OVER THE BERING SEA AND THE WESTERN CONUS. MODEL SOLUTIONS ARE
SHIFTING QUITE A BIT FROM RUN TO RUN AND THE DAILY EVOLUTION OF THE SYNOPTIC
PATTERN SUGGESTS A LARGE-SCALE REALIGNMENT POTENTIALLY OCCURRING DURING 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 EAST
OF THE ROCKIES, PARTICULARLY FOR EAST OF THE MISSISSIPPI RIVER WHERE
PROBABILITIES OVER 80% ARE WIDESPREAD. BELOW-NORMAL TEMPERATURES ARE WIDELY
FAVORED FOR THE WESTERN CONUS AS COOLER AIR MOVES IN ASSOCIATED WITH THE
AMPLIFIED TROUGH OVER THE REGION. THIS SHIFT TO COOLER TEMPERATURES IS FAVORED
TO BEGIN PRIOR TO THE 6-10 PERIOD AND SPREAD SOUTHWARD QUICKLY, RESULTING IN
WIDESPREAD COVERAGE OF PROBABILITIES EXCEEDING 50% FOR BELOW-NORMAL
TEMPERATURES. MODEL SOLUTIONS INDICATE STRONG SURFACE LOW PRESSURE OVER THE
GULF OF ALASKA, BRINGING SOUTHERLY TO SOUTHWESTERLY FLOW OVER THE STATE,
GENERALLY FAVORING ABOVE-NORMAL TEMPERATURES FOR THE SOUTHERN AND EASTERN
MAINLAND, WHILE NEAR-NORMAL TEMPERATURES ARE MOST LIKELY FOR THE WESTERN COAST
AND PORTIONS OF THE ALASKAN INTERIOR, AND BELOW-NORMAL TEMPERATURES ARE
SLIGHTLY FAVORED FOR THE PANHANDLE.
TROUGHING OVER THE WESTERN CONUS TILTS THE ODDS TOWARDS ABOVE-NORMAL
PRECIPITATION FOR MUCH OF THE NORTHWESTERN AND CENTRAL CONUS, WITH ENHANCED
ODDS (>50%) OVER PORTIONS OF THE GREAT PLAINS AND MISSISSIPPI VALLEY DUE TO THE
POTENTIAL FOR LEE CYCLOGENESIS AND ENHANCED BAROCLINIC INSTABILITY AS THE
UPPER-LEVEL TROUGH APPROACHES FROM THE WEST. NEAR- TO BELOW-NORMAL
PRECIPITATION IS FAVORED FOR PORTIONS OF THE SOUTHEAST U.S. AND MUCH OF THE
MID-ATLANTIC AND NORTHEAST U.S. WITH POSITIVE 500-HPA HEIGHT ANOMALIES OVER THE
EAST COAST. NEAR-NORMAL PRECIPITATION IS FAVORED FOR MUCH OF CALIFORNIA,
NEVADA, AND ARIZONA, TOO FAR SOUTH TO BENEFIT FROM THE ENHANCED PACIFIC MOIST
FLOW AND TOO FAR WEST TO BENEFIT FROM LEE CYCLOGENESIS. 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 33% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 34% 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: FORECAST CONFIDENCE: BELOW
AVERAGE, 2 OUT OF 5, WITH REASONABLE AGREEMENT AMONG FORECAST MODELS ON THE
OVERALL SYNOPTIC PATTERN, OFFSET BY A LARGE SPREAD AMONG INDIVIDUAL MODELS AND
AN ANTICIPATED REALIGNMENT OF SYNOPTIC FEATURES DURING THE FORECAST PERIOD.
8-14 DAY OUTLOOK FOR NOV 01 - 07 2024
MODEL ENSEMBLES DEPICT A SIGNIFICANT SHIFT OF THE SYNOPTIC PATTERN FROM THE
6-10 DAY PERIOD. THE WEEK-2 PERIOD AVERAGE NO LONGER APPEARS AS A WAVETRAIN
PATTERN OVER NORTH AMERICA. WEAK POSITIVE 500-HPA HEIGHT ANOMALIES REMAIN OVER
THE EAST COAST AND A WEAK EASTWARDLY TILTED TROUGH EXTENDS FROM THE NORTHERN
PLAINS TO THE GULF OF CALIFORNIA, BUT ANOMALOUS HEIGHT ANOMALIES OVER THE
PACIFIC ARE ALIGNED ZONALLY, RESULTING IN A TIGHT PRESSURE GRADIENT AND BROAD
TROUGHING EXTENDING EASTWARD INTO THE CANADIAN PACIFIC. MODEL SOLUTIONS ARE
TENDING TO SETTLE INTO A LONGER WAVELENGTH SYNOPTIC PATTERN OVER NORTH AMERICA
WHICH TENDS TO FAVOR PERSISTENCE, THUS THE 8-14 DAY OUTLOOKS DO NOT STRAY TOO
FAR FROM THE 6-10 DAY PERIOD.
