textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the forecast with the thunderstorm threat late Thursday into Thursday night.

KEY MESSAGES

1) The next round of widespread showers and storms will be associated with a cold front that will track through late Thursday into Thursday night.

DISCUSSION

KEY MESSAGE 1...

Quasi-zonal mid-level flow for the middle of this week will become amplified once again across the eastern half of the CONUS late this week as an elongated, but strong cold front propagates north to south through OH starting late Thursday afternoon. A broad area of moist SWerly flow from the lower MS Valley into the OH Valley will help raise surface dew points up to 60 degF for portions of OH. After lingering light precipitation Thursday morning, widespread showers and thunderstorms are expected to develop along the frontal boundary continuing through Thursday night. The latest SPC Outlook for Thursday shows a Slight Risk (Level 2/5) for severe thunderstorms with shear profiles around 50 kt as a strong jet moves overhead. Instability looks to be greatest across western OH highlighting the area more likely to see stronger storm development with the frontal passage, but a stout capping inversion indicated on latest forecast soundings will likely limit any prefrontal development. Strong winds and periods of heavy rainfall look to be the main hazards with these storms. With this cold front, 850mb temps will drop from 12-14 degC Thursday to near -10 degC late Friday resulting in maxTs on Friday and Saturday at least 10 degF below normal for late March.

AVIATION /18Z Tuesday THROUGH Sunday/

VFR conditions expected across area terminals through the forecast period. Passing SCT-BKN mid level clouds continue across northern OH terminals, while remaining SKC elsewhere through mid-afternoon. Winds will continue to shift from out of the southeast to southwest as high pressure continues to slide east of the area. The few exceptions this afternoon will be KCLE and KERI with lake breeze influences before 00z. Increasing mid to high level clouds are likely headed into this evening, but should remain at VFR levels.

Outlook...Non-VFR conditions are possible with periodic rain and/or snow this Thursday through early Friday afternoon. Scattered thunderstorms are possible Thursday afternoon through evening.

MARINE

Primarily S'erly to SW'erly winds around 5 to 15 knots are expected this afternoon through Thursday afternoon as the high pressure ridge exits slowly E'ward. Waves remain 3 feet or less.

A strong cold front should sweep SE'ward across Lake Erie Thursday evening and cause SW'erly winds around 10 to 20 knots to veer to NW'erly to N'erly and freshen to around 15 to 25 knots. Waves should build to as large as 3 to 5 feet and a Small Craft Advisory should be needed. Behind the front, a strong high pressure ridge should build from the northern Great Plains and vicinity through Friday. Winds should be primarily NW'erly to N'erly and ease gradually to around 5 to 15 knots by Friday evening. Waves initially as large as 3 to 6 feet should subside to 3 feet or less by sunset Friday evening.

On Saturday, the ridge should exit SE'ward from Lake Erie and allow another warm front to sweep generally N'ward across the lake. Then, a subtle trough should move generally E'ward across Lake Erie. This weather pattern evolution should allow winds around 5 to 15 knots to back from N'erly to SW'erly and then veer to W'erly. Waves should remain 3 feet or less.

CLE WATCHES/WARNINGS/ADVISORIES

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