textproduct: State College

WHAT HAS CHANGED

* Severe weather outlook area shifted a bit eastward for Saturday afternoon/evening; Slight risk now along and west of I-99 and Marginal risk extends across nearly the entire CWA

KEY MESSAGES

1) Boom and gloom conditions precede the first severe thunderstorm risk of 2026 on Saturday afternoon/evening

2) Significant Springtime warming Saturday through Wednesday followed by seasonal moderation/cool down into mid-March

DISCUSSION

KEY MESSAGE 1: Boom and gloom conditions precede the first severe T-storm risk of 2026 on Saturday afternoon/evening

Clouds are slowly but surely thinning out east of I-99 and US-15 this afternoon, with plentiful sunshine and pleasant temperatures farther west. The boom refers to temperatures soaring into the mid 60s to low 70s across western PA where southwesterly flow has eroded away at the cloud cover and given a glimpse of spring. Meanwhile, low clouds, some patchy fog, and scattered rain showers farther east are much more "gloom", with temperatures stuck in the low to mid 40s. The 24-hr max temp for Saturday will likely be reached shortly before 12AM Sunday in the eastern zones.

The first severe T-storm risk for CPA in 2026 still on track for Saturday afternoon and evening. The primary threat area and greatest risk (level 2 out of 5) will be focused from the Upper Ohio Valley into western PA with the eastern extent along the I-99 corridor. The likelihood of increasing stability to the east of the mtns will greatly reduce the severe storm risk across the central and especially eastern portions of the fcst area, though a Marginal Risk is in place there. A few morning showers and storms will move across south central PA before more substantial clearing builds in from the west. A linear convective mode is favored with a potential line of strong to severe storms capable of damaging winds tracking eastward from Ohio into western PA late in the afternoon or evening.

The kinematic profile looks impressive for Pennsylvania standards tomorrow, with steep mid-level lapse rates, elongated right turning hodographs with 250-350 m2/s2 0-3km SRH, and 50kts of deep-layer shear. The limiting factor, as usual, will be thermodynamics thanks to the persistent cold wedge that will be slow to erode tomorrow. A stronger surface inversion with eastward extent means convection will tend to become elevated as it moves into the eastern PA and that should limit the ability for damaging winds to mix down the surface. Sufficient MLCAPE on the order of 1000-1500J/kg along and west of the I-99/US-15 corridor will support the best chance for damaging winds (and perhaps some hail or a tornado). The strength of storms as they move east of I-99 will be dependent on time of day and degree of clearing ahead of the line of storms. If storms are slower to arrive and clearing occurs farther east than expected, the risk of severe weather could expand.

KEY MESSAGE 2: Significant Springtime warming Sunday through Wednesday followed by seasonal moderation/cool down into mid- March

Cool wedge pattern finally breaks down and allows for a significant springtime warming from Sunday into the middle of next week. Frontal showers exit the area Sunday morning with rain-free conditions likely holding into Tuesday. Dry and breezy conditions on Monday could lead to the first elevated risk of rapid wildfire spread for the year, especially across southeast PA where less rain is expected over the next 36 hours. Southwest flow builds by Tuesday, with a surge in temperatures and dewpoints anticipated. April to May- like max/min temps fcst +20-30 degrees above the historical average will challenge daily records in some areas Tue/Wed. Cold frontal passage Wed/Thu will bring some rain followed by a seasonable cool down for late in the week into mid-March.

AVIATION /00Z SATURDAY THROUGH WEDNESDAY/

As noted below, VFR conditions still across the far west as of early this evening. Low CIGS and fog across the area to the east already on the downward trend.

There could be a few showers, but mainly dry overnight.

For Saturday expect the far west to pick up a gusty southwest wind at sites like JST and BFD.

Further east at UNV and AOO, CIGS will likely edge up some but remain MVFR, while the visibilities come up.

The far eastern sites like IPT, MDT, and LNS will likely remain MVFR and IFR all day, as cold air remains near the ground.

The cold front is still a ways to the northwest at 00Z Sunday, so used VCTS across the west at sites like JST and BFD, where a storm could get into the area before 00Z and with the warmer airmass. Storms a bit less likely and later at sites like AOO and UNV.

Across the far east at sites like IPT, MDT, and LNS, the airmass will be cooler and more stable, thus storms less likely. Also the activity would be mainly later after 00Z.

Earlier discussion below.

Late afternoon update.

Adjusted TAFS for current obs and trends. Leading edge of the clearing and milder air just east of a BFD, FIG, JST line.

More information below.

Low level wind shear will become a concern on Saturday as a low level jet builds across northwest PA. Periods of rain are possible in the morning before a more robust line of showers and storms moves across the region in the afternoon and evening. Visibility restrictions from storms should be relatively brief (on the order of 20 to 40 minutes).

Outlook...

Sun...Trending towards VFR.

Mon...Restrictions possible as low-level moisture increases.

Tue...Restrictions possible in the morning due to low-level moisture. Showers later in the day.

Wed...Restrictions likely in showers.

CTP WATCHES/WARNINGS/ADVISORIES

None.