Area Forecast Discussion
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000 FXUS61 KPBZ 161715 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1215 PM EST Tue Jan 16 2018 .SYNOPSIS... Low pressure will bring relatively light snow to the region today followed by bitter cold on Wednesday. Warmer temperatures and dry conditions expected the remainder of the week. && .NEAR TERM /THROUGH TONIGHT/... Update to expand advisory to Westmoreland Ridges and to extend the headline in time through the tonight period. The upper jet has been slow to depart, preventing the cold front from making ewd progress and maintaining warm advection aloft through the dendritic growth zone. Ridge snow will be rather efficient, and light snow will continue all areas through much of the day. Previous discussion follows... Morning update with changes to PoPs based on slower snow erosion. Very little perpendicular push to the front and associated snow will mean longer residence time over the eastern half of the forecast area. PoPs have been raised and slowed to account for this change. Kept snow totals largely intact, but did make some adjustments upward for eastern locations where snow will hold the longest. This pushes the Advisory areas up to 4-6" total while most other locations have storm total snows of 2-4". The fluffy nature of this snow will allow some to see the higher end of those ranges, but with a long duration event (started midday yesterday), 12hr Advisory criteria will likely not be met outside of current Advisories, thus no changes to headlines were made. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... Snow showers will taper off and cold air will move in behind the front early Wednesday...with single digit overnight lows forecast. Below normal temperatures will continue through Wednesday with northwesterly flow maintaining potential for light snow...primarily along and north of I-80. A warming trend in temperatures will commence on Thursday as ridging builds back in over the forecast area. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... High pressure looks to be the dominant feature for much of the period with a building southeastern ridge resulting in well above normal temperatures by the weekend. Moist advection around the western flank of the ridge will keep at least chance PoPs in for for the early weekend. By this time, temperatures should be warm enough to support all rain. Models show relatively good agreement with the next frontal system impacting the region next Monday. && .AVIATION /17Z TUESDAY THROUGH SATURDAY/...
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Widespread IFR snow will carry into the early evening hours before beginning to taper down from west to east. The light snow has been efficient in reducing visibilities, while ceilings remain largely MVFR. Expecting some gradual improvement to restrictions as the snow begins to erode. MVFR with spotty IFR overnight but daybreak Wednesday should bring further improvement as deeper mixing commences. Surface flow will be out of the west at 10kt or less. .OUTLOOK... Northwest flow may lead to further restrictions Wednesday.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...Winter Weather Advisory until 6 AM EST Wednesday for MDZ001. OH...None. PA...Winter Weather Advisory until 1 AM EST Wednesday for PAZ074- 076. WV...Winter Weather Advisory until 1 AM EST Wednesday for WVZ510- 511. Winter Weather Advisory until 6 AM EST Wednesday for WVZ512>514. && $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.