Freeze Warning 3, NWS State College, PA

928 
WWUS71 KCTP 270114
NPWCTP

URGENT - WEATHER MESSAGE
National Weather Service State College PA
914 PM EDT Thu Oct 26 2017

PAZ026-035-036-271200-
/O.CON.KCTP.FZ.W.0003.171027T0400Z-171027T1200Z/
Huntingdon-Fulton-Franklin-
Including the cities of Huntingdon, Mount Union, McConnellsburg, 
and Chambersburg
914 PM EDT Thu Oct 26 2017

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM EDT FRIDAY...

* TEMPERATURES...Lower 30s.

* TIMING...Temperatures will fall near to or just below freezing 
  late tonight. The coldest areas will be in the rural valleys.

* IMPACTS...Damage to vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Those with agricultural or gardening interests should protect
vegetation if they wish to extend the growing season.

&&

$$

PAZ027-028-045-046-049>053-056>059-063>066-271200-
/O.CON.KCTP.FR.Y.0007.171027T0400Z-171027T1200Z/
Mifflin-Juniata-Southern Clinton-Southern Lycoming-Union-Snyder-
Montour-Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-
Cumberland-Adams-York-Lancaster-
Including the cities of Lewistown, Mifflintown, Lock Haven, 
Williamsport, Lewisburg, Selinsgrove, Danville, Sunbury, 
Shamokin, Bloomsburg, Berwick, Newport, Harrisburg, Hershey, 
Pottsville, Lebanon, Carlisle, Gettysburg, York, and Lancaster
914 PM EDT Thu Oct 26 2017

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT FRIDAY...

* TEMPERATURES...In the upper 30s.

* TIMING...Areas of frost will form first in the colder rural 
  valleys around midnight, then expand across the Advisory area 
  through the predawn hours.

* IMPACTS...Damage to sensitive vegetation likely if not 
  protected.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Those with agricultural or gardening interests should protect
sensitive vegetation if they wish to extend the growing season.

$$

Area Forecast Discussion
National Weather Service State College PA
1048 AM EDT Thu Oct 26 2017

.SYNOPSIS...
Seasonably cool and mainly dry weather will prevail in Central
Pennsylvania through Friday, followed by a brief spell of above
slightly normal temperatures on Saturday. A strong and rather
slow-moving cold front will bring a widespread soaking rainfall
Saturday night into early Monday as a wave with tropical origin
races north along the frontal boundary. Near to below average
temperatures and dry conditions will close out the month.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...
Many breaks in the strato cu (and some other overlying cloud
decks) now, with biggest breaks in the SE and SW. Slight SE
winds at cloud levels will take some of it that way, but lots
should dissipate slowly in place. Tough sky cover grids today.
Have removed mentions of precip from the east, despite radar
echoes there as it would have 8-10kft to drop through to make it
to the ground.

Prev...
Extensive stratocu will continue to cover much of central PA
through this morning, thanks to slow moving and sharp upper
trough tracking east across the Central Appalachians.

The wind and clouds factor into the mins early today, keeping
mins a deg or two on the warm side of model blend guidance over
most of the area.

The Deepest moisture remains well east of the region today.
However, there still may be just enough local upslope and
dynamic lift via a few weak bands of FGEN forcing to produce
light isolated light showers over the region this morning.

Boundary layer temps may get just cold enough for some flurries
to mix in at the very highest of elevations, especially in any
brief periods of heavier precip.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM FRIDAY/...
Ridging at the surface and aloft will follow with clear to
partly cloudy skies for later tonight and Friday after the llvl
flow from the Glakes gets cutoff via passage of the 850 mb
ridge axis and boundary layer flow backing from WNW to southwest
then south.

Painted in areas of frost across the entire region for late
tonight and early Friday morning (and collaborated with WFOs LWX
and PHI to our south and east to arrive at a Frost Advisory
across much of the central counties and Susq Valley, where there
has yet to be a widespread freeze).

Elsewhere min temps will be quite uniform and generally in the
low-mid 30s as periods of high clouds spread in from the west
and thicken-up at times across the typically colder NW mtns and
Laurel Highlands.

A Surface ridge will build east across the region early Friday
before reaching the Mid Atlantic Coast Friday afternoon. Expect
dry and slightly milder weather Friday with variable
amounts/thickness of primarily high clouds.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A strong frontal system will bring widespread, soaking rainfall
to central PA - focused during the second half of this weekend
across much of central and eastern PA.

