Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Pittsburgh PA
842 am EDT Thursday Oct 2 2014
the next chance for rain will come with a Friday cold front. Much
cooler temperatures are expected for the weekend.
Near term /until 6 PM this evening/...
morning fog will be slow to burn off. Dense fog adzy was extended
until 10am. Previous discussion follows...
Widespread dense fog will continue Erly this morning with low level moisture in place
under an inversion. Will continue with the dense fog advisory through 9am. The
fog should dspt by middle morning as fog depth is not as great as yesterday.
Otherwise...experimental ridging and warm advection today with dry weather. Cirrus from weakening
thunderstorms over Illinois should work into the area later today...though this
should be thinning and decreasing as the clouds run into drier air. Temperatures
should be several degree above seasonal avgs today.
Short term /6 PM this evening through Sunday/...
ridging will gradually shift eastward tonight with continued warm advection. A cold front will
advance east across the region lt Friday and Friday evening...though initial shower
activity will likely develop along a pre frontal trough earlier in the day.
GFS/European model (ecmwf) forecasts show limited instability...though with winds aloft and
shear increasing Friday will maintain a chance of thunderstorms in the forecast.
After frontal passage...an upper low is prognosticated to set up across Ontario...with a
series of shortwaves rotating around the low into the Great Lakes region. This
will keep some chance for showers mainly north of pit...though did maintain
some unmentionable slight chance probability of precipitation further S.
Above average temperatures on Friday will be replaced with temperatures well below seasonal
levels by the weekend as 850mb temperatures drop to around zero.
Long term /Sunday night through Wednesday/...
strong closed low aloft will wobble north of the Great Lakes
through Tuesday with coo temperatures. A shortwave will bring
bring increasing clouds and shower chances later Sunday night and
Monday. A reinforcing cold front and shortwave will cross the
region Tuesday with additional shower chances. By midweek upper
trough will lift north with zonal flow developing across the Ohio
Valley bringing temperatures back to near seasonal averages.
Aviation /13z Thursday through Monday/...
condition deterioration is expected overnight with fog and stratus
under a strengthening inversion. IFR for all sites with LIFR at
times. Improvement after daybreak is expected with mixing for VFR
through the day.
Outlook.../Thursday night night through Monday/...
the next chance for widespread restrictions will come with a Friday
cold front. Restrictions will be possible in showers Monday.
Maryland...dense fog advisory until 10 am EDT this morning for mdz001.
Ohio...dense fog advisory until 10 am EDT this morning for ohz039>041-
PA...dense fog advisory until 10 am EDT this morning for paz007>009-
WV...dense fog advisory until 10 am EDT this morning for wvz001>004-