Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 251132
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
632 AM EST Sat Feb 25 2017

.SYNOPSIS...
A strong cold front will plow east across the region today
accompanied by a few bands of showers and perhaps a narrow line
of strong, gusty thunderstorms. Gusty westerly winds and colder
temperatures will follow the frontal passage. Some snow showers
are also expected late today, tonight and Sunday across the
western highlands. High pressure builds in from the Ohio Valley
for Sunday but weak waves of low pressure will move up the Ohio
River Valley Monday into Tuesday may bring some mixed
precipitation to the northern half of the area, and mainly rain
in the south.

&&

.NEAR TERM /UNTIL NOON TODAY/...
Incredibly mild early morning temps for late February (in the
upper 50s to low 60s), and running some 30+ degrees above
normal night-time lows.

All-time February record highs were set at both Williamsport
(76F) and State College (PSU weather center - 74F) on Friday.
Balmy southerly wind will continue prior to a strong cold
frontal passage (during the mid to late morning hours across the
western third of the state).

Greatly weakened late evening squall line over Ohio (just ahead
of the cold front) has been making steady, but slow eastward
progress overnight, and is pushing to near the I-79 corridor
in Western PA at 10000Z.

The leading edge of the showers will continue to slowly track
across ELK and McKean Counties through 1130Z...then reach a line
from KELZ to KUNV and KAOO between 15-18Z. Temps will slip into
the L50s by 12Z across the far NW zones.

&&

.SHORT TERM /NOON TODAY THROUGH 6 PM SUNDAY/...
CFROPA expected around 12Z across the region near and just to
the west of the RT 219 corridor, 14-18z across the Central
Mtns, and 18Z-21Z across the eastern part of the CWA.

SPC has the eastern half of PA in a Slight Risk for today with a
MRGL risk for svr extending back to the far NW part of the CWA
associated with the early to mid- morning convection. Confidence
is increasing for several hundred J/Kg of cape (and as much as
pockets of 750 J/Kg) fueling a NCFRB that will intensify and
solidify across the Central mtns and Susq Valley during the late
morning and early afternoon. This line will be capable of
tapping and mixing down to the sfc 50kt WSW winds that are
present around 5 KFT AGL on model forecast soundings at regional
gridpoints.

Gusty west wind are anticipated post-cold-frontal, but not Wind
Advisory worthy.

Widespread cloudiness will hinder destabilization during the
morning - esp in the NE where some light showers or local
drizzle may be found during the first part of the day. The
front will push across steadily and only taking about 6 hours to
cross the entire CWA. POPs will be pegged at 100s.

Temps will drop very quickly and should be back into the L-M30s
in the NW by the end of the aftn. SHRA will turn to SHSN there
in the aftn. Winds will be gusting into the 30s with some peaks
in the 40s behind the front. But, at this point, it does not
look like a wind advy is necessary.

Cold northwesterly flow could allow for snow showers Saturday
night into Sunday. However lack of moisture will only bring
light accumulations with the highest amounts in the NW mtns.

After some morning flurries and scattered snow showers in the
NW Sunday, the trough will continue its eastward trek and a more
zonal pattern will overtake the region. This will bring more
tranquil conditions with some sunshine expected for Sunday
afternoon, along with decreasing winds.
 However, max temperatures on Sunday will be back to near
normal. Heights are forecast to rebuild across the eastern
half of the conus early next week on broad southwesterly flow
ahead of troffing developing over the Rockies.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
The latest 00Z Oper and EFS runs show a warm frontal boundary
moving into the region Tuesday. This will bring the next chance
for light precipitation with possible warmer than normal
temperatures though not as high as currently. Another upper
level trough moving through the Great lakes could bring another
cold front through the mid Atlantic region later next week.
There are inconsistencies in timing and placement.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Not much change since 5 AM.

Isolated thunderstorms gone now, but will see some heating
here shortly, mainly to the east.

Earlier discussion below.

Most of the low clouds to the east are gone, as the winds at
low levels are still gusty at times.

The cold front to the west will continue to move rather fast
across the region today. The front should be east of the area by
late afternoon. Bands of showers and scattered thunderstorms
will move across the area, with gusty winds.

Mainly VFR after the the cold front moves east of the area.

Still some lower conditions will be possible across the
northwestern mountains and Laurel highlands late today
into tonight, as the colder air works into the area. There
could be some snow showers as well in these areas. The amounts
will be limited, given the lack of deep cold air. Also quite
a lot of directional shear, thus hard to see real heavy snow
showers later today.

Outlook...

Sun-Mon...No sig wx expected.

Tue-Wed...Rain showers/reduced CIGS possible.

&&

.CLIMATE...
***February Warmth 2017*** Updated 2/25/17 at 1 am EST

Records were broken at both Williamsport and Harrisburg
on Friday.

High at Williamsport at 76 degrees at 337 PM.

High at Harrisburg at 76 degrees at 241 PM.

Also records at Bradford, Altoona, and Johnstown.

High at Johnstown 72 degrees at 357 PM.

High at Bradford 69 degrees at 503 PM.

High at Altoona 75 degrees at 322 PM.

Previous information below.

Record high temperatures for select sites for Feb. 24:
----------------------------------------------------------

Harrisburg 2/24: 75 in 1985; all-time Feb record is 78F

Williamsport 2/24: 71 in 1985; all-time Feb record is also 71F

Altoona 2/24: 69 in 1985; all-time Feb record is 74F

Bradford 2/24: 59 in 1961; all-time Feb record is 64F

-----------------------------------------------------------

Most 60 degree days in February at Harrisburg. Based on the
latest forecast, add 4 more days to the list and finish tied
for second with 7 days.

1. 10 days in 1976
2. 7 days in 1930
3. 5 days in 1991, 1943
5. 4 days in 1997, 1985, 1954, 1939
9. 3 days in 2017, 2016, 1996, 1990, 1961, 1932, 1890

------------------------------------------------------------

Warmest February on Record (Avg. Temperature through 2/21)

Harrisburg: 2017 rank=4 (38.6)
1. 40.4 in 1998
2. 39.6 in 1976
3. 39.4 in 1954

Williamsport: 2017 rank=4 (35.4)
1. 37.0 in 1998
2. 36.1 in 1954
3. 35.6 in 2002

Altoona: 2017 rank=2 (36.5)
1. 37.4 in 1976
Evening cooling will be a little slower than last
night.

Bradford: 2017 rank=6 (29.3)
1. 32.3 in 1998
2. 30.1 in 2002
3. 29.6 in 2012
4. 29.5 in 1990/1976
-------------------------------------------------------------

&&

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

&&

$$
SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Dangelo/Lambert
LONG TERM...Lambert/Ceru
AVIATION...Martin
CLIMATE...Martin


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