As we mentioned yesterday evening, Old Man Winter makes a return to Texas early next week with the arrival of a major arctic cold front.  Cold air has been bottled up over Alaska and Western Canada for quite some time now and it’s currently predicted to begin spilling  into the northern US by this weekend as a large upper level trough of low pressure swings south out of Canada.    This will be quite a change from the unseasonably mild weather we’ve been experiencing recently!  Exact timing of frontal passage for Texas remains a bit uncertain at this time, but it looks like it could begin making its way through northern portions of the state by late Sunday or into Monday morning.  Parts of the panhandle and northwest Texas could easily plummet into the teens by Monday night if the cold air advection continues to look as robust as it does right now.

As for any snow or rain potential…forecast models are still not quite in agreement on this.  Previous model runs were indicating a piece of his low will do what’s called “cut off” from the main flow,  swing further south,  then ride northeast over New Mexico and Texas bringing moisture up with it.   Now, it’s looking more like the main flow will dig further south then ride up northeast through New Mexico and west Texas.   This action could have a significant impact on the amount of rain, or even snow, that could affect parts of Texas both ahead of and behind the front.

To demonstrate this, and the current model disagreements, I’ve got two graphics below for you.  The first is from the European model (ECMWF) for Monday, December 10th, midnight to 6am.  The blue line depicts the freezing line.  Precip behind that would most likely be falling as snow or a winter mix, the precip ahead of the blue line would be falling as rain.   Now scroll further down and take a look at the second graphic from the American model (GFS) for the same time period.  Yeah…it’s that much of a difference.

Current thinking amongst the local forecasters is somewhere in between; however, increased chances of precip are being tossed about, so we remain hopeful that Texas can get at least a little bit of beneficial rain out of this system.

We will continue to keep you updated!  ~Jenny

2/10/12 – Midnight to 6am


2/10/12 – Midnight to 6am