textproduct: Cleveland

WHAT HAS CHANGED

The frost potential continues to decrease as clouds look to build over the area tonight with scattered showers. Best chance for any patchy frost may be the inland portions of NW PA.

KEY MESSAGES

1) Cool temperatures linger through tonight with scattered showers possible. Clouds and rain showers should inhibit any frost formation for much of the area, but some patchy frost is possible in inland NWPA.

2) Multiple cold fronts will push east this weekend, resulting in multiple rounds of showers. Rain totals should remain less than one inch over two days, keeping any flooding potential at bay.

3) Another cool airmass arrives early next week with below average temperatures expected across the area.

DISCUSSION

KEY MESSAGE 1... Below average temperatures are being observed today with highs only climbing into the low to mid 50s as a surface ridge lingers across the area. Tonight, an upper level short wave will impact the area as a weak warm front is expected to lift north. Isentropic lift coupled with mid-level energy will provide enough support for isolated light showers to occur and for widespread clouds to develop. These showers and cloud coverage should minimize any frost potential as the lack of radiational cooling allows temperatures to remain in the upper 30s to low 40s. The possible exception may be in portions of inland NW PA where breaks in cloud coverage early may allow for temperatures to fall a bit quicker and patchy frost to develop. Confidence is very low at this point, so opted to keep any frost mention out of the forecast, but it wouldn't hurt to protect vulnerable vegetation given the very marginal conditions.

KEY MESSAGE 2... As the upper level trough become centered over the region it will support the development of a surface low pressure. Multiple cold front associated with this low pressure are expected to push east on Friday through Sunday, bringing multiple rounds of rainfall to the area. The most widespread and consistent rain is expected to occur late Friday into Saturday a cold front supported by an upper level shortwave trough and LLJ of 30-35 knots pushing northeast. Additional cold fronts on Saturday and Sunday should provide an additional focus for more shower development with little time to dry out this weekend. Temperatures on Friday will be a touch warmer in the low 60s before warming into the mid to upper 60s on Saturday. As the final cold front pushes east on Sunday, high temperatures will trend back down to below average. Although this will be a prolonged event, the overall airmass should support PWAT values that are below average for this time of year, ultimately resulting in less than one inch of precipitation over the 3 day time span. Given the limited QPF totals and the extensive time frame, there remain no flooding concerns. In addition, given the overall marginal forcing and lack of instability, not expecting any thunder to associated these showers.

KEY MESSAGE 3... The roller coaster of temperatures is expected to continue into next week as another Canadian airmass pushes southeast across the area behind the departing cold front on Sunday. Highs through midweek are expected to remain in the 50s before possible gradually warming near the end of the work week. Overnight lows will follow a similar pattern with temperatures Sunday and Monday nights in the upper 30s to low 40s. Not expecting any frost at this point, however will have to monitor the cloud coverage potential as widespread clearing could result in temperatures a bit cooler than currently forecast.

AVIATION /00Z Friday THROUGH Tuesday/

Primarily VFR conditions are expected across terminals through the TAF period. Some light rain showers will enter from the west this evening and spread eastward through the overnight hours. Expecting for cigs/vis to remain VFR but drop to 3500ft and 6SM. There remains a locally higher chance of MVFR cigs in rain showers at KERI through ~12Z/Fri. Have this timeframe highlighted in the TAF with a PROB30 group at all TAF sites.

There will be a dry window where cigs will rise above 5000ft Friday morning/afternoon before another round of rain showers enters the region late in the TAF period on Friday evening. Guidance indicates a higher probability of non-VFR ceilings with patchy non-VFR visibilities with the second round of rain showers. Have kept all terminals except the 30-hr KCLE TAF at VFR with this round of rain showers, but future TAFs will likely need to add in a mention of MVFR to IFR ceilings Friday night into Saturday morning.

Winds will vary between westerly to southwesterly at 5-10 knots through the TAF period. There may be a brief window of 15-20 knot westerly gusts at eastern terminals Friday afternoon.

Outlook...Non-VFR conditions are possible in periodic showers and isolated thunderstorms Friday night through Sunday.

MARINE

The weather and marine conditions for Lake Erie will generally be quiet with some wind shifts through the weekend. High pressure over is nearby the lake today bringing a westerly flow of 10 to 15 knots that will continue through Friday morning. A weak low pressure system will track through the area late Friday into Friday night with a brief window of light and variable winds as it passes by. Southwesterly flow will develop 10 to 15 knots on Saturday ahead of an approaching cold front. The weak front will move across the lake Saturday night with a shift to northerly flow 8 to 15 knots Sunday into Monday as high pressure builds in over the Great Lakes region. A light southerly flow will return by Tuesday 5 to 12 knots. Waves will be 1 to 2 feet today through Saturday. Waves will increase 1 to 3 feet Sunday into Monday with some 4 feet possible in the open water from the northwesterly flow.

CLE WATCHES/WARNINGS/ADVISORIES

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