textproduct: Cleveland

WHAT HAS CHANGED

Decreasing threat for strong to severe thunderstorms into this evening. Increased sky cover tonight through Saturday morning and lowered high temperatures on Saturday, particularly along the lakeshore.

KEY MESSAGES

1) Decreasing threat for strong to severe thunderstorms later this afternoon and evening with a cold front. Dreary weather expected tonight into Saturday morning behind the front.

2) Conditional strong to severe thunderstorm threat remains for Sunday afternoon and evening ahead of a cold front, mainly along and south of US-30.

3) Another system will move east through the Great Lakes on Thursday, though impacts to the local area remain uncertain.

DISCUSSION

KEY MESSAGE 1...

Scattered to widespread showers, especially east of I-77, will persist into this evening ahead and along of a cold front. Some thunderstorms are possible along the front, evident by recent glaciating cloud tops in southern Ontario in the presence of elevated instability, though the threat for any strong to severe thunderstorms appears to be decreasing given the pre-frontal widespread cloud cover and rain showers.

Behind the front overnight, shallow moisture will quickly become trapped underneath a strong low-level inversion, resulting in widespread low cloud cover which could potentially persist through much of Saturday morning. Lower confidence in drizzle and/or fog given the shallow moisture profile (generally beneath 850 mb) and elevated boundary layer winds (5 to 7 knots). Have slightly lowered high temperatures areawide on Saturday given the lingering cloud cover. Further decreased temperatures along the lakeshore (some spots not getting out of the 40s) as weak, onshore flow is expected.

KEY MESSAGE 2...

Another system will move east through the Great Lakes on Sunday, extending a strong cold front across the region. This will present another opportunity for strong to severe storms in the afternoon and evening, mainly along and south of the US-30 corridor, with strong mid-level shear in place approaching 50 knots. Although this set up appears more favorable than today's (Friday), there remain limiting factors in place, including mid-level capping and pre-frontal convection trending further south in today's guidance, meaning the strongest storms would form south of the area. If elevated instability can recover north of the pre-frontal convection, the environment could still yield a marginal hail threat across much of the current SWODY3 marginal risk area.

A brief cool-down is expected behind the front, with temperatures in the upper 30s to lower 40s on Monday.

KEY MESSAGE 3...

A third system will develop and move east through the Great Lakes, extending a cold front across the area Thursday night. Chances for showers and perhaps a few thunderstorms will increase in the afternoon and evening ahead of the front, though specifics on any potential impacts remain uncertain. Another sharp decrease in temperatures is expected behind the front, with highs in the upper 30s to lowers 40s on Friday.

AVIATION /06Z Saturday THROUGH Wednesday/

In the wake of the cold front that came through earlier this evening, low stratus is developing and some mist/fog as well. This will be the story for the remainder of the overnight period and into the first part of the day Saturday as mixing of the boundary layer and erosion of the inversion will be slow to take place and may not occur until after 18Z in some locations. IFR/LIFR will become VFR fairly quickly when the transition does occur however. Easterly winds become southwesterly, and LLWS returns with low level winds increasing ahead of the next cold front that will affect the region later this weekend.

Outlook...Non-VFR possible in rain showers and low ceilings on Sunday with another cold front.

MARINE

A cold front will settle south across Lake Erie late this afternoon with winds shifting to the north at 10-15 knots behind the front. High pressure builds east on Saturday with light northeasterly winds, then begins to increase out of the southwest around 15 knots late Saturday night into Sunday. Depending on the track of surface low pressure on Sunday, winds may decrease during the morning as the low approaches. A cold front does move south across Lake Erie Sunday afternoon into Sunday night with increasing north winds and a Small Craft Advisory may be needed for the mid-section of the lake Sunday night into Monday. High pressure builds in behind it with marine conditions improving for the early part of next week.

CLE WATCHES/WARNINGS/ADVISORIES

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