textproduct: State College

WHAT HAS CHANGED

* Frost Advisory issued for the western Alleghenies late tonight into early Friday morning

KEY MESSAGES

1) Cool and unsettled pattern to end April and start May with shower chances and frost/freeze risk through the weekend

DISCUSSION

KEY MESSAGE 1: Cool and unsettled pattern to end April and start May with shower chances and frost/freeze risk through the weekend

Several disturbances rotating around a persistent upper level closed low centered over Ontario and Quebec will help to reinforce broadly deep troughing across the eastern U.S. through much of next week. This pattern will keep conditions cool and unsettled at times as multiple frontal systems move through. In addition to shower chances, the fronts will bring reinforcing surges of cool air, keeping temperatures near to below seasonal averages. Chilly nighttime lows will also lead to frost and freeze concerns Thursday-Saturday night, particularly now that the growing season is now active across all CPA zones.

Frost advisory issued for tonight is a somewhat lower confidence headline given the potential for clouds/breeze associated with a (less than ideal) the broad cyclonic mean flow. We took a measured approach and will allow dayshift to expand the advisory eastward as needed. A similar scenario unfolds Friday night with renewed potential for clouds/breeze to limit extent of frost. Frost/freeze potential remains highest Saturday night into Sunday morning with high pressure nosing in from the Tennessee Valley.

Bouts of showers appear most likely during the afternoon today and Friday followed by a general drying trend through the first weekend of May. NBM and AI models are signaling several opportunities for rain next week.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Two areas of showers will bring brief reductions to CIGS and VSBYS early today as a weak cold front pushes east across the Susquehanna Valley during the predawn hours and a mid/upper level cool pool approaches from the Ohio Valley. KIPT and KMDT will be the targets for a few showers very early this morning, while the best chance for showers and KBFD will be broader period from the mid morning through mid afternoon hours today.

As the transition to the deepening, cool NW flow occurs today, we'll see the typical lower conditions (IFR to low end MVFR) at KBFD and KJST while mainly MVFR CIGS and VFR Vsbys will be found at KAOO, KUNV and KIPT. IFR and MVFR conditions at KMDT and KLNS respectively at 06Z will gradually improve through MVFR this morning and reach VFR conditions between 15-17Z today as downsloping NW low-level flow of drier air lifts the cloud bases.

Winds will become moderately gusty (high teens to low 20s (KTS)) late this morning and this afternoon as high pressure builds east town the area in the wake of the departing low. Rain chances return for the midday and afternoon hours Friday.

Outlook...

Fri-Sat...Mainly VFR with brief restrictions possible in showers.

Sun...Restrictions possible northwest in -RA and possibly some -SN.

Mon... Models hinting at another low pressure wave to our west, precip may lead to restrictions, particularly in the west.

CLIMATE

*Daily record rainfall of 1.18 inches at KJST yesterday 4/29 breaking the previous record of 1.13 inches set back in 1964 *Despite a cool end to the month, April 2026 will end as one of the warmest on record

CTP WATCHES/WARNINGS/ADVISORIES

Frost Advisory from midnight tonight to 8 AM EDT Friday for PAZ004>006-010-011-017-024-033.