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Area Forecast Discussion (AFD)

Issued by State College, PA (CTP)

                            
000
FXUS61 KCTP 231848
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
248 PM EDT Tue Apr 23 2019

.SYNOPSIS...
A cold front will move through the forecast area early tonight.
Wednesday and at least the first part of Thursday will feature 
mainly dry conditions once again under the influence of another 
area of high pressure. Fast flow aloft will keep it unsettled 
into next week, with the next frontal system slated to affect 
the area late Thursday night into late Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Thunderstorms moving in along a pre-frontal trough, but showers
out ahead of the better (non-sfc-based) instability has made
rain and likely cooled things a bit and kept it even more
stable. Dewpoints still in the 40s all over the area, and a
meager cap around 12kft are going to be negatives to severe
weather today. However, the shear is strong and storms are
already underway. Will need to monitor the radar closely with
MRGL risk and some possibility of supercells per SPC SWODY1.

The real cold front is likely still back in central OH and srn
IN. This should follow the first cluster of SHRA/TSRA and make a
few SHRA as it moves through later this evening. Worked-over 
air and setting sun should help squash the convection this
evening. Coverage of the showers will get less after 03Z. The 
front will press on through and begin to clear things out by 
06Z. However, clouds will hang tough over the Alleghenies and 
Laurels tonight. Temps probably level off during and stick there
until shortly after the rain, then dip after clearing in the 
south.

&&

.SHORT TERM /WEDNESDAY/...
Gusty WNW wind on Wed. But, it may likely become a little less 
noticeable through the day as high pressure builds in from the 
west and gradient slackens slightly. Early clouds in the NW 
should clear out very nicely to leave a mostly sunny day. Maxes 
in the m50s N, but nr 70F in the SE valleys. Could be a 1 on the
local, experimental JB Index, but the wind probably keeps it as
a 2.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
High pressure will in and lead to a chilly start to Thursday 
before temps rebound back to slightly above normal. Morning lows
likely dip into the low-mid 30s in the valleys of the northern 
mountains.

Models then focus on a vigorous shortwave sliding through the 
Gr Lakes for Thursday night and Friday. The surface low is made
to track north of the region leading to another cold front
moving through the region during the day Friday. Guidance is
rather stingy with the forecast instability so for now at least,
I left out the mention of thunder. 

Sat will bring another shot of cooler air and breezy conditions
with temps recovering back to normal by Sunday. The chance of 
rain will return Monday as a warm front approaches the region.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
Rain showers affecting KBFD and will march slowly eastward
through the beginning of the forecast period. Lightning has
diminished, however, kept mention of VCTS in the western
airfields.

By the time the rain showers make it to KMDT and KLNS, they will
have diminshed to the point of just VCSH. After 00Z, conditions
will improve with breezy winds from the west and northwest. The
remainder of the forecast period will feature good VFR with
winds gusting to 25 knots.


.Outlook...

Wed-Thurs...No sig wx.

Thurs PM-Fri...SHRA/TSRA. Restrictions probable.

Sat...Mainly VFR, low chc SHRA/TSRA.

&&

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

&&

$$
SYNOPSIS...Dangelo/La Corte
NEAR TERM...Dangelo
SHORT TERM...Dangelo
LONG TERM...La Corte
AVIATION...Dangelo/Tyburski