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000 
FXUS61 KCTP 170908
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
508 AM EDT Sat Aug 17 2019

.SYNOPSIS...
Very warm and humid conditions will persist through this weekend,
and a trough of low pressure at the surface will combine with a 
few level disturbances to keep the weather unsettled this 
afternoon and evening, and again on Sunday. The most numerous 
showers and thunderstorms this afternoon and evening will be 
found across the Northern Mountains, while Sunday should see 
multiple areas impacted by the showers and storms.

Temperatures today will be several degrees above normal and 
it will be rather humid.

By late in the weekend through the first half of the upcoming 
next week look for hot and humid conditions, especially across 
the southeast portions of the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
latest RAP/NAM models show a well defined and rather narrow llvl
theta-e ridge extending from Scent PA to the North Branch Valley
of the Susq River (about 15-25 NM west of the I-81 corridor. 

Within this ribbon of moisture, several small showers were drifting
slowly to the Northeast and training over the same locations 
just to the north of Bloomsburg and Berwick where MRMS rainfall
has totaled over one half of an inch over the past 6 hours.
Elsewhere any spotty rainfall over the Susq Valley was less than
one tenth of an inch. 

Target areas for rainfall today are 1) near this aforementioned
Theta-E boundary across the eastern part of our CWA, and 2) over
the NW mtns of PA where the left exit region of a compact albeit
potent 80KT Upper Level jet max will induce a llvl trough and
help to enhance larger scale lift above the boundary. 

Fairly decent mid level flow and associated 0-6km shear could 
support a few rotating updrafts and possible isolated severe 
weather across the northern half of the state Saturday 
afternoon. 

Our far NE zones are within WPC's Marginal Risk area for 
excessive rain today, while the rest of the Northern Mountains
are within the Marginal ERO area for Sunday. 

Partly cloudy skies, light wind and cool temps early today
across the northern mountains have led to areas of very low cigs
and dense fog. Temps have dipped to the mid 50s - lower 60s
across the NRN mtns with KBFD coming in as the cold spot in the
entire eastern U.S. with a 09Z reading of 54F.
 
High temps this afternoon will range from 80F over the northern
mtns, to near 90 in the SE Metro areas.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Another shortwave is progged to track north of Pa on Sunday.
Still, enough UVVEL will form over fairly subtle boundaries and
a Lake Erie and Atlantic Ocean breeze penetrating inland to our
NW and SE zones to bring additional showers and scattered TSRA 
Sunday afternoon and evening.

Sunday's high temps will be a deg or 2 warmer than those of 
today (Saturday).

Highs will range from around 80 along the NY border to around 
90 along the Mason-Dixon line. The combination of heat and 
humidity will drive Heat Indices into the mid 90s over the Lower
Susq Valley for a few hours Saturday afternoon.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Rounds of showers and thunderstorms are likely Tuesday and
Wednesday in advance of a cold front pushing southeast from the
Great Lakes. Would not be surprised to see at least a marginal 
severe storm risk evolve in this window at shorter ranges. 

The uptick in clouds and storms should trim back temperatures 
from near-record levels, but readings will still be above 
average for late August. Max heat index values should also 
trend lower Tue-Wed. 

Pockets of locally heavy rainfall will be possible through 
midweek although frontal progression should limit totals to some
extent. The risk for storms shifts to the south on Thursday as 
push of cooler and drier air brings a refreshing end to the 
week.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
MVFR to IFR ceilings will plague the eastern airfields this
morning while patchy fog reduces visibility near or below
airfield minimums at some northern/western sites. Expect low
clouds and fog to dissipate through mid morning with all sites
trending VFR by 15-16Z. Another repeat pattern of widely 
scattered showers and thunderstorms developing through this 
afternoon with focus across the northern and eastern airspace.
Convection will fade into tonight with patchy fog and low cloud
restrictions possible into Sunday morning. 

.Outlook...

Mon-Wed...Rounds of showers/thunderstorms possible, mainly in 
the afternoon/early evening hours. Late night and early morning 
fog/low clouds.

&&

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

&&

$$
SYNOPSIS...La Corte/Lambert

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