textproduct: Cleveland

WHAT HAS CHANGED

Severe weather threat and flash flooding threat has subsided as storms move off to the east. The Severe Thunderstorm and Flood Watches have be canceled.

KEY MESSAGES

1) Below average temperatures arrive to end the weekend and start the upcoming week. Periodic lake-enhanced rain showers will primarily impact portions of Northeast OH and Northwest PA late tonight through at least Monday night, with a few showers or storms elsewhere Sunday afternoon/evening.

2 A period of dry and quiet weather is expected the first half of the week. Scattered showers thunderstorms return Wednesday night into Thursday.

DISCUSSION

KEY MESSAGE 1... After pulling a cold front across the area this evening, the surface low and upper trough across the central/eastern Great Lakes will continue to deepen through Sunday while beginning to stack, cut-off, and slow. The system will then start to slowly fill/weaken Sunday night and Monday while drifting to the east- northeast across southeastern Canada and New England. The seasonably chilly airmass pulled in behind the cold front and lingering moist cyclonic flow behind the stacking surface low/ upper trough will give us an early taste of fall to end the weekend and start the week...including some lake-enhanced rain. 850mb temperatures will bottom out at 6-9C Sunday night into early Monday, with 700mb temperatures dipping a bit below 0C as 500mb temperatures fall to around -20C.

Most of the area will dry out late this evening into the overnight as the cold front exits, though as cooler west- northwest flow aligns over the ~25C lake waters some lake- enhanced showers will begin developing and moving into Northeast OH/Northwest PA. A vort max and low-level trough axis will cross the region very late tonight into early Sunday, likely causing activity to peak in organization. While some lake effect showers will continue on Sunday across Northeast OH/Northwest PA, the activity will likely lose organization and intensity for several hours after the morning trough passage. Another potent vort max and low-level trough axis will drop in from the northwest late Sunday afternoon and evening, bringing another uptick in lake-enhanced shower activity over and east-southeast of Lake Erie from as far west as the Islands and Sandusky points east. There will also be an uptick in showers across the rest of the area with the trough passage late Sunday afternoon and evening. Chilly, cyclonic west-northwest flow continues through at least Monday night or early Tuesday and some lake effect/ enhanced shower activity remains likely. However, there will likely be a trend for activity to become less intense/organized later Sunday night and beyond as high pressure builds in. A possible exception is Monday night when another vort max and trough passage is hinted at. That could cause one last uptick in the lake-driven showers, especially farther east.

In terms of any hazards, instability will be deep enough over the lake for some thunder/lightning potential with the lake- enhanced activity...especially through the first half of Sunday night. The overall set-up with a somewhat shorter west-northwest fetch and some wind shifts through the event isn't overly favorable for intense, banded rainfall with a flash flood risk across the snowbelt. However, rain amounts will gradually add up (especially through Sunday evening) where lake-enhanced showers are most frequent and the potential for localized flooding will need to be kept in mind, especially if parts of Northeast OH or Northwest PA see locally heavy rain today. The heaviest rain amounts will likely occur slightly inland from the lakeshore form the Cleveland area points east-northeast. Otherwise, with cold air aloft and stronger winds towards and above 500mb, any thunderstorms with the trough passage late Sunday afternoon/ evening may produce gusty winds and/or small hail...especially over and downwind of Lake Erie.

KEY MESSAGE 2.. Locations outside of any lake enhanced rain showers are expected to dry out Sunday night and remain dry into the first half of the week. Lake enhanced rain will gradually dwindle starting late Sunday night and eventually end by Tuesday as discussed above. Overall, this will lend to a tranquil first half of the week across much of the area. Temperatures will slowly rebound towards normal starting on Tuesday. Another trough is expected to dig into the Great Lakes Wednesday night and Thursday. This will likely be accompanied by another surface low and its associated fronts. Chances for showers and some storms may arrive as early as Wednesday afternoon/evening, but are most favored on Thursday with this system.

AVIATION /00Z Sunday THROUGH Thursday/

Showers and thunderstorms continue to move through Eastern Ohio and into Pennsylvania late this evening. KYNG and KERI may see impacts over the next couple of hours until it pushes further off east. Non- VFR ceilings and visibility are possible in thunderstorms with gusty winds. MVFR ceilings may linger across Northeastern Ohio and Northwestern Pennsylvania through tonight as well. The cold front continues to move through Northern Ohio and winds will shift to be west to northwesterly at around 10 knots. Winds will be gusty tomorrow out of the west to northwest up to 20 knots starting around 14-15Z and persist through much of the day.

Lake effect showers and periodic thunderstorms are possible late in the TAF period for KCLE and terminals to the east. Non-VFR visibility is possible in any showers/thunderstorms that occur with this.

Outlook...Non-VFR conditions will be likely Sunday through Monday morning with lake enhanced rain showers and isolated thunder possible for areas downwind of Lake Erie in Northeast Ohio and Northwest Pennsylvania.

MARINE

A cold front will move across the lake through this evening bringing the chance for showers and thunderstorms. Some of these storms could be strong to severe with isolated wind gusts as high as 40-50 knots. Winds will shift around from the west to northwest tonight 15 to 20 knots and continue Sunday through Monday. Waves will increase 3 to 7 feet later tonight and those rough conditions will likely continue Sunday through Monday. Waterspouts will be very possible on Lake Erie starting tonight and lingering through Monday. Small Craft Advisories and Beach Hazard Statements for rip currents have been issued late tonight through Monday afternoon and evening. High pressure will slowly build in Monday into Tuesday with conditions on Lake Erie improving. By Tuesday, winds will be westerly to southwesterly 5 to 15 knots and waves decreasing to 1 to 2 feet.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Beach Hazards Statement from midnight EDT tonight through Monday afternoon for OHZ009-010. Beach Hazards Statement from midnight EDT tonight through Monday evening for OHZ011-012-089. PA...Beach Hazards Statement from midnight EDT tonight through Monday evening for PAZ001. MARINE...Small Craft Advisory from midnight tonight to 5 PM EDT Monday for LEZ144-145. Small Craft Advisory from midnight tonight to midnight EDT Monday night for LEZ146>149.