Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
624 PM EDT Monday Aug 3 2015
A cold front will push southeast and through the state this
evening and overnight. High pressure will dominate the midweek
before unsettled conditions return for Thursday and Friday as a
slow moving front moves back into the region.
Near term /until 6 am Tuesday morning/...
Relatively stable air developed over most of the forecast area this
afternoon effectively capping convection ahead of the advancing
weak cold front. The atmosphere has recovered over southwestern PA where
the most active storms are in progress as of 6 PM. The hrrr tracks
these storms east through the south central mountains...while
keeping more scattered showers and thunderstorms developing and
affecting the region into the wee hours of Tuesday morning.
Confidence is low on the additional convection development as we
typically see it become more stable after we lose the solar
Although the Storm Prediction Center day one outlook keeps the slight risk over
almost all of central PA...have downplayed the potential for
strong storms given the marginal instability and approaching
Lows early Tuesday will range from the middle 50s in the northwest to middle
60s over the southeast.
Short term /6 am Tuesday morning through 6 PM Tuesday/...
a rather strong upper trough and secondary cfront will be diving
southeast from the upper glakes region. Although the low level environment
will be drier and slightly cooler in the wake of Monday night/S
cfropa...strong forcing beneath the l.E. Region of a 95 knots jet will
likely spark at least isolated to scattered thunderstorms and rain across the
central and northern mountains
Maximum temperatures will vary from the 70s across the northwest half of the
County Warning Area...to the 80s in the southeast half. Close to normal for late Summer.
Long term /Tuesday night through Monday/...
the upper low over northern Quebec should continue to drift to
the northeast and zonal to slightly northwest flow is expected to
follow as a quasi-stationary boundary hangs out just to the south
of the state. Uncertainty remains in the placement of the
boundary so will keep some pop in the southern part of the state...but
most locations will be dry until Thursday into Thursday night.
Then a stacked low will slide eastward from the middle Mississippi
Valley and may make a more-or- less constant rain instead of
showery/convective precipitation. The upper level low will finally move
off late next weekend which will be a Herald for quieter weather.
Temperatures should trend cooler later in the week before warming
up into next week.
Aviation /22z Monday through Saturday/...
an approaching cold front and preceding surface/Lee trough over the
susq valley will act as two areas of focus for late
afternoon/evening rain showers thunderstorms and rain with scattered/brief MVFR ceilings and visibilities.
A few of the storms may be strong to severe...with very brief IFR
visibility in +ra and highly-localized westerly surface wind gusts at or above
40kts. Will continue to use -shra with thunderstorms in the vicinity between 20-22z to show
thunderstorm impact risk at all terminals.
Tuesday...VFR. Isolated-scattered p.M. Rain showers/thunderstorms and rain central and northern Penn.
Wednesday...VFR. No sig weather.
Thu-Fri...VFR/MVFR with rain possible as low pressure tracks south of
Sat...VFR with a low chance of MVFR in isolated afternoon rain showers.
near term...la corte/Lambert