textproduct: Cleveland

WHAT HAS CHANGED

Severe weather and flooding remain possible this afternoon and evening with storms ahead of a cold front. A colder pattern shift early next week will allow for periodic precipitation and the potential for some accumulating snowfall in NE OH and NW PA on Monday night.

KEY MESSAGES

1) Severe weather and flooding remain possible this afternoon and evening with storms ahead of a cold front. The main window for strong to severe storms remains from 3 to 10 PM. Flooding remains a concern in North Central Ohio, where area rivers and creeks still have high flows. Additional rain this afternoon and evening may allow for flooding to linger into Sunday.

2) A pattern shift begins on Sunday and will carry through Tuesday with cooler than normal temperatures and scattered rain/snow chances, especially in lake effect/upslope areas of NE OH and NW PA. Some light snow accumulations are possible in the snow belt area on Monday night.

3) The pattern will shift again starting in the middle of the week with temperatures returning to normal and at least one day of dry weather on Wednesday. Rain chances may return late in the week.

DISCUSSION

KEY MESSAGE 1... Overall, the severe weather setup continues as advertised across the area. The warm front wraps around the southern shore of Lake Erie this afternoon. The Toledo metro started cool this morning but the front has surged north to at least the state line. Over in NW PA, the front is struggling to get to the city of Erie with cold northeast flow off the lake, but the front may still have some time to get there. Otherwise, temperatures are doing well in the warm sector with widespread 70s and some record high temperatures have already been achieved. Winds are mixing down fairly well in the warm sector with 30 to 40 mph wind gusts throughout central Ohio and spreading north.

There are two areas to look for severe weather this afternoon. The first concerning area will be from North Central Ohio and east. A cumulus field has filled in across the area this afternoon. More robust cumulus is seen extending from the Lake Erie Islands south through Columbus into southern Ohio. These clouds have the ability to develop this afternoon and may turn into scattered showers and storms that will move through the eastern half of the area. There is a fair amount of low level instability that will build ahead of this future area of convection that will not have anything working over the atmosphere ahead it. However, the one limiting factor is a slight cap from 500-650 mb that really weakens the mid-level lapse rates and could prevent convection from forming ahead of the main cold front. The other concerning area will be with the ongoing convection ahead of the cold front that is crossing the IN/OH state line. This line has already produced some just sub-severe wind gusts in Indiana and will enter an environment that will become increasingly favorable for severe wind gusts this afternoon with better DCAPE and low level lapse rates. The limiting factor for this line will be any convection that develops ahead of it that could work over the atmosphere and diminish the wind threat.

For the flooding threat through tonight, storms will be progressive across the area with at best two rounds of precipitation expected. Overall, the QPF forecast remains limited with one inch of rain or less expected with the rain ahead of the cold front. There is ongoing flooding of note in North Central Ohio, mainly in the Mohican River basins, and flooding here may be slower to recede with this next round of rain. Flooding outside of this region would be limited to localized urban issues where FFG values have lowered over the past week.

KEY MESSAGE 2... Tonight's cold front will be the start of a significant pattern change across the region. Sunday's high temperatures are likely to be early in the morning before the main cold front rolls through the region. Cold advection will persist across the area on Sunday as the main upper trough axis moves through the Great Lakes region. This trough could allow for some modest lift to allow for some light rain showers on Sunday, especially downwind of Lake Erie where there could be some upslope in the higher hills of NE OH and NW PA. For Monday into Monday night, a secondary push of energy will move aloft through the region and provide more lift for precipitation. With 850 mb temperatures in the -6 to -8C range, there will be the opportunity for some lake enhanced precipitation with some upslope enhancement as well and have increased PoPs for this period. On Monday night, a more firm changeover to snow is likely and snow accumulations are possible in the hills of NE OH/NW PA. It would not be unreasonable to see 1-3" of snow by Tuesday morning where scattered snow showers persist.

KEY MESSAGE 3... The cooler high pressure system from earlier in the week will shift east and allow for warmer, return flow into the region. Temperatures will return back to normal on Wednesday with upper 50s and dry conditions. There is still some uncertainty on the timing of the late week system and cold front with some guidance suggesting rain ahead of this feature entering on Thursday and other guidance suggesting that rain hold off until Friday. Temperatures may get a bit warmer into the 60s ahead of this front but not near the 70s and 80s from this afternoon. Therefore, any storm potential seems low at this time.

AVIATION /00Z Sunday THROUGH Thursday/

Two lines of showers ahead of/along a cold front will continue to move east across the area into this evening. The overall thunder risk remains relatively low, but these storms are capable of producing non-VFR conditions in moderate to heavy rain and lower ceilings in addition to gusty winds to 30 to 40 knots (isolated higher gusts possible). The showers should largely taper off from west to east tonight with rain ending at KYNG/KERI by 09Z or 10Z. Behind the rain, ceilings will fluctuate between MVFR and low- end VFR (around 3500 ft AGL) throughout the remainder of the TAF period.

Winds ahead of the front will be out of the south/southwest before becoming more westerly behind the front. Sustained winds will generally be between 10 and 15 knots for the majority of the TAF period, although sustained winds just ahead of the front may reach or briefly exceed 20 knots this evening. Wind gusts will be 20 to 25 knots through 00Z Monday, however periodic gusts to 30 knots are possible tonight and again during the day Sunday.

Outlook...Non-VFR may return Monday and Monday night in rain and/or snow showers.

MARINE

South to southwest winds this afternoon will become westerly as a strong cold front pushes east across the lake by tonight. Winds will increase to 15-25 kts across the lake early Sunday, and have issued a Small Craft Advisory for 3-5 ft. wave expected. Winds will remain westerly Sunday night into Monday but will decrease a bit as a trough lingers north of the lake. A cold front will push south across the lake Monday night, with northwest winds of 15-25 kts possibly necessitating another Small Craft Advisory. Ridging builds across the lake into midweek with calming conditions on the lake.

CLIMATE

New high temperature records are occurring at area climate sites this afternoon. Here are the current record high temperatures for all six of our climate sites for April 4:

Date Toledo Mansfield Cleveland Akron Youngstown Erie 04-04 78(1882) 79(1921) 77(1882) 77(1921) 76(1981) 77(1928)

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory from 8 AM to 11 PM EDT Sunday for LEZ145>149.