textproduct: Cleveland

WHAT HAS CHANGED

No significant changes to the forecast or the overall expected pattern change beginning this weekend.

KEY MESSAGES

1) Lake effect/lake enhanced rain showers expected in low level northwest flow behind the cold front that has just moved southeast of the CWA.

2) Significant warming trend expected beginning this weekend.

DISCUSSION

KEY MESSAGE 1... Post-cold frontal airmass has 850mb temperatures falling once again into the lower single digits, and saturated low level flow in aligned northwesterly winds across Lake Erie brings a fairly broad area of showers possible for the eastern CWA. This will begin largely after 03Z, and will receive an assist in terms of lift from an upper level trough axis swinging through from the north in the 09Z time frame. High pressure advances eastward from the plains region, and that will ultimately shut off the threat west to east through the early part of the day Thursday, lingering in northwest PA into early Thursday night. Low QPF event, and although coverage of the showers is somewhat large, largely expected to be scattered in nature. Temperatures may not make it out of the 40s for eastern portions of Erie/Crawford counties in PA. Further west, while still in the shower potential, 50s expected, and away from that activity in the western third of the CWA, 60s expected.

KEY MESSAGE 2... Upon exit of the upper trough for the end of the week, expecting the flow to turn more zonal, a change from the dominant upper level troughing that has kept the region on the cooler side for the past couple of weeks. 850mb temperatures recover, and the cooler airmasses will become locked mainly north of the border, at least until the middle of next week. Warming trend will commence for the weekend as a warm front will lift north of the southern Great Lakes, allowing 850mb temperatures to push into the upper teens. This will provide the first summer-like feel to the sensible weather for the calendar, not only in the temperatures that will push the 90F mark Monday and Tuesday, but dewpoints well into the mid to upper 60s. Expecting temperatures to drop back mid week, but only into the 70s, and not a return to the seasonably cool conditions that we have become accustomed to for the first half of May. As can be expected, chances for showers and storms will return for early next week, and with a cold front coming through, will need to assess any sever potential as we near that part of the forecast which is in the day 5- 7 range at this point.

AVIATION /00Z Thursday THROUGH Monday/

Generally MVFR across the TAF sites this evening, with MVFR and pockets of IFR conditions to continue through Thursday morning. These non-VFR conditions are mainly associated with low ceilings, though can't rule out some lower MVFR to perhaps IFR vsbys in mist and/or drizzle, especially at YNG/ERI later tonight into Thursday morning. Otherwise, ceilings are expected to improve to VFR from west to east overnight into Thursday afternoon.

Winds are generally out of the northwest this evening, 10 to 15 knots. Northwest winds will remain elevated overnight, around 10 knots, increasing again into the 10 to 15 knot range with periodic gusts of 20 to 25 knots possible late Thursday morning and afternoon.

Outlook...Non-VFR becoming more likely in showers and thunderstorms Saturday afternoon and evening. Additional non-VFR possible in scattered showers and thunderstorms Sunday afternoon and evening, though chances are lower.

MARINE

A trough will linger across Lake Erie tonight through Thursday providing a continued period of hazardous marine conditions. Small Craft Advisories remain in effect through noon tomorrow. Northwest winds 15 to 25 knots will continue through Thursday afternoon allowing for wave heights in the open waters to remain between 3 and 6 feet. As high pressure builds overhead tomorrow, northwesterly winds will diminish to 10-15 knots before turning southerly and decreasing to 10 knots or less by Friday. Generally offshore flow between 5-10 knots will remain across the lake this weekend.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until noon EDT Thursday for LEZ142>149.