textproduct: Cleveland

WHAT HAS CHANGED

Confidence continues to increase in the strong wind potential across the area on Friday. As a result, a High Wind Watch has been issued across the entire area from early Friday morning through the evening.

KEY MESSAGES

1) Strong winds expected Friday as robust low pressure pushes east.

2) Active pattern continues into early next week with multiple low pressure systems expected to impact the area.

DISCUSSION

KEY MESSAGE #1: Late Thursday into early Friday, a strong low pressure system will begin to impact the area. An associated strong LLJ with winds of 60 to 70 knots will surge over the area with a push of warm air advection. The strongest part of the jet is expected to only move over the western portion of the area with a 'weaker' jet of 40 to 50 knots impacting the eastern portion. Steepening lapse rates throughout the day and mixing level almost to 850mb should be adequate to mix these strong winds to the surface. Many hi-res models have wind gusts in excess of 58mph (50kts) across western counties with slightly weaker gusts in the 45 to 50 mph across eastern counties. Although the overall environment should be conducive to bringing the strong winds to the surface, local downslope enhancement is expected to impact the lakeshore area across NWPA. In addition, overall precipitation chances are minimal and should be isolated to the northern half of the CWA, but with any showers that do occur, expect additional mixing to bring strong gusts to the surface. Moral of the story is that it is going to be quite windy on Friday.

To highlight this hazard, a High Wind Watch has been issued for the entire CWA beginning late tonight/early Friday and continuing into Friday evening. Expect this headline to be upgraded to a advisory and/or warning in future forecast updates.

KEY MESSAGE #2: The weather pattern into next week will remain very active with multiple low pressures moving east across the area. This will bring multiple chances of precipitation (both rain and snow) and a roller coaster of temperatures. The first system will impact the area on Friday (see key message #1) which will bring a chance of showers across the area. Initial showers should be primarily snow Friday morning before transitioning to all rain by Friday evening.

Another strong low pressure is expected to impact the area on Sunday into Monday which is expected to be a bigger producer of precipitation across the area. Initially on Sunday, a warm front will lift north, ushering in warmer temperatures once again. Ahead of this boundary, a mix of rain/snow is expected before transitioning to all rain behind the warm front. These rain showers will persist into Sunday night before transitioning back to a rain/snow mix Sunday night as a cold front pushes east. The current storm total QPF for this entire system is generally 0.6 to 1 inch with the highest totals expected across the western counties. Periods of heavy rain may result in localized flooding concerns, but given the current lower levels in rivers not expecting anything widespread at this point. Will have to continue to monitor this system for any convection potential as well given the robust synoptic support, but confidence is too low to add any thunder mention at this point.

AVIATION /12Z Thursday THROUGH Monday/

Mainly VFR across the TAF sites this morning, though MVFR ceilings may linger at ERI through this morning. A few isolated to scattered snow showers may develop this afternoon and could impact ERI, so have introduced a vcsh group in this update. Apart from ERI, ceilings are anticipated to remain at VFR through the TAF period, gradually lowering to 10kft, then around 5kft by early Friday morning.

Otherwise, the main concern for the TAF period period will be increasing south to southwest winds towards the end of the TAF period beginning early Friday morning. Have begun to introduce south winds of 15 to 25 knots with gusts of 30 to 35 knots through 11Z Friday. Winds are expected to continue increasing through the morning into the afternoon and expect more additions of 40+ knot wind gusts by the next package.

Outlook...Non-VFR possible in scattered rain/snow showers on Friday with strong west to southwest winds in excess of 40 knots expected. Non-VFR likely to return in rain/snow showers Saturday night into Sunday. Non-VFR may linger in scattered rain/snow showers on Monday.

MARINE

The Gale Watch has been upgraded to a Gale Warning with this package, in addition to the issuance of a Low Water Advisory for the western basin of Lake Erie. A potent storm system will move east through the Great Lakes on Friday, ushering in southwest, then west winds of 25 to 35 knots and gusts up to 50 knots across the lake. In addition, water levels across the western basin could fall 1 to 2 feet below low water datum. Attention then turns towards the next system towards the end of the weekend (Sunday into Monday) when another system moves east through the Great Lakes. Confidence for southwest to west Gales continues to increase with this package. Elevated westerly winds of 25 to 30 knots could persist through Tuesday.

CLE WATCHES/WARNINGS/ADVISORIES

OH...High Wind Watch from late tonight through Friday evening for OHZ003-006>010-017>019-027>030-036-037-047. High Wind Watch from Friday morning through Friday evening for OHZ011>014-020>023-031>033-038-089. PA...High Wind Watch from Friday morning through Friday evening for PAZ001>003. MARINE...Small Craft Advisory until 10 AM EDT this morning for LEZ142>144. Gale Warning from 8 AM Friday to 4 AM EDT Saturday for LEZ142>147-162>167. Low Water Advisory from 8 AM Friday to 4 AM EDT Saturday for LEZ142>144-162>164. Small Craft Advisory until 4 PM EDT this afternoon for LEZ145>149. Gale Warning from noon Friday to 4 AM EDT Saturday for LEZ148- 149-168-169.