Winterplace Ski Resort

Summary

SYNOPSIS

... A cold front will bring additional showers and storms this evening, with some storms becoming strong to severe, before promoting cooler weather for Friday and the weekend.

NEAR TERM /THROUGH FRIDAY/... As of 750 PM Thursday...

Scattered strong thunderstorms have developed across portions of the forecast area this evening in advance of and along a cold front, with isolated severe storms possible over the next few hours. The main threats continue to be damaging wind gusts, hail, and localized flash flooding, with the northeast portion of the CWA having the greatest chance for impacts. Some weak rotation has been noted with the cells this evening, so an isolated, brief spin-up cannot entirely be ruled out. Activity will continue to quickly shift southeastward over the next few hours, with the severe threat quickly diminishing/exiting from ~ 10 PM to midnight. Have updated PoPs, temperatures, and cloud cover throughout the night to represent the latest trends. The rest of the forecast remains on track.

As of 220 PM Thursday...

Showers and thunderstorms are likely to fire up this afternoon, as west to southwest low level flow increases ahead of an approaching low pressure center and cold front. This will begin with isolated to scattered activity this afternoon, followed by a segmented line of convection drifting southeastward this evening into tonight.

Clouds were limiting heating across much of the middle Ohio Valley, versus areas nearer and in the mountains. With the opposite pattern in terms of bulk shear, near 60 kts west but down around 40 kts east integrated 0-6 km, overall severe potential is marginal. Also, modest low level storm relative helicity peaking in the 150-200 m2/s2 range will also support some rotation in more organized cells, like within any line segments later on.

Pockets of one hour flash flood guidance values of an inch or less, particularly over the middle Ohio Valley, make such areas vulnerable to excessive runoff from any heavier thunderstorm, but vegetation nearing full growth has proven to be a mitigating factor this week.

Cooler air and low clouds roll in behind the cold front tonight, and Friday will be a noticeably different day with the low overcast in place. Showers are possible in the afternoon as a mid-upper level short wave trough crosses, but instability, if any, will be limited.

After one last warm afternoon for a few days, central guidance reflects cooling from northwest to southeast behind the cold front tonight, and a noticeably cooler day on Friday with lower 60s most of the afternoon across the lowlands, actually below normal for this time of year.

SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... As of 225 PM Thursday...

Precipitation ends from west to east Friday night as transient ridging builds into the region ahead of a northern stream disturbance approaching during the day Saturday.

With relatively cool air left in the wake of the Friday system along with relatively early arrival of associated cloudiness, won't realize very much surface heating. Still, should be able to generate some conditional instability, perhaps 500J/kg in the presence of rather stout deep layer shear of 40 to 50KTs by Saturday afternoon. With rather cool air aloft, graupel showers are likely, with some stronger cores also possible yield strong to perhaps marginally severe wind gusts.

LONG TERM /SUNDAY THROUGH THURSDAY/... As of 225 PM Thursday...

Ridging building into the region yields mainly dry conditions from late Sunday afternoon through Monday. Deep southwesterly flow associated with the next southern stream system will begin to advect moisture back into the region Monday afternoon into Monday evening. Upper level forcing arriving late Monday afternoon into early Tuesday morning will yield an uptick in precipitation coverage. Given the low amplitude of this feature and varied model timing, confidence is not especially high.

Transient ridging builds back into the region briefly Wednesday before another system arrives Thursday.

Severe risk through this period appears low given a relatively weak flow regime.