066
FXUS02 KWBC 031833
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
133 PM EST WED DEC 3 2025
VALID 12Z SAT DEC 06 2025 - 12Z WED DEC 10 2025
..OVERVIEW
A CENTRAL TO EASTERN U.S. MEAN UPPER TROUGH AND BROAD CYCLONIC
FLOW WITH REINFORCING SHORTWAVES WILL CONTINUE TO DOMINATE DURING
MUCH OF THE MEDIUM RANGE PERIOD ACROSS THE CONUS. THIS WILL FAVOR
BELOW TO WELL BELOW NORMAL TEMPERATURES FOR THE PLAINS TO THE EAST
COAST. NEAR TO ABOVE NORMAL TEMPERATURES ARE FAVORED FOR THE
WESTERN STATES UNDER THE INFLUENCE OF UPPER RIDGING. A LINGERING
FRONTAL SYSTEM OVER THE SOUTHEAST WILL LIKELY PROMOTE AN AREA OF
LOCALLY HEAVIER RAIN WHILE A COUPLE OF CLIPPER SYSTEMS WILL IMPACT
THE NORTHERN TIER STATES AS WELL WITH WITH A MODEST SNOW CHANCES.
HEAVIER COASTAL RAINS AND TERRAIN ENHANCED SNOWS MAY DEVELOP INLAND
FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN ROCKIES EARLY NEXT
WEEK ALONG WITH A THREAT OF HIGH WINDS TO MONITOR.
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE CONTINUES TO SHOW GOOD AGREEMENT SYNOPTICALLY THROUGH THE
MEDIUM RANGE PERIOD BUT THERE REMAINS QUITE A BIT OF UNCERTAINTY
IN THE DETAILS AND THE TIMING OF MULTIPLE SHORTWAVES THROUGH THE
NORTHERN TIER IMPACTING SENSIBLE WEATHER GRIDS. A GENERAL BLEND OF
THE DETERMINISTIC MODEL GUIDANCE CONTINUES TO OFFER A GOOD
STARTING POINT FOR THE FIRST HALF OF THE PERIOD, WITH INCREASING
WEIGHTING OF THE ENSEMBLE MEANS ONWARD INTO DAYS 6 AND 7. THE 13
UTC NBM SEEMED TO PROVIDE A REASONABLY GOOD STARTING POINT FOR
MOST OF THE SENSIBLE WEATHER GRIDS, BUT DID HAVE TO SUPPLEMENT NBM
QPF TO INCREASE COVERAGE OF WEEKEND LIGHT PRECIPITATION WITH
SYSTEMS MOVING THROUGH THE NORTH-CENTRAL U.S./MIDWEST AND ALSO OVER
THE EASTERN CAROLINAS WITH FRONTAL WAVE PASSAGE. I ALSO GENERALLY
INCREASED WINDS/WIND GUSTS FROM THE CASCADES EASTWARD THROUGH THE
GREAT LAKES THROUGH THE PERIOD IN ENERGETIC AND PROGRESSIVE FLOW.
..WEATHER/HAZARDS HIGHLIGHTS
HEAVY RAIN ALONG A FRONTAL BOUNDARY SHOULD CONTINUE INTO SATURDAY
FOR PARTS OF THE SOUTHEAST. THE WPC DAY 4/SATURDAY ERO SHOWS A
MARGINAL RISK FROM THE FLORIDA PANHANDLE TO FAR SOUTHERN GEORGIA,
ALONG THE FRONTAL BOUNDARY, WHICH MAY STALL FOR A PERIOD OF TIME
ALLOWING FOR SOME TRAINING OF STORMS. INSTABILITY MAY BE LACKING
OVERALL WHICH SHOULD LIMIT THE FLASH FLOOD THREAT TOWARD THE I-10
CORRIDOR. BY SUNDAY, SOME GUIDANCE SHOWS RAINS HANGING AROUND
ALONG THE TRAILING FLORIDA COLD FRONT, BUT WITH LOWER AMOUNTS,SO
OPTED FOR NO RISK AREAS AT THIS TIME FOR THE DAY 5 ERO.
SEVERAL DYNAMIC PACIFIC SYSTEMS WILL PUSH INTO WESTERN CANADA AND
THE PACIFIC NORTHWEST, ESPECIALLY INTO NEXT WEEK, WITH RAIN/SNOW
OVER WA/OR AND EASTWARD TO THE NORTHERN/CENTRAL ROCKIES. THIS
ACTIVITY SHOULD BE ESPECIALLY ON THE INCREASE FOR THE PACIFIC
NORTHWEST WHERE SOME SIGNIFICANT MULTI-DAY TOTALS ARE POSSIBLE AND
WILL BE MONITORED FOR LATER PERIOD ERO THREAT AREA CONSIDERATION.
THERE IS ALSO A PROTRACTED RISK FOR TERRAIN ENHANCED WINDS INTO
NEXT WEEK EXTENDING EASTWARD INTO THE NORTH- CENTRAL STATES.
SEVERAL CLIPPER LIKE SYSTEMS WILL ALSO BRING SOME RAIN AND SNOW TO
PARTS OF THE MIDWEST, GREAT LAKES/APPALACHIANS AND THE NORTHEAST.
TEMPERATURES ACROSS THE NORTH-CENTRAL U.S. TO THE EAST WILL REMAIN
BELOW NORMAL AT LEAST THROUGH THE WEEKEND, WITH SOME MODERATION
FROM WEST TO EAST EARLY NEXT WEEK. THIS WEEKEND, DAYTIME HIGHS AND
MORNING LOWS COULD BE 10-15 DEGREES BELOW NORMAL IN THE NORTHERN
PLAINS/UPPER MIDWEST, WITH THIS AIRMASS TRANSITIONING INTO THE EAST
ON MONDAY. THE WEST WILL TREND WARMER INTO NEXT WEEK UNDERNEATH
UPPER RIDGING, WITH WARMER THAN AVERAGE TEMPERATURES ALSO SPREADING
INTO THE CENTRAL AND SOUTHERN PLAINS NEXT TUESDAY AND WEDNESDAY.
SANTORELLI/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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