Strong dynamics aloft along with slightly above normal PWATs
across the eastern half of our CWA (and even possible
incorporation of tropical moisture/low pressure racing north
along the front) will support a risk for heavy rainfall.

The models are in decent agreement in principle for a
significant system to affect the area, with differences
centering around timing and complex surface low
evolution/intensification near the Mid Atlantic coast.

Will continue employing a blended approach of WPC/NBM QPF along
with the QPF of individual operational Models - NAM/GFS and EC.
This broad average provides us with a reasonable starting point
for storm total rainfall amounts ending early Monday, with a
large area of of 1-2 inches of rain occurring from Saturday
night through Sunday night (00z Sunday- 12z Monday) with locally
higher amounts of 2.5 to 3 inches likely near and to the east
of the Susq's Mainstem.

The parent upper trough is fcst to go negative tilt Sunday
night into early Monday with the core pivoting over the area.
Colder air wrapping into the backside of the system could
support a rain/wet snow mix developing over the Alleghenies
especially at the highest elevations.

A second area to keep a close eye on for up to a few inches of
slushy late night snow accumulation will be over the higher
terrain of Schuylkill, Columbia, Sullivan and Tioga counties.

Precip focus will shift downwind of the Great Lakes early next
week, supported by a chilly mean cyclonic flow. West- southwest
low level wind trajectories favor the highest POPs along the
Lake Erie shoreline from extreme northwest PA into southwest NY.
After a wet and chilly end to the weekend, look for seasonably
cool and dry weather to close out the month for Halloween.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Most of the area still has a stratocu deck, but big breaks have
developed. The strato cu will lose more coverage as there is
some heating as well as a downslope in the east. Mid clouds
floating around, too, on the back side of a deepening low
offshore. Conditions improve later this afternoon, as weak high
pressure builds eastward.

Outlook...
Still some mix of clouds across the area.
Fri...VFR/no sig wx.

Sat...VFR.

Sat PM-Sun PM...Becoming MVFR/IFR in RA/low cigs. LLWS
possible.

Mon...MVFR cigs, mainly NW half.

&&

.CLIMATE...
Through 10/24/17, the average monthly temperature at Harrisburg
is 63.4F (+8.1F) and 61.4F (+8.6F) at Williamsport. If the
month were to end, these values would top 2007 and rank as the
warmest October on record. The daily running mean ranks #2
warmest at both sites.

Seasonably colder, near-to-below average temperatures are
forecast through the end of the month. This should result in a
drop from the current rankings but still retain a spot in the
top 10 warmest Octobers.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from midnight tonight to 9 AM EDT Friday for
PAZ026>028-035-036-045-046-049>053-056>059-063>066.

&&

SYNOPSIS...Lambert
NEAR TERM...Dangelo/Lambert
SHORT TERM...Dangelo/Lambert
LONG TERM...Lambert/Gartner/Steinbugl
AVIATION...Martin
CLIMATE...

Hazardous Weather Outlook
National Weather Service State College PA
951 AM EDT Thu Oct 26 2017

PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-271400-
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Somerset-Bedford-Tioga-
Northern Lycoming-Sullivan-
951 AM EDT Thu Oct 26 2017

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Moderate to heavy rain is expected to occur late Saturday into
Sunday night. Minor flooding of small streams and creeks is
possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

PAZ026>028-035-036-045-046-049>053-056>059-063>066-271400-
Huntingdon-Mifflin-Juniata-Fulton-Franklin-Southern Clinton-
Southern Lycoming-Union-Snyder-Montour-Northumberland-Columbia-Perry-
Dauphin-Schuylkill-Lebanon-Cumberland-Adams-York-Lancaster-
951 AM EDT Thu Oct 26 2017

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM EDT
FRIDAY...

This Hazardous Weather Outlook is for central Pennsylvania.

.DAY ONE...Today and Tonight.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Frost Advisory.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

Please listen to NOAA Weather Radio or go to
weather.gov/StateCollege on the internet for more
information about the following hazards.

   Frost Advisory.

Moderate to heavy rain is expected to occur late Saturday into
Sunday night. Minor flooding of small streams and creeks is
possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.