Friday, February 12, 2016

A Model Idiot?

The models are struggling with this event and it's not unexpected. With VERY cold air in place, being dislodged as the storm comes in, the models are struggling. I expect the models to trend much colder as we approach this event.


at 84 hours, here is the GFS (American model) It's trying to hold cold air in place to the east, but eroding it to the west. As a result, it's 31 in Richmond with snow and 40 with Rain in Roanoke (1pm Monday) This never happens.

At this point, there has been a couple of inches of snow. 


Here is the NAM at the same time. 

The wedge is in much better shape and we've had as modeled, 3-6 inches in our region. What happens is warmed air overruns the cold air trapped against the mountains. This reinforces the cold air to hold in place longer.  It would infer that snow would be here sooner and heavier. 


There should be some type of a 30 mile wide band of heavy snow that develops. Being on the southern fringe 84 hours, may not bode well BUT once it gets a full grip on the cold air in place, it may actually trend south before it trends north again. 

What does this mean?

Snow starts after midnight Monday west and races east by 3 AM (Lynchburg area) Monday is pretty snowy, could be heavy at times with 1-3 near the VA/NC state line, mixing early and 3-6  HWY 460 north. This will eventually mix and change to freezing rain from 460 north and back to I-81. Could be as early as early evening Monday, could be as late as Midnight. I think we stay below freezing until Tuesday AM.  If we change early that 1-3 south, 3-6 north will be the ballpark of total snow. IF we can cling to snow until Midnight or later, those totals could double. Then we tack on some sleet and freezing rain. 


Here is a sounding at 84 for LYH (1pm Monday). I've circled the temps.. the lower you go on the chart I posted, the higher the you are in the sky. You see some temps between -1.5 and -2.  I suspect the warmth comes in the area that is near -3. I would suspect this is at least a few more hours of snow. Height in second column is elevation in meters. This model isn't great at 84 hours, but I think the better resolution is catching on sooner. 


I will continue to tweet out thoughts as model runs continue. I do have growing concerns about power issues in the Roanoke and Lynchburg area. Even if we just get 3-6 inches of snow and then freezing rain, the weight of the snow PLUS adding on ice could be BIG trouble for trees and power lines. Double those snow totals and it's even worse


No comments:

Post a Comment