Winter Weather Advisory 

Posted: 5:13 pm Monday, January 15th, 2018

By Kirk Mellish

As usual, when there is a threat of the white stuff in the deep South states it’s rarely strait forward and this is no exception. About the only thing models agree on is it will quickly turn “cold enough” to snow even if it starts as drizzle in some areas, the big question marks are about moisture extent and location as well as vertical motion (lift) in the atmosphere.

The Euro model had been one of the more moist, now it’s one of the driest. This kind of model flip flop so close to the ‘event’ is maddening.

This season with the various events there has been no clear-cut winner model to lean on, so its a you know what shoot.

Even though no heavy amounts are expected (even the ‘worst-case scenario’ which is NOT being forecast, is 2-3 inches), the temperature drop expected with and immediately after any snow means there can be impacts on roads for adverse travel in at least parts of the Metro.

Right now it looks to me (subjective estimate) that the odds of getting at least some precipitation is 60-70%, but the odds of getting an inch or more snow is only about 20%, for most of us anyway.

WINTER WEATHER ADVISORY FROM NWS IN PURPLE:

Screen Shot 2018-01-15 at 4.29.51 PM

There may be some drizzle or flurries in parts of the Atlanta area in the afternoon Tuesday, especially late, but coverage and intensity of light snow will increase across the Atlanta Metro around and after sunset, ending before sunrise Wednesday.

Anything that accumulates will hang around a while as temperatures by Wednesday morning fall into the teens with wind chill factor in the single digits.

As is often the case, the area least likely to see accumulation is the far south and east suburbs Fayette to Rockdale to Clarke Counties and points South and East from there.

BEST ESTIMATE FOR TUESDAY EVENING:

Screen Shot 2018-01-15 at 4.59.12 PM

***The above dividing line subject to shift 20-30 miles North or South.

Above amounts also subject to decrease or increase obviously, per my previous blog post on the model range of just a trace or nothing to 2 inches.

There is no winter storm low pressure system, instead it’s a strong arctic cold front with upper-level cyclonic vorticity.

Given the inconsistency in the various algorithms it is not possible to pin-point WHERE it will just be a dusting or where it will be an inch or more. I’d rather tell the truth and say I don’t know than give you fake precision.

Follow my updates on the radio and on Twitter all day tomorrow as things no doubt will change.

 

 

 

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