921  
FXUS02 KWBC 010743  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
343 AM EDT WED OCT 1 2025  
 
VALID 12Z SAT OCT 04 2025 - 12Z WED OCT 08 2025  
 
   
..OVERVIEW  
 
DEEP UPPER TROUGHING IS FORECAST TO PROGRESS THROUGH THE WEST TO  
ERODE A STRONG RIDGE INITIALLY DOMINATING THE EASTERN TWO-THIRDS OF  
THE COUNTRY. THIS CHANGE IN THE PATTERN WITH PROMPT A SHOCK OF  
COLD AIR, LEADING TO THE FIRST FROST/FREEZE OF THE SEASON INTO  
THE LOWER ELEVATIONS FROM THE NORTHERN ROCKIES TO THE NORTHERN  
PLAINS IN THE WAKE OF A PROLONGED PERIOD RECORD WARMTH IN THE  
UPPER MIDWEST. TROPICAL MOISTURE INTERACTING WITH A STATIONARY  
FRONT COULD DELIVER HEAVY RAIN AND THUNDERSTORMS ALONG THE EAST  
COAST OF FLORIDA AND ALONG PORTIONS OF THE CENTRAL GULF COAST.  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT  
 
IN GENERAL, THERE DECENT AGREEMENT WITH THE EVOLUTION OF THE LARGE  
SCALE PATTERN FROM A STRONGER RIDGING ALOFT TO ARRIVAL OF A DEEP  
UPPER TROUGH FOR THE WESTERN U.S. BY EARLY NEXT WEEK, MODELS SHOW  
GOOD AGREEMENT FOR AN UPPER LOW TO DETACH FROM THE MAIN POSITIVELY-  
TILTED UPPER TROUGH OVER THE SOUTHWEST. ACROSS THE NORTHERN TIER  
STATES, MODEL CONSENSUS SHOWS A SIGHTLY FASTER EASTWARD PROGRESSION  
OF THE COLD FRONT AND THE POSITIVELY- TILTED UPPER TROUGH BY EARLY  
NEXT WEEK.  
 
THE WPC MEDIUM-RANGE FORECASTS UTILIZED A BLEND COMPRISED OF THE EC/GFS/CMC  
AND THEIR MEANS, WITH HEAVIER WEIGHTING FROM THE ENSEMBLE MEANS  
FOR DAYS 5-7. THIS APPROACH MAINTAINED A SENSE OF CYCLE TO CYCLE  
CONTINUITY.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS  
 
PORTIONS OF THE GULF COAST AND SOUTHEAST COAST WILL REMAIN IN AN  
ACTIVE, WET PATTERN AS TROPICAL MOISTURE INTERACTS WITH A  
STATIONARY FRONTAL BOUNDARY. A COUPLE OF WEAK LOW PRESSURE CENTERS  
MAY FORM ON THE FRONT AND COULD LIFT NORTH TO ENHANCE RAINFALL  
NEAR THE CENTRAL GULF COAST, AND FROM THE EAST COAST OF FLORIDA UP  
INTO THE GEORGIA COAST OVER THE WEEKEND. A MARGINAL RISK OF  
EXCESSIVE RAINFALL WAS MAINTAINED FOR DAY 4 AND AND RAISED FOR DAY  
5 ALONG THE EASTERN COAST OF FLORIDA AS URBAN AREAS TEND TO BE MORE  
SENSITIVE. ADDITIONALLY, A DAY 4 MARGINAL WAS RAISED FOR SOUTHEAST  
LOUISIANA WERE HEAVY SHOWERS AND THUNDERSTORMS ARE EXPECTED ALONG  
THE COASTLINE AND POINTS INLAND IN FAR SOUTHEAST REACHES OF THE  
STATE. LOCALLY, 3 TO 4 INCHES OF RAIN WILL BE POSSIBLE AND MAY LEAD  
TO ISOLATED AREAS OF FLOODING.  
 
MULTIPLE ROUNDS OF PRECIPITATION IS FORECAST FOR THE WEST AND  
INTERMOUNTAIN WEST AS SHORTWAVES WITHIN THE WESTERN U.S. UPPER-  
TROUGH AND ASSOCIATED SURFACE FRONTS TRACK EASTWARD, ESPECIALLY FOR  
THE ROCKIES AND INTERMOUNTAIN WEST. THE HIGHER ELEVATIONS CAN  
EXPECT SNOW WITH THE PASSAGE OF THE UPPER TROUGH. MOISTURE LEVELS  
WILL BE ABOVE NORMAL, BUT THE RAIN SEEMS UNLIKELY TO CAUSE FLOODING  
CONCERNS WITH NOT MUCH INSTABILITY IN PLACE, LIMITING RAIN RATES.  
THE PACIFIC NORTHWEST COULD SEE PRECIPITATION. RAIN CHANCES ARE  
FORECAST TO EXPAND INTO THE NORTH- CENTRAL U.S. LATE WEEK INTO THE  
WEEKEND AS A COUPLE OF FRONTAL SYSTEMS EMERGE INTO THE PLAINS.  
 
SUMMER-LIKE TEMPERATURES WILL HOLD ON ACROSS MUCH OF THE CENTRAL  
U.S. UNDER THE DEEP-LAYER RIDGE. EACH DAY THE MAXIMUM TEMPERATURES  
WILL AVERAGE 15 TO 25 DEGREES ABOVE NORMAL THROUGH LATE WEEK, WELL  
INTO THE 80S EVEN TO THE CANADIAN BORDER WHERE DAILY RECORD HIGH  
TEMPERATURES WILL MOST LIKELY BE CHALLENGED OR BROKEN SATURDAY  
AFTERNOON. FOR THE DESERT SOUTHWEST AND TEXAS, 90S ARE LIKELY TO  
CONTINUE FOR EARLY OCTOBER. BY THE WEEKEND, WARMER THAN AVERAGE  
TEMPERATURES COULD SHIFT A BIT EAST AND COVER THE GREAT LAKES  
REGION AND NORTHEAST, WHILE THE NORTHERN PLAINS COOLS. MEANWHILE,  
BELOW NORMAL TEMPERATURES ESPECIALLY FOR HIGHS ARE LIKELY ACROSS  
THE WEST DUE TO UPPER TROUGHING AND RAINY/CLOUDY CONDITIONS.  
 
CAMPBELL/KONG  
 
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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