textproduct: Cleveland

WHAT HAS CHANGED

Temperatures continue to trend slightly higher for early to mid-next week.

KEY MESSAGES

1) Temperatures will continue to warm through the weekend, becoming above-average by early to mid-next week. Heat headlines are possible.

2) An unsettled weather pattern will develop across the Great Lakes early to mid-next week, resulting in increased shower and thunderstorm chances. Strong storms and heavy rainfall are possible.

DISCUSSION

KEY MESSAGE 1... A large upper-level ridge will build east across much of the Central and Eastern CONUS by the end of the weekend into mid- next week. At the surface, a warm front will lift northeast through the area late Sunday into Monday, ushering in above- average temperatures across the region. Highs in the mid to upper 80s on Sunday will increase further into the upper 80s to lower 90s by Monday, and perhaps reaching the mid-90s in some spots by Tuesday or Wednesday with the ridge axis overhead, yielding heat indices in the upper 90s to near 100 at times. All this said, it is still not a slam-dunk heat event given increasing chances for showers, storms, and residual cloud cover during this same time period. Will continue to watch trends over the next couple of days.

KEY MESSAGE 2... An unsettled weather pattern will develop across the Great Lakes by the end of the weekend into mid-next week as several mid- level shortwaves track east along the upper-level ridge axis, providing increased flow needed to support organized convection.

The first period of concern will be Sunday night into Monday behind the warm front as guidance favors the development of a complex of showers and storms generally moving southeast through the Central and Eastern Great Lakes. This appears to be a glancing blow at this time, mainly across far Northeast Ohio or Northwest Pennsylvania. Precipitation chances have generally trended lower for Tuesday with the ridge axis overhead with chances increasing again by Tuesday night through Wednesday as a strong upper-level trough swings east through the Upper Great Lakes. In addition, anomalously-high PWATs in excess of 1.80 inches could lead to torrential rainfall and isolated flash flooding where storms persist. Still quite a bit of uncertainty with regards to shower and thunderstorm timing and coverage, though given the favorable environmental shear in place, the chance for strong to severe storms remains possible. Will continue to monitor trends.

AVIATION /00Z Saturday THROUGH Wednesday/

Clear/VFR tonight with high pressure in control. FEW cumulus FL045, SCT cirrus Saturday. Winds under 12kts. Outlook...Mainly VFR, but with patchy non-VFR possible in fog/mist early in the mornings on Saturday and Sunday.

MARINE

Northeasterly winds of 5-10 knots will decrease overnight and veer to southerly. A stretch of good marine conditions is expected through Monday with winds of generally 10 knots or less. Southwesterly winds will increase into the 10-15 knot range Tuesday and Wednesday. There is a low end threat of thunderstorms beginning Sunday night and peaking on Wednesday. Thunderstorms can result in erratic wind and wave conditions.

CLE WATCHES/WARNINGS/ADVISORIES

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