textproduct: Cleveland

WHAT HAS CHANGED

Reduced pops slightly for the evening given recent radar trends. Trended temperatures down in the north and east slightly for both Sunday and Monday with lake breezes or flow off the lake.

KEY MESSAGES

1.) Active weather continues this evening with a few strong to severe thunderstorms and locally heavy rainfall possible into early this evening. Rivers are experiencing rises due to the recent rainfall and a few have exceeded minor flood. A Wind Advisory also remains in effect through 2 AM Sunday for Erie County Pennsylvania.

2.) Additional showers and thunderstorms are possible late afternoon through the evening on Sunday with conditions drying out for the Memorial Day Holiday.

3) Above normal temperatures in the lower 80s return for Tuesday and Wednesday.

DISCUSSION

KEY MESSAGE 1... Low pressure is located across NW Ohio this afternoon and we are monitoring radar trends as the atmosphere is gradually destabilizing. Only modest instability with ML CAPE of 200-400 J/kg is expected across southern portions of the forecast area. Shear values are highest across NE Ohio where surface winds are backed more southeasterly with veering aloft to the southwest with 35-40 knots at 850mb. Hodographs are favorable for rotation if we can get discrete cells on the leading edge of the showers, generally between now and 7 PM. This is the window of concern for a short-lived and generally weak tornado or two before the low departs to the north and the system occludes. Thus far not seeing a sufficient uptick on radar to be concerned but the window of potentially stronger activity is just getting started. Coverage of storms has been less than expected today and trended pops downward slightly with this forecast. Storm motion to the northeast could support some training but eastern portions of the forecast area did not receive as much rain (~0.50-0.75 inch overnight) and should be able to handle the rain in the absence of robust convection.

Rivers are rising across portions of the area and minor flooding is ongoing on Killbuck Creek and the Scioto River at Larue. The heaviest rain last night of 1.5 - 2.5 inches occurred in a swath from Marion/Morrow Counties northeast towards Erie/Huron Counties in Ohio. We are monitoring rivers in the Great Lakes basin as well including both the Sandusky River at Tiffin and the Huron River at Milan which are rising quickly.

KEY MESSAGE 2... The trough over the Plains states lifts northeast on Sunday. A band of showers and thunderstorms is expected to develop upstream and move into NW Ohio late Sunday afternoon. In addition, moisture spreads back north ahead of the trough and could result in a few showers and thunderstorms ahead of the main line, generally after 2 or 3 PM. Temperatures do trend warmer on Sunday with southerly flow ahead of a weak area of surface low pressure. Modest instability is expected but tempered by a wind shift off Lake Erie later in the afternoon. The heavier rainfall of a half inch to an inch looks to be across NW Ohio but focused north of the heavier axis from last night which is good. In the wake of this trough, high pressure and drier air pushes south into the area with a dry Memorial Day forecast.

KEY MESSAGE 3... Broad upper level ridge focused along the East Coast expands north into the area Tuesday and Wednesday with temperatures returning to the lower 80s. This looks to be accompanied by a return of showers and thunderstorms lifting north into the area on Wednesday.

AVIATION /18Z Saturday THROUGH Thursday/

A mixed bag across terminals from LIFR to VFR in the wake of rain showers earlier this morning and afternoon. Some light and isolated rain showers will persist over the next few hours across western and extreme eastern TAF sites. Biggest change to the TAF with this update was to include a 2-3 hour TEMPO group for TSRA across eastern terminals (KCLE/KCAK/KYNG/KERI). Have the TEMPO group between ~19Z/Sat to ~00Z/Sun as a line of showers and thunderstorms develops and moves east late this afternoon into this evening.

Aside from lingering precipitation chances, expect for MVFR to IFR conditions, and possibly some LIFR, to continue through the overnight hours and into Sunday morning. Guidance continues to indicate that all terminals will see a window of at least IFR cigs with the potential for IFR/MVFR visibilities in BR. Best chance for LIFR conditions will be across central and Northwest Ohio terminals.

Gusty southerly to southeasterly winds will continue through this evening. Gusts will generally range between 20-25 knots with locally higher gusts of 35-40 knots near the lakeshore (KERI) in downsloping. Expect for gusts to diminish overnight tonight as the surface low exits to the northeast giving way to light and variable winds late tonight through Sunday.

Outlook...Non-VFR expected late Sunday into early Monday in showers and thunderstorms. Non-VFR possible again Wednesday into Thursday.

MARINE

Small Craft Advisory from Avon Point to Ripley NY remains in effect through 4 AM Sunday as strong southerly to southeasterly winds 20-30 knots persist. Given the offshore component, highest waves will occur in the open waters. The current swim risk for the central and eastern basins remains low given the location of highest waves. Southerly winds will diminish through Sunday morning as the parent low pressure exits the region giving way to light and variable winds and waves 1 foot or less through the middle of next week.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...Wind Advisory until 2 AM EDT Sunday for PAZ001-002. MARINE...Small Craft Advisory until 4 AM EDT Sunday for LEZ146>149.