textproduct: State College

WHAT HAS CHANGED

* Increased sky cover and trimmed dewpoints for rest of today * Added chance of heavy rain for Sunday in level 2/4 WPC ERO

KEY MESSAGES

1) Comfortable and dry to end July 2) Rain most likely Sunday with increased risk of flooding downpours

DISCUSSION

KEY MESSAGE 1: Comfortable and dry to end July Refreshing northerly breeze and uptick in daytime stratocu providing another Fall-ish type day for late July across CPA. Still can't rule out a brief and negligible shower/sprinkle rotating around the backside of the departing upper level low across the eastern periphery of the CWA; however the majority of the area will hold onto dry weather to close out the month.

Clearing skies expected tonight with decreasing wind as high pressure slides eastward from the Ohio Valley. Areas of fog are likely to develop in the valleys across the west-central Alleghenies with min temps in the 50-60F range into early Friday morning. Comfortably warm and dry end to July on Friday with a mix of sun and clouds and max temps in the low to mid 80s.

KEY MESSAGE 2: Rain most likely Sunday with increased risk of flooding downpours

An axis of anomalous PW ~1.5" along and ahead of an approaching cold front combined with favorable upper dynamics should support active convection reaching CPA as early as late Saturday night with max POPs centered on the 24hr Sunday window. With some potential for training in the moist low level SW flow parallel to the front and increased vulnerability given recent very heavy rainfall, WPC introduced a level 2/4 excessive rain outlook (ERO) that covers much of north central PA. Exact timing and placement of max QPF remains a bit unclear as there is still some model differences regarding the evolution of the upper trough.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

Widespread VFR conditions across all of central Pennsylvania this evening with the main concern for the 00Z TAF package being the potential for some valley fog, especially across the northern half of the forecast area and some potential for fog across southeastern Pennsylvania. Overall, fog potential at BFD/IPT/UNV looks to be relatively low with the bulk of fog being confined to the valleys close to these airfields. If using a persistence-based forecast for BFD, fog looks less likely than last night which is another reason for leaning against no fog mentions overnight. Thus, moderate confidence (50-60%) in no fog overnight at the airfields, but cannot rule it out 100% between 09-12Z Friday. Some potential also exists at LNS but continued to lean against sub-VFR conditions given the potential for light winds and clouds lingering on slightly longer this evening.

Outlook...

Sat...Mainly VFR early with increasing chances of SHRA/TSRA later in the evening hours. Restrictions possible.

Sun...More widespread SHRA with PM TSRA possible, increased chances of restrictions in heavier SHRA/TSRA.

Mon...AM SHRA with PM TSRA possible. Restrictions possible, especially SE where chances for SHRA/TSRA are higher.

Tue...Upper-lvl low over the Ohio Valley may bring SHRA/TSRA with possible restrictions to the Commonwealth, though lower confidence in SHRA/TSRA compared to previous days.

CLIMATE

Here are a few key callouts to wrap up the month of July:

6th wettest at Altoona 2nd wettest at Bradford 10th wettest at State College

6th most # of days with maxT >=100F at Harrisburg (3) T3rd most# of days with maxT >=100F at Williamsport (2)

CTP WATCHES/WARNINGS/ADVISORIES

None.