550
FXUS06 KWBC 221902
PMDMRD
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER COLLEGE PARK, MD
300 PM EDT TUE OCTOBER 22 2024
6-10 DAY OUTLOOK FOR OCT 28 - NOV 01, 2024
TODAY’S MODEL SOLUTIONS FROM THE GEFS, ECMWF, AND CANADIAN ENSEMBLE MEANS FOR
500-HPA HEIGHTS AND ANOMALIES ALL DEPICT A HIGH FREQUENCY WAVE TRAIN PATTERN
OVER THE NORTH PACIFIC AND NORTH AMERICA ON DAY-6, BUT AFTER THIS POINT THE
MODELS DIVERGE QUICKLY AS THE HIGHER FREQUENCY WAVETRAIN BREAKS DOWN AND A
LONGER AMPLITUDE BECOMES THE PREFERRED SOLUTION. 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,
PARTICULARLY FOR MUCH OF THE MISSISSIPPI VALLEY, OHIO VALLEY, AND GREAT LAKES
WHERE PROBABILITIES EXCEED 80%. CHANCES OF ABOVE-NORMAL TEMPERATURES HAVE
INCREASED FOR THE EAST COAST AS WELL, ESPECIALLY FOR NEW ENGLAND WHERE
YESTERDAY’S 6-10 DAY OUTLOOK FAVORED NEAR-NORMAL TEMPERATURES. NEAR- TO
BELOW-NORMAL TEMPERATURES ARE 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 BERING 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 WESTERN CONUS ALONG WITH FAVORABLE POSITIONING OF THE MJO
OVER THE AMERICAS TILTS THE ODDS TOWARDS ABOVE-NORMAL PRECIPITATION FOR MUCH OF
THE WESTERN AND CENTRAL CONUS, WITH ENHANCED ODDS (>50%) OVER PORTIONS OF THE
CENTRAL PLAINS DUE TO THE POTENTIAL FOR LEE CYCLOGENESIS AND ENHANCED
BAROCLINIC INSTABILITY AS THE UPPER-LEVEL TROUGH APPROACHES FROM THE WEST. MUCH
OF THE MID-ATLANTIC AND NORTHEAST U.S. TILTS TOWARDS BELOW-NORMAL PRECIPITATION
WITH POSITIVE 500-HPA HEIGHT ANOMALIES OVERLYING THE REGION. NEAR-NORMAL
PRECIPITATION IS FAVORED ALONG THE U.S.-MEXICO BORDER, 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 45% OF TODAY'S 0Z GFS
ENSEMBLE MEAN CENTERED ON DAY 8, 35% 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: 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 OCT 30 - NOV 05, 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. AMPLIFIED RIDGING CONTINUES OVER THE EAST COAST, AS
DOES WEAK TROUGHING OVER THE WESTERN CONUS, BUT ANOMALOUS HEIGHT ANOMALIES OVER
THE PACIFIC ARE ALIGNED ZONALLY, RESULTING IN A TIGHT PRESSURE GRADIENT AND
BROAD TROUGHING EXTENDING EASTWARD INTO THE PACIFIC NORTHWEST. THIS SETUP WOULD
TEND TO RESULT IN SLIGHTLY MORE PERSISTENT WEATHER PATTERNS OVER NORTH AMERICA,
THUS THE 8-14 DAY OUTLOOKS DO NOT STRAY TOO FAR FROM THE 6-10 DAY PERIOD.
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 CONTINUE TO BE HIGH IN THE LATER FORECAST PERIOD; AT LEAST 70%
CHANCES ARE ALMOST UNIVERSAL EAST OF THE MISSISSIPPI RIVER. 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 CENTRAL CONUS CONTINUES TO TILT TOWARDS ABOVE-NORMAL PRECIPITATION
FOR WEEK-2. ODDS ARE WEAKER FOR THE NORTHWESTERN CONUS 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. 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, 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:
19561023 - 19631004 - 19731002 - 19831003 - 19891024
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:
19731001 - 19561023 - 19631004 - 19831006 - 19561010
6-10 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 28 - NOV 01, 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 N N COLORADO A 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 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 B KENTUCKY A B
TENNESSEE A B 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 B
MARYLAND A B DELAWARE A B VIRGINIA A B
N CAROLINA A B S CAROLINA A N GEORGIA A N
FL PNHDL A N FL PENIN A A 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 A
8-14 DAY OUTLOOK TABLE
OUTLOOK FOR OCT 30 - NOV 05, 2024
STATE TEMP PCPN STATE TEMP PCPN STATE TEMP PCPN
WASHINGTON B A OREGON B N NRN CALIF N N
SRN CALIF B N IDAHO B N NEVADA B N
W MONTANA B A E MONTANA A N WYOMING B A
UTAH B N ARIZONA B N COLORADO N 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 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 N
TENNESSEE A N ALABAMA A N 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 B NEW JERSEY A B W VIRGINIA A B
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.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page