Scientific Forecaster Discussion
Area forecast discussion
National Weather Service State College PA
810 am EDT Friday Aug 1 2014
a trough of low pressure over eastern Canada will keep
temperatures slightly below average for the next several days.
Several areas of disturbed weather will keep the chance for
showers and thunderstorms in the forecast for the next several
Near term /until 7 PM this evening/...
The low clouds and ceilings over central Pennsylvania should burn
off this morning. The NCEP narre suggests the timing for is 9 to
10 am...close to climatology. But in the southeast the easterly
flow and moisture stream will keep clouds in an lower ceilings
late this afternoon and evening. The surface visibility and fog
burn off faster.
The models show deepening moisture to our east and the narre
ensemble reflectivity shows rain and showers moving into
southeastern PA and moving into central PA this afternoon. Slowly
pulled probability of precipitation north in grids keeping lowest in north and northwest.
The marine/moisture boundary and increasing cape suggest
thunderstorms over most of the Easter half of the region possible
The models and mesoscale ensemble guidance implies
our high temperature forecasts are a bit optimistic today.
Short term /7 PM this evening through 6 PM Saturday/...
The boundary and low level southeasterly flow will keep chance of
rain higher in south/south east and Southwest Mountains these
evening and into early Saturday. The deep moisture is forecast to
stay to our east so rainfall amounts are not significant.
At this time...cape forecasts appear lower on Saturday than today.
Similar to today...best chance of rain will be in east in the
deeper moisture plume. Kept most probability of precipitation in chance range and kept it
Retrograding upper level trough...retreating anticyclone to our
northeast and a plume of deep moisture in the coastal plain can be
kind of ugly this time of year.
Long term /Saturday night through Thursday/...
no major changes from what has become an extended period of
unsettled weather. Eastern US will remain in a trough...though
not nearly as anomalously cool as this week. Will see several
disturbances move across the region. Exactly where the
disturbances go is uncertain this far out...and will keep
temperatures close to average and probability of precipitation in the forecast just about
every day next week.
Aviation /12z Friday through Tuesday/...
variable conditions across central PA due to fog...with a stripe
across central sections where it rained yesterday dipping to IFR.
Elsewhere generally MVFR to some VFR. In most areas...conditions
should quickly return to VFR...though in thicker fog /like kunv-
kfig/ it will take a little longer like 14z for VFR to again
As stubborn trough lingers over the region...expect another round
of scattered showers and isolated thunderstorms mainly during the
afternoon hours. Highest likelihood will be across central and
southern areas...with rain showers introduced after 18z in the lower susq.
No thunder mentioned this far out.
The weekend will see lower clouds edge toward the region from the
southeast...but likely struggling to make it into central PA as
baroclinic zone remains along the coast. But daily poss of
showers/isolated thunderstorms continue.
Sat-sun...mainly VFR...but scattered afternoon rain showers/thunderstorms and rain impacts poss.
Monday...possible am fog. Otherwise mainly VFR.
Tuesday...scattered rain showers/thunderstorms and rain with approaching cold front.