textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the upcoming forecast.

KEY MESSAGES

1) Showers and thunderstorms are expected across parts of Northeast Ohio and Northwest Pennsylvania this evening into early tonight. Locally heavy rainfall, gusty winds and small hail is possible this evening.

2) Cooler weather with occasional lake effect rain showers continue across parts of Northeast Ohio and Northwest Pennsylvania through early Tuesday.

3) Scattered showers and thunderstorms are possible Wednesday night into Thursday.

DISCUSSION

KEY MESSAGE 1... An upper-level low remains situated over the Great Lakes region today with the occluded surface low right along the Ontario/Quebec border. A compact mid-level shortwave trough is working its way around western edge of the upper low and will approach the forecast from the north this evening. Paired with the left exit region of a jet streak over the western Great Lakes and we have solid forcing for ascent and pretty good confidence in timing and areal extent of precipitation this evening into early tonight.

We start with scattered showers and storms areawide this afternoon as MLCAPE exceeds 250 J/kg underneath the jet streak forcing. The impending shortwave will focus a better period of thunderstorm development roughly along and northeast of I-80 in Northeast Ohio and Northwest Pennsylvania between 7 PM and 12 AM. This is where MLCAPE will be greatest (>500 J/kg) and exists the chance for organized convection that will have the potential for lightning, gusty winds (most likely in the 40-50 mph range), small hail, and heavy rain.

While the mid-level speed max will be offset to the southwest, effective bulk shear of around 25-35 knots should be sufficient for an organized convection. Deep layer shear should be enough to produce strong winds but lack of DCAPE and waning low-level lapse rates is likely to make 40-50 mph gusts more common rather than 58+ mph (severe thunderstorm warning criteria). Small hail is likely to be pretty common in most thunderstorms this evening, aided by low freezing heights around 8-9kft and modest mid-level lapse rates. Large hail at or exceeding 1" is unlikely but possible with any rotating updrafts.

Heavy rain is likely with thunderstorms with minor flooding possible is low-lying or flood-prone areas. Precipitation is unlikely to reach amounts for flash flooding.

KEY MESSAGE 2.. Below normal temperatures continue through at least Tuesday with lake effect rain showers continuing tonight through Tuesday morning. Rain is likely to be more more persistent in Northwest Pennsylvania, compared to the "snowbelt" region of Northeast Ohio where rain showers will be more intermittent.

KEY MESSAGE 3... Temperatures and humidity build back to near normal Wednesday and Thursday ahead of our next upper-level trough and low pressure system. Scattered showers and thunderstorms are expected Wednesday night into Thursday with PoPs peaking in the 40-60% range. Can't completely rule out severe weather, but at this point most storms look to remain sub-severe.

AVIATION /00Z Monday THROUGH Friday/

VFR is expected across the western terminals through the TAF period as periodic lake effect showers and clouds impact terminals from KCLE eastward. A round of showers/thunderstorms are moving over Lake Erie currently and will impact KCLE and KERI through the next few hours. Stronger gusts to around 30 knots out of the northwest are possible if thunderstorms impact station. Lingering showers are possible, especially at KERI, behind the thunderstorms. Confidence is lower in showers impact KYNG and KCAK. All terminals except KERI will dry out after midnight tonight with VFR ceilings expected across the region tomorrow.

Gusts will begin to subside over the next hour and will be sustained at around 10 knots out of the west-northwest. Winds will pick up again around 14-15Z tomorrow and gusts up to 20 knots are expected throughout the day.

Outlook...Non-VFR possible in lake effect rain and/or low ceilings in far NE OH and NW pa Monday into Tuesday. Non-VFR may return in showers and thunderstorms Wednesday night into Thursday.

MARINE

Rough marine conditions will continue across much of Lake Erie through Monday with elevated west to northwest winds of 15 to 25 knots resulting in waves of 3 to 6 feet. Marine conditions will gradually improve Monday night into Tuesday as winds subside to 10 knots or less. Winds will shift towards the south to southwest on Wednesday, increasing into the 10 to 15 knot range by Thursday.

A few stronger wind gusts in excess of 34 knots are likely across the central and eastern basin of Lake Erie through this evening, associated with showers and thunderstorms. There is also a risk for waterspouts into Tuesday morning.

CLE WATCHES/WARNINGS/ADVISORIES

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