764
FXUS02 KWBC 140734
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
334 AM EDT TUE OCT 14 2025
VALID 12Z FRI OCT 17 2025 - 12Z TUE OCT 21 2025
..GUIDANCE/PREDICTABILITY ASSESSMENT
MEDIUM-RANGE GUIDANCE SHOWS GOOD MID-LARGER SCALE AGREEMENT ON AN
AMPLIFIED UPPER PATTERN EVOLUTION. AN AMPLIFIED WESTERN U.S. TROUGH
INTO FRIDAY WILL WORK STEADILY EASTWARD TO THE EAST COAST BY EARLY
NEXT WEEK AS A LEAD WARMING DOWNSTREAM RIDGE SHIFTS FROM THE EAST-
CENTRAL U.S. FRIDAY TO THE WESTERN ATLANTIC ON SUNDAY. UPSTREAM, AN
AMPLIFIED UPPER TROUGH/LOW IS SLATED TO BREACH THE WEST COAST INTO
EARLY NEXT WEEK. OVERALL, FAVOR A COMPOSITE BLEND OF BEST CLUSTERED
GUIDANCE OF THE 18 UTC GFS/GEFS, 12 UTC ECMWF/ECMWF ENSEMBLE MEAN
AND CANADIAN ENSEMBLE MEAN AND 01 UTC NATIONAL BLEND OF MODELS
GUIDANCE FOR MUCH OF THIS FORECAST PERIOD. THIS SOLUTION HOLDS GOOD
WPC CONTINUITY MAINLY IN LINE WITH NEW 00 UTC GUIDANCE COMPOSITE.
..WEATHER/HAZARDS HIGHLIGHTS
LINGERING UPPER TROUGHING IN ATLANTIC CANADA (TIED TO THE CURRENT
COASTAL STORM) STILL SUPPORTS CONTINUED UNSETTLED/WINDY CONDITIONS
OVER NEW ENGLAND THROUGH LATE WEEK WITH COOLER THAN NORMAL
TEMPERATURES TO START THAT WILL SLOWLY MODERATE.
THE TROUGHING AND ASSOCIATED SURFACE FRONTAL BOUNDARY IN THE WEST
WILL PROMOTE COOL AND SHOWERY (WITH SOME SNOW AT HIGHER ELEVATIONS)
CONDITIONS OVER THE NORTHERN/CENTRAL ROCKIES TO START, WITH
BROADER LIGHT RAIN IN ADVANCE OF THE SURFACE LOW THAT IS POISED TO
TRACK FROM THE NORTHERN PLAINS INTO SOUTHERN CANADA. AS THE
ATTENDANT COLD FRONT PASSES THROUGH THE PLAINS, MOISTURE WILL
INCREASE IN ADVANCE OF IT THROUGH THE MID-MS VALLEY WHERE RAINFALL
COULD INCREASE BY SATURDAY. THE WPC DAY 5/SATURDAY EXCESSIVE
RAINFALL OUTLOOK (ERO) INTRODUCES A MARGINAL THREAT AREA CENTERED
OVER THE MID-SOUTH GIVEN FAVORABLE UPPER SUPPORT AND RETURN FLOW.
THIS RAINFALL WILL CONTINUE EASTWARD NEXT SUNDAY AND MONDAY/TUESDAY
INTO THE NORTHEAST NEAR THE TRACK OF DEEPENING/CONSOLIDATING LOW
PRESSURE (AND INTO THE SOUTHEAST AHEAD OF THE COLD FRONT).
TEMPERATURES WILL BE MILD AHEAD OF THE COLD FRONT WITH VALUES WELL
INTO THE 70S/80S FRIDAY FROM THE CORN BELT TO THE OZARKS WITH 90S
ACROSS SOUTH TEXAS.
BY LATE NEXT WEEKEND INTO EARLY NEXT WEEK, ANOTHER DEEPENED SYSTEM
WILL ENTER THE PACIFIC NORTHWEST/WEST COAST WITH ANOTHER ROUND OF
VALLEY RAIN AND HIGHER MOUNTAIN SNOW THAT WILL THEN DIG AND SPREAD
ACROSS THE WEST AND DOWNSTREAM TO THE ROCKIES. THE DAY5/SATURDAY
ERO INTRODUCES A COASTAL WASHINGTON MARGINAL THREAT AREA GIVEN A
FAVORABLE GUIDANCE SIGNAL.
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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