textproduct: Cleveland

WHAT HAS CHANGED

Forecast remains on track with no major changes.

KEY MESSAGES

1) Lake effect showers continue this evening through Sunday with rain and rain/snow mix expected. Light snow accumulations are possible across NE OH and NW PA tonight.

2) High pressure builds in early next week with drier, seasonable weather expected through the majority of the week.

DISCUSSION

KEY MESSAGE 1... Upper level troughing continues across much of the eastern CONUS and north into Eastern Canada and will slowly deepen off to the east throughout the weekend. Meanwhile, shortwave features are expected to move north to south along the western periphery of the trough bringing reinforcing upper level support and colder air into the region. 850mb and 500mb temperatures have bottomed out at around -6C and -25 to -30C, respectively, this morning and will be steady through the overnight before gradually warming throughout the day Saturday.

Currently, flow is out of the north across the region allowing for a lake effect band to set up from Erie Co, OH south trough Knox Co. Generally, this band has been primarily rain with some rain/snow showers mixed in. Given the flow, this band has been able to tap into the moisture from Lake Huron, and to a lesser extent, Lake St. Clair. Flow will begin to shift to be out of the north to northwest this evening into Saturday and as a result, the band will shift to the east towards the Cleveland metro area. There will be a reinforcing vort max moving south as the flow does shift that will help in giving the band more strength. Temperatures will also drop to the coldest expected this weekend with lows in the upper 20s to low 30s and the lake shore staying in the mid to upper 30s. With the areas near the shore being warmer, and any precipitation that falls is expected to stay as rain through the overnight hours. Further south away from the lake shore where the temperatures are colder and the elevation rises, rain will transition over to a rain/snow mix overnight. There will be periods of only snow, but expect it to be mainly a mix. Light accumulations are possible as well, though with the ground being fairly warm, it will limit the overall totals. There may be some areas across Northeastern Ohio and Northwestern Pennsylvania that could see around an inch or two of accumulation by tomorrow morning but expect those occurrences to be isolated.

Throughout the day Saturday, flow will continue to shift to be more northwesterly and veer to be more west of north further up in the column. This will create a more multi-banded set up impacting Northeastern Ohio and Northwestern Pennsylvania throughout the day. There will still be some support from the Lake Huron connection but drier, low-level air will start to push in from the west as the trough begins to push east and the ridge builds in from the west. Temperatures will rise into the mid 40s tomorrow as well, so expect precipitation to fall mainly as rain after the morning hours. A final, vort max will move south through the region late Saturday night into Sunday morning that will reinvigorate the lake effect band with additional moisture through Sunday morning. With temperatures warming, and staying above freezing for much of the region, expecting this precipitation to stay as rain overnight. There will be some exceptions as the higher elevations of Northwest Pennsylvania could see some rain/snow mix, but with little to no accumulation.

Lingering lake effect rain showers are possible across Northeastern Ohio and Northwestern Pennsylvania throughout Sunday and into early Monday morning as there will be some low level moisture across that area. Elsewhere, should begin to see the lake effect cloud cover begin to dissipate Sunday night through Monday as the 925mb and 850mb ridges build east across the region. Dry weather is expected across the region after Monday morning with high pressure building in.

KEY MESSAGE 2... The upper level trough will exit to the east Sunday night into Monday as an upper level ridge builds in across the Northern Great Plains into the Great Lakes regions. This will build eastward through the early part of next week as a more amplified ridge builds across the Rockies and progresses eastward. All that being said, surface high pressure will build in from the northwest into the Ohio Valley Monday through the middle of the week with dry, quiet weather expected. Temperatures will start off chilly to begin the week with high in the upper 40s to low 50s and progressively warm as the high builds east and the region moves into southwesterly flow. By Thursday, highs will be more seasonable, if not a few degrees warmer, in the upper 50s to low 60s. Overnight lows will follow a similar pattern, starting off in the mid to upper 20s and warm into the 30s by mid week.

AVIATION /18Z Friday THROUGH Wednesday/

Upper level low pressure continues to dominate the region. While ceilings have lifted to VFR for most locations, MVFR ceilings are expected to return tonight as -SHRA/-SHRASN activity ramps up again for northern OH and northwestern PA. Some IFR ceilings towards morning cannot be ruled out, and precipitation is likely to continue for CAK/YNG/CLE through much of the forecast window. Winds northerly tonight 10kts turn northwesterly and gust again to 20kts after 16Z Saturday.

Outlook...Non-VFR will linger across Northeast Ohio and Northwest Pennsylvania through the weekend.

MARINE

Conditions across Lake Erie will continue to be unsettled through the weekend. North winds will shift to be more northwesterly by early Saturday morning increasing to 15-25 knots. Generally, the strongest winds will be from the Islands east through Conneaut, OH and waves will build as a result to 3-5 feet tonight and 4-7 feet by Saturday evening. A Small Craft Advisory has been issued for those nearshore zones begin this evening at 7PM through Sunday morning. The nearshore zones to the east towards Ripley, NY will reach Small Craft Criteria Saturday morning and last through early Sunday morning. Additionally, with the lake being warm still, there's enough instability for a chance of waterspouts in rain showers through Saturday. Stronger winds may inhibit waterspout formation Saturday afternoon and evening. Winds and waves will begin to diminish Sunday afternoon into Monday with winds at 10-15 knots staying northwesterly. Waves will also diminish to 1-3 feet by Sunday evening as well. From Monday through the middle of the week, winds will shift to be out of the west to southwest at 10 knots with waves 2 feet or less across the lake.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until 10 AM EST Sunday for LEZ144>148. Small Craft Advisory from 10 AM Saturday to 4 AM EST Sunday for LEZ149.