textproduct: Cleveland

WHAT HAS CHANGED

Several rounds of showers and thunderstorms are expected to move across the region through tonight. With much of northern Ohio receiving 1 to 2+ inches of rain since Sunday and another 1 to 2 inches of rain with locally higher amounts expected today, have issued a Flood Watch for a large portion of northern Ohio from 11 AM Tuesday to 8 AM Wednesday. The system that has impacted the region over the past several days will continue to bring rain chances Wednesday and now into Thursday. The dry weather has been delayed into Friday and Saturday.

KEY MESSAGES

1) Additional showers and thunderstorms are expected through Thursday. The most impactful storms will be today and tonight, as multiple rounds will move through the region with heavy rainfall that may lead to flooding. Severe weather is also possible this afternoon as a line of storms may move through the southwest half of the area, bringing a damaging wind threat to the region.

2) Dry weather is expected on Friday through at least Saturday afternoon, giving a break in the active pattern. Temperatures and humidity will taper off with high pressure entering the region.

3) Unsettled weather may return starting Saturday night and remain through Monday with scattered showers and storms in the region.

DISCUSSION

KEY MESSAGE 1... Yet another round of showers and storms are moving northeast through Northeast Ohio early this morning with the third complex in about 36 hours across the region. The next round of shower and storm activity is already brewing in northern Indiana and southwestern Lower Michigan early this morning and will arrive in the western portion of the forecast area right around daybreak. With the latest storms wiping out much of the instability and a strong near surface stable, the upper bound of this activity will be limited but an organized storm or two is possible with some marginally acceptable 0-3km shear around 30 kts in the region. This activity will move southeast through the the forecast area this morning. There could be potential for this activity to become severe later in the morning (much like Monday) as the surface stability wanes with daytime heating.

The big show for today will be a line of thunderstorms that will develop with a shortwave along the front Minnesota and Iowa. This line has great potential to be a healthy, severe MCS with ample instability over the Midwest and great support with the shortwave aloft. The angle of this complex will largely take it southwest of the forecast area this afternoon and evening. However, the northeast extent of this line could reach into the forecast area and bring severe, damaging wind gusts to the area. If this complex does become organized and ends up more into the area, then there could be potential for 75+ mph wind gusts.

Several rounds of showers and thunderstorms are expected to move across the region through tonight. With much of northern Ohio receiving 1 to 2+ inches of rain since Sunday and another 1 to 2 inches of rain with locally higher amounts expected today, have issued a Flood Watch for a large portion of northern Ohio from 11 AM Tuesday to 8 AM Wednesday.

Once this larger MCS exits the region, this should allow for convective activity to wane for Tuesday night into the first part of Wednesday as the surface front will be pushed well south of the area. The front will make a resurgence into region later on Wednesday into Thursday as additional shortwaves in the northwest flow will move through the region and help support more showers and storms. The potential for severe weather and flooding is becoming more limited on Wednesday with the front starting so far south. With the front returning and lasting into Thursday, there could be some low end severe and flooding potential with storms on Thursday.

KEY MESSAGE 2... With the early week system slowing down, high pressure will be delayed in entering the region until Friday. This will bring dry weather and less humidity into the region, giving some relief from the active and humid conditions from earlier in the week. A delayed surface high will allow for dry weather to persist into Saturday, which will be a welcomed treat for the first half of the weekend. Temperatures will fall back into the 70s with the cooler system overhead.

KEY MESSAGE 3... The upper ridge axis will push east on Saturday night and allow for northwest flow to return to the Great Lakes region. A shortwave within the northwest flow will move through the region and support a low pressure system across the area. This will bring rain chances starting on Saturday night with the bulk of the wet weather on Sunday and potentially into Monday. There is low confidence on any severe weather or flooding potential at this time.

AVIATION /12Z Tuesday THROUGH Saturday/

A very challenging forecast in terms of timing showers and thunderstorms continues today as multiple rounds move through the area. The first round is exiting the area currently and should be out of KMFD and KCAK by 15Z allowing VFR to return there. Another round currently moving east from northern Indiana could clip KFDY between 13 and 15Z. Outside of these areas, a few vicinity showers will be around through the morning, otherwise, low end VFR and patchy MVFR cigs will be the rule through this afternoon until the next round of showers and thunderstorms approaches by late afternoon. Consensus is that the afternoon and evening round will mainly impact KFDY, KMFD, and KCAK, but maintained PROB30 groups for some MVFR or lower thunderstorms at all sites late this afternoon into this evening (except for KERI) since there is still uncertainty on how far north and east some of the precip will reach. KERI has the best chance to stay dry and VFR. The active frontal boundary will finally start to sag south of the region tonight allowing drier air to work in, but confidence is increasing that most terminals will fog in. At this time, brought IFR vis into KMFD, KCAK, and KYNG since those are the typical spots for it (with MVFR elsewhere), but these visibilities will likely trend lower at most sites.

Light and variable winds this morning will become SW at 5-10 knots this afternoon before becoming light and variable again tonight.

Outlook...Periods of non-VFR conditions are expected in multiple rounds of convective activity through Thursday. Low ceilings possible outside of storms at times as well. Non-VFR possible in showers and thunderstorms Saturday afternoon into Saturday night.

MARINE

The average flow on Lake Erie will remain southwesterly today with showers and storms moving northeast across the lake early this morning. A large complex of storms is expected to pass southwest of the lake later today and may shift flow more to the west. This complex will drive a front further away from the lake and may allow for more variable flow through Wednesday. A larger trough will move through the region on Wednesday night into Thursday, which will allow for northwest flow to develop on the lake. High pressure will build into the region on Friday and bring northerly flow to the basin. This system will move east on Saturday, bringing a window of easterly flow before the next system arrives later in the weekend.

CLE WATCHES/WARNINGS/ADVISORIES

OH...Flood Watch from 11 AM EDT this morning through Wednesday morning for OHZ003-006>011-017>021-027>032-036>038-047. PA...None. MARINE...None.