Wednesday, April 4, 2012

By Jay Grymes & Steve Caparotta

Vivid lightning, winds gusting above 50 mph, pockets of hail and heavy downpours prompted a number of Severe Thunderstorm Warnings between midnight and 7:00AM.  In fact, lightning was the cause of at least two house fires in the Baton Rouge area and numerous power outages.  Given the lightning activity we were tracking during the overnight and early morning hours, it is somewhat surprising that there weren’t many more lightning-related incidents!

Radar image from 4:30 a.m. Wednesday with lightning strikes overlaid. Nearly 3,300 cloud-to-ground lightning strikes were detected in a 15-minute period over south Louisiana...translating into a rate of more than 13,000 strikes per hour!

But with the wave of south-bound traveling storms pushing through the viewing area early in the day, those storms reduced the overall degree of instability across the region.  Remember, the greater the level of instability, the more likely we are to have showers and storms develop.  Instability is enhanced by daytime heating, but the cloud deck over the region through the morning and into the afternoon helped to slow the afternoon heating, keeping many of us out of the 80°s for the first time in nearly two weeks.
The result: a relatively quiet Wednesday afternoon and early evening.
But we still have a cool front to get through the region, and that front will be sufficient tonight to help produce lift - - and lift is another indicator of instability.  In addition, as the air aloft cools later tonight, the temperature difference between the relatively warm low levels and the cooled upper levels enhances lift.  The bottom line: we anticipate another round of showers and t-storms overnight and into the early hours of Thursday - - for now, we’re posting a 40% to 50% chance of rain for your backyard.  Storms along the Texas coastline this afternoon could spread in our direction late tonight.
4:35 PM Wednesday radar image showing storms along the Texas coastline that could build in our direction later tonight.
We don’t think that this next round of storms will be widespread nor as ‘energized’ as those storm clusters that paraded through our viewing area last night and early this morning.  That said, the NWS Storm Prediction Center has all of our viewing area - - in fact, all of the Bayou State - - included under a ‘Slight Risk’ for severe weather from Wednesday afternoon into early Thursday morning. Additionally, the National Weather Service has extended the Flash Flood Watch through 7 a.m. on Thursday.

We expect any serious storms to be through our area by the early morning, but that could include the morning commute, especially for WAFB communities east and south of the BR metro area.  By lunchtime, most if not all of the rains are out of here, with clearing expected during the latter half of the day.
Then comes the pay-off for our mid-week storms:  sunny skies, a little cooler and much less humid for Friday and Saturday, and a good looking weather day ahead for Easter Sunday as well!
And a final note...the forecast team led by Dr. Philip Klotbach and Dr. William Gray of Colorado State released their forecast today for the 2012 Atlantic Hurricane season. The researchers are calling for a slightly below-average season, citing recent cooling of waters in the Atlantic and the potential development of an El Nino this summer (both negating factors for Atlantic storm development). However, as we always say, remember it only takes one storm hitting your area to make it an 'active' season.

1 comment:

  1. What will an El Niño summer mean for Louisisna's weather patterns?