Scientific Forecaster Discussion
fxus61 kpbz 280118
Area forecast discussion
National Weather Service Pittsburgh PA
918 PM EDT Sat may 27 2017
crossing low pressure will return areawide rain for Sunday and
Near term /until 6 am Sunday morning/...
no changes were needed for the late eve update.
the early eve update featured a precip prob reduction for areas
south of I 70 as per exiting shortwave support and southward
positioning of the sfc front. Shortwave ridging will maintain
dry weather overnight, but with seasonably warm temperature.
Short term /6 am Sunday morning through Monday night/...
another shortwave emerging from the base of northern plains low
pressure is forecast to quickly return rain to the region on
Sunday. Storm Prediction Center has a marginal risk of severe storms with that
scenario, but instability and deep layer shear remain questionable
do no hazard mention will be included. Despite a rich moisture
feed, any flood issues look to be local at best and confined to
poor drainage areas given system progression.
The system cold front is projected across the ridges by daybreak
Monday, hence the majority of the days looks dry under briefly
building high pressure. Under the subsequent upper troughing
pattern, some isolated showers could develop over northern
counties Monday night as a shortwave skims the region.
Long term /Tuesday through Saturday/...
periodic shower chances will continue through midweek, as
shortwaves rotate through a broad upper trough over the NE Continental U.S.
And Great Lakes. Drier weather is figured for Thursday and
Friday as surface high pressure travels through the ridge,
although rain chances may return for Friday night/Saturday
behind the high. Temperatures should average near to a few
degrees below seasonal levels.
Aviation /01z Sunday through Thursday/...
after residual cu diminishes tonight, radiational cooling may
support a period of fog across the terminals in the vicinity of
the stationary boundary along the SW PA/north WV border. At this
time, have trended toward low MVFR for most locations south and
east of kpit, with greatest confidence at mgw and lbe.
Aforementioned boundary will lift northward on Sunday. Thus,
while fog may lift and dissipate, restrictions will still be
possible in any showers/storms that develop through Sunday
Wind with be light and northerly through tonight, backing to
southerly toward morning.
rain and restriction potential will continue with a cold front Sunday
night. Fronts Tuesday and Wednesday may support further restrictions.