Bye Bye Warm Weather!

The nice La Nina weather we've had over the past several days is going to end in the days to come.  If you've been observing the Facebook updates, you know that there is a pattern change on the way.  Tomorrow will be gorgeous with readings likely topping 70, however, the first in series of changes will occur Saturday.  A cool front will push through our area early Saturday, preventing temperatures from reaching the 70's. 

Attention then turns to an upper low that will be off to our west Sunday.  This low will bring varying weather across the state of Texas and pars of Oklahoma.  Right now I don't want to get into too many details of the system because it will change as we get closer to the event, and especially once the system is sampled.  But, right now it appears that moisture will be on the increase Sunday.  This increase in moisture should cause widespread clouds and light rain showers, Sunday evening.  Dewpoints will be on the rise too, especially in eastern Texas.  The increasing dewpoints means the possibility of heavy rainfall will exist and the possibility of thunderstorms will be present.

This graphic from the HPC shows widespread rainfall, some very heavy, across Texas and parts of southeastern Oklahoma.  I believe the best precipitation chances will be east of HWY 75 and south of the Red River; these locations could easily pick up 1-2" of rainfall. (Great news for the drought-stricken areas!)  This heavy rainfall could come at a cost, though; severe weather could be a possibility.  It's still way too early for specifics, but with a strong closed low (cold air aloft/shear), and with moisture moving in off of the Gulf, there's a small threat.  At this time, the best locations appear to be east of HWY 75 and south of I-20. (Keep in mind that threat could be expanded to the northwest, or even taken out of the forecast completely.) 

Now let's get to the fun part, SNOW.  Several Texoma Weather fans have been asking about snow!  This system does have the possibility to produce some snowfall on its backside.  Several of the models have produced a significant trowal, as the system exits early Tuesday.  Right now it appears that the surface temperatures will be above freezing, but enough cold air aloft will be in place for a changeover from rain to snow.  The best locations for this changeover will be west of I-35, but there's adequate time to adjust that changeover line to the east of west, if need be.

Tonight we will provide some eye candy, as we did last night!
This is what the JMA model is showing for Monday.  (Note: I rarely use the JMA, and this is only one model and one run from that model.)
This is the JMA for Tuesday!  This particular model has had several runs showing some interesting weather for Texoma.

The GFS has been showing light snow occurring in parts of Texas/Oklahoma for several runs.  This graphic shows accumulations from the 18Z. (Just a side note: the 00Z GFS is showing snow across parts of Texas/Oklahoma, west of I-35!)

It's still too early, and the evolving pattern is too unclear, to say, with certainty, which areas will see snow and severe weather.  However, the possibilities are there, and as a forecaster I want to giver everyone a heads up on the possibility next week.  As the models emerge on a scenario for next week, the details will then become more clear. (By Saturday morning we should have a good idea on how everything will pan out.) 

Following the system it appears an arctic cold front will ooze through Texoma late next week. This could be the start of winter in terms of very cold temperatures and possible winter precipitation events in the Southern Plains, to end the month! (The AO is tanking and the cold air is continuing to build!)  Texoma Weather will continue to keep you updated on this developing system. Again, we should have better idea by Saturday as to what this system will do; the system still needs to be sampled!  As we've been hinting at over the past few days, Texoma Weather has a huge announcement to make, soon!  Continue to check back for updates, and the big news.