textproduct: Cleveland

WHAT HAS CHANGED

Raised pops for tonight and shifted northward to encompass most of the area in showers tonight into Friday morning. Lowered temperatures slightly in the east to allow a low chance of snow to mix with rain in Ashtabula and inland NW Pennsylvania generally early Friday morning. Added a chance of rain near and south of Lake Erie on Friday night for North Central Ohio which did result in less coverage of frost.

KEY MESSAGES

1) Below normal temperatures are expected through the weekend and a Frost Advisory is in effect for inland portions of Erie and Crawford County PA for tonight. Potential for frost will expand Friday night and Saturday night.

2) Rain expected late tonight through Friday morning. A few wet snow flakes could mix in but not expecting impacts.

3) A warmer pattern returns next week with the potential for showers and thunderstorms through the first half of the week.

DISCUSSION

KEY MESSAGE 1...

A cool airmass has settled over the region with temperatures this afternoon ranging from the upper 40s to lower 50s. Cloud cover has a cumuliform appearance to it and expect to see a decrease in coverage through this evening. Temperatures will drop quickly in the east with very light winds while western areas will see cloud cover already on the increase ahead of the next system. A Frost Advisory remains in effect for inland Northwest Pennsylvania through tonight although temperatures may start to recover late tonight as clouds and showers approach. These showers will keep temperatures cool on Friday and lowered highs slightly, with a few locations in the east seeing highs in the upper 40s. Temperatures on Friday will average around 15 degrees below normal.

For Friday night, some cloud cover and even a low chance of showers is expected with an upper level trough over the Central Great Lakes. Given the cold airmass with 850mb temperatures of around -5C, low temperatures are still expected to fall into the low 30s with light winds. The coverage of cloud cover complicates the frost forecast with greatest potential for frost on all fringes of the forecast area. Portions of inland NW Pennsylvania may even see a freeze. Expecting less cloud cover by Saturday night with more areas experiencing a widespread frost.

KEY MESSAGE 2...

A shortwave trough can be seen dropping through the Upper Midwest on water vapor imagery as it rounds the broad upper level trough over the Great Lakes Region. Surface low pressure is starting to develop over northern Illinois this afternoon and will slide east across the local area through Friday morning. Precipitation will develop along a fairly compact baroclinic zone overhead with widespread rain in the forecast for late tonight into Friday morning. It is worth noting that while temperatures will tend to be near 40 degrees during the rain event, some cooling due to melting where good rates are occurring to the north of the low may allow temperatures to briefly dip into the upper 30s. Can not rule a little mix with wet snow although potential for any wintry impacts is low. Did included a short window of a rain/snow mix in far Northeast Ohio and Northwest Pennsylvania late tonight into early Friday. The trend over the last several cycles has been to the north with around a quarter of an inch of rain across our northern counties and closer towards a tenth of an inch closer to Central Ohio.

KEY MESSAGE 3...

The persistent upper level trough departs on Sunday with a warm front lifting north of the area on Monday. Winds back to the southwest on Sunday but still under the influence of high pressure. Moisture return in conjunction with a low level jet Sunday night with a few showers or thunderstorms possible. Better instability returns on Monday in the warm sector with additional chances for thunderstorms. Better forcing looks focused on Tuesday ahead of the associated cold front. Temperatures trend cooler again behind the front for the middle to end of next week.

AVIATION /00 Friday THROUGH Tuesday/

Conditions are starting out as VFR and will continue through the late evening hour. Eventually MVFR to lower end MVFR ceilings will move in from west to east during the late night and early Friday morning. Some TAF sites like TOL, FDY, CLE, and ERI may see IFR ceilings by early Friday morning. Ceilings will become MVFR to VFR later in the TAF period or late Friday afternoon. Scattered rain showers will move in later tonight through Friday morning causing 3sm to 5sm visibilities. Winds will generally be from the west or northwest 5 to 10 knots.

Outlook...Non-VFR possible in scattered showers and thunderstorms on Monday into Tuesday.

MARINE

Conditions across Lake Erie will stay generally quiet through the weekend. Winds will be predominately out of the north to northwest at 5-15 knots through Saturday before shifting to be out of the west on Sunday. Waves during this time period will stay less than 3 feet. High pressure will pass to the south on Sunday and winds will increase out of the west to 10-20 knots and then shift to be out of the southwest by the evening. By Monday morning, winds will increase to 15-25 knots out of the southwest and persist into Tuesday and waves will build to 2-4 feet.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...Frost Advisory from 11 PM this evening to 9 AM EDT Friday for PAZ002-003. MARINE...None.