textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast. Severe weather potential remains for late tonight and Monday evening with low confidence in coverage and timing.

KEY MESSAGES

1) Chances for showers and thunderstorms increase today with severe weather potential late tonight and late Monday evening. Afterwards, periodic showers possible across NE OH and NW PA into Wednesday.

DISCUSSION

KEY MESSAGE 1... The upper level ridge across the Central CONUS continues to build as a series of shortwaves move around the northern periphery through the middle of the week. Firstly, there is a slight chance for diurnal showers and thunderstorms this afternoon into the evening, though coverage should be minimal. Late tonight into early Monday morning, the first of the shortwaves will move just west of the region and precipitation chances will increase. Current guidance has an MCS tracking along a thermal gradient that is situated northwest to southeast across Indiana. Recent trends have this feature not impacting northwestern Ohio until Monday morning, if the precipitation does reach this far east. Any storms that do reach the area have the potential for strong to severe winds, and as a result, much of the region is under a Marginal Risk (level 1 out of 5) for severe weather on SPC's Day 1 Severe Weather Outlook.

There will be a lull in precipitation into the afternoon on Monday before the second shortwave ahead of a surface low pressure tracks through the Great Lakes region to the southeast. The upper level ridge, and thermal gradient will have shifted to the east a little more as well. Out ahead of the surface low, bulk shear vectors will be out of the northwest at 40-50 knots that will support strong to severe thunderstorms Monday evening. As the front approaches late Monday night, storms will develop into a more linear mode. Damaging winds will be the main threat throughout the event, especially with the linear mode, but can't rule out any large hail given the strength of the deep layer shear and instability in any cells developing ahead of the line. There is still some uncertainty given how the 12Z models have handled this feature, with the HRRR keeping it well to the west and the NAM Nest developing it across central Michigan and moving into northern Ohio. In addition, how long precipitation lingers through the morning and coverage of any late evening storms may inhibit storm development with the front. Highest confidence currently is in northwestern Ohio to Cleveland, south through the Mansfield area for damaging wind impacts. SPC currently has the entire area in a Slight Risk (level 2 out of 5) for severe weather with the main driver being the damaging wind threat.

Behind the cold front Tuesday morning, a surface trough will linger across the eastern portion of the region with strong northerly flow expected. Residual moisture is expected, primarily across Northeastern Ohio and Northwestern Pennsylvania that will aid in lake effect showers developing. Periodic showers are possible across the aforementioned area through at least Wednesday when drier air moves into the region from the west with high pressure.

AVIATION /18Z Sunday THROUGH Friday/

Some MVFR broken to overcast clouds have moved into the region this afternoon ahead of a warm front that is trying to slowly nudge eastward. These clouds should thin with eastward extent this afternoon, so have mainly VFR prevailing. Confidence for all terminals begins to decrease tonight and especially Monday. That warm front will continue to bisect the area from N to S tonight and Monday, and scattered showers and thunderstorms may drop N to S near the boundary at times. Very hard to time and pinpoint the locations of any showers and thunderstorms, but introduced some VCSH and VCTS at KCLE and KERI since hi-res model guidance is starting to key in on possible activity near KERI late Monday morning/early afternoon and near KCLE late Monday afternoon. Otherwise, the better chance for showers and thunderstorms will occur after the TAF period Monday night as a low pressure system and strong cold front cross the Great Lakes.

W to NW winds will average 5-10 knots this afternoon and evening before turning light S to SW tonight. Winds will turn mainly W again Monday morning and increase to 5-10 knots.

Outlook...Non-VFR possible with periodic showers and thunderstorms Monday morning through Tuesday.

MARINE

Mainly light winds and waves will continue on Lake Erie through Monday, except for locally higher in and near any thunderstorms that drop across the lake tonight through early Tuesday morning. Confidence in thunderstorms tonight is low, but confidence and potential is higher Monday and especially Monday night as one or two clusters may drop across the lake.

Otherwise, W winds will increase to 10-15 knots Monday night as a strong cold front crosses Lake Erie, with winds becoming NNW and increasing to 15-25 knots Tuesday. NNW winds will continue at 15-25 knots at times through Wednesday, so Small Craft headlines and Beach Hazard Statements for rip currents are likely Tuesday through Wednesday. NNW winds will gradually diminish to 5-10 knots by early Thursday, becoming light and variable Friday as high pressure settles overhead.

CLE WATCHES/WARNINGS/ADVISORIES

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