Area Forecast Discussion
Issued by NWS State College, PA

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487
FXUS61 KCTP 290223
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1023 PM EDT THU JUL 28 2016

.SYNOPSIS...
Low pressure will track south of Pennsylvania overnight. An upper
level trough will remain just west of the region through early
next week, then high pressure will build over the northeast conus
for the second half of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Regional radar at 02Z showing periods of lgt to moderate stratiform
rain falling across much of central and southern Pa in region of
lg scale forcing ahead of approaching shortwave. SPC mesoanalysis
showing practically no CAPE left across the region to support
excessive, convective rainfall. Thus, have cancelled the flood
watch. Latest SSEO supports this idea with its 3hr probability of
2+ inch amts near zero tonight.

Will continue to maintain categorical Pops across
central/southern Pa overnight, as mid lvl shortwave interacts
with anomalous PWATS. Blend of SSEO and latest HRRR supports
overnight additional rainfall of 0.25 to 0.75 inches across the
southern half of the cwa, with near zero in most spots across the
north.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
Near term mdl data indicates the back edge of the rain will be
exiting the se counties btwn 12Z-15Z Friday with passage of
shortwave. Behind this feature, expect brightening skies during
late am/early aftn. Diurnal heating could support a few late day
tsra, primarily across the Alleghenies/Central Mtns, per latest
GEFS/SSEO. GEFS mean 850mb temps of arnd 16C should translate to
max temps in the 80s.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Friday night a short-wave trough will move across Indiana and
Ohio spreading showers and possible thunderstorms into western
PA. Central PA will see increasing chances for rain becoming
likely by afternoon. A second wave moves through in cyclonic flow
Sunday keeping the POPs in the 50-70 range with highest chances
over the eastern counties. Short-wave moves to the coast Sunday
night with ridging building in across Central PA helping clear
things out.Monday should be a drier day with sunshine and temps in
the 80s.Hi pres ridge should hold through Wednesday though the
GFS tries to indicate maybe an isolated afternoon/evening shower
or thunderstorm over the Laurel Highlands both days.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
Widespread rain and showers over much of the southern two thirds
of central Pennsylvania this evening, with a few more isolated
convective cells across the northern tier counties. Tough forecast
for aviation this evening, as conditions will likely be highly
variable through the evening and into the overnight.

Latest HRRR continuing the trend of keeping a decent amount of
widespread, mainly light, precipitation across the region. For
TAFs, have generally followed the guidance of a more steady rain
in the south, with showers and rain across central and northern
sections.

Expect most TAFs to be varying from VFR to IFR during the evening
into the overnight. More widespread restrictions overnight, even
if just due to fog rather than rain.

As the system moves out tomorrow morning conditions should rapidly
improve from west to east.

OUTLOOK...

FRI...Some restrictions SHRA/BR in the morning. Some scattered
convective cells possible in the afternoon.

SAT-MON...Generally VFR through the period, but this will be
punctuated by occasional restrictions in SHRA/TSRA. Overnight fog
formation also expected, with associated restrictions.

TUE...Mainly VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...DeVoir/Fitzgerald
NEAR TERM...Fitzgerald
SHORT TERM...Grumm/Fitzgerald
LONG TERM...Watson
AVIATION...Grumm/Jung



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