559
FXUS02 KWNH 200807
PREEPD
PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
306 AM EST THU NOV 20 2025
VALID 12Z SUN NOV 23 2025 - 12Z THU NOV 27 2025
..SOUTHERN PLAINS HEAVY RAIN/RUNOFF THREAT SUNDAY/MONDAY
..OVERVIEW
A MAJOR CLOSED UPPER LOW WILL WORK INTO/SOUTH OF AN UNSETTLED
SOUTHWEST U.S. INTO THIS WEEKEND AND EJECT TO THE SOUTH-CENTRAL
U.S. INTO MONDAY. LEAD RETURN FLOW IS SET TO FUEL ANOTHER SOUTH-
CENTRAL U.S. HEAVY RAINFALL/RUNOFF THREAT THERE. THE SYSTEM WILL
THEN SHEAR EASTWARD AND BRING MODERATING RAINFALL POTENTIAL ACROSS
THE EAST-CENTRAL U.S. TO THE MID-ATLANTIC/EAST EARLY NEXT WEEK,
WITH LINGERING ACTIVITY LATER NEXT WEEK POSSIBLY TRAILING BACK
OVER THE SOUTHEAST/SOUTH. MEANWHILE, A COUPLE OF UPPER LEVEL
TROUGHS WILL SWING ACROSS THE NORTHERN TIER OF THE NATION IN MORE
PROGRESSIVE FLOW, RESULTING IN SOME PERIODS OF PRECIPITATION FOR
THE NORTHWEST AND WITH MORE SUBSTANCE OVER THE NORTHEAST,
ESPECIALLY SUNDAY AND MID-LATER NEXT WEEK.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MEDIUM-RANGE GUIDANCE FORECAST SPREAD HAS DECREASED RECENTLY AND
SHOWS A PATTERN TRANSITION NEXT WEEK FROM SPLIT FLOW TO MORE STREAM
ENERGY PHASED. HOWEVER, THERE REMAINS AMPLE RUN TO RUN EMBEDDED
SYSTEM TIMING VARIANCES, SO THE WPC MEDIUM RANGE PRODUCT SUITE WAS
MAINLY DERIVED FROM A COMPOSITE BLEND OF REASONABLY WELL CLUSTERED
GUIDANCE OF THE GFS/ECMWF/CANADIAN/UKMET AND INCREASING OVER TIME
AN INFUSION OF THE GEFS/ECMWF/CANADIAN ENSEMBLE MEANS. THIS BLEND
IS COMPATIBLE WITH 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. WPC DAY
4/SUNDAY AND DAY 5/MONDAY MARGINAL RISK EXCESSIVE RAINFALL OUTLOOKS
WITH EMBEDDED SLIGHT RISK AREAS HAS BEEN ISSUED OVER THE SOUTH-
CENTRAL U.S.. THE SYSTEM THEN SHEARS WITH ORGANIZED BUT MODERATING
PRECIPITATION FOR THE EAST-CENTRAL TO EASTERN U.S. MONDAY-TUESDAY.
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. UPPER TROUGH/SURFACE
SYSTEM ENERGY PRESSING INLAND WILL ALSO SPREAD SOME ENHANCED
MOUNTAIN SNOW CHANCES OVER THE INTERMOUNTAIN WEST/ROCKIES.
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.
OUDIT/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
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