textproduct: State College

WHAT HAS CHANGED

* No sig changes.

KEY MESSAGES

1) Unseasonably mild through Friday with 2.5 weeks-long dry spell coming to an end overnight into Thursday

2) Trending cooler this weekend with lake enhanced rain showers beneath upper level low

DISCUSSION

KEY MESSAGE 1: Unseasonably mild through Friday with 2.5 weeks- long dry spell coming to an end late tonight into Thursday

Anomalous upper level ridging and south-southwest flow aloft will maintain unseasonably warm temperatures through late week. Max/Min temps will be 10 to 20 degrees above the historical average for the first week of November, but should fall short of daily record highs (see climate section).

A leading frontal band of light rain should reach the western Alleghenies by midnight and continue spreading eastward across central PA through Thursday morning. Fcst rainfall amounts are 0.25" inch or less through 00Z Fri in most areas and will end the 2.5 weeks-long dry spell.

The front slows/stalls near the I95 corridor Thursday night. A shortwave trough/closed H5 low dropping southeast from the Great Lakes is expected to reinvigorate precipitation along the nearly stationary frontal zone on Friday which could clip the far southeast zones/Lower Susquehanna Valley. Model trends have been shifting this rain farther to the east/closer to the coast over the past few cycles. A dry slot may keep most locations dry Thursday afternoon into Friday following the initial period of rain late tonight through Thursday morning.

KEY MESSAGE 2: Trending cooler this weekend with lake enhanced rain showers beneath upper level low

Seasonably cooler/breezy pattern to start the first full weekend of November. The passage of closed H5 low followed by mean cyclonic flow favors persistent clouds and periods of lake enhanced rain over the western and central Alleghenies on Saturday. We were keen to manually adjust max temps a few degrees lower on 11/7 to account for the cooler pattern shift which looks to continue into early next week.

AVIATION /00Z THURSDAY THROUGH MONDAY/

Several bands of showers over Ohio and far western PA early this evening, ahead of a cold front over northwest Ohio will slowly push to the east overnight. The airmass is not real moist and there is no instability, so the activity will continue to weaken.

For Thursday, most of the area will in a a dry slot, with the most likely area to have the showers continue to be over the far east, spots like IPT, MDT, and LNS. Far western locations such as BFD and JST will likely get some showers from the upper level low, but this will be on Friday vs. anything earlier.

Thus, for the overnight period and through early Thursday afternoon, I made very few changes, see below.

More information below.

Between 03Z and 06Z Thursday MVFR cigs and showers with periods of MVFR vsby are likely to arrive at BFD and JST, with widespread restrictions expected to expand from west to east through the remainder of the overnight. IFR ceilings are likely areawide along with LLWS given the presence of a 40-50kt 850mb LLJ.

Improvement is expected though the day on Thursday as rain pulls away from west to east and conditions trend toward MVFR and ultimately VFR for most airfields by late Thu afternoon.

Outlook...

Fri...Showers and cig restrictions becoming likely in the NW later in the day as a cold front approaches.

Sat...Cig restrictions expected for central and especially western airfields. Light rain showers, most numerous in the NW. Breezy W to NW flow.

Sun...Rain showers and MVFR cigs remain possible in the NW, with some improvement late.

Mon...Mostly VFR.

CLIMATE

Current Consecutive Days streak without measurable rain:

10/17 through 11/3 (18 days): Harrisburg, Williamsport, Altoona, State College

10/18 through 11/2 (17 days): Johnstown

Daily record highs for 11/4 and 11/5:

Harrisburg 78/1994 | 79/1975 Williamsport 75/2003 | 77/1994 Altoona 77/2003 | 77/2015 Bradford 74/2015 | 76/2024 State College 78/2003 | 75/2015

CTP WATCHES/WARNINGS/ADVISORIES

None.