Area Forecast Discussion
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FXUS61 KCTP 242005
Area Forecast Discussion
National Weather Service State College PA
405 PM EDT WED AUG 24 2016
A seasonably warm and humid late-summer weather pattern will
continue across Central Pennsylvania through the weekend. The
best chance for scattered showers or thunderstorms will come on
Thursday and early next week.
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Deep layer moisture continues to increase over central PA early
this afternoon as return southwest flow has commenced west of the
850 mb ridge moving offshore south of Long Island.
Sct fair weather cumulus has slightly more vertical extent than
Tuesday as a result...but mid to upper trop is stable and not
expecting any diurnal activity this afternoon or evening.
Tonight will be fair as deep layer moisture continues to increase.
Late night convective complex over the Ohio Valley will be
weakening as it makes a dive towards southwest PA in the pre dawn
hours...which could bring the West Central Mountains and Laurel
Highlands some showers early Thursday morning before complete
dissipation. Earlier ARW-E depicted more of a classically right
turning complex dissipating as it reached the MD panhandle Thu
morning...while latest HRRR is indicating a line of showers and
thunderstorms extending from southwest trip of Lake Ontario to
southeast Ohio by 07z tonight. Think the latter is more likely to
occur...as good moisture convergence along the elongated 850 mb
jet advancing from the eastern GLAKS should maintain convection
through late tonight before slowly weakening in the pre dawn hours
Thu morning. Will adjust pops accordingly for late tonight into
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
Decaying frontal boundary will feed on 2"+ PW Thursday leading to
scattered coverage of showers and thunderstorms on Thursday. Main
problem may be developing sufficient CAPE as overnight convective
remnants from the Ohio Valley may plague a good portion of central
PA into Thu afternoon. Latest SPC Day 2 has western portion of my
CWA in MRGL risk for Thu afternoon...as setup is far from ideal.
Still...the moist and unstable air mass will support scattered
convection ahead of the weakening front.
Sfc dewpoints will make a run at or exceed 70 in many areas...so
it will be noticeably stickier than Wed afternoon. Highs central
and north should be a few degrees lower due to cloud cover...while
southern areas will warm another degree or two over Wed highs.
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
The high pressure over the southeast will weaken the trough moving
through and it will become very diffuse on Friday as it slips
south toward the Mason Dixon line. Temperatures and humidity will
be on the rise with 90F heat likely returning to the Lower
Susquehanna Valley by Friday and through the weekend. A drier air
mass will reside over the area through most of Sunday.
The deep-layer ridge will gradually slide off the Mid Atlantic
coast this period, which allows another frontal boundary to sink
southward from the Lower Lakes and become quasi-stationary over
PA early next week. This will favor unsettled conditions Mon-Tue
with POPs trending upward following a mainly dry weekend. Temps
will remain above normal by late August standards.
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions will prevail through this evening. Isolated MVFR
conds in shra from dying convective complex overnight may impact
far western terminals Thursday morning. Sct mainly afternoon shra
and tsra central and western areas on Thursday.
Wed...Patchy AM fog possible, otherwise VFR.
Thu...Generally VFR, but with Isold pm tsra impacts possible,
mainly w and c mtns.
Fri...Morning low cigs possible across the
Western Mountains, otherwise VFR.
Sat-Sun...No sig wx expected.
Mon...Generally VFR...but with Isold pm tsra impacts possible.