textproduct: State College

WHAT HAS CHANGED

*Increased gradient wind gusts by about 5 mph Thursday

KEY MESSAGES

1) Seasonably pleasant start to the week with low humidity and no rainfall

2) Severe thunderstorm risk for Wed night/Thursday 6/17-18, with near Advisory gradient wind gusts possible Thursday

DISCUSSION

KEY MESSAGE 1: Seasonably pleasant start to the week with low humidity and no rainfall

Diurnal heating and the passage of a weak shortwave trough aloft will focus the bulk of the deeper/bkn cu field across the SE half of the CWA for the rest of today, with flatter and generally SCT CU elsewhere for the rest of today.

Becoming clear tonight with a NW Breeze decreasing to under 10 mph this evening, becoming light/variable overnight.

Mins tonight will be pretty chilly for mid-June, 44-54F across the CWA and wind could go calm. That could make a little river valley fog in the N.

Tonight, it will be the dryness of the airmass that could keep fog from forming (vs the wind this morning). Will hold off on mentioning fog for tonight. Later shifts can refine. Temps bounce up 5-10F on Tues, with sky cover similar to today. A couple of really nice days.

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KEY MESSAGE 2: Severe thunderstorm risk for Wed night/Thursday 6/17-18, with near Advisory gradient wind gusts possible Thursday

Latest model guidance is 6-8+ hours faster with the cfropa Thursday than runs from 24-28 hours ago, which focuses the bulk of the convection and severe weather threat with a high shear/low CAPE setup. The nose of a very strong, 40+ KT swrly 850 mb jet 50+ KT at 700 mb (both being 3+ sigma on the standardized anomaly scale), the the right entrance region of a 100 KT 250 mb jet and PWATS around 1.5 inches (with the potential of a EML surging in from the west ahead of a strong sfc cold front) will bring a favorable synoptic setup for severe weather here in the CWA.

We'll be monitoring the potential timing for severe weather closely. It could be one of those rare nights where the number and timing of storms makes it a rather noisy night to sleep undisturbed.

The main weather factor for the bulk of the daylight hours Thursday may be the high likelihood of 30-35 kt gradient, westerly wind gusts.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

High pressure will cotinue to build into central PA overnight. Winds will weaken after sunset and skies will clear.

Some clouds across the western part of PA later Tuesday afternoon, as winds shift more to the southwest.

At least through 00Z Wed, conditions will remain VFR.

Some showers possible overnight Tuesday into Wed.

More in the way for LLWS and storms Wednesday night into Thu. Gusty winds will prevail on Thursday as well.

Outlook...

Wed...Higher chances for -SHRA/-TSRA, restrictions more likely late. High probability (90+ percent) for LLWS Wed night into Thursday morning as the axis of an anomalously strong south/southwesterly LLJ slides east across the Commonwealth.

Thu...Restrictions possible in -SHRA/-TSRA.

Fri...Showers ending.

Sat...Chance of showers and storms later in the day across the north and west.

CTP WATCHES/WARNINGS/ADVISORIES

None.