Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Pittsburgh PA
628 am EDT Friday Jul 31 2015
mainly dry weather with seasonal temperatures through Sunday.
Near term /through tonight/...
no major changes for the dawn update. Previous...high pressure
ridge will slide east today with seasonal temperatures. Weak
shortwave will slide southeast tonight in northwest flow. NAM
seems to be outlier producing more in the way of showers and
storms. For now will go with a combo of the European model (ecmwf) and GFS...with
limited moisture and instability low chance probability of precipitation mainly along the
Short term /Saturday through Monday/...
shortwave in northwest flow will have little moisture to work
with Saturday with low probability of precipitation again across the far north. Later
Monday stronger impulse arrives late day with deeper moisture and
chance probability of precipitation. Temperatures close to average through the period.
Long term /Monday night through Thursday/...
a broad eastern Continental U.S. Upper trough is prognosticated to persist through the
period with slightly cooler than average temperatures. Much of the
time should be dry...though a few shortwaves advancing through the
trough should bring periodic shower chances. Followed close to wpc
ensemble based guidance to smooth out individual model
differences...though did adjust guidance probability of precipitation downward with
shortwave timing and available moisture in question.
Aviation /10z Friday through Tuesday/...
VFR conditions are expected through tonight under high
pressure...with cumulus rule indicating scattered diurnal cumulus. A weak
shortwave is prognosticated to move across the Great Lakes
tonight...though the best upper support for any precipitation should
stay north of the area.
Outlook...Saturday through Tuesday...
restriction potential returns early next week with crossing