Here’s a quick update to this week’s severe weather potential for the central and southern plains. First, let’s take a look at the latest Storm Prediction Center (SPC) severe weather outlook maps.
The map for Wednesday is quite a bit the same as yesterday, but the 15% probability outlook area is slightly larger. Confidence in severe weather occurring on Wednesday is increasing among SPC forecasters at this time, but there are some pieces to the puzzle that are missing…hence their decision to keep the 15% probability for now. As more data comes in and Wednesday draws closer, the probability of severe weather may be increased and the outlook area will be more specifically refined. It’s common to have a scenario such as this where the chances of severe weather are almost certain, but the “where and when” is somewhat muddled. What isn’t muddled are the chances of supercell thunderstorms occurring with all modes of severe weather (large hail, damaging straight line winds, flash flooding, and tornadoes) possible with any storm that develops. From the SPC discussion, “SHEAR WILL FAVOR LONG-LIVED SUPERCELLS AND ATTENDANT RISK FOR VERY LARGE HAIL…DAMAGING WINDS…AND TORNADOES. GIVEN UNCERTAINTY DUE TO STORM COVERAGE…WILL MAINTAIN ONLY 15% PROBABILITY AREA ATTM — DESPITE SIGNIFICANT SEVERE WEATHER POTENTIAL WITH ANY STORM THAT DOES DEVELOP.” Remember from the previous post…”shear” is the way winds flow in the atmosphere…changing direction with increasing altitude…that allow storms to rotate. Now let’s take a look at Thursday.
As was the case with Wednesday, the outlook map for Thursday is largely unchanged with the exception of the 15% probability area slightly larger, especially in Texas. Here’s where the headaches for the forecasters begin. Confidence in severe weather occurring is still high, but there are uncertainties regarding the coverage and timing of storms. How will Wedneday’s storms affect the conditions necessary for storms to form on Thursday? Will the atmosphere have time to “recover” or will it be stabilized to a degree? Regardless of these issues, the SPC discussion says, “SUPERCELL STORMS AND ASSOCIATED RISK FOR VERY LARGE HAIL…DAMAGING WINDS…AND TORNADOES CAN BE EXPECTED.” Taking into account the latest SPC outlook and my own subjective analysis, Wednesday and Thursday will be active severe weather days across much of the southern and central plains. In fact, a few storms could give us an appetizer” on Tuesday evening…so that bears watching as well. One of the challenges that SPC forecasters are currently dealing with are discrepancies between computer forecast models. As more data from the models comes in and better observation data is available, it will be easier to pin down more specific forecasts as to where and when storms will occur. One important thing to keep in mind is the fact that we’re dealing with a three-dimensional fluid that is in a constant state of flux. This is just the nature of the atmosphere and an example of the constant every-day challenges that meteorologists face. While the SPC wants to make you, the general public, aware of the severe weather threat, they also don’t want to alarm you unnecessarily. We’ve been aware of the threat for severe weather midweek for several days…so you have had plenty of “heads up” warning. If you’d like to take a look at the entire SPC outlook, you can find it here at their website.
After more information becomes available, we’ll take another look at this setup tomorrow. By then, the potential scenario will become much more clear.
Now go get that emergency kit ready and check your NOAA weather radio… 🙂