893
FXUS02 KWBC 020723 AAA
PMDEPD
EXTENDED FORECAST DISCUSSION...UPDATED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
323 AM EDT THU OCT 2 2025
VALID 12Z SAT OCT 4 2025 - 12Z WED OCT 8 2025
..GENERAL OVERVIEW
A GENERAL UPPER RIDGE WILL BE SITUATED OVER THE INTERMOUNTAIN WEST
ALONG WITH A BUILDING UPPER RIDGE OVER THE EASTERN HALF OF THE
NATION. THERE WILL LIKELY BE A SPLIT FLOW PATTERN ALOFT, WITH THE
SOUTHERN STREAM SHOWING INCREASED POTENTIAL FOR A CLOSED UPPER LOW
TO DEVELOP OVER CALIFORNIA/NEVADA BY EARLY NEXT WEEK. MEANWHILE,
THE NORTHERN STREAM WILL SUPPORT AN AMPLIFYING SHORTWAVE WITH AN
ATTENDANT COLD FRONT, USHERING IN MUCH COLDER TEMPERATURES ACROSS
THE NORTHERN ROCKIES AND NORTHWESTERN PLAINS, AND HEAVY SNOW FOR
THE HIGHER MOUNTAIN RANGES OF WYOMING AND MONTANA. FARTHER SOUTH,
TROPICAL MOISTURE INTERACTING WITH A LINGERING STATIONARY FRONT
WILL LIKELY PRODUCE PERIODS OF HEAVY RAIN AND THUNDERSTORMS ALONG
THE EAST COAST OF FLORIDA, AND ALSO PORTIONS OF THE CENTRAL GULF
COAST FOR THE UPCOMING WEEKEND.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST SUITE OF GUIDANCE CONTINUES TO SHOW A FAIRLY WELL
CLUSTERED PATTERN, FEATURING A LARGE, POSITIVELY TILTED TROUGH
EXTENDING BEYOND THE FOUR CORNERS REGION WITH RIDGING OVER THE
SOUTHEAST/EAST COAST AND RIDGING APPROACHING FROM THE NORTH
PACIFIC. WHILE THERE IS A NORMAL DEGREE OF VARIANCE IN
TIMING/LOCATION OF INDIVIDUAL FEATURES, CENSUS SHOWS A COUPLE OF
COLD FRONTS SLOWLY PROGRESSING EASTWARD FROM THE PLAINS TO THE
EAST. THE WPC PREFERRED BLEND CONSISTED OF THE THE EC/GFS/CMC WITH
A SLOW INCREASE OF THE ENSEMBLE MEANS AS MESOSCALE DIFFERENCES
INCREASED.
..WEATHER/HAZARDS HIGHLIGHTS
COASTAL PORTIONS OF THE CENTRAL GULF COAST AND SOUTHEAST GEORGIA
INTO FLORIDA WILL REMAIN IN AN ACTIVE, WET PATTERN AS TROPICAL
MOISTURE INTERACTS WITH A STATIONARY FRONTAL BOUNDARY, AND A
COUPLE OF WEAK LOW PRESSURE CENTERS MAY FORM ON THE FRONT AND
ENHANCE THE RAINFALL. A MARGINAL RISK OF EXCESSIVE RAINFALL WAS
MAINTAINED FOR BOTH DAY 4 AND DAY 5 ALONG THE EASTERN COAST OF
FLORIDA, WITH URBAN LOCATIONS MOST PRONE TO FLOODING. THE DAY 4
MARGINAL REMAINS FOR SOUTHEAST LOUISIANA WHERE HEAVY SHOWERS AND
THUNDERSTORMS ARE EXPECTED ALONG THE COASTLINE FOR DAY 3 AND
CONTINUING INTO DAY 4 FOR THE SOUTHEAST PARISHES. LOCALLY, A TWO
DAY ACCUMULATION MAY EXCEED 3 TO 4 INCHES OF RAIN AND WITH
ADDITIONAL RAIN EXPECTED, THE THREAT FOR EXCESSIVE RAINFALL WITH
REMAIN ELEVATED.
MULTIPLE ROUNDS OF PRECIPITATION ARE FORECAST FOR THE WESTERN U.S.
AS SHORTWAVES WITHIN THE UPPER TROUGH AND ASSOCIATED SURFACE
FRONTS TRACK EASTWARD, ESPECIALLY FOR THE ROCKIES AND INTERMOUNTAIN
WEST. THE HIGHER ELEVATIONS CAN EXPECT MODERATE TO LOCALLY HEAVY SNOW
WITH THE PASSAGE OF THE UPPER TROUGH, ESPECIALLY FOR THE HIGHER
TERRAIN OF WESTERN WYOMING AND SOUTHWESTERN MONTANA. SCATTERED TO
WIDESPREAD SHOWERS AND THUNDERSTORMS TRACKING THROUGH THE PLAINS
MAY HAVE LOCALLY HEAVY AMOUNTS FROM KANSAS/NEBRASKA NORTHEAST TO
THE WISCONSIN/ILLINOIS BORDER. A MARGINAL RISK AREA WAS RAISED ON
DAY 5 FOR THE POTENTIAL FOR LOCALLY EXCESSIVE RAINFALL AND ISOLATED
FLASH FLOODING.
SUMMER-LIKE TEMPERATURES WILL PERSIST ACROSS MUCH OF THE CENTRAL
U.S. UNDER THE DEEP-LAYER RIDGE. DAILY MAXIMUM TEMPERATURES WILL
AVERAGE 10-20+ DEGREES ABOVE NORMAL. FOR THE DESERT SOUTHWEST AND
PORTIONS OF TEXAS, 90S ARE LIKELY TO CONTINUE FOR EARLY OCTOBER. WARMER
THAN AVERAGE TEMPERATURES WILL SPREAD TO THE EAST, OVERSPREADING
THE GREAT LAKES REGION AND NORTHEAST. MEANWHILE, COOLER
TEMPERATURES WILL PUNCH INTO THE NORTHERN PLAINS BEHIND THE
STRONG COLD FRONT. BELOW NORMAL TEMPERATURES ESPECIALLY FOR HIGHS
ARE LIKELY ACROSS THE WEST DUE TO UPPER TROUGHING AND RAINY/CLOUDY
CONDITIONS.
CAMPBELL/HAMRICK
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,
QUANTITATIVE PRECIPITATION FORECAST (QPF), EXCESSIVE RAINFALL
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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