textproduct: Cleveland

WHAT HAS CHANGED

The Winter Weather Advisory has been expanded to Portage and Trumbull Counties through 7 PM where accumulating snow has been heaviest across northern portions of the counties. Precipitation amounts have trended slightly upward Wednesday evening and night behind a strong cold front.

KEY MESSAGES

1) Snow showers will continue to lead to slick driving conditions in portions of the Ohio snowbelt through 7 PM and in Pennsylvania through this evening.

2) A strong cold front will arrive Wednesday afternoon with rain transitioning to snow that may impact the evening commute.

3) Below normal temperatures and opportunities for snow are possible into this weekend.

DISCUSSION

KEY MESSAGE 1... By 330 PM we have seen the intensity of snow across the snowbelt starting to decrease. Dryer air is approaching from the northwest while a surface trough is pushing inland. The colder cloud tops and deeper moisture noted on satellite imagery have pushed east into Pennsylvania which is allowing the intensity of snow to trend down. Advisories in Ohio remain in effect until 7 PM when the moisture at 850mb starts to strip away and the Advisories may be able to be cancelled early if snow tapers off. We maintain the northwest flow so some snow showers are likely to continue, especially where upslope flow is focused towards inland Erie County, so the Advisory remains in effect until 1 AM for the Pennsylvania portion.

Clearing is noted across eastern lower Michigan and northern Lake Huron where subsidence is stronger behind the upper trough axis. This has resulted in a rapid decrease in lake enhancement off Lake Huron while a stratus remains socked in back to Illinois. Generally expect mostly cloudy conditions for the overnight period as the surface ridge expands north towards Lake Erie.

KEY MESSAGE 2... The local area will undergo a quick warm-up Monday into Tuesday with ridging aloft. An upper level trough will deepen over the Upper Midwest on Tuesday with the leading piece of energy quickly advancing through the eastern Great Lakes Tuesday night. Surface low pressure passes north of the Great Lakes and tracks northeast into Quebec by Wednesday morning, with the trailing cold front/trough pushing south across the area as another piece of energy dives south out of Canada across Lake Michigan. High temperatures will occur early in the day on Wednesday before falling through the afternoon. With that we will see any rain that may be ongoing ahead of the front make a transition over to snow by evening as coverage of precipitation expands. Timing will be crucial on Wednesday as this transition seems to be trending more towards before or during the evening commute in Northeast Ohio and Northwest Pennsylvania, leading to travel concerns. In addition, the 12Z/11 GFS and ECMWF are both showing the upper level trough closing off over the Ohio Valley which could lead to some enhanced precipitation in an area of strong mid-level frontogenesis on the northeast flank of the system. It is too early to tell if this band will be over eastern portions of our forecast area or some location to the south and east. Did raise qpf slightly on Wednesday night and will have to keep an eye on how this pattern evolves that could yield an efficient snowfall.

KEY MESSAGE 3... Long range models show a full latitude trough extending south to the Gulf on Thursday replaced by another upper trough that crosses the Great Lakes Friday through the weekend. This lends confidence to a cold stretch with below normal temperatures and several opportunities for additional snow. Winds chills look to be in single digits at times, especially Thursday/Thursday night and again Saturday night into Sunday. Model differences are high enough to make timing periods of snow difficult this far out with uncertainty in storm track and wind direction, but most models suggest some snow is possible Friday night and Saturday. Ice on Lake Erie is mainly confined to the western basin north of the Lake Erie islands so this cold stretch will allow for continued lake effect snows given favorable wind directions and a very cold airmass.

AVIATION /06Z Monday THROUGH Friday/

Mixed-bag of VFR and MVFR across the TAF sites this evening, associated with low ceilings. Ceilings will become predominately MVFR overnight, with gradual improvement to VFR expected from west to east through Monday morning. Westerly winds of 10 to 12 knots overnight will favor a southwest direction by Monday morning and afternoon, increasing to 12 to 15 knots with periodic gusts of 22 to 25 knots.

Outlook...Non-VFR becoming more likely in rain Tuesday night into Wednesday. Non-VFR will continue into Thursday as rain transitions to snow late Wednesday. Non- VFR may return in snow showers on Friday.

MARINE

Strong WNW winds will continue on Lake Erie through early evening behind a cold front, especially on the eastern basin from Avon Point to Ripley where a Gale Warning remains in effect until 00Z. A brief break in the winds will occur early tonight before winds back to WSW and rapidly increase to 15-25 knots again by 12Z Monday. Have extended the Small Craft Advisories from Maumee Bay to the Islands through 18Z Monday and from the Islands to Avon Point through 20Z Monday to cover this next round of winds only separated by a short break. Small Craft Advisories will need to be extended from Avon Point to Ripley through at least Monday evening, but will wait for the ongoing Gale Warning to expire this evening before replacing it with Small Craft headlines.

Another short break is expected Monday night before another rapid increase in winds for Tuesday as SW winds increase to 15-25 knots ahead of a Clipper low moving into the northern Great Lakes. This low could phase with some southern stream energy late in the week, supporting an arctic cold frontal passage Wednesday and W to NW winds of at least 10-15 knots, occasionally up to 20-25 knots, behind the system late Wednesday through Friday as a deep arctic airmass settles over the central and eastern CONUS. This could also lead to patchy freezing spray and renewed ice growth by the end of the week.

CLE WATCHES/WARNINGS/ADVISORIES

OH...None. PA...None. MARINE...Small Craft Advisory until 1 PM EST Monday for LEZ142-143. Small Craft Advisory until 3 PM EST Monday for LEZ144>149.