Area Forecast Discussion
Issued by NWS State College, PA

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562
FXUS61 KCTP 222359
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
659 PM EST Wed Feb 22 2017

.SYNOPSIS...
An extended period of very mild weather will continue into
Saturday. A strong cold front is expected to bring showers and
thunderstorms on Saturday. Gusty westerly winds, colder
temperatures, and snow showers across the western mountains will
follow the frontal passage for later Saturday into early
Sunday.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Yet another mild February evening across central PA with
temperatures some 15 to 20 degrees above average. Final vestages
of shower activity associated with lifting warm front are
exiting my northeast counties. Localized fog now being reported
over the northwest mountains, but should not last long given
freshening southwest boundary layer flow late this evening.

No low/mid clouds over the srn tier early this evening and for
at least the first half of the night, it should remain pretty
much clear aside from thin high clouds. This should allow
better radiational cooling over the south/east. However, a moist
swrly flow will probably cause/hold lots of low clouds and
perhaps some DZ later tonight in the western highlands. Have
also mentioned some patchy fog over all of the area as many
locations should get down near the already- mild dewpoints. Mins
will run between 45F E and 50F W.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
Low clouds and mid-level moisture will make Thursday another
day of struggling to see the sun. However, the extremely mild
start (45-50F) to the day will yet again allow the temps to be
very much above normal through the whole day. A shearing "cold"
front will dip down into the northern tier. POPs are a
difficult call. The morning will still hold some --SHRA or -DZ
in the NW. Any fog should take a while to burn off with
dewpoints so high. The warm sector and the passage of a very
subtle short wave trough may pop some showers (probably no
thunder) over SWrn PA and slide them to the east during the
aftn. The warm front itself will be another focus for some
convergence and sct showers. Maxes will be even warmer than
today(Wed). 60s should be widespread with the warmest numbers in
the south.

The front will probably stall out for a short time Thurs night,
but push northward as a warm front late. This feature will keep
clouds around, and is yet another reason to remain very high on
temps for Thurs night. Mins will again be 45-50F area-wide.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Upper ridging over the east coast at the start of the period
will be temporarily squashed as a decent nothern stream
shortwave moves east through the Ohio Valley and across the
Middle Atlantic states over the coming weekend. This will bring
a pronounced cold front across the region late Saturday.
Heights are forecast to rebuild across the eastern half of the
conus early next week ahead of troffing developing over the
Rockies.

Very mild temperatures will persist for the end of the
week, likely reaching records levels at least in some locations
once again Friday afternoon. The aforementioned cold front will
return temps to near or closer to near seasonal normals for
Sunday into early next week.

Several shortwaves withing the developing southwest flow aloft
will bring several weak fronts across the region. This will
lead to less than pristine sky conditions...but the time period
will be generally dry. However, enough low pressure lurking at
the surface could lead to a system of more significance sometime
during the week.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
BFD will have the SHRA overhead move off to the E/NE shortly.
But, there are still some IFR clouds just to the west.
Therefore, I must be cautious in improving the conditions there.
Elsewhere, VFR will hold for at least the first half of the
night. However, a moist SW flow into the wrn mtns will bring
the low clouds into KJST and renew them in KBFD. There may also
be some patchy DZ or --SHRA later tonight. The decoupled sfc
will allow for good but not ideal radiational cooling as there
will still be some higher clouds around the rest of the area.
Thus, will mention fog in many locations, but not go into IFR
outside of the wrn terminals. A cfront will dip into the area
from the N on Thurs and could make the entire day into one of
IFR in KBFD. Elsewhere, the low clouds and fog should burn away
and some instability in the south could allow for a SHRA or two.
Timing would be in the aftn. The front will likely hang around
Thurs night but then lift to the north early Friday.

Outlook...

Fri...IFR/MVFR psbl early - mainly N. Chance of rain mainly N.

Sat...LLWS. Strong FROPA with sub-VFR likely in moderate rain
showers and sct TS. Post-frontal WNW wind gusts 25-35kts.

Sat night-Sun...Sub-VFR NW third with sct shsn. Gusty NW wind.

Mon...Reduced CIGs psbl in RA/SN.

&&

.CLIMATE...
***February Warmth 2017*** Updated 2/22/17 at 8am EST

Record high temperatures for select sites from Feb. 22-24:
----------------------------------------------------------

Harrisburg 2/22: 71 in 1974
Harrisburg 2/23: 70 in 1985
Harrisburg 2/24: 75 in 1985

Williamsport 2/22: 66 in 1974
Williamsport 2/23: 70 in 1985
Williamsport 2/24: 71 in 1985

Altoona 2/22: 62 in 1974
Altoona 2/23: 66 in 1977
Altoona 2/24: 69 in 1985

Bradford 2/22: 57 in 1975
Bradford 2/23: 57 in 1977
Bradford 2/24: 59 in 1961

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

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

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...Dangelo
NEAR TERM...Dangelo/DeVoir
SHORT TERM...Dangelo
LONG TERM...Lambert/Gartner
AVIATION...Dangelo
CLIMATE...



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