textproduct: Cleveland

WHAT HAS CHANGED

No major changes to the forecast at this time.

KEY MESSAGES

1) Dry weather with below normal temperatures is expected through Tuesday. There is high confidence in widespread frost on Monday night.

2) A system will enter for Tuesday night through Thursday, bringing the next chance of rain for the region. Some storms and moderate rainfall could be possible on Tuesday night into Wednesday.

DISCUSSION

KEY MESSAGE 1... A reinforcing cold front will make a dry passage during the first half of the day before high pressure builds into the region. This high pressure system will stay in place through Tuesday and promote dry weather, while keeping temperatures cool for mid-May. Clouds will remain across the region today and tonight, and this will likely keep low temperatures more in the upper 30 to lower 40s, limiting the frost threat for tonight. However, clearing conditions will enter for Monday, which should allow for a clear, calm, and decoupling atmosphere and low temperatures in the 30s are anticipated. There is high confidence in a widespread frost on Monday night and some eastern areas may even have a freeze, if lower 30s can be achieved. High temperatures on Monday will generally be in the 50s. Highs on Tuesday will be in the upper 50s to 60s with high pressure moving out and some return flow entering the region ahead of the next low pressure system.

KEY MESSAGE 2... Unsettled weather will return starting Tuesday night, as a low pressure system moves through the Great Lakes region, bringing rain chances through Thursday. Some instability may build on the warm side of the system on Tuesday night and this could support some initial thunderstorms through Wednesday. However, the late diurnal timing and waning instability should preclude any organized severe weather threat. There could also be some moderate rain on Tuesday night into Wednesday morning with the thunderstorms and will need to watch for trends with that part of the forecast for any future flood concern. Rain will continue through Thursday as the system departs to the east and rainfall should be lighter on the back end of the system. Temperatures for the middle of the week should be fairly seasonable in the 60s, perhaps a touch below normal, compared to the upper 60s for mid-May.

AVIATION /12Z Sunday THROUGH Thursday/

A surface ridge builds slowly from the Canadian Prairies and the north-central United States through 12Z/Mon. Our regional surface winds trend around 5 to 10 knots and primarily NW'erly to NE'erly through 00Z/Mon. Between 00Z and 12Z/Mon, our regional surface winds trend light and variable. As the upper-reaches of a cold front continue to exit SE'ward from our area this morning, isolated rain showers associated with the front should exit to the east by ~13Z/Sun. These showers may be accompanied by brief MVFR. Otherwise, dry weather and VFR are expected through 12Z/Mon.

Outlook...Periodic showers and thunderstorms with non-VFR are expected Tuesday afternoon through Wednesday night. Non-VFR may linger across eastern portions of our area due to rain showers and low ceilings this Thursday.

MARINE

A ridge affects Lake Erie as the embedded high pressure center moves from the Canadian Prairies toward Atlantic waters near the Mid- Atlantic states through Tuesday. Primarily NW'erly to N'erly winds around 5 to 15 knots through Monday should become variable in direction Monday night through Tuesday. Waves should trend 3 feet or less.

The ridge should exit E'ward Tuesday night through Wednesday night as a low wobbles ESE'ward from the northwestern Great Lakes toward Lake Ontario and weakens gradually. Accordingly, a warm front should sweep N'ward across Lake Erie Tuesday night and cause SE'erly winds to veer to S'erly to SW'erly as winds freshen to around 15 to 25 knots. A cold front should then sweep E'ward across Lake Erie late Wednesday morning through Wednesday night and cause winds to veer to W'erly to NW'erly as wind speeds ease to around 10 to 20 knots. Waves should build to as large as 3 to 6 feet during the Tuesday night through Wednesday night time frame. Forecast trends may prompt the eventual issuance of a Small Craft Advisory.

Behind the cold front, another high pressure ridge should build from the western Great Lakes through Thursday. On Thursday, W'erly to N'erly winds should ease further to around 5 to 15 knots. In response, waves should subside to 3 feet or less.

CLE WATCHES/WARNINGS/ADVISORIES

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