Thursday, December 6, 2012

December 9-12 Winter Storm

Models and ensembles remain somewhat unsure on this system, although the modest consensus beginning to form indicates that this winter storm will not be a big event as was earlier anticipated, and snowfall will not be as significant as earlier forecasts had indicated.

The above image shows the GFS model 12z forecast in red, with the NCEP Ensembles in blue superimposed on the image. The GFS model is right in the middle of these ensembles, and they all seem like they know what's going on. However, upon an analysis of other ensembles and model solutions, it becomes clear that the solutions being offered up by different forecasts vary as far as who could get how much precipitation, as well as the billion dollar question: Who will get snow?

The GFS model's snowfall forecast describes a nice storm for Wisconsin and Minnesota. The amounts in Illinois and Iowa were from an earlier system. This snowfall forecast is quite a change from what we had been seeing yesterday, where the models brought big snows to Iowa, Wisconsin and Nebraska. Now, the first and third states look like they're in trouble.

The presence of an east-based negative NAO and a positive PNA trying to sneak in adds to a New England ridge to try and promote a Midwestern storm track for this system. I believe that the GFS has a good handle on the track, but I don't want to trust any precipitation type forecasts until we get this system on US soil, where weather balloon data can greatly help the models in their forecasts.



Anonymous said...

So, what of this low that is supposed to track south through Colorado? all of our news crews are not telling the whole story, and I see very conflicting data between the Colorado Springs precip outlook and Denver's outlook, with Denver's favoring nearly half an inch of precip in my area and Colorado Springs's virtually dissipating the entire storm as it heads into Colorado, with little more than flurries outside the mountains, I know that both cities are using different models, however, my billion dollar question is, can you tell me what the weathermen are not? can you elaborate what the most current and most likely projections are for this storm? I would like to know if this storm is going to mean anything for the Front Range, or should I lose interest in any prospect of accumulating snows?

Anonymous said...

The models have been a little less consistent as of late with this system.

Anonymous said...

Andrew what do you think central iowa will see as far as acumiliating snow is concerned and how much?

Anonymous said...

What about this secondary low at is showing up going through Tennessee just as the main low goes to great lakes? Saw on several models....thoughts?

Wally Gullang Huntley, Ill said...

Just watched Tom Skilling on WGN in Chicago and he is calling for just a rain event

Anonymous said...

Wheres all.the snow?
Indiana needs some!