textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast.

KEY MESSAGES

1) Heat builds into the region today through Wednesday as temperatures climb to well above normal with heat indices in the mid 90s to low 100s.

2) Rounds of thunderstorms are possible this evening through Friday with low confidence in location and timing.

DISCUSSION

KEY MESSAGE 1... An upper level ridge will build into the southeastern CONUS today and persist through Friday. This will allow for an influx of southern humidity and heat to move into the region as low level flow with generally be southwest to westerly. 850 temperatures are expected to climb in to the upper teens by Tuesday and peak around 20-22C Wednesday. Surface temperatures as a result will start the week in the mid to upper 80s today and climb into the low 90s for Tuesday and Wednesday. Dew points will increase as well to the upper 60s to low 70s resulting in heat indices in the upper 90s to low 100s.

KEY MESSAGE 2... With the upper level ridge in place, there will be multiple shortwaves moving along the northern periphery bringing energy to produce rounds of thunderstorms through Friday. With the elevated heat and humidity in place over the region, this will help provide ample instability to go along with northwesterly oriented bulk shear vectors of 30-40 knots. There's still some uncertainty in how the amplified the ridge will be and locations of the shortwave vort maxes as they move across the Great Lakes region. The highest confidence for thunderstorm chances will be across NE OH and NW PA throughout the week, though elsewhere will still have chances to see thunderstorms. This is outlined within the SPC's Day 2 severe weather outlook for Tuesday with a Marginal risk for the majority of the CWA and a Slight risk for far eastern NW PA. This aligns well with models location of the vort max moving through the Great Lakes on Tuesday, though the better environment will be to the east in PA and NY. With the uncertainty mentioned above, will need to monitor how this feature develops to have a better idea of impacts to the CWA.

The next round of thunderstorms will be late Wednesday night into Thursday morning as a low pressure system moves through the Northern Great Lakes. This will drag a cold front across the region and given the timing of it being overnight, the severe weather potential will be lower, though will not be zero. The upper level ridge will begin to retreat on Thursday into Friday to the west over the south- central CONUS. Thunderstorm and severe weather chances will decrease into the weekend, though a few lingering showers and thunderstorms will still be possible on Friday with a shortwave moving through.

AVIATION /06Z Monday THROUGH Friday/

Very light showers will move across northern Ohio overnight, with mostly VFR conditions, as a weak upper trough slides east under the ridge. Meanwhile, a quasi-stationary boundary remains draped from Michigan, across Lake Erie, and into southwestern PA, providing an focal point for continued rain and embedded, high based thunderstorms. This will continue at times through the day Monday, primarily impacting KERI. Southerly winds will shift southwesterly by mid-day tomorrow, as high pressure over the Carolinas remains fully entrenched, and remain 10kts or less. High VFR cumulus is likely to develop in the hot, humid atmosphere under the high, with ceilings around FL100.

Outlook...Non-VFR conditions are possible Tuesday, with scattered showers and thunderstorms across far northeast OH and northwest PA. Unsettled conditions, with von-VFR in showers and thunderstorms, are expected Wednesday through Friday.

MARINE

Marine weather will be unsettled and stormy at times during this week, especially Wednesday and Thursday. A warm front has stalled out just north of the area this week with multiple rounds of storms possible. Outside of severe thunderstorms on the lake this week, winds will generally be from the southwest 5 to 15 knots with waves 1 to 2 feet. The 10 to 15 knots winds will favor the midday and afternoon hours this week, and will mostly be over open waters. Any organized convection, gust fronts, and outflows from storms may cause rapid changes in marine weather conditions. No marine headlines are anticipated this week on the lake at this time, but continue to monitor forecasts for up to date information.

CLE WATCHES/WARNINGS/ADVISORIES

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