Area Forecast Discussion

WHAT HAS CHANGED

The forecast largely remains on track and no significant changes were needed with this update.

KEY MESSAGES

1) Shower and thunderstorm chances return tonight through late this week. A few strong storms are possible in Northwest Ohio tonight.

2) Unsettled weather pattern continues into the weekend.

DISCUSSION

KEY MESSAGE 1... The majority of the forecast area should remain dry through this evening ahead of a period of unsettled weather. Low pressure pushing east across Ontario into Quebec will lift a warm front across the forecast area today. After a brief window of cooler conditions, highs will rise into the low/mid 80s for most and the upper 70s for eastern zones. Scattered showers and thunderstorms will approach the region from the west as the low drags a cold front into the eastern Great Lakes tonight. There remains some potential for an isolated strong to severe thunderstorm in Northwest Ohio where the SWODY1 Marginal Risk (Level 1 of 5) remains.Primary hazard will be damaging wind gusts. However, confidence remains fairly low given the disjointed timing of best instability and the arrival of the cold front. In addition to an isolated strong storm, there remains the potential for locally heavy rainfall within these storms across Northwest Ohio. The WPC maintains their Day 1 Marginal Risk (Level 1 of 4) for excessive rainfall across Northwest Ohio tonight. Will continue to monitor the locally heavy rainfall potential as recent runs of the HREF and REFS highlight stripe of 6-hour rainfall amounts between 2 and 3 inches in their localized probability-matched mean products.

The cold front will waver across the Ohio Valley Wednesday into Thursday. Additional rounds of showers and thunderstorms will be likely through late week. There remains uncertainty on if any storms will reach strong to severe limits mid to late week given the placement of the surface boundary. Despite this, a very warm and moist airmass will be in place with PWATs in the 1.5-2.0 inch range. Any storm will be capable of producing heavy rainfall, particulary in training showers and thunderstorms.

KEY MESSAGE 2... High pressure and dry conditions briefly return Friday into early Saturday before unsettled weather returns. A series of shortwaves aloft will move overhead Saturday into early next week. Daily shower and thunderstorm chances continue Saturday afternoon into Monday, though forecast confidence decreases Monday onward.

AVIATION /06Z Tuesday THROUGH Saturday/

VFR conditions will continue for the bulk of the TAF period with high pressure exiting out of the region. On the back side of this system, winds are becoming southerly across the region with a mix of mid- and high-level clouds entering with a warm front. Some low cumulus clouds will try to develop during the afternoon hours today and some mixing in the warm sector behind the warm front could allow for some brief 20 to 25 kt wind gusts. A weakening cold front will approach from the west toward the end of the TAF period, bringing lowering ceilings along with some rain and storm chances. With the front on a slowing and weakening trend and entering during a diurnal minimum, rain will be fairly scattered and any thunder activity will be limited to Northwest Ohio, where some PROB30s for TS have been introduced. Otherwise, the bulk of rain activity will hold off until after the TAF period and TS chances will remain low until Wednesday for most sites.

Outlook...Non-VFR possible at times in scattered showers/storms Wednesday through Thursday night.

MARINE

Offshore flow between 15-20 knots continue today before turning southwesterly ahead of an approaching cold front. Winds shift northerly and decrease to 10-15 knots behind the cold front by Wednesday morning. Northerly to northeasterly winds will continue though late week as the cold front wavers across the Ohio Valley region Wednesday into Thursday. No marine headlines are expected through the end of the week.

CLE WATCHES / WARNINGS / ADVISORIES

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