2013 so far

The only real weather events here this winter have been a severe weather bust, an underperforming snowstorm, and a blizzard that missed OKC-Norman.  The pattern gets a lot less interesting now, if you believe long-range models.  This might be all until the first real spring outbreak, so here:

Tough forecast in OK

It's 12:30 Thursday morning.  With another winter storm brushing the area, it's a hard call for forecasters along I-40 as far as rain/sleet/freezing rain.  Snow looks likely in far northern OK, and rain is certain to the south.  It's a classic problem that comes out at least once a winter in central Oklahoma, and one that requires a look through multiple layers of the troposphere.  RAP forecast soundings show a large "warm nose" from ~700 mb to ~925 mb, with temperatures diving well below freezing around 950 mb, then rising back to within a few degrees of the freezing mark at the surface.  NAM had been leaning this way since Wednesday morning in the OKC area.  RAP suggests moderate ZR from OKC or Shawnee eastward along the I-40 corridor into Arkansas, extending northward through the northeastern part of the state--Tulsa certainly included.

Currently, Mesonet observations indicate lowest dewpoints in eastern Oklahoma--generally upper 20s.  Get a little precip falling into that, and surface temps hovering at freezing will drop sufficiently for a significant icing event.  Based on those observations, as well as numerical guidance, I might as well throw out a forecast:

OKC:  Some freezing rain early morning with little accumulation.  Any icing will be very short-lived as the surface warms.

Norman:  Rain.

Locally significant freezing rain event in eastern/far northeastern OK, including:

Vinita
Miami
Jay
Tahlequah
Sallisaw
Stigler
Eufaula
Checotah
Okemah

All I've got time for.  Back to math.