textproduct: State College

WHAT HAS CHANGED

* Lowered maximum temperatures Friday, Saturday, and Sunday * Lowered minimum temperatures tonight and added patchy frost over the northern tier * Removed chance of thunderstorms Friday and Saturday

KEY MESSAGES

1) Noticeably cooler into Memorial Day weekend with record challenging low maximum temperatures Saturday

2) Widespread soaking to beneficial rain dampers outdoor plans and activities to start Memorial Day weekend

DISCUSSION

KEY MESSAGE 1: Noticeably cooler into Memorial Day weekend with record challenging low maximum temperatures Saturday

Expect at least partial clearing over the northern tier tonight as seasonably strong 1030mb (+2-3SD MSLP) high pressure dome migrates eastward from the Upper Great Lakes. Undercut min temps by a few degrees with patchy frost potential near the NY border.

Model data shows the anomalous high pressure channeling southward down the east side of the Appalachians, setting up a classic cool wedge/cold air damming (CAD) pattern into Memorial Day weekend. We continue to reiterate a bearish outlook for daytime temps Fri-Sun with record challenging low maxes on the table for Saturday (see climate section below). Steady rain/drizzle and very chilly east/southeast wind will make it feel downright dreary/raw and pretty miserable for this time of year especially for outdoor activities Friday afternoon through Sunday morning. The 2-3 day cool stretch will certainly be noticeable following an early summerlike surge, but won't have staying power with temperatures forecast to moderate and trend above normal into the middle of next week.

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KEY MESSAGE 2: Widespread soaking/beneficial rain dampers outdoor plans and activities to start Memorial Day weekend

Light rain near/southeast of I-81 this afternoon will gradually sink to the south into the evening, setting up a lull in precip tonight into early Friday morning. Low clouds will continue to blanket south central PA.

Rain will gradually spread northward Friday afternoon through Friday night with Saturday looking like a total washout at this point. Expect widespread 1-2" rainfall totals which will be very beneficial for D1-D2 drought areas in the far southern tier into the LSV. Precip pattern transition from steady rain/drizzle to more of a showery/low chance thunder regime for 2H of the holiday weekend Sunday into Monday.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

As of early evening, most of the rain now south of PA. Overall we will have rather good conditions for aviation this evening, especially across the north. The north is rather clear, but with a slight breeze, did not fcst fog at BFD.

Conditions will lower later tonight into Friday aft. I went slower with the decrease in conditions, given that the airmass is rather dry and the sun angle is high now.

Once conditions lower later on Friday, wet weather and poor conditions will set in through at least early Sunday.

Lets hope things improve later Sunday into Memorial Day, given that is one of the big weekends of the summer season.

Outlook...

Fri...Restrictions likely with rain moving in from south to north, lasting into Fri night.

Sat-Tue...Restrictions likely with rain.

CLIMATE

Daily Record Low Maximum Temperatures for May 23:

Harrisburg54 in 1982 Williamsport57 in 1982 Altoona52 in 2005 Bradford45 in 1963 State College53 in 1968

CTP WATCHES/WARNINGS/ADVISORIES

None.