textproduct: State College

WHAT HAS CHANGED

* A bit faster on the ending time of the steady rain late today and tonight.

KEY MESSAGES

1) Noticeably cooler start the last weekend of April with rain/drizzle today into tonight before ending early Sunday.

2) More seasonable/cooler end to what has been one of the warmest April's to date; much below normal temperatures possible to start May along with renewed frost/freeze risk.

DISCUSSION

KEY MESSAGE 1: Noticeably cooler start the last weekend of April with periods of rain/drizzle into tonight before ending early Sunday.

Back edge of the steady rain over western PA as of early aft. Radar trends and models support this area to keep moving along, with little if anything left late tonight. This rain into the southeast part PA now, will help with edging off the real dry conditions some.

Sunday should feature some sun later on, but cooler than normal temperatures for late April.

Clear/calm conditions with very low pwats associated with high pressure migrating over the area may result in a frost risk across some parts of the north Sunday night into early Monday morning.

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KEY MESSAGE 2: More seasonable/cooler end to what has been one of the warmest April's to date; much below normal temperatures to start May along with renewed frost/freeze risk.

Most sites are tracking top 5-10 warmest April-to-date. The much above normal to near-record warmth over the past 3-4 weeks is expected to fizzle out through month-end with increasing confidence in below normal temperatures into early May. This late Spring setback will also feature a renewed frost/freeze risk for a growing season that started weeks in advance of the climatological/historical average.

Monday will feature the best day to dry out for outside work, and temperatures near normal.

More wet conditions for later Tuesday into Wednesday, as the next frontal system moves in. Things dry out for later in the week, but temperatures will be well below normal. Frost and even freeze potential for the north if not central zones.

Models show signal well out into longer time frames to cutoff an upper level low over or nearby the lower Great Lakes area, keeping the colder than normal temperatures over the area.

This would also support frequent chances for rain, especially across the east and south now.

AVIATION /00Z SUNDAY THROUGH THURSDAY/

A low pressure system moving across the Mid-Atlantic will maintain IFR ceilings/visibilities across the region through 12Z Sunday, with steady rain diminishing to light rain & drizzle later this evening. Pockets of LIFR driven by low clouds are expected to develop across the Northern Tier (KBFD) and along the Allegheny Mountains (KJST/KAOO/KUNV) later this evening.

The steadier rain currently being observed across Central PA will move east of the region by 06Z as low pressure moves offshore, though low-level easterly winds from the low over DelMarVa will keep drizzle and low clouds in place through 12Z Sunday.

After 12Z Sunday, as the low pressure moves farther offshore, high pressure over Southern Canada will nose into the region and shift winds to be more northwesterly, ultimately bringing in drier continental air from the northwest. Regionwide improvements to MVFR are expected between 15Z-17Z Sunday, with improvements to VFR being likely (80% chance) after 18Z-19Z Sunday.

Outlook...

Mon...VFR likely.

Tue...VFR early, with restrictions west to east as ceilings lower and showers move in.

Wed...Restrictions likely with rain expected regionwide.

Thu...VFR/MVFR favored as rain ends west to east.

CTP WATCHES/WARNINGS/ADVISORIES

None.