Area Forecast Discussion
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000 FXUS61 KPBZ 171739 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1239 PM EST Fri Nov 17 2017 .SYNOPSIS... Dry weather is expected today with high pressure. Rain can be expected Saturday with crossing low pressure and a cold front. Gusty winds and a few snow showers are expected behind the front Sunday. && .NEAR TERM /THROUGH TONIGHT/... Didn`t need to make any wholesale changes to the forecast but did make some adjustments to cloud cover based on the lightest satellite trends. Stratocu should start to erode but high clouds will quickly fill in advance of the next system. Still think there may be enough filtered sunshine for some more optimistic wording, though temperatures will likely stay cooler than average despite increasing warmth aloft. Clouds should continue to increase tonight as low pressure tracks from the Plains to the Upper Midwest/Great Lakes area. Rain should overspread the region overnight and Saturday morning as the low`s warm front tracks N. Strong warm advection should hold temperatures up slightly overnight, especially over our westernmost zones. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Periods of rain are expected to continue Saturday as a series of shortwaves in SW flow ahead of an approaching upper trough cross the area. Strong winds just above the surface are progged over the area Saturday, though model soundings continue to indicate a capping inversion aloft, keep these winds from reaching the ground. The low is progged to track to Southern Ontario Saturday evening, dragging a cold front across the area. Showers are expected with FROPA. Steepening lapse rates with cold advection, and strong winds aloft should result in wind gusts of 30-40 mph behind the front Saturday night. Higher gusts are possible in the PA/WV/MD ridges. Snow showers are expected by Sunday morning as the main upper trough crosses the Lower Great Lakes/Upper OH Valley region. Maintained the highest POPs for areas near and N of I 80 and in the PA/WV/MD ridges where lake/terrain enhancement is expected. Generally forecasting 1-3 inches of snow in these favored areas. A limiting factor in the upslope snow could be a lack of saturation in the snow growth region on model soundings. Snow is still likely, though rates could be limited by this factor. Another shortwave rotating through the main trough should maintain scattered to numerous snow showers Sun afternoon and early evening. Winds and precip should diminish Sunday night with building high pressure and backing winds. && .LONG TERM /MONDAY THROUGH THURSDAY/... Dry weather is expected early in the week under ridging. A weak trough could return precip chances by mid week for areas N of PIT. Surface high pressure is progged to build under broad, weak upper troughing for the rest of the week, resulting in dry and cool weather. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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With the dissipation of the lower clouds from this morning, VFR flight conditions are expected through the remainder of the afternoon and into the evening hours, with only mid and high clouds expected. Starting around midnight, a developing low level jet will create ideal conditions for low level wind shear, with 40 to 50 knot winds trapped above an inversion just off of the surface. LLWS has thus been added to all TAFs. Rain will arrive in the hours leading up to sunrise ahead of an advancing warm front. Restrictions will likely arrive after 12Z, with ceilings and visibility dropping to MVFR at times as the rain becomes more widespread. IFR will be possible towards the end of the TAF period at FKL/DUJ. The stronger winds will remain just off the surface, but some gusts out of the southwest at 20 to 25 knots are expected by midday. .Outlook... Restrictions are likely with a Sat cold front and with Sun upper troughing and cold NW flow.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$

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