413   
FXUS21 KWNC 011800  
PMDTHR  
US HAZARDS OUTLOOK  
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT NOVEMBER 01 2025  
  
SYNOPSIS: MID-LEVEL LOW PRESSURE FORECAST OVER THE NORTHEASTERN PACIFIC FAVORS   
AN INCREASED RISK OF HEAVY PRECIPITATION, HIGH ELEVATION SNOWFALL, AND HIGH   
WINDS OVER PORTIONS OF THE NORTHWESTERN CONTIGUOUS U.S. (CONUS) AND   
SOUTHEASTERN ALASKA DURING WEEK-2. ADDITIONAL SHORTWAVE ENERGY IS PREDICTED TO   
TRAVERSE THE NORTHERN TIER OF THE CONUS DURING THE PERIOD FAVORING ENHANCED   
CHANCES FOR HIGH WINDS AND HEAVY PRECIPITATION OVER THE NORTHEAST AND HIGH   
WINDS IN THE GREAT PLAINS. INCREASING MODEL SPREAD REDUCES FORECAST CONFIDENCE   
DURING THE SECOND HALF OF WEEK-2.  
  
HAZARDS  
  
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND   
NORTHERN CALIFORNIA, SUN-WED, NOV 9-12.  
  
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS NEW ENGLAND, SUN, NOV 9.  
  
SLIGHT RISK OF HEAVY SNOW ACROSS PORTIONS OF THE CASCADES, SUN-WED, NOV 9-12.  
  
SLIGHT RISK OF HEAVY SNOW ACROSS PORTIONS OF THE NORTHERN ROCKIES, SUN-WED, NOV   
9-12.  
  
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND NORTHERN   
CALIFORNIA, SUN-WED, NOV 9-12.  
  
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE GREAT LAKES, APPALACHIANS,   
MID-ATLANTIC, AND NORTHEAST, SUN-MON, NOV 9-10.   
  
SLIGHT RISK OF HIGH WINDS ACROSS PORTIONS OF THE PLAINS AND THE UPPER AND   
MIDDLE MISSISSIPPI VALLEY, SUN-TUE, NOV 9-11.  
  
DETAILED SUMMARY  
  
FOR TUESDAY NOVEMBER 04 - SATURDAY NOVEMBER 08:   
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
  
FOR SUNDAY NOVEMBER 09 - SATURDAY NOVEMBER 15: THE 0Z GEFS, ECENS, AND CMCE   
MODELS REMAIN IN FAIR AGREEMENT REGARDING TROUGHING ACROSS THE NORTHEASTERN   
PACIFIC PERSISTING INTO WEEK-2. THE MODELS HAVE DIFFERENCES IN THE TIMING AND   
INTENSITY OF VARIOUS SHORTWAVE TROUGHS AND RIDGES ALONG THE WEST COAST. THIS   
INCREASES THE UNCERTAINTY OF THE STRENGTH AND TIMING OF ANY ENHANCED ONSHORE   
FLOW. NEVERTHELESS, TOOLS ARE CONSISTENT FOR PERIODS OF ENHANCED PRECIPITATION   
AND COASTAL HIGH WINDS THROUGH THE FIRST HALF OF WEEK-2. BOTH THE GEFS AND   
ECENS PROBABILISTIC EXTREMES TOOLS (PETS) INDICATE AT A 20-30 PERCENT CHANCE   
3-DAY PRECIPITATION TOTALS EXCEED THE 85TH CLIMATOLOGICAL PERCENTILE AND 1.5   
INCHES EARLY IN WEEK-2, WITH CHANCES DECREASING LATER IN THE PERIOD. THE ECENS   
INTEGRATED VAPOR TRANSPORT (IVT) TOOL CONTINUES TO INDICATE ENHANCED   
PROBABILITIES OF IVT VALUES EXCEEDING 250 KG/M/S THROUGH ABOUT DAY-11 (NOV 12),   
WHILE THE GEFS IVT HAS A WEAKER SIGNAL EARLY IN THE PERIOD BEFORE A RESURGENCE   
TOWARDS THE MIDDLE OF WEEK-2. THIS IS CONSISTENT WITH THE ECENS, AND ALSO THE   
CMCE, SHOWING A STRONGER RIDGE ACROSS THE INTERIOR WEST PERSISTING THROUGH THE   
MIDDLE OF THE PERIOD WITH A MORE PROGRESSIVE GEFS WITH A SHORTWAVE TROUGH AXIS   
OVER THE INTERIOR WEST EARLY IN WEEK-2. BASED ON THE ABOVE GUIDANCE, THERE IS   
ENOUGH SUPPORT TO MAINTAIN THE SLIGHT RISK FOR HEAVY PRECIPITATION ACROSS THE   
PACIFIC NORTHWEST AND NORTHERN CALIFORNIA THROUGH NOV 12. ANY HEAVY   
PRECIPITATION IS LIKELY TO LEAD TO INCREASED STREAMFLOWS AND POSSIBLY ISOLATED   
URBAN FLOODING WITHIN THE HIGHLIGHTED PRECIPITATION AREA.  
  
