312
FXUS02 KWNH 190806
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
304 AM EST WED NOV 19 2025
VALID 12Z SAT NOV 22 2025 - 12Z WED NOV 26 2025
..SOUTHERN PLAINS HEAVY RAIN/RUNOFF THREAT SUNDAY/MONDAY
..OVERVIEW
A MAJOR CLOSED UPPER LOW WILL DIG INTO/SOUTH OF AN UNSETTLED
SOUTHWEST THIS WEEKEND AND EJECT TOWARD THE SOUTH-CENTRAL U.S.
INTO EARLY NEXT WEEK WITH LEAD RETURN FLOW SET TO FUEL ANOTHER
SOUTHERN PLAINS HEAVY RAINFALL THREAT. THE SYSTEM WILL THEN SHEAR
EASTWARD WITH MODERATING RAINFALL POTENTIAL ACROSS THE EAST-
CENTRAL U.S. TO THE MID-ATLANTIC/EAST INTO NEXT MIDWEEK. MEANWHILE,
A COUPLE OF UPPER LEVEL TROUGHS WILL SWING ACROSS THE NORTHERN
TIER OF THE NATION IN MORE PROGRESSIVE FLOW, RESULTING IN PERIODS
OF PRECIPITATION FOR THE NORTHWEST AND THE NORTHEAST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE FORECAST SPREAD HAS SIGNIFICANTLY DECREASED OVER THE PAST
FEW CYCLES, NOW IN A PATTERN WITH SEEMINGLY ABOVE NORMAL
PREDICTABILITY OVERALL. THERE REMAINS POTENTIALLY LOCAL WEATHER
IMPORTANT SMALLER SCALE DIFFERENCES IN GUIDANCE, SO THE WPC MEDIUM
RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A COMPOSITE BLEND OF
BEST CLUSTERED GUIDANCE OF THE GFS/ECMWF AND GEFS/ECMWF ENSEMBLE
MEANS ALONG WITH THE NATIONAL BLEND OF MODELS AND WPC CONTINUITY.
THIS FORECAST PLAN SEEMS TO OFFER A SOLID FORECAST BASE AND THE
BLEND TENDS TO MITIGATE LINGERING GUIDANCE VARIANCES AS CONSISTENT
WITH INDIVIDUAL PREDICTABILILTY.
..WEATHER/HAZARDS HIGHLIGHTS
LIGHT TO MODERATE PRECIPITATION SHOULD SPREAD ACROSS THE SOUTHWEST
THIS WEEKEND, AND THE POTENTIAL FOR HEAVIER RAINFALL AMOUNTS LOOKS
TO RETURN TO THE SOUTH-CENTRAL U.S. SUNDAY INTO MONDAY. THERE ARE
SIGNALS THAT THIS COULD BE A SIGNIFICANT RAINFALL EVENT, AND THIS
POTENTIAL WILL CONTINUE TO BE MONITORED. A DAY 5/SUNDAY MARGINAL
RISK ERO AREA AND EMBEDDED SLIGHT RISK AREA HAS BEEN INTRODUCED
OVER THE SOUTHERN PLAINS AND THE RISK CONTINUES INTO MONDAY. THE
SYSTEM MAY SLOWLY SHEAR WITH ORGANIZED BUT MODERATING PRECIPITATION
ACROSS THE EAST-CENTRAL TO EASTERN U.S. TUESDAY INTO WEDNESDAY.
PERIODS OF PRECIPITATION WILL ALSO BE POSSIBLE IN THE NORTHEAST
AND NORTHWEST AS A SERIES OF QUICK- MOVING UPPER TROUGHS/SHORTWAVES
SWEEP ACROSS THE NORTHERN TIER OF THE NATION. THERE IS STILL SOME
UNCERTAINTY WITH THE AMPLITUDE AND TIMING OF A STRONGER UPPER
TROUGH SLATED TO DIG INTO THE NORTHWEST EARLY NEXT WEEK. HOWEVER,
FAVORED ENSEMBLE MEANS OFFER A COMPROMISE SOLUTION THAT STILL HAS A
DYNAMIC UPPER TROUGH/SURFACE SYSTEM THAT SPREADS SOME MODERATE TO
HEAVY PRECIPITATION INTO THE NORTHWEST TO INCLUDE ENHANCED MOUNTAIN
SNOWS INLAND TO THE ROCKIES LATER PERIOD WITH PROGRESSIVE FLOW.
PRE-FRONTAL TEMPERATURES WILL LINGER MUCH WARMER THAN AVERAGE FOR
PORTIONS OF THE SOUTHERN/SOUTHEAST THIS WEEKEND TO INCLUDE A FEW
RECORD TEMPERATURES, INCLUDING SOME OVERNIGHT MINIMUM TEMPERATURES
10-20+ DEGREES WARMER THAN NORMAL. THE NORTH-CENTRAL U.S. CAN ALSO
EXPECT ABOVE AVERAGE TEMPERATURES, ESPECIALLY THIS WEEKEND INTO
MONDAY. MEANWHILE, CALIFORNIA AND THE WEST/SOUTHWEST WILL SEE BELOW
AVERAGE HIGHS 5-10+ DEGREES BELOW NORMAL WITH CLOSED LOW PASSAGE.
SCHICHTEL
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
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page