As discussed early this week ("A Pattern Shift in the Making"), the prolonged cold snap earlier this month is but a distant memory as we are now in a much more active pattern with mild temperatures and storm systems affecting the region frequently.
This morning, some of you might have awakened to our first thunder in 2010 as an upper-level impulse rolled through with enough elevated instability to produce some lightning and thunder in the pre-dawn hours. Rainfall totals came in between 0.25-0.75" depending on your location.
Yet another system, this one stronger and surface-based, will move into the region tonight. While a chance of showers and a few thunderstorms exists today, most residents of the metro area will see more dry hours than wet ones through the day and evening. By midnight, the approaching low pressure will be shifting quickly into the region and showers and thunderstorms will be a good bet. Rainfall totals from this next round will likely be 1.5-2.0" for just about everyone with some isolated higher amounts, so the National Weather Service has issued a Flash Flood Watch effective from 9pm tonight to 3pm Thursday.
In addition, the Storm Prediction Center has placed the area under a slight risk of severe thunderstorms for the overnight hours tonight (see graphic above), calling for the possibility of a line of storms with possibly damaging wind and hail after midnight. The strongest weather, including the possibility of tornadoes, is expected to go by to our south. However, with a good fetch of Gulf moisture being fed in on southerly wind, the approach of surface low pressure and a favorable jet stream overhead, some thunderstorms could become severe overnight and early Thursday. A few showers and thunderstorms could also form during the afternoon hours Thursday ahead of the main cold front. Thursday will be a windy and mild day, which would aid in the development of additional scattered precipitation later in the day.
The Mid-South should then get a break from the wet weather for about 48 hours before yet another strong cold front brings a round of rain and thunderstorms Saturday afternoon or evening. More on that later...
With the possibility of severe weather, check out MWN's newest feature - automated delivery of severe weather alerts for Shelby County on Twitter! If you use Twitter, be sure to follow @shelbyalerts (http://twitter.com/shelbyalerts) to get weather warnings as they are issued. It's the perfect product to use for mobile alerts, so be sure to select "Send to Mobile Phone" when you follow! If you aren't on Twitter, you can still get weather alerts by e-mail as well. For more information on both of these services, check out the Weather Alert Notification page on MWN.