textproduct: State College

WHAT HAS CHANGED

No significant changes.

KEY MESSAGES

1) Periods of rain and breezy conditions from Isaias arrive tonight and continue through Sunday

2) Warmer and more humid next week with a couple rounds of rain showers possible Tuesday and again late in the week

DISCUSSION

KEY MESSAGE 1: Periods of rain and breezy conditions from Isaias arrive tonight and continue through Sunday

High to mid level clouds will continues to expand over CPA this evening into tonight. Rain associated with Isaias is projected to reach the Laurel Highlands/southern Alleghenies around midnight and gradually expand to the north/east across central PA into Sunday morning. Periods of rain continue Sunday morning/afternoon into Sunday night before tapering off by early Monday. There has been an uptick in QPF along with the probability of 2" of rain over parts of south central into southeast PA/Lower Susq Valley. Rain may be heavy at times, but aside from any isolated urban runoff issues, we believe there will not be any excessive rainfall issues across these areas. The recent dry spell will also provide a cushion. Total rainfall amounts are now projected between 0.50-2.00 over a 36-hr duration between 8PM tonight and 8AM Monday.

Post-tropical Isaias tracks from the TN Valley into WV early Sunday before curving east and exiting the Delmarva/NJ coast Monday morning. Expect gusty winds in the tightening pressure gradient between the post-tropical low and departing high in the Gulf of Maine. Max gusts in the 45-50 mph range are expected in the Laurel Highlands particularly along and to the westside of the highest ridgetops (downslope wind from the southeast). A Wind Advisory remains in effect for Cambria and Somerset counties.

KEY MESSAGE 2: Warmer and more humid next week with a couple rounds of rain showers possible Tuesday and again late in the week

Warmer and noticeably more humid to start next week. Max temps on Tuesday are forecast to peak 10-15 degrees above the historical average for mid October with highs in the 70-80F range. Improving weather conditions can be expected Monday as the remnants of Isaias exit the Mid Atlantic. Rain chances on Tuesday appear to be maximized over the northern tier where a shortwave aloft and sfc cold front (infused with moisture from TS Rachel?) streak eastward from the Great Lakes. Another period of rain is possible later next week, but there is low confidence in the timing of the front.

AVIATION /18Z SATURDAY THROUGH THURSDAY/

A nice afternoon with jsut some hi clouds will give way to lower CIGS and visibilities late tonight into Sunday, as the remnants of Isaias track northeast up the Ohio Valley and high pressure moves off the coast. This will set up a gusty southeast flow, wth LLWS across the far west at BFD and JST, where the wind fields will be a bit stronger.

A soaking rain will be in store for Sunday, resulting in IFR conditions. While a rumble of thunder could occur, rather cool temperatures are expected on Sunday, so more of an elevated storm environment.

Conditions improve some on Monday, but another frontal system for Tuesday likely to bring more showers and storms to the area with lower conditions again.

Outlook...

Mon...Partial clearing.

Tue...VFR favored, though a FROPA may bring restrictions in -SHRA. AM fog possible.

Wed...AM ceiling restrictions possible from post-frontal stratocu, with VFR otherwise favored. Slight chance of -SHRA due to lingering moisture behind front.

CTP WATCHES/WARNINGS/ADVISORIES

Wind Advisory from 8 PM this evening to 2 PM EDT Sunday for PAZ024-033.