731
FXUS02 KWBC 020615
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
115 AM EST SUN NOV 2 2025
VALID 12Z WED NOV 05 2025 - 12Z SUN NOV 09 2025
..OVERVIEW
THE UPPER LEVEL WEATHER PATTERN WILL BE CHARACTERIZED BY MAINLY
ZONAL FLOW WITH SEVERAL PROGRESSIVE TROUGHS/DISTURBANCES MOVING
WEST TO EAST ACROSS THE COUNTRY. THIS PATTERN WILL BRING SEVERAL
LOW PRESSURE SYSTEMS ACROSS THE NORTHERN TIER OF THE NATION AND
SUPPORT PRECIPITATION CHANCES FROM THE NORTHWEST TO THE NORTHEAST.
THE HEAVIEST PRECIPITATION WILL LIKELY FOCUS OVER THE WEST COAST
WHERE PERSISTENT STORMY CONDITIONS ARE EXPECTED AS PACIFIC LOW
PRESSURE SYSTEMS MOVE ONSHORE. THE UPPER LEVEL PATTERN SHOULD
AMPLIFY MORE LATER THIS WEEK AS A STRONGER UPPER LEVEL LOW/TROUGH
APPROACHES THE WEST COAST. PRECIPITATION CHANCES WILL LIKELY
EXPAND INTO THE OHIO AND TENNESSEE VALLEYS LATER THIS WEEK AS WELL
WITH BACK-TO-BACK LOW PRESSURE SYSTEMS MOVING ACROSS THE REGION.
MUCH OF THE SOUTHERN AND CENTRAL U.S. WILL REMAIN DRY THROUGH THE
PERIOD UNDER THE INFLUENCE OF WEAK MEAN RIDGING.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ON THE OVERALL LARGE SCALE
PATTERN, WITH DIFFERENCES IN THE DETAILS OF INDIVIDUAL SYSTEMS. THE
MOST UNCERTAIN PART OF TODAY'S FORECAST IS THE TIMING OF EACH
FAST-MOVING SYSTEM AS IT MOVES ACROSS THE COUNTRY. THE 18Z GFS WAS
THE MOST PROGRESSIVE TOWARDS THE END OF THE PERIOD WHILE THE ECMWF
AND CMC FAVORED A SLIGHTLY SLOWER, MORE AMPLIFIED SOLUTION. WPC'S
FORECAST ALSO FAVORED THE MORE AMPLIFIED SOLUTION, WHICH IS
SUPPORTED BY THE 00Z SOLUTIONS FROM THE AVAILABLE DETERMINISTIC
MODELS.
WPC'S FORECAST BLEND WAS COMPOSED OF MAJORITY DETERMINISTIC
GUIDANCE WITH ENSEMBLE MEANS ADDED IN INCREASING AMOUNTS (UP TO
50%) THROUGH THE PERIOD. GIVEN GOOD AGREEMENT, A NEAR EVEN BLEND OF
GFS, ECMWF, AND CMC DETERMINISTIC AND ENSEMBLE GUIDANCE WAS USED.
..WEATHER/HAZARDS HIGHLIGHTS
PRECIPITATION CHANCES WILL FOCUS OVER THE NORTHWEST AND NORTHEAST
AS A SERIES OF UPPER TROUGHS AND ACCOMPANYING SURFACE LOW PRESSURE
SYSTEMS MOVE ACROSS THE NORTHERN TIER OF THE COUNTRY. THESE
SYSTEMS SHOULD BE FAIRLY PROGRESSIVE, BUT REPEATED ROUNDS OF RAIN
AND MOUNTAIN SNOW OVER THE TERRAIN ALONG THE WEST COAST COULD
RESULT IN LOCALLY HEAVY PRECIPITATION AMOUNTS. PRECIPITATION RATES
WILL LIKELY BE HIGH ENOUGH ALONG THE COAST FROM NORTHERN CALIFORNIA
THROUGH OREGON AND WASHINGTON TO POSE A RISK OF ISOLATED INSTANCES
OF FLASH FLOODING, ESPECIALLY NEAR STEEP TERRAIN AND BURN SCAR
AREAS. THEREFORE, THERE ARE MARGINAL RISKS OF EXCESSIVE RAINFALL IN
EFFECT FOR PORTIONS OF THE COASTLINE ON WEDNESDAY AND THURSDAY.
PRECIPITATION CHANCES WILL CONTINUE ACROSS THE NORTHWEST THROUGH
THE END OF THE WEEK, BUT PRECIPITATION INTENSITIES ARE FORECAST TO
DECREASE.
ELSEWHERE, PRECIPITATION RATES WITH THESE SYSTEMS WILL LIKELY BE
LIGHT TO MODERATE OVER THE INTERIOR NORTHWEST, GREAT LAKES, AND
NORTHEAST, AND THERE WILL BE WINTER WEATHER POTENTIAL IN THE
NORTHERN ROCKIES AND NORTHERN NEW ENGLAND. PERIODS OF MOUNTAIN SNOW
ARE EXPECTED WITH EACH PASSING SYSTEM IN THE NORTHERN ROCKIES, AND
SOME WRAP AROUND SNOW WILL BE POSSIBLE ON THE BACKSIDE OF THESE
SYSTEMS LATER THIS WEEK IN NORTHERN NEW ENGLAND. SNOW AMOUNTS
SHOULD BE RELATIVELY LOW IN NORTHERN NEW ENGLAND, BUT COULD BE
ENOUGH TO SHOVEL. PRECIPITATION CHANCES ARE EXPECTED TO EXPAND INTO
THE OHIO AND TENNESSEE VALLEYS LATER THIS WEEK AS THE PATTERN
AMPLIFIES AND TWO BACK-TO-BACK LOW PRESSURE SYSTEMS SWEEP ACROSS
THE REGION.
FOR THE SOUTHERN AND CENTRAL U.S., WEAK UPPER LEVEL RIDGING WILL
DOMINATE THE WEATHER PATTERN, KEEPING THE FORECAST MOSTLY DRY,
EXCEPT FOR SOME ISOLATED SHOWER CHANCES OVER THE FLORIDA PENINSULA
AND POSSIBLY SOME SHOWERS IN THE NORTHERN PLAINS LATE THIS WEEK.
RIDGING WILL ALSO RESULT IN ABOVE AVERAGE TEMPERATURES, WITH HIGH
TEMPERATURES FORECAST TO RUN 10-20 DEGREES ABOVE AVERAGE.
ELSEWHERE, TEMPERATURES SHOULD BE NEAR AVERAGE.
DOLAN
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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