Temperatures plunge into the lower and middle 20s overnight, so any ‘wet’ or ‘slushy’ roads will have solid ice on them by sunrise.
Saturday looks blustery and cold: highs around 29ºF with a stiff northwest wind making it feel more like the single digits in the morning and the teens in the afternoon. It will be dry, though!
Sunday and Monday: A frigid start to Sunday morning looks cold enough to be dangerous for pipes and pets again. Expect morning lows around 15ºF, but some sunshine helps push temperatures above freezing for a few hours in the afternoon.
We’ll get another night in the upper 10s and lower 20s before a quick push of warmer air raises temps into the low-40s Monday afternoon. That comes ahead of the most significant shot of cold air thus far; it will arrive Tuesday with another chance of some snow coming with it.
Really? Another chance of snow? By now you’re thinking, sure, yeah, it’s barely snowed or iced at all these past three times in North Alabama. To look at the model guidance, you’d think the same thing will happen again; however, we’re dealing with extremely cold arctic air that is an efficient producer of snow with limited moisture. We’re too far out to know for sure (it may end up totally, 100% dry and cold), but don’t turn your back on this situation and just think ‘nah, it ain’t gonna happen.’ It’s the kind of system that could have a fairly high impact if it actually does develop.
The late-evening guidance coming in Friday showed a chance of roughly 0.02″ to 0.15″ of precipitation Tuesday: all snow. Climatological data suggests our snow-to-liquid (the 0.02″ to 0.15″) ratio would be about 8-to-1 (8″ of snow per 1″ of rain). This would be in arctic air: a much more efficient snow-maker. The ratio could be as high as 20:1 or even 30:1 making that tiny bit of liquid go a long, long way.
In fact, 0.05″ at 20:1 yields 1 inch of snow. At 30:1, that’s 1.5″ of snowfall.
If there’s snow on the ground, we will see the first sub-zero temperatures in Huntsville in nearly 30 years; that’s how seriously cold this may get.
One of the analogs (similar events) to this set up is January 20-21, 1985: an accumulation of sleet and snow, brutally cold air, and one of the coldest temperatures on record in Huntsville: -11ºF.
Let’s be clear here: the -11ºF and 4″ of snow is not exactly ‘likely.’ A light covering of snow leading to temperatures in the -5ºF to 0ºF range is possible; however, there’s still a lot of time to watch this, and we’ll keep you updated!