472
FXUS02 KWBC 141827
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
227 PM EDT FRI MAR 14 2025
VALID 12Z MON MAR 17 2025 - 12Z FRI MAR 21 2025
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS AND ENSEMBLES OVERALL CONTINUE TO OFFER REASONABLE
AGREEMENT, AT LEAST ON THE LARGE SCALE, THROUGH THE MEDIUM RANGE
PERIOD, BUT SOME NOTABLE DIFFERENCES IN THE DETAILS WHICH WOULD
HAVE IMPACTS ON SENSIBLE WEATHER THREATS. A TROUGH EXITING THE EAST
COAST EARLY NEXT WEEK HAS TRENDED BETTER IN TERMS OF TIMING. THE
NEXT TROUGH INTO THE CENTRAL U.S. LOOKS TO SPIN UP A MODESTLY
STRONG SURFACE LOW NEXT TUESDAY-WEDNESDAY, BUT THE MODELS CONTINUE
TO INDICATE SOME TIMING QUESTIONS ON BOTH THE SHORTWAVE AND SURFACE
LOW. THE GFS REMAINS ON THE FAST SIDE, WITH THE ECMWF/CMC/UKMET
RUNS TODAY CLUSTERED CLOSE AND SLOWER. WPC FAVORED THE SLIGHTLY
SLOWER EC/CMC/UKMET (WITH THE EC MEAN) FOR THIS, WHICH WAS ALSO
CLOSE TO WPC CONTINUITY. WORTH A NOTE THAT THE NEW 12Z CMC TODAY
(AVAILABLE AFTER FORECAST GENERATION TIME) DID TREND EVEN SLOWER
WHILE THE 12Z ECMWF TRENDED SLIGHTLY FASTER. THE NEXT TWO SYSTEMS
MID TO LATE NEXT WEEK SHOW SOME TIMING VARIABILITY AS WELL, BUT
THIS WAS COVERED WELL WITH INCORPORATION OF THE ENSEMBLE MEANS INTO
THE BLEND FOR THE LATE PERIOD.
..WEATHER/HAZARDS HIGHLIGHTS
AN AMPLIFIED UPPER TROUGH AND LEAD/WAVY COLD FRONT WILL EXIT THE
EAST COAST BY MONDAY TO MODERATE TEMPERATURES BRIEFLY AND SWEEP
WIDESPREAD THUNDERSTORMS OUT TO SEA; WITH POSSIBLE LOW DEEPENING
OUT OVER THE WESTERN ATLANTIC A POSSIBLE MARITIME HAZARD.
TEMPERATURES ARE FORECAST TO WARM BACK UP IN THE CENTRAL AND THEN
EASTERN U.S. AS THE WEEK PROGRESSES. THIS OCCURS WITH ADVENT OF
UPPER RIDGING AS A NEXT MAIN UPPER TROUGH MOVES ACROSS THE WESTERN
AND CENTRAL U.S. EARLY-MID NEXT WEEK AND ONWARD TO THE EAST LATER
NEXT WEEK. DYNAMICALLY AND TERRAIN ENHANCED RAIN AND ELEVATION
FOCUSING SNOW IS FORECAST TO SPREAD OUT FROM THE WEST COAST TO
THROUGH THE INTERIOR WEST MONDAY- TUESDAY. CYCLOGENESIS OVER THE
PLAINS ON TUESDAY AND SUBSEQUENT MAIN/WINDY LOW TRACK THROUGH THE
MIDWEST/GREAT LAKES INTO THURSDAY WILL COMBINE WITH SECONDARY COLD
FRONTAL COOLING TO ENHANCE UPSLOPE AND WRAPBACK HEAVY SNOW
POTENTIAL FROM THE NORTH-CENTRAL ROCKIES/PLAINS THROUGH THE UPPER
MIDWEST TUESDAY- THURSDAY. A WAVY TRAILING COLD FRONT WILL HAVE
LESS MOISTURE THAN THE EARLY WEEK SYSTEM, BUT WILL ALIGN SHOWERS
AND THUNDERSTORMS ACROSS THE CENTRAL U.S. THEN THE EAST, EXITING
NEXT THURSDAY/FRIDAY AS NEW PACIFIC SYSTEM ENERGIES AND LATE WINTER
PRECIPITATION WORK BACK INTO THE WEST/NORTHWEST.
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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