Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
746 PM EDT Tuesday Sep 1 2015
warm and humid conditions will continue through the week with
isolated afternoon showers and thunderstorms possible.
Near term /until 6 am Wednesday morning/...
forecast right on track. No updates will be issued late this
afternoon/early evening. Previous discussion below..
Upper level shortwave over the Ohio Valley will continue to
weaken as it is absorbed into the upper level flow through the
period. However...with its progression toward PA not anticipated
until Wednesday morning...its influence on the forecast should be
limited to support of some isolated convection generally along and
south of the I 70 corridor this afternoon. Otherwise...though
ample surface based instability resides over the region...warm middle
levels will inhibit moist...deep convection.
Overnight temperatures were forecast via persistence.
Short term /6 am Wednesday morning through Thursday/...
weak trough will drive to the southeast on Wednesday...allowing
for the ridge axis to retrograde to the west Thursday. With a
return of northwest flow...this could spawn slightly better chances for
showers and thunderstorms areawide both Wednesday and Thursday.
However...warm midlevels will continue to be the limiting factor.
Will carry mainly slight chance probability of precipitation for diurnal convection both
Seasonably warm temperatures are expected to continue.
Long term /Thursday night through Tuesday/...
the strong middle/upper ridge is prognosticated to rebuild through the long
term period. Slight to chance probability of precipitation under weak middle Atlantic region
troughing on Friday were thus tampered off into the weekend. Relief
from the dry and warm conditions may come with a middle week cold front.
Aviation /00z Wednesday through Sunday/...
any remaining showers this evening will not affect terminals. VFR
conditions can be expected with exceptions for isolated
convection and predawn fog. With little change in airmass between
Tuesday and Wednesday morning...forecasts for Wednesday morning
are very similar to Tuesday morning observations.
Outlook...Wednesday night through Sunday...
brief restrictions are anticipated with predawn fog and isolated