613
FXUS02 KWBC 221858
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
158 PM EST SAT NOV 22 2025
VALID 12Z TUE NOV 25 2025 - 12Z SAT NOV 29 2025
..GENERAL OVERVIEW
A WEAKENING LOW PRESSURE SYSTEM WILL TRACK NORTHEAST TOWARDS THE
OHIO VALLEY ON TUESDAY WHILE ANOTHER STORM SYSTEM STRENGTHENS OVER
THE NORTHERN PLAINS AND UPPER MIDWEST. THIS NORTHERN SYSTEM WILL
BECOME THE DOMINANT WEATHER FEATURE BY MID-WEEK AND WILL BRING
WIDESPREAD PRECIPITATION CHANCES TO THE NORTHERN AND EASTERN U.S.,
WITH POTENTIALLY HEAVY SNOW IN THE UPPER MIDWEST. MEANWHILE,
PERIODS OF RAIN AND MOUNTAIN SNOW ARE LIKELY FOR THE PACIFIC
NORTHWEST WITH AN ACTIVE STORM TRACK OVER THE NORTHEAST PACIFIC,
AND AN UPPER TROUGH WILL LIKELY AMPLIFY OVER THE INTERIOR WEST
LATER IN THE WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE HAS SHOWN IMPROVING AGREEMENT TODAY, RESULTING IN
ABOVE AVERAGE CONFIDENCE IN THE UPPER LEVEL AND BROAD SYNOPTIC
PATTERN. THERE STILL REMAINS SOME UNCERTAINTY IN THE DETAILS OF
INDIVIDUAL SYSTEMS, BUT THAT IS TO BE EXPECTED AT THIS TIME RANGE.
THERE WERE NO MODEL OUTLIERS TODAY, EXCEPT MAYBE THE GFS TOWARDS
THE END OF THE PERIOD, WHICH IS NOT AS PRONOUNCED AS THE ECMWF/CMC
WITH THE DEEPENING UPPER TROUGH/LOW OVER THE WEST.
GIVEN GOOD AGREEMENT, A NEAR EVEN BLEND OF THE LATEST DETERMINISTIC
MODEL RUNS FROM THE GFS/ECMWF/CMC/UKMET PROVIDED A GOOD STARTING
POINT FOR THE WPC FORECAST. ENSEMBLE MEANS FROM THE
GEFS/ECENS/CMCE WERE ADDED IN INCREASING AMOUNTS THROUGH THE SECOND
HALF OF THE PERIOD TO HELP SMOOTH OUT MODEL DIFFERENCES.
..WEATHER/HAZARDS HIGHLIGHTS
THE LOW PRESSURE SYSTEM THAT IS FORECAST TO BRING HEAVY RAIN TO THE
SOUTH-CENTRAL U.S. SUNDAY INTO MONDAY WILL TRACK NORTHEAST WHILE
WEAKENING ON TUESDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD
OF THE SYSTEM ACROSS THE EASTERN U.S., AND LOCALLY HEAVY RAINFALL
WILL BE POSSIBLE OVER THE INTERIOR SOUTHEAST. TO ACCOUNT FOR THIS,
THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL IN THE DAY 4
(TUESDAY) OUTLOOK FROM EASTERN MISSISSIPPI TO THE SOUTHERN
APPALACHIANS.
PRECIPITATION IS ALSO EXPECTED ACROSS THE NORTH-CENTRAL AND
NORTHEASTERN U.S. ON TUESDAY AS ANOTHER LOW PRESSURE/FRONTAL SYSTEM
STRENGTHENS OVER THE NORTHERN PLAINS AND UPPER MIDWEST. WINTRY
PRECIPITATION IS EXPECTED ALONG THE NORTHERN SIDE OF THE SYSTEM,
AND A SWATH OF MODERATE TO POTENTIALLY HEAVY SNOW WILL BE POSSIBLE
FROM EASTERN NORTH DAKOTA THROUGH NORTHERN MINNESOTA. THE TWO LOW
PRESSURE SYSTEMS WILL TRANSLATE EAST ACROSS THE NATION ON WEDNESDAY
THEN PUSH OFFSHORE BY THURSDAY, WITH LINGERING PRECIPITATION
CHANCES ALONG THE EAST COAST ON WEDNESDAY. NORTHWESTERLY WINDS ON
THE BACKSIDE OF THE SYSTEM WILL RESULT IN LINGERING LAKE EFFECT
SNOWS DOWNWIND OF THE GREAT LAKES WEDNESDAY THROUGH FRIDAY.
MEANWHILE, PRECIPITATION CHANCES WILL INCREASE ACROSS THE NORTHWEST
AS SEVERAL PACIFIC FRONTAL SYSTEMS MOVE INTO THE REGION THROUGHOUT
THE WEEK. THE HEAVIEST PRECIPITATION IS FORECAST ACROSS WESTERN
WASHINGTON AND NORTHWESTERN OREGON ON WEDNESDAY, WHICH MAY RESULT
IN ISOLATED FLOODING CONCERNS ALONG THE COAST AND FAVORED UPSLOPE
REGIONS OF THE OLYMPICS AND CASCADES. THERE IS A MARGINAL RISK OF
EXCESSIVE RAINFALL FOR THESE AREAS IN THE DAY 5 (WEDNESDAY)
OUTLOOK. PRECIPITATION WILL FALL AS SNOW IN THE HIGHER ELEVATIONS,
AND LOCALLY HEAVY SNOW MAY BE POSSIBLE IN THE CASCADES IN
WASHINGTON.
TEMPERATURES ARE EXPECTED TO BE MILD FOR THIS TIME OF YEAR FROM
THE GULF COAST TO THE GREAT LAKES ON TUESDAY AND FOR THE EAST
COAST ON WEDNESDAY, WITH HIGH TEMPERATURES RUNNING 10-15 DEGREES
ABOVE AVERAGE. A COLD FRONT WILL BRING A RETURN TO SLIGHTLY BELOW
AVERAGE TEMPERATURES FOR THE CENTRAL AND EASTERN U.S. MID-TO-LATE
WEEK. A MODEST WARM-UP IS LIKELY FOR THE NORTHWESTERN U.S. TOWARDS
THANKSGIVING AS THE EARLY COLDER AIRMASS MODIFIES AND FLOW FROM
THE PACIFIC MOVES INTO THE REGION.
DOLAN/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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