The models continue the trend of slowing down the storm a bit this morning. What has remained consistent is the high amount of moisture, the threat of significant icing, and the likely changeover to snow.
Based on what I’ve seen from the overnight models, and the first bits of this morning’s model runs, it looks like the rain really starts in earnest on Thursday instead of Wednesday night. The cold air still plunges through Oklahoma during the day Thursday with rain changing to freezing rain and continuing into Thursday night. The changeover to snow may be delayed until late Thursday night, then ending late Friday morning.
My concern is that a lot of this moisture will fall as freezing rain in central and southern Oklahoma. The cold air that will move in on Thursday is currently residing just to our north over the central Plains. Fresh snow cover (Des Moines picked up 6″ yesterday) is in place over Iowa and parts of the Midwest and that will insure that our temperatures fall quickly below freezing on Thursday.
The moisture will move in from the south, overriding the colder air moving in from the north. These are classic conditions for significant icing. Even though the air at ground level will be below freezing, the mid levels of the atmosphere will remain relatively warm, so freezing rain and sleet will be common much of Thursday.
The changeover to snow will happen with the mid levels cool down Thursday night. Our most likely time for accumulating snow will be Thursday night to noon Friday. The more moisture that falls as freezing rain and sleet, the less there will be for snow.
So what does all of this mean for Oklahoma? I believe the best chance for significant icing of more than a quarter inch will be in central and southern Oklahoma. With increasing winds, power outages are likely in these areas. Snow amounts in central Oklahoma Thursday night and Friday morning are likely to be around 4 inches on average, but as much as a foot in some locations. Again, it just depends on how quickly we change from sleet and ice over to snow.
Use today and tomorrow to prepare for the storm. Make sure you’re stocked up on groceries, ice salt, medications, etc. Take time to gas up the car and make sure the ice scraper is handy.
By the way, we’ll have the live blog up and running today from 1-2 pm. If you have any questions for me I’d be happy to try to answer them. See you at 1.