LINGERING POSITIVE 500-HPA HEIGHT ANOMALIES OVER EASTERN NORTH AMERICA CONTINUE
TO FAVOR ABOVE-NORMAL TEMPERATURES FOR THE CONUS EAST OF THE ROCKIES. CHANCES
OF ABOVE-NORMAL TEMPERATURES ARE REDUCED FROM THE EARLIER FORECAST PERIOD,
HOWEVER AT LEAST 50% CHANCES REMAIN FOR MUCH OF THE EAST COAST. THE AMPLIFIED
TROUGH DEPICTED OVER THE WESTERN CONUS DURING THE 6-10 DAY PERIOD IS FAVORED TO
FLATTEN DRASTICALLY, FAVORING A MODERATION TO NEAR-NORMAL TEMPERATURES EAST OF
THE ROCKIES. THE SYNOPTIC PICTURE OVER THE ALASKA REGION IS QUALITATIVELY
UNCHANGED, RESULTING IN A CONTINUED TILT TOWARDS ABOVE-NORMAL TEMPERATURES FOR
MUCH OF EASTERN AND SOUTHEASTERN ALASKA, WHILE NEAR- TO BELOW-NORMAL
TEMPERATURES ARE FAVORED ALONG THE WESTERN COAST AND ALEUTIAN ISLANDS. HAWAII
CONTINUES TO TILT STRONGLY TOWARDS ABOVE-NORMAL TEMPERATURES ALTHOUGH ODDS ARE
REDUCED SOMEWHAT FOR THE BIG ISLAND, CONSISTENT WITH THE ERF CONSOLIDATION AND
HAWAII FORECAST TOOLS.
MUCH OF THE CENTRAL AND NORTHEAST CONUS TILTS TOWARDS ABOVE-NORMAL
PRECIPITATION FOR WEEK-2 WITH LINGERING BAROCLINIC INSTABILITY OVER THE GREAT
PLAINS. ODDS OF ABOVE-NORMAL PRECIPITATION ARE WEAKER FOR THE NORTHWESTERN
CONUS AND MUCH OF THE REST OF THE WESTERN CONUS TRENDS TOWARDS NEAR-NORMAL
PRECIPITATION AS THE TROUGH FLATTENS, WHILE RETURN FLOW AROUND A SURFACE HIGH
OVER THE EASTERN CONUS IS FAVORED, ENHANCING ABOVE-NORMAL PRECIPITATION ODDS
FOR PORTIONS OF THE SOUTHERN PLAINS. NEAR-NORMAL PRECIPITATION REMAINS FAVORED
FOR MUCH OF NEW ENGLAND UNDER THE CONTINUED INFLUENCE OF POSITIVE 500-HPA
HEIGHT ANOMALIES. NEAR-NORMAL PRECIPITATION IS ALSO FAVORED OVER THE
SOUTHEASTERN U.S. WHERE MODEL GUIDANCE AND FORECAST TOOLS OFFER A WIDE RANGE OF
SOMETIMES CONTRADICTING SOLUTIONS. 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 ENHANCED ALONG THE SOUTHEASTERN COAST RELATIVE TO THE EARLY
PERIOD, WHILE ALL OF HAWAII CONTINUES TO LEAN TOWARDS ABOVE-NORMAL
PRECIPITATION.
THE OFFICIAL 8-14 DAY 500-HPA HEIGHT BLEND CONSISTS OF: 38% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 11, 25% OF TODAY'S 0Z EUROPEAN ENSEMBLE MEAN
CENTERED ON DAY 11, AND 37% OF TODAY'S 0Z CANADIAN ENSEMBLE MEAN CENTERED ON
DAY 11
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD: BELOW AVERAGE, 2 OUT OF 5, WITH
REASONABLE AGREEMENT AMONG MODELS REGARDING THE SYNOPTIC PATTERN, OFFSET BY
LARGE SPREAD IN MODEL SOLUTIONS AND AN APPARENT SYNOPTIC REALIGNMENT FAVORED TO
OCCUR DURING 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 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:
19831004 - 19711031 - 19831009 - 19561023 - 19911022
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:
19831007 - 19561010 - 19711101 - 19561024 - 19911021
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 30 - NOV 03, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B A NRN CALIF B N
SRN CALIF B N IDAHO B A NEVADA B N
W MONTANA B A E MONTANA N A WYOMING B A
UTAH B A ARIZONA B N COLORADO B A
NEW MEXICO B A N DAKOTA N A S DAKOTA N A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
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 A KENTUCKY A A
TENNESSEE A A ALABAMA A A NEW YORK A N
VERMONT A N NEW HAMP A N MAINE A N
MASS A B CONN A B RHODE IS A B
PENN A N NEW JERSEY A B W VIRGINIA A N
MARYLAND A B DELAWARE A B VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A A FL PENIN A A AK N SLOPE A A
AK ALEUTIAN N A AK WESTERN N A AK INT BSN N A
AK S INT A A AK SO COAST A A AK PNHDL B A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR NOV 01 - 07 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON N A OREGON N N NRN CALIF N N
SRN CALIF N N IDAHO N N NEVADA N N
W MONTANA A N E MONTANA A N WYOMING N N
UTAH N N ARIZONA N N COLORADO A N
NEW MEXICO A N N DAKOTA A N S DAKOTA A A
NEBRASKA A A KANSAS A A OKLAHOMA A A
N TEXAS A A S TEXAS A A W TEXAS A A
MINNESOTA A A IOWA A A MISSOURI A A
ARKANSAS A A LOUISIANA A N WISCONSIN A A
ILLINOIS A A MISSISSIPPI A N MICHIGAN A A
INDIANA A A OHIO A A KENTUCKY A A
TENNESSEE A N ALABAMA A N NEW YORK A N
VERMONT A N NEW HAMP A N MAINE A N
MASS A N CONN A N RHODE IS A N
PENN A A NEW JERSEY A A W VIRGINIA A A
MARYLAND A A DELAWARE A A VIRGINIA A N
N CAROLINA A N S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A A AK N SLOPE A A
AK ALEUTIAN B A AK WESTERN N 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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page