textproduct: Cleveland

WHAT HAS CHANGED

Timing and impacts of thunderstorms for Saturday have become more refined. Otherwise, no major changes to the forecast.

KEY MESSAGES

1) Periodic showers and thunderstorms possible this weekend with a passing warm front with a few possible strong storms on Saturday. Additional rain/thunderstorm chances increase again mid-week with a cold front passage.

2) There will much warmer temperatures across the region Monday and Tuesday being on the southern side of the warm front.

DISCUSSION

KEY MESSAGE #1: Late this evening a warm front will lift north across the region with temperatures and dew points increasing behind it. There will be a remnant complex moving across northern Indiana up into Michigan that will enter northern Ohio around 12Z tomorrow morning. This feature may have some stronger storms along with it as it enters the CWA with bulk shear of around 35-45 knots and MUCAPE values being marginal around 500-1000 J/kg. Lapse rates will be lacking given the time of day this feature will pass through as well. Showers/thunderstorms may have a brief lull as the morning precipitation exits off to the east by mid-day. In the afternoon, there will be a weak shortwave moving across the Ohio Valley that will help support additional showers/thunderstorms in the afternoon into the evening. With the break in precipitation mentioned above, there may be some opportunity for instability to increase in the western two-thirds of the CWA and less so with the eastern portion given showers may linger over into peak heating preventing ample warming. Regardless, with the morning precipitation across the region, how much the area clears out and destabilizes again will be the main question. Though with decent flow aloft, as mentioned above with the bulk shear, there has been a marginal risk of severe weather introduced for the western two-thirds of northern Ohio for Saturday. This is due to the isolated strong to damaging wind threat across the region with the morning convection as there is less confidence during the afternoon/evening in potential strong to severe weather. Showers and thunderstorms will begin to exit out to the east Saturday evening as the shortwave support moves off.

With the warm front stalling out to the north of the region by Sunday morning, there will continue to be some shower and thunderstorm chances, though will generally be on the low end. An additional shortwave may pass through the region Sunday afternoon that could help support a few more showers as well. Precipitation chances decrease into Monday as the drier air moves into the region.

Precipitation chances return to the region mid-week as a low pressure system enters the Great Lakes region. PoP chances will increase Tuesday ahead of the low and with increase moisture flow. There still some uncertainty of when the cold front will be and will impact any thunderstorm chances across the region. Additionally, there looks to be some potential for severe weather with this system on Tuesday, so will need to monitor how it progresses as the forcing with the cold front will be key to the development.

KEY MESSAGE #2: As the warm front lifts north of the region tonight, temperatures will begin to warm to be well above average by Monday and Tuesday. 850 temperatures will rise to 16-18C across the region that will help support highs in the mid to upper 80s with a few spots possibly touching 90. The warmest of the days will be Monday as there will be clear skies allowing for temperatures to warm. Tuesday won't be quite as warm as cloud cover will begin to move into the region from the west, though highs will still be around the mid 80s. Additionally, dew points will climb as well with the increased south to southwesterly flow across the region. Dew points will climb up into the low to mid 60s on Monday and close to 70 on Tuesday. Not expecting any heat related headlines for either day, though given how early in the season it is, there will be a heat risk. From the NWS Heat Risk product, it has been highlighting the region with moderate heat risk for both Monday and Tuesday, and approaches major in a few locations for heat related impacts. With moderate level heat risk, this highlights days with increased impacts due to heat, and to promote precautions for outdoor plans and/or those with heat sensitivities. Temperatures will begin to moderate Wednesday as a cold front moves through the region with precipitation expected.

AVIATION /00Z Saturday THROUGH Wednesday/

Widespread VFR conditions will persist through tonight as high pressure persists. Late tonight into early Saturday morning, a warm front is expected to push north across the area bringing the potential for widespread showers and possibly a few rumbles of thunder to all terminals. Precipitation should begin around 12Z before spreading further east. As the boundary lifts north, a strong LLJ will creep into the area, increasing winds from the south-southwest to 12-15 knots with gusts up to 25 knots possible from late morning through the afternoon. The strongest gusts should be isolated to terminals along and west of I-71.

Another round of showers and storms is possible in the afternoon as a cold front approaches the area from the west. This second round of showers will bring widespread MVFR ceilings and possible reductions in visibilities within the heaviest showers. Cannot rule out additional thunder, however the thunder potential will be highly dependent on how quickly the atmosphere rebounds from earlier convection. Any storms that develop will have strong gusty winds associated with them.

Outlook...Non-VFR possible in scattered showers and thunderstorms Sunday afternoon and evening, though chances are lower. Non-VFR to return on Tuesday in showers and thunderstorms.

MARINE

Winds become south 10-20kts tonight into Saturday with a warm front moving across the lake, then southwesterly 10-20kts through late Saturday. Wave heights less than 2ft nearshore, but 2-4ft in the open water zones. A stationary front over Lake Erie Sunday brings variable winds less than 10kts and waves continued less than 2ft, and then back to offshore early next week 15-20kts Monday and Tuesday, where wave heights once again will increase with distance from shore.

CLE WATCHES/WARNINGS/ADVISORIES

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