As expected, the forecast has slightly changed for the impending winter storm. The areas in pink in the photo above have been upgraded to a winter storm warning from noon Tuesday, through 6:00 pm Wednesday. The purple counties have changed to a winter weather advisory from noon Tuesday, through 6:00 pm Wednesday.
A winter weather advisory is issued when there is a probability of any amount of freezing rain, or accumulating snow which will cause travel issues.
A winter storm warning is issued when there is a significant combination of hazardous winter weather occurring or imminent. Significant and hazardous winter weather is defined as a combination of:
1) five inches or more of snow/sleet within a 12-hour period or seven inches or more of snow/sleet within a 24-hour period
2) Enough ice accumulation to cause damage to trees or power lines.
3) a life threatening or damaging combination of snow and/or ice accumulation with wind.
Even though we are within 24 hours of this event occurring, there is still some uncertainty about who will get what. The photos above are two different snow forecast through 3:00 pm (right) and 10:00 am. The one on the right is keeping the heaviest snow in a band from the Permian Basin through southwest Oklahoma. This is the most likely path of the heaviest snow. More forecasts are showing the swath of heaviest snow to be southeast of Lubbock.
The model on the left is pushing the heaviest snow just outside of our area, with more moderate amounts for the central and western counties. No matter which forecast you look at, you can really get an idea of where the projected accumulating snow will be located. All of west Texas will see accumulating snow through early afternoon on Wednesday.
The photo above is a closer look at a computer forecast of accumulations for our area. The exact numbers are not really the thing to take away from this, as it is not exact. However, you can see that this model is showing the highest accumulations off the Caprock, southeast of Lubbock. From the computer forecasts on the maps above and this accumulation map, things are lining up for the heaviest snow to affect Motley, Cottle, Dickens, King, Garza, Kent, Dawson, Borden and Scurry Counties.
Once the event is done tomorrow and the amounts are, you will be able to see why you can't take any forecast as Gospel. You can just look at one forecast as say this is exactly going to happen. That is bad forecasting. You have to look at several models, plus look at atmospheric dynamics and where exactly the storm is coming from. It makes a difference if it's coming from the north, or southwest. Knowledge of the area and previous winter storms is also key to putting together a winter weather forecast.
With all of that said, here is the most updated snowfall accumulations from midnight tonight, through noon on Wednesday. Now, some snow will linger in the eastern counties through 2:00-3:00 pm tomorrow. This system will clear our area from west-to-east tomorrow. We'll actually see mostly sunny skies by tomorrow afternoon. However, highs will only be in the low 30s on Wednesday. The wind will make things feel more like the teens and low 20s.
Lubbock is forecast to receive between 2-4" of snow. Some locations within Lubbock County can get up to 6" of snow; but those will be patchy. The northern areas, under the winter weather advisory, will see some rain/snow mix and sleet late tonight/early tomorrow before they see snow. That is why lower amounts are forecast there. The target for the heaviest snow is off the Caprock. Anywhere in the pink counties should expect to see between 4-6" of snow. Some spots in those counties will see up to 8" of snow.
This storm will obviously cause major issues on the roads on Wednesday morning. Driving is not going to be encouraged, unless you absolutely need to head out. I am guessing that several school will be closed tomorrow. Please be very careful driving on Wednesday. You don't want to crash and end up spending thousands of dollars repairing your vehicle; plus the huge jump in insurance costs. Stay home if at all possible. The air will be very cold on Thursday morning, with the low reaching 15° in Lubbock. So there will be ice on roads Thursday morning. However, we'll see highs in the low 50s Thursday afternoon.