Dick Faurot's Weather Blog: Winter Weather is Over, For Now

Monday, February 16th 2015, 5:02 pm
By: News On 6

Given the combination of precipitation types last night, figured another look at how the vertical temperature profile impacts those kinds of events would be helpful.

The first image shows the temperature change with elevation that is associated with snow, sleet, and freezing rain. As you can see by looking at the image, it is not just the surface temperature that determines our precipitation type but the depth and magnitude of any warm air aloft.

Sometimes those changes can occur very rapidly, going from one type to another, and that is what happened last night.

Also, the longer it takes for that transition to occur will have a tremendous impact on the amounts that reach the ground, which makes forecasting how much will accumulate at a given location extremely difficult.

Although we receive 5 minute updates of surface temperatures via the OK Mesonet, we do not have that luxury aloft, and therein lies the problem with trying to forecast surface accumulations in marginal winter weather events.

At other times when the atmosphere is known to be cold enough at the surface and aloft to support all snow, the estimation of how much will reach the ground is a little more straight forward.

The most snow reported from the event last night was 6” in the Bartlesville area. Other locations, particularly in the more southern counties, received nearly an inch of sleet with little or no snow and other locations had a mixed bag of sleet, snow, and some freezing rain thrown in for good measure.

The ‘official' total recorded at the NWS office near 169 & 11th Street was 2.7” of sleet/snow. That brings our total frozen precipitation so far this cold season to right at 5”.

As you can see on our forecast page, we are not through with the cold weather either, as temperatures will remain well below normal all this week and right on through the coming weekend.

In fact, looking at the 8-14 day outlook also has a strong signal for below normal temperatures, so it looks like the month of February will end on a cold note.

As far as any additional wintry precipitation, that is also a consideration.

Much colder air will be in place aloft when another disturbance moves over the NE corner of the state late Tue into early Wednesday. That is expected to wring out some light snow or flurries, but little or no accumulation is expected with that system due to a lack of moisture.

Temperatures will try to moderate some later in the week and another system aloft will bring another chance of wet weather starting later Friday and extending through the weekend and quite possibly early next week.

At those time frames, the longer range guidance is not on the same page regarding how cold we will be for that event, so there is considerable uncertainty regarding precipitation type and amounts.

Notice the 7 day QPF map which does suggest another ½” or so will be possible on our side of the state but how much, if any of that, will be of the wintry variety will take several days to sort out.

In the meantime, stay tuned and check back for updates.

Dick Faurot