Heat, Humidity, And Storms…In February.February 21st, 2014 at 9:04 am by Jeremy Wheeler under Weather
Usually when you have temperatures starting in the 60s in February, you are asking for trouble. Some trouble may be on the way for us this afternoon. As mentioned, we started with temperatures in the 60s already.
We are going to go up from here. Winds were out of the south/southwest at 10-20mph with gusts to 25mph. Winds will increase later this morning with gusts up to 35mph. This will be even before the storms arrive. At the time of this writing showers and storms were moving into the Lynchburg and Charlotte areas.
A warm front moved through Hampton Roads last night. A cold front is approaching from the west. Today we are in what’s called the warm sector, which is south of the warm front and east of the cold front.
The main area of low pressure is sitting over the Great Lakes region. This low will stay well to our north. That is good as it will lessen the chance for tornadoes. However, we do have a decent chance for severe straight-lined winds. A severe wind is one with 58mph or greater. Our whole area is under a slight risk according to the Storm Prediction Center. With our temperatures forecast to be in the mid 70s and dew points (a measure of moisture) in the low 60s we’ll develop a good amount of instability. One way that we measure instability is through something called CAPE (Convective Available Potential Instability). You don’t have to know exactly what it is, but it is a scale for measuring the energy that a thunderstorm can tap into. 500 is about minimal for strong storms. 1000-1,500 is moderate CAPE. Anything 1,500 or higher is considered high in this region. Today we are looking at around 1,500. So strong thunderstorms will be a good bet. They will be able to tap into the strong mid-level winds and pull them down to the surface. So that is where those strong winds will come from. The wind shear also will be fairly high today. That is the increase in wind speed with height. With a higher wind shear storms can have a better structure. It tilts the storm so that the falling rain doesn’t cut off the rising warm air directly below. I don’t think we’ll have too much change in the wind direction with height. So all of that typically spells out a higher chance for severe straight-lined winds with a lower chance for tornadoes, but not a zero chance. I don’t think we’ll see too much hail today, but I won’t rule it out either. Storms are forecast to start up around 1pm, but with the latest trend in the radar I wouldn’t be surprised if some storms move in by noon. Here is what the latest version of Future Trak shows for 3pm today.
The storms will push through until the 5-6pm hour. Then we’ll dry out tonight. Temperatures will drop all the way down to the upper 30s and low 40s tonight. That will be a big change from today’s highs in the 70s. The good news is that tomorrow looks great.
Behind the front we will cool down, but not too much. We’ll see highs in the low 60s with mostly sunny skies. Winds will be out of the northwest at about 8-12mph.
Sunday won’t be too shabby either. Highs will be in the upper 50s with partly cloudy skies. We are still looking colder next week. Highs will be in the 40s. By Wednesday some models show a rain/snow mix. At least over parts of the viewing area. Highs temperatures are forecast to be in the 40s though as I mentioned. So I don’t see any problems for now, but stay tuned.
Keep two things in mind about the storms later today. 1. Storms will probably be around as you pick the kids up from school, or shortly before. Make sure they get home from the bus as soon as possible. Also, it’s possible that some schools may hold the kids longer or let them go early. 2. If it’s your trash day, then make sure your cans are secured. The winds will be strong enough to either blow them over or even down the street. Be safe today.
Meteorologist: Jeremy Wheeler