textproduct: State College

WHAT HAS CHANGED

* Bumped up QPF in the southeast zones for Thursday

KEY MESSAGES

1) Scattered strong to severe thunderstorms possible Thursday PM, along with a potential period of very heavy rain in the Lower Susq Valley

2) Variable sky conditions for the lunar eclipse Thursday night

DISCUSSION

KEY MESSAGE 1: Scattered strong to severe thunderstorms possible Thursday PM, along with a potential period of very heavy rain in the Lower Susq Valley

Scattered thunderstorm development is expected Thursday afternoon ahead of a cold front across CPA. SPC expanded the level 2/5 severe t-storm risk southward to include the Lower Susquehanna Valley. WPC upgraded the ERO to level 2/4 for areas near and to the east of US-15. Short term model guidance continues to highlight the eastern 1/3 of CPA with the most favorable CAPE/shear profiles and highest pwats/slowest storm motions. A predominantly multicellular storm mode is expected with damaging winds the primary threat, however a few supercells may also be possible. Southwest flow along a southwest-northeast oriented slow moving cold front could yield multiple rounds of training convection in the southeast, with rainfall totals potentially topping 2 inches in spots. Higher FFGs could offset the flash flood risk in the eastern zones to some extent, with the most saturated soils and lowest FFG over the southwest quadrant of the CWA. Subsequent shifts will continue to evaluate the need for a flood watch in the southeast.

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KEY MESSAGE 2: Variable sky conditions for the lunar eclipse Thursday night

Forecast viewing conditions for the lunar eclipse range from fair to poor Thursday night across central PA. The eclipse will begin at 10:34 pm EDT and last for about 3 hours, ending at 1:52 am EDT Friday. The worst view is most likely over the eastern half of CPA due to exiting storms and associated cloud cover. The eclipse will take place during August's full moon, commonly referred to as the Sturgeon Moon. It will also be the last full moon of the summer with the next full moon set to rise a few nights after the autumnal (Fall) equinox on September 22nd.

A drying trend is forecast Friday through the last weekend of August, thanks to high pressure building into the area behind the cold front. This will likely setup a couple of foggy mornings. Rainfall looks fairly limited heading into the first week of September; however despite the start of meteorological Fall the summer is not over with temps expected to rise above the historical average into the 80-90 degree range.

AVIATION /18Z WEDNESDAY THROUGH MONDAY/

Some bands of mid level ACCAS clouds, as warm advection starts to set in.

While there could be an isolated shower later this afternoon along the higher terrain, went with a dry fcst for now.

Late tonight, potential for lower clouds across the east late. Used a TEMPO group for this.

Cold front moves into the northwest early Thursday aft. Dewpoints not fcst that high most of the area, thus think main chance for storms with strong winds and heavy rain across the far east later Thursday afternoon and evening. This would be after 18Z anyway, outside the new TAF package.

Clearing on Friday, looking like a dry weekend for a change with mainly VFR conditions.

Outlook...

Fri...Clearing, mainly VFR.

Sat-Mon...AM Fog; otherwise VFR.

CTP WATCHES/WARNINGS/ADVISORIES

None.