textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast.

KEY MESSAGES

1.) One last dry day and continued warming.

2.) Showers and storm chances return Friday night through early Saturday night.

3.) Upper level ridge builds in through the middle of next week with more summer-like warmth.

DISCUSSION

KEY MESSAGE 1... A bit more warming today with return flow into the region and 850mb temperatures climbing into the upper teens. With sun and a dry ground, this will translate to widespread upper 80s across the region ahead of a cold front that will be approaching from the west for the first rain chances in several days beginning Friday night. KEY MESSAGE 2... Flow aloft will become cyclonic tonight with a surface prefrontal trough moving through, sparking the first chances for showers and a few isolated thunderstorms in several days. During the overnight period, instability will be hard to come by, and elevated, making thunderstorms not expected on a scale more than isolated despite an increase in the low level flow. Different story into Saturday with some daytime heating aiding in the development of instability that will end up closer to the surface. Some risk for severe thunderstorms here with 0-6km bulk shear around 30kts to go with around 1000J/kg CAPE and increases in surface/low level dewpoints. In the end, damaging winds will be the greatest threat for Saturday with the cold front coming through late Saturday into Saturday night, taking the POPs with it by Sunday morning.

KEY MESSAGE 3... Quick return to upper level ridging early next week with temperatures on the rise again and a two day dry period before getting back into POPs midweek with another trough aloft. Heat will begin to build with another upper level ridge into the end of next week with what may be considered the first hot and humid weather of the season as dewpoints could eclipse the 70F mark.

AVIATION /18Z Friday THROUGH Wednesday/

VFR conditions will persist through 00Z with moistening of the atmosphere and chances for showers and/or thunderstorms returning tonight through Saturday. Chances of precipitation will arrive near TOL between 00-03Z but not expected to impact additional terminals for several hours as storm motion is to the northeast. Showers are expected to spread east and be near CLE and ERI towards 08Z. Can not entirely rule out a thunderstorm tonight but potential is low. Chances of showers will move south with time across the forecast area. More uncertainty lies with where and when re-development will occur on Saturday afternoon. It looks as thought additional showers and thunderstorms will fire across the area after 18Z and will need to be monitored for IFR visibilities in heavy rain a gusty winds. Timing will need to be refined as we get a better handle on timing.

In addition, southwest winds will be breezy today with gusts of 20-25 knots. Winds gusts are expected to generally drop off tonight as a 35 knot low level jet moves overhead. This will be close to low level wind sheer criteria but generally just under. Winds will increase with height through 2K feet. Surface wind gusts will resume on Saturday morning with gusts to 25 knots possible.

Outlook...Limited non-VFR in a cluster of weakening showers and thunderstorms tonight into early Saturday. Non-VFR possible again Saturday afternoon and evening as thunderstorms develop along and ahead of a cold front.

MARINE

Southwesterly winds generally remain between 5-15 knots through this evening before increasing to the 15-20 tonight range tonight through Saturday morning. A cold front will move across the lake on Saturday evening allowing for winds to turn northerly while decreasing to 10 knots or less by Sunday morning as high pressure builds overhead. Light and variable flow is expected as the high remains in control on Sunday. Winds will favor an easterly component Monday while remaining in the 5-15 knots range ahead of an approaching low pressure system that will enter the Upper Ohio Valley by mid-week.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...None.