After some unexpectedly heavy lake effect snow last night, more snow moves in this afternoon and evening. The snow will be heavy at times from the Cleveland metro points east through the Snowbelt later this afternoon through this evening, before winding down by noon Friday. This evening commute and Friday morning’s commute may be impacted in some areas…
Short technical thoughts:
The forecast upper-low and surface low track have shifted east since Wednesday morning’s model runs, which results in the best shot of synoptic lift and snow occurring mainly across the primary NE OH Snowbelt, and also increases the snow a bit for NW PA. This has resulting in some reduction on the southern and western sides from yesterday. Forecast amounts for this leg of the event in the primary Snowbelt remain similar, but this map doesn’t reflect last night’s lake effect and only shows additional snow.
For some specifics, obs and radar support snow rates probably maxing out around 1”/hour in eastern lower MI this morning. Given a good shot of lift from positive vorticity advection beneath a fairly potent vort max, low to mid-level frontogenesis, and low-level convergence, along with some enhancement from Lake Erie, still think we’re on track to see snow ramp back up this afternoon and peak late afternoon through the evening, with rates of 1-2” per hour still possible at times where the better organized areas of low-level convergence and lake enhancement occur. Model soundings still show steep lapse rates and moisture to around 500mb for quite a while later this afternoon and this evening in NE OH, with decent snow growth as well until late tonight when the better mid-level support diminishes.
Wasn’t expecting the lake effect to be so organized and far south still, but think as winds turn SW over the lake over the next few hours that may still try to lift north for a time. If not, it’s beginning to get enhanced by synoptic moisture and will put down additional accums until it lifts north (assuming it ever does).
Given a few hours of potentially heavy rates in the primary Snowbelt and getting into the Cleveland area, with some light snow before and also after lingering into Friday morning, think 6-10” of additional snow is still doable. The snow may diminish for a few hours late tonight and briefly re-intensify Friday morning with a shortwave going by, some lake induced instability, and a flow around 280 degrees, but am only figuring an additional 1-3” Friday morning from Cuyahoga County points north/east. Lowered amounts a bit in the secondary Snowbelt, but still have 3-6” there. Winds only get up to 280 to 290 degrees later tonight which can get a band into that area, but it’s a little iffier now and the synoptic snow will be lighter there than initially thought. Even so, still think they see a 15 or so hour window for snow that’s moderate at times and fairly high ratio, so think several inches will still be possible. This isn’t a good setup for the lakeshore, so aside from the eastern lakeshore where some lake effect snow is still ongoing this morning am not expecting more than 1-4” along the shore. Went a little on the higher end of model guidance down towards Akron and Youngstown. The flow not gaining as much of a northerly component makes it iffier down that way, but the synoptic snow will still push SE this evening and they may still see some lake enhancement, so was nervous to go less than 2-4” for that corridor. Interior NW PA has a better shot at 4-8” of snow tonight through Friday AM with a better burst of synoptic snow this evening than thought yesterday.