Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
914 PM EDT Wednesday Jul 23 2014
shower and thunderstorm chances will diminish with passage of a
cold front this evening.
Near term /until 6 am Thursday morning/...
updated to remove all probability of precipitation behind the advancing dewpoint
boundary...and also to reduce them ahead of it. Only a few rain showers
now left as many of them dissipated with the loss of daytime
heating. Do think this boundary loses its push overnight as the
lower levels stabilize...so will hang on to a very low pop in the
southeast County Warning Area overnight. Sky grids are tricky...think area to the
south will see an increase while the northwest will get a late
decrease with advance of drier air. Formation of stratocu patches
possible pretty much anywhere overnight. Low temperatures looked
reasonable and no change there.
Short term /6 am Thursday morning through Saturday/...
lingering slight...to chance numbers were retained for areas S and east of
pit through early Thursday given the forecast of another shortwave across
the stabilizing upper Ohio region.
Cooler and drier air will be advecting over the entire region
through the short term period. Temperatures were forecast closer to bias
corrected GFS MOS.
Long term /Saturday night through Wednesday/...
low confidence forecast for the beginning of the long term period.
Models exploring some different options with a shortwave trough
that will cross the area sometime on Saturday. This part of the
forecast will need to be refined once model run to run becomes
The next system will bring showers and storms to the area Sunday
and Monday and much cooler air for the end of the long term.
Aviation /01z Thursday through Monday/...
difficult aviation forecast tonight as the front has just about
pushed through all terminals nearing 00z. Dewpoints are falling
quickly behind the front and cold air advection has developed some
stratocu in the wake. Satellite imagery offers a pretty ragged
depiction of the cloud deck that is far from uniform. Although
many of the sites ceilings will bounce tonight...the overall trend is
to drop ceilings into the MVFR range with a few crossing IFR
Thursday any stratus will give way to a scattered to broken cloud deck nearing
5kft. VFR conditions should prevail there on with high pressure
Outlook.../Wednesday through Sunday/...
the next chance for restrictions will come later Saturday and
Sunday as low pressure approaches.