textproduct: State College

WHAT HAS CHANGED

* Added more details about Wednesday's severe threat.

KEY MESSAGES

1) Spring-like weather continues through Wednesday with temperatures approaching record warmth Tuesday & Wednesday.

2) A strong cold front accompanying a potent upper trough will bring showers and thunderstorms Wed followed by rain/snow showers, gusty winds, and sharply colder temperatures into Thursday.

3) Settling into a cooler pattern for the end of the week and weekend.

DISCUSSION

KEY MESSAGE 1: Spring-like weather continues through Wednesday with temperatures approaching record warmth Tuesday & Wednesday.

High pressure gave the region a nice early Spring day, with highs just a few degrees below record levels. Many of the records today were set in 2016. As noted yesterday, March 2012 featured very warm temperatures. Temperatures came up over 40 degrees in many locations from overnight lows.

Very dry air in place early could result in some spots dropping quickly off to 5 to 10 degrees lower from nearby areas early tonight. Dewpoints fcst to climb late, will monitor, have spot fcst to go out Tuesday morning.

Earlier discussion below.

As heights continue to build over the eastern U.S. Tue-Wed, temps in central PA may challenge daily records as they surge +20-30 degrees above the historical average. With highs in the upper 60s-70s and lows in the 50s (Tue night), it will feel more like an average day in mid May than mid March. See the climate section for more information on possible records. A few isolated to scattered light showers are possible on Tuesday, with enough cold air aloft to create lift despite the big dome of high pressure.

KEY MESSAGE 2: A strong cold front accompanying a potent upper trough will bring showers and thunderstorms Wed followed by rain/snow showers, gusty winds, and sharply colder temperatures into Thursday.

Will continue to monitor SPC outlooks, minor shifts from day to day so far for Wed. Thermal ridge gets east of the area later in the day, not the best for central PA. Also timing of the cold front will be a big factor.

Earlier discussion below.

A cold front will sweep through Wednesday night into Thursday, as an upper trough approaches the region. The SPC Day 3 (Wednesday) Slight Risk area includes much of central PA south of I-80 and west of the Susq River. There is still considerable uncertainty regarding the extent to which destabilization can occur on Wed, especially with quite a bit of cloud cover in the forecast. Nonetheless, with winds of 40-50 kts in the lowest 3km of the atmosphere, it wouldn't take much to bring some damaging winds down the ground. In contrast with the system over the weekend, there will be more shower activity during the day on Wednesday (limits instability) and a much warmer & more moist airmass in place before storms arrive (more favorable for storms). The net result may be something comparable to last weekend, though the likelihood of strong storms across Central and Eastern PA is a bit higher overall.

As the base of the trough and associated surface cold front cross PA, a sharp temperature drop in the wake of the cold front may result in any lingering postfrontal precip changing over to snow Wed night into Thu. Temperatures ahead of the front will remain in the 60s to near 70F Wednesday night and will drop into the 25-45F range by Thursday morning. Gusty winds will also accompany the system, with gusty southwest winds ahead of it and brisk northwest winds behind it. A strong pressure gradient may result in the need for a Wind Advisory Thursday afternoon.

KEY MESSAGE 3: Settling into a seasonably cooler pattern for the end of the week and weekend.

Trending toward the longwave pattern that we saw most of the winter. Regardless of this, weather systems will be moving fast so a lot of day to day variation likely.

Earlier discussion below.

Periodic shortwaves in the prevailing upper level pattern will lead to chances for precipitation every few days from this weekend into early next week. At this point, the storm track favors the primary corridor of precipitation passing north of the area. With overnight lows within a few degrees of the freezing mark forecasted, precipitation type will be largely dependent on what time of day it moves through. But as of this time, no significant systems or appreciable precipitation are expected.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

Abundant sunshine in place across the Commonwealth today with picture-perfect flying conditions. Southwest winds will continue to gust to 15-25 kts this afternoon across the higher terrain.

Clouds will increase late tonight across western PA ahead of our next system. Lowering ceilings are likely areawide through Thursday, with restrictions expected at BFD (MVFR to IFR) and JST (MVFR) and possible at AOO, UNV, and IPT. Despite an isolated chance of a shower, dry weather should prevail for most of the day and for most locations.

Outlook...

Tue...Cigs becoming MVFR over NW PA; otherwise predominantly VFR. Scattered showers possible N/W later in the day.

Tue night...Patchy fog possible

Wed-Wed night...Restrictions likely in more numerous showers and some thunder.

Thu-Fri...Windy and colder. Scattered rain and snow showers with restrictions possible.

CLIMATE

Near-record warmth is expected Tuesday into Wednesday across Pennsylvania with highs in the 60s & 70s and lows in the 50s.

RECORD TEMPERATURES TUE 3/10 WED 3/11 MAX T MIN T MAX T Altoona 72 (1986) 49 (1990) 74 (2025) Bradford 66 (1986) 49 (2021) 66 (2025) Harrisburg 79 (2016) 49 (1955) 76 (2021) State College 76 (2016) 52 (2016) 72 (1986) Williamsport 71 (1977) 50 (1898) 75 (2025)

CTP WATCHES/WARNINGS/ADVISORIES

None.