textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the previous forecast.

KEY MESSAGES

1) Below normal temperatures and dry conditions will trend towards seasonal values by Saturday.

2) Shower and thunderstorm chances return Sunday through Tuesday. Confidence is increasing for a few stronger storms during this timeframe.

DISCUSSION

KEY MESSAGE 1... The upper-level trough responsible for the cooler airmass over the region will gradually exit east into New England today as a large upper ridge begins to expand east into the Midwest and Great Lakes into Saturday. Mainly dry and seasonable weather will continue as surface high pressure remains across the area. A few showers or storms are possible across far Northeast Ohio and Northwest Pennsylvania Saturday afternoon as a weak shortwave moves east through the Lower Great Lakes, aided by a developing lake breeze.

Temperatures will gradually warm in the mid to upper 70s today, increasing into the low to mid-80s by Saturday.

KEY MESSAGE 2... Confidence is increasing for a few stronger storms beginning late Sunday into Tuesday as several potent shortwaves traverse the base of a strong upper-level trough across Hudson Bay.

There will be a couple of periods to watch for developing storms, the first of which appears to be Sunday night into Monday as a leading shortwave enters the Lower Great Lakes, though confidence is a bit lower given the more mesoscale dynamics at play. Slightly higher confidence exists for a more widespread strong thunderstorm potential in the Monday night into Tuesday timeframe with convection supported by the passage of a potent mid and upper-level trough. Given the favorable northwesterly shear and anticipated linear storm mode, if any storms were to become strong to severe, damaging wind gusts appear to be the primary hazard. Will continue to monitor the threat over the next couple of forecast iterations.

AVIATION /12Z Thursday THROUGH Monday/

VFR prevailing through the forecast period. Cumulus field FL045 develops with daytime heating today. Winds become northerly less than 10kts. Cumulus field dissipates with the loss of heating this evening/tonight.

Outlook...Non-VFR possible with periodic showers and thunderstorms Sunday through Tuesday.

MARINE

High pressure today brings light onshore winds with wave heights 1ft or less. Winds become offshore tonight, and then northeasterly Friday with wave heights greatest in the central basin at around 1ft. Winds westerly 5-10kts Saturday with wave heights continuing to remain a foot or less. Winds become southwest Sunday and Monday with wave heights 1-2ft east of Cleveland and around 1ft west towards the islands.

CLE WATCHES/WARNINGS/ADVISORIES

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