textproduct: State College

WHAT HAS CHANGED

* Freeze Warning for late tonight into Wednesday morning * Freeze Watch continues for Wednesday night into Thursday morning

KEY MESSAGES

1) Brief surge of cold air with moderately gusty west northwest winds today followed by Freeze headlines tonight and again for Wednesday night

2) Warming trend ramps up into late week with low humidity and little to no precipitation forecast through the upcoming weekend

DISCUSSION

KEY MESSAGE 1: Brief surge of cold air with moderately gusty west northwest winds today followed by Freeze headlines tonight and again for Wednesday night

Vertical mixing up to 4-5 KFT AGL will continue to erode the shallow strato cu across all of the region, except for the NW Mtns of PA, where just enough llvl moisture off the Glakes, Orographic lift and slightly colder air aloft will help to maintain bkn cigs with some brief snow showers along the PA/NY border.

Clouds there will diminish during the late afternoon hours.

In the wind category, a tight pressure gradient between compact sfc low exiting the New England coast and 1036mb high migrating eastward across the Ohio Valley will result in breezy conditions with wind gusts 25-35 mph. Today will likely be one of/if not the coldest days until Fall with max (wind- chilled) apparent temps between 20-40 degrees from NW to SE.

Favorable radiational cooling under the strong anticyclone with PWATS less than 0.4 of an inch across the entire CWA will help foster one of/if not the coldest nights until Fall with min temps ranging from the mid teens to mid 20s.

Freeze warnings are in effect for late tonight through the mid morning hours Wed for the recently activated/early onset growing season counties based on a very warm March-early April period and GDD tracking indices. A Freeze Watch remains in effect for Wednesday night with fcst min temps closer to/but still below the freezing mark.

KEY MESSAGE 2: Warming trend ramps up into late week with low humidity and little to no precipitation forecast through the upcoming weekend

An increasingly milder southwest flow will transport warmer air back into CPA by the second half of the week through the upcoming weekend. A pair of weak cold fronts bring minimal rain chances with dry conditions expected most of the time. The overall lack of rain won't help improve drought conditions across the southeast part of the forecast area and may also bring an uptick in wildfire risk.

AVIATION /14Z TUESDAY THROUGH SATURDAY/

Aside from a few more hours of varying high end MVFR CIGS and low end VFR bkn-ovc cigs INVOF KBFD, conditions will be VFR.

West-Northwesterly winds will continue to blow at speeds of 15-20 kts with gusts to around 25 kts expected.

Very high confidence (>95%) in VFR across all terminals (including KBFD) after 21Z as the shortwave and colder air aloft moves off the New England coast and high pressure build east from the Ohio Valley.

After 06Z, the LAMP highlights a low chance (20%) of visibility restrictions at KBFD/KJST as the high pressure moves overhead, with clearing skies and diminishing winds hinting at favorable conditions for radiational fog. At this time, visibilities were kept at P6SM during this timeframe given the low probabilities, but this possibility will continue to be monitored.

Outlook...

Wed-Thu...VFR.

Fri...Chance of rain showers especially in the western airspace.

Sat...Restrictions poss early N/W, then trending VFR.

CTP WATCHES/WARNINGS/ADVISORIES

Freeze Warning from midnight tonight to 9 AM EDT Wednesday for PAZ026>028-035-036-049>052-056-057-059-063>066. Freeze Watch from late Wednesday night through Thursday morning for PAZ026>028-035-036-049>052-056-057-059-063>066.