textproduct: Cleveland

WHAT HAS CHANGED

The forecast remains largely unchanged. A marginal risk of severe thunderstorms has been added south of a line from Mount Gilead to Canton to Youngstown for Friday afternoon. Temperatures have been adjusted along the northeast lakeshore to account for temperatures ahead of and behind the various boundaries.

KEY MESSAGES

1) A warming trend is expected into this weekend with showers and a low chance of thunderstorms Friday. There is potential for an isolated severe thunderstorm late Friday afternoon/evening closer to Central Ohio.

2) Well above normal temperatures are expected Sunday followed by showers with a chance of thunderstorms Sunday night as a strong cold front pushes south, ushering in much cooler air for Monday.

DISCUSSION

KEY MESSAGE #1... Low pressure will slide east into the Great Lakes region on Friday ahead of a shortwave trough moving through the northwest flow aloft. A warm front lifts north ahead of this feature overnight with a southwesterly low level jet of 45-55 knots crossing Lake Erie. Mixing heights will be somewhat shallow on Friday, exceeding 3K feet during the afternoon which will yield wind gusts of 25-35 mph. Despite good coverage of mid and high level clouds, high temperatures are forecast to be above normal ranging from the mid 60s in NW Ohio to mid 50s in NW Pennsylvania. Low levels are forecast to be dry in the warm sector during the morning with chances of showers developing in the northeast first, then accompanying a cold front pushing south across north central and northeast Ohio during the afternoon. Instability ahead of the front will be limited with dewpoints generally in the upper 40s but there is a window of time where instability reaches 200-400 J/kg. There will be 45-50 knots of shear available so if a thunderstorms does develop we will need to monitor intensity, but storms are more likely to intensify as they move out of our area. This is the location that the Storm Prediction Center has placed a Marginal Risk of Severe Weather.

Temperatures drop back slightly behind the cold front on Saturday and have lowered high temperatures along the northeast lakeshore where the marine airmass is likely to have an influence. Skies will also be clearing with light winds making for a pleasant day. KEY MESSAGE #2... A broad ridge aloft expands east into the area on Sunday ahead of low pressure approaching from the Plains. The warm front lifts back north on Saturday night with the area located in the warm sector on Sunday. Conditions will be breezy again on Sunday with another low level jet of 40-50 knots aloft, resulting in winds gusting to at least 30-35 mph. Depending on the degree of mixing heights, we could see winds gusting to 40 mph at times. Temperatures at 925mb warm to 18-21C and highs look to reach 65-75 degrees. The morning will be dry with rain holding off until moisture starts to increase ahead of the cold front late afternoon. Low pressure passes just south of Lake Erie during the afternoon and pulls a strong cold front south across the area as a shortwave moves through the flow aloft. Dewpoints and low level moisture will again be a limiting factor and soundings look to remain capped until evening. A few thunderstorms could develop along the front during the evening as its moving south out of the area.

Strong cold advection will follow Sunday night into Monday as 850mb temperatures fall by nearly 20 degrees. Temperatures on Monday will be approximately 30 degrees cooler on Monday with potentially a brief shower before high pressure builds in.

AVIATION /00Z Friday THROUGH Tuesday/

Mainly VFR ceilings are expected for this TAF update and through Friday afternoon. A cold front will move in late in the TAF period with an increase in cloud cover. MVFR ceilings will likely move into ERI towards the end of the time period. Have included -SHRA for CLE, CAK, YNG, and ERI after 14z through the end of the TAF period.

Winds will briefly become light and variable this evening before becoming southerly and increasing to 8 to 14 knots by early Friday morning. A low level jet will move over the area early Friday morning, resulting in a period of LLWS due to 2000ft AGL winds to 45 to 50 knots. Winds will increase by a few knots by mid-morning Friday with gusts to 25 to 30 knots anticipated as once mixing develops. The LLWS risk will diminish as gusts increase.

Outlook...Non-VFR possible in rain showers low ceilings on Sunday.

MARINE

Light and variable winds will persist through this evening before winds shift to the south/southwest and increase to 15 to 20 knots Friday morning. Winds may briefly meet Small Craft Advisory criteria in the eastern basin at some point Friday morning or early Friday afternoon, but conditions will likely be very brief if they occur so opted against issuing a Small Craft Advisory at this time. Winds will become northwesterly and diminish to 6 to 12 knots Friday evening with light and variable winds developing for Saturday. On Sunday morning, winds will become southwesterly at around 10 knots before shifting to the north/northwest behind a cold front Sunday evening. Small Craft Advisories will likely be needed as winds/waves increase through Monday morning.

CLE WATCHES/WARNINGS/ADVISORIES

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