Marine Weather and Tide Forecast for Refton, PA

NEAR TERM /THROUGH TONIGHT/
Early this morning, a near-record cold blob of air aloft is centered over Virginia as a lobe of the Polar Vortex rotates through the Mid-Atlantic. At the surface, record cold temperatures extend from Tennessee to Florida where Freeze Warnings are in effect. Closer to home, temperatures at daybreak will range from the upper teens across the typical cool spots to near 30 toward Harrisburg. Gusty westerly winds are making it feel like the single digits or teens across much of the area - so bundle up if you have to head out this morning.

Northwest flow in the wake of a strong low that tracked across the Great Lakes will continue to bring lake effect/upslope snow showers to Central PA today. No changes to the Lake Effect Snow Warning/Winter Weather Advisories. Snow showers with a Lake Huron connection oriented NW to SE will slowly shift to a more W to E alignment today as winds turn counter clockwise thanks to the retreating low pressure center. With such cold temperatures aloft, strong snow showers/squalls will remain possible through the day and we could even see a few showers make it into southeast PA.

The Snow Squall Parameter lights up impressively along and north of I-80 this afternoon, so scattered to numerous squalls seem like a good bet. As is typical in this westerly flow regime in the cold season, cloudy skies will persist along/west/north of I-99 & I-80 while downsloping east of the Allegheny Front should support some breaks in the clouds farther southeast. Air temperatures increasing to above freezing this afternoon across southeast PA will help mitigate the risk for flash freeze conditions there, but the risk will be maximized along and north of I-80. Motorists should delay travel or exit the highway when a snow squall warning is issued.

With high pressure over the southeast US and the retreating low over New England, a tightening pressure gradient will support gusty winds this afternoon, especially east of the tallest ridges in the Alleghenies. A Wind Advisory is in effect from 7AM to 3PM from Somerset and Bedford Counties up the spine of the Alleghenies to Clearfield and Northern Centre. Here we expect gusts to 45 or 50mph, which could knock down some branches or trees and make it difficult for high-profile vehicles.

Southwest winds and a quick upper level disturbance bringing clouds overhead tonight mean slightly milder temperatures. We'll see precipitation continue north of I-80 with perhaps a bit more rain mixing in with snow. A coating to a half inch of additional snow is possible in the typical higher elevations west of the Allegheny Front.

SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/
Wednesday looks similar to Tuesday, though just a bit warmer. A tight pressure gradient will allow for winds gusts in the 30 to 35 mph range Wednesday, with some guidance suggesting the potential for gusts over the Laurel Highlands to approach 40 to 45 mph. A Wind Advisory will likely be needed, though perhaps not extending as far north.

Winds aloft will be more zonal, helping steer lake effect showers (rain/snow mix) mainly north of I-80 on Wednesday. Warm advection will keep temperatures trending up, with highs ranging from the middle 30s in the northern tier to low 50s in the southeast. Gusty winds will still pack a punch, but won't feel quite as chilling when the temperatures are noticeably warmer.

LONG TERM /THURSDAY THROUGH MONDAY/
Upper-level troughing will remain in place through the end of the week, keeping the chance for rain and snow showers in the forecast each day through Thursday, especially over northwest PA. Clouds will persist in the northwest, while a mix of sun and clouds is more of the norm in the southeast.

The December-like cold airmass is forecast to retreat later in the week, with temperatures returning closer to seasonal averages. High pressure looks build in from the southwest Friday into early Sunday, which should keep us mainly dry into the beginning of the weekend.

Another northern stream upper shortwave traversing the Northern Plains will reach the Great Lakes early in the weekend and support a low pressure/frontal system that will move across PA Sunday into next Monday. At this point, this system appears to be not as strong or as cold as our current one, so any precip looks to be mainly in the form of rain/rain showers.

AVIATION /09Z TUESDAY THROUGH SATURDAY/
Low-level flow will gain more of a westerly component overnight and will direct heavy lake effect snow bands into Central PA.
Several bands of lake effect snow have already caused reductions in visibility over central PA. UNV has dropped to less than 2 miles as a consistent band remains over that terminal. Within the next couple of hours more upslope snow showers at JST and AOO are anticipated.

Expect IFR/LIFR conditions at BFD for much of the night, while JST likely remains MVFR with brief periods of IFR possible. Most guidance indicates the potential for some of the heavier snowbands to make it all the way down to UNV and IPT by early morning. MDT and LNS will likely remain VFR through the TAF period, though there is around a 15 percent chance of a few snow showers making it that far southeast. Snow lifts north of JST and AOO by mid- morning, but snow will continue at BFD into the afternoon.

Strong winds a few thousand feet above the surface should mix down fairly easily tonight and during the day on Tuesday, with gusts of 25 to 35 knots expected at all TAF sites. VFR conditions may briefly return area-wide late in the TAF period with just a few lingering snow showers near BFD. Snow chances increase again Tuesday night into Wednesday morning.

Outlook...
Wed-Thu...Rain and snow showers over northwest PA along with gusty winds.

Fri...Improvement expected, with winds diminishing and lingering -SHSN across NW PA diminishing as well.

Sat...Dry, generally VFR.

CTP WATCHES/WARNINGS/ADVISORIES
Lake Effect Snow Warning until 1 PM EST this afternoon for PAZ004.
Winter Weather Advisory until 1 PM EST this afternoon for PAZ005-010.
Wind Advisory until 3 PM EST this afternoon for PAZ017-018-024- 025-033-034.