A SLIGHT RISK FOR HIGH WINDS IS ALSO POSTED OVER COASTAL AREAS OF THE PACIFIC   
NORTHWEST AND NORTHWESTERN CALIFORNIA, WHERE THE GEFS AND ECENS PETS DEPICT AT   
LEAST A 20 PERCENT CHANCE WIND SPEEDS EXCEED 25-MPH, ALONG WITH AN ENHANCED   
SIGNAL FOR WIND SPEEDS EXCEEDING 40-MPH JUST OFFSHORE. LASTLY, SLIGHT RISKS FOR   
HEAVY SNOW ARE POSTED ACROSS THE CASCADES AND NORTHERN ROCKIES. SIGNALS IN THE   
MODELS ARE MARGINAL, BUT 24-HOUR AMOUNTS EXCEEDING 4-INCHES ARE POSSIBLE, WITH   
HIGHER TOTALS FAVORED OVER THE NORTHERN CASCADES. THE AFOREMENTIONED WIND AND   
SNOW HAZARDS ARE VALID THROUGH NOV 12.  
  
THERE IS MORE UNCERTAINTY FURTHER EAST. THE TIMING AND PLACEMENT OF MULTIPLE   
SHORTWAVE TROUGHS OVER THE CENTRAL AND EASTERN CONUS IS DIFFERENT BETWEEN THE   
GEFS, ECENS, AND CMCE AND DIFFICULT TO PLACE. INITIALLY, AN AREA OF LOW   
PRESSURE IS FORECAST TO BE OVER OR NEAR THE NORTHEAST. THE ECENS IS A BIT   
SLOWER WITH THIS FEATURE MAINTAINING HIGH WINDS AND A HEAVY PRECIPITATION   
CHANCES OVER THE GREAT LAKES AND NORTHEAST UNTIL DAY 8. MEANWHILE, MOST OF THE   
GEFS SIGNAL HAS ALREADY MOVED OFFSHORE BY THE START OF WEEK-2. IN DEFERENCE TO   
CONTINUITY, HAVE MAINTAINED A SLIGHT RISK OF HEAVY PRECIPITATION OVER NEW   
ENGLAND FOR NOV 9. A BROADER SLIGHT RISK OF HIGH WINDS IS FORECAST FOR THE   
GREAT LAKES AND NORTHEAST FOR NOV 9-10 AS WINDS MAY REMAIN ELEVATED FOLLOWING A   
FRONTAL PASSAGE.  
  
MEANWHILE, THE GEFS FAVORS BRINGING ANOTHER SHORTWAVE TROUGH INTO THE ROCKIES   
AND SPINNING UP AN AREA OF LOW PRESSURE IN THE LEE OF THE ROCKIES. THE GEFS PET   
AND RAW ENSEMBLE GUIDANCE SUPPORT A RELATIVELY BROAD SLIGHT RISK OF HIGH WINDS   
ACROSS MUCH OF THE PLAINS. THE ECENS AND THE ECENS AI RAW GUIDANCE IS NOT AS ON   
BOARD WITH THIS SOLUTION AS THE MEAN ENSEMBLE GUIDANCE DOES NOT SUPPORT A   
SHORTWAVE TROUGH EARLY IN THE PERIOD. HOWEVER, THERE IS SOME SUPPORT FROM THE   
ECENS PET FOR WIND SPEEDS EXCEEDING THE 85TH PERCENTILE. THEREFORE, A SLIGHT   
RISK OF HIGH WINDS IS POSTED FOR NOV 9-11.   
  
ACROSS ALASKA, PERIODS OF HIGH WINDS AND LOCALLY HEAVY PRECIPITATION ARE   
POSSIBLE OVER THE SOUTHEAST ASSOCIATED WITH ANOMALOUS MID-LEVEL TROUGHING OVER   
THE NORTHEASTERN PACIFIC AND BERING SEA. HOWEVER PETS SHOW PRECIPITATION   
AMOUNTS AND WIND SPEEDS LIKELY REMAINING BELOW HAZARD THRESHOLDS.  
  
FORECASTER: RYAN BOLT   
  
  
 
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