textproduct: Cleveland

WHAT HAS CHANGED

No significant changes from the previous forecast package. The main concern continues to be the potential for a widespread light to moderate accumulating snow across the region on Friday, followed by another blast of arctic air this weekend.

KEY MESSAGES

1) Confidence remains medium to medium-high on a widespread light to moderate accumulating snow on Friday, though uncertainty remains on the placement of the higher-end snow amounts.

2) Sub-zero wind chills will return across the region this weekend, with the coldest values expected Friday night into Saturday morning.

3) Light snow will continue into this evening, particularly across Northeast Ohio and Northwest Pennsylvania, as a cold front moves south through the area.

DISCUSSION

KEY MESSAGE 1...

A potent clipper system will move southeast through the Great Lakes on Friday, sweeping an arctic cold front across the region Friday night into Saturday. This system will also lift a warm front northeast into the area Friday afternoon, and will be one feature to watch for any localized higher snowfall amounts, particularly immediately along or ahead of the front. Areas behind the front may briefly warm near or even slightly above freezing in the afternoon, before temperatures plummet area-wide to the single digits or even sub-zero Friday night - more on that in Key Message #2.

Confidence remains medium to medium-high (50 to 70%) for a 2 to 4- inch snowfall across much of the area east of the I-75 corridor on Friday, with the heaviest snow expected to fall Friday morning into the early afternoon. The higher-end of totals will most likely be found across the snowbelt where some lake-enhancement is possible behind the arctic front Friday evening and overnight.

KEY MESSAGE 2...

An arctic cold front will follow Friday's clipper system, with temperatures quickly dropping into the single digits to even sub- zero Friday night into Saturday morning. A combination of cold temperatures and gusty winds behind the front will likely result in dangerously-cold wind chills of -15 to -24 degrees F into Saturday morning. Confidence remains rather high for this occurrence, 60 to 90%, particularly across Northeast Ohio into Northwest Pennsylvania.

For the rest of the weekend, sub-zero wind chills of generally -5 to -10 degrees F are expected to persist in the overnight and early morning hours into Monday morning.

KEY MESSAGE 3...

Satellite and radar signatures continue to suggest weak lake- enhancement across the snowbelt as boundary-layer flow remains westerly ahead of an approaching cold front. The latest observations indicate the cold front is quickly moving southeast across eastern Michigan and Ontario. Anticipate a brief up-tick in snow showers across the region later this afternoon and evening along the front, though accumulations should be relatively light, generally an inch or less. High pressure building from the west on Wednesday should allow any remaining snow showers to diminish, albeit periodic lake effect clouds may persist.

AVIATION /18Z Tuesday THROUGH Sunday/

Persistent light snow showers streaming off of Lake Erie have reduced conditions downstream of the lake to MVFR and IFR visibilities with a consistent ceilings of MVFR heights. Elsewhere, there is a mix bag of MVFR to VFR conditions, which should steadily become widespread MVFR ceilings as a cold front moves east across the area. This cold front will bring the potential for snow showers primarily across northern terminals, although cannot rule out a few stray snow showers further south. Overall impact should remain at MVFR, with brief periods of IFR visibilities possible in the heaviest snow showers. These MVFR conditions should persist through the remainder of the period with a very brief lifting of ceilings possible near 00Z. Winds will be light and variable.

Outlook...Periods of non-VFR expected in low-level clouds and/or snow showers through Thursday. Non-VFR likely Thursday night into Friday as a cold front moves through the region with more snow expected.

MARINE

Lake Erie remains mostly ice covered with the latest analysis indicating 95 percent coverage. This coverage along with the thickness of the ice sheet is expected to continue to expand as below average temperatures linger through this weekend.

A cold front will push east this evening with winds becoming north-northwesterly at 5-10 knots tonight. High pressure will build over the area tonight, maintaining these winds into Thursday. On Friday, a warm front will lift north across Lake Erie, shifting winds to become southwesterly at 10-15 knots. A strong cold front will push east lake Friday, shifting winds to northwesterly and increasing them to 20 to 30 knots into Saturday. High pressure returns this weekend and winds will weaken to 10-15 knots.

CLE WATCHES/WARNINGS/ADVISORIES

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