textproduct: State College

SYNOPSIS

* Bands of Lake Effect and upslope snow across the Northern and Western Mountains of PA will bring another 1 to 2 inches of snow today and tonight, with locally higher amounts of 3 to 4 inches. * Arctic blast with locally heavy lake effect and upslope snow across western PA Sunday and Sunday night. * The wind will be gusty, leading to potentially dangerous wind chills when combined with the cold air Sunday. * A period of milder conditions is expected for the middle of the week ahead, before colder conditions for late week.

NEAR TERM /UNTIL 6 PM THIS EVENING/

A strong upper level trough will drift over the region today with strong low level cold advection and increasing winds.

Weather and POP grids similar to earlier fcst. Wind gusts to around 40 mph likely over the higher elevations. Temperatures today will be similar to the last few events, where daytime temperatures will not change much.

High temps Sunday will drop by 10-20 degrees vs. Saturday with mean departures from climo on the order of 15 to 25 degrees. A few locations could see highs close to the daily record low max. Across the higher spots in Cambria and Somerset County and perhaps isolated spots elsewhere across the higher elevations, A Cold Weather Advisory is in place.

The low DGZ will reside in the 1-4 KFT above ground layer today and tonight, which will lead to plenty of flurries across the Central Ridge and Valley region of the state. Narrow bands of LES briefly drop vsbys to under 1/2SM today.

SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/

Very cold air for this time of year with variables amount of clouds and some flurries/brief LES bands impacting the Central Ridge and Valley region of the state.

More persistent lake effect/upslope snow showers continue for tonight into Monday, mainly across Northern Mckean and Warren Counties. A weak system passing to the north will bring a thickening clouds and few more snow showers to the area later Monday.

High Temps on Monday will moderate by 2-6 deg F in all locations.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

A large scale pattern shift will support a west to southwest flow of milder air into the area by later Tuesday into Thursday. Some spots will have readings in the 40s.

A cold front by Friday will edge things back down some, but not the really cold that has been typical this month so far. The month has been nearly 10 degrees colder than normal up to this point, which is nearly half of December.

Always need to watch the precipitation type and timing with such a pattern. Weather systems will moving at a fast clip.

AVIATION /12Z SUNDAY THROUGH THURSDAY/

The back edge of the steady light to moderate snowfall is through MDT as of 0915z. Expect vsby at LNS to remain between 1/2SM and 2SM thru 11-12z before the back edge moves through. Elsewhere to the north and west, vsby is generally 5sm or better in light snow, except for IFR vsby at JST with upslope -SN and brief drops in vsby elsewhere in light lake effect streamer bands.

Lake effect snow bands will ramp up in intensity this afternoon. That could put the usual sites of BFD and JST back down to L/IFR for brief times later today and through at least 02-06z tonight before a subsidence inversion decreases the LES threat.

Much of the area will see MVFR/VFR cigs much of today and tonight. Winds will be gusty out of the WNW with peak gusts 25-35 kt.

Outlook...

Mon...IFR to MVFR w/SCT SHSN N (BFD), --SN poss elsewhere.

Tue-Wed...No sig wx.

Thu...Widespread rain reducing conditions to IFR. May end as a brief period of snow in the west.

CLIMATE

Astronomical winter (solstice) begins at 10:03 a.m. on Sunday, December 21st.

CTP WATCHES/WARNINGS/ADVISORIES

Lake Effect Snow Warning until 7 AM EST Monday for PAZ004-005. Winter Weather Advisory until 7 AM EST Monday for PAZ010-017- 024-033. Cold Weather Advisory from 1 AM to 9 AM EST Monday for PAZ024. Cold Weather Advisory until 9 AM EST Monday for PAZ033. Winter Weather Advisory until 8 AM EST this morning for PAZ053- 057>059-064>066.