Area Forecast Discussion
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FXUS61 KCTP 231936
Area Forecast Discussion
National Weather Service State College PA
336 PM EDT TUE AUG 23 2016
We should remain on the northern edge of the large subtropical
ridge over the southeastern United States and on the southern edge
of the westerlies for the next week. Weak fronts should push
through our area as they try to move over the ridge. Ahead of each
front there will be some minor surges in moisture. After each
front high pressure will drift by. Bottom line relatively dry and
comfortable late summer pattern for the next week or so.
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
Big Bubble no trouble. Nudged grids to new guidance and put the
HRRRV2 which is now the operational HRRR on top of this for some
hourly texture. Fantastic day ideal temperatures and humidity.
Get out there and ENJOY.
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Updated through 0000 UTC Thursday...just nudged the forecast grids
for all fields. Retreating high pressure should lock in another
fine day with some rebounding temperatures and some rebounding
humidity as the day goes on. But still quite comfortable.
Overnight Wed from previous: The GEFS seems to think any
rain/showers would be in extreme western Pennsylvania overnight
Wednesday but the probability is quite slow low east of McKean
County. Most areas will be rain free. POPS generally below 10
percent Wednesday night except chance POPS in the two northeastern
most counties. GEFS and SREF have low-end QPF bias and our blends
are clearly too wet.
.LONG TERM /THURSDAY THROUGH TUESDAY/...
No changes to previous forecast in store for this package.
However, extended models do back off slightly on precipitation
coverage for Thursday but slight to chance PoPs are still
Model data shows another glancing blow from passing shortwave
energy/height falls to the NW of the area on Thursday as upper
ridge holds firm from the Mid South up along the Atlantic coast.
However, there appears to be sufficient moisture/instability with
the weakening cold front/surface trough to trigger scattered to
numerous thunderstorms during afternoon/evening. Consensus blend
yielded max POPs over the NW 1/3 of the CWA. The front should
become rather diffuse on Friday with risk of thunderstorms
confined along/ahead of the boundary. The best location at this
time appears to be the southeast 1/3 of the CWA and therefore
painted low POPs during the day before drying things out Friday
night. Forecast CAPE/shear profiles support MRGL risk outlook
from SPC into far western PA on Thursday/D3, with room to expand
and/or possibly increase level in later outlooks. Anomalous PWs
will support localized heavy downpours.
Another extensive upper ridge resumes control of the weather
pattern into the weekend. This should translate into a seasonably
warm and somewhat muggy period although not anything like the 70+
dewpoints we experienced around mid-month. The models seem to open
the door for isolated airmass/terrain-induced convection by Sunday
afternoon, however the odds still favor a mainly dry weekend for
most locations. For next week, the guidance is suggesting a
shortwave tracking to the north of PA will drag a trailing frontal
boundary into PA which may become quasi-stationary Mon-Tue. This
feature would provide a focus for thunderstorm activity and have
generally trended POPs upward beyond Sunday.
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
As noted earlier...VFR light winds. Great day to fly.
Patch valley fog overnight. Could make locally MVFR and patchy
areas in near water IFR. Clears out fast Wednesday morning.
Another light wind kind of day.
Wed...Patchy AM fog possible.
Thu...Isold pm tsra impacts possible, mainly w mtns.
Fri...AM low cigs possible w mtns.
Sat...No sig wx expected.