Severe Saturday Ahead...

Saturday, April 24, 2010

The blog remains in severe weather mode.

Here's the rundown on what to expect later today.

The majority of the forecast area is now under a Moderate Risk for severe storms. Portions of NE LA, much of MS and AL are under a rare high risk (graphical representation to follow). The threat for severe weather will rapidly increase this morning especially around daybreak as the main upper level storm system and associated cold front move into the forecast area.

Showers & a few thunderstorms are beginning to develop out ahead of the main activity over the coastal waters. These streamer showers will move NE and into the inland portions of the forecast area later this morning. The strong cap that has been in place throughout the day on Friday and into Friday evening is eroding, and it won't take much longer now for the storms to initiate over land. More widespread activity in the form of an MCS is moving E through Texas this morning. As of 2a.m. CDT the stronger activity was from near San Antonio to near Tyler, Texas and points further N and E of that. A plethora of tornado watches, and one severe thunderstorm watch are currently in effect from the Red River Valley up into the Mid West, including the Northern half of Louisiana. It is just a matter of time before we are included in a watch box now.

A very strong and intense Jet Stream is moving over the area, and this will combine with the presence of wind shear, incredible amounts of low-level moisture and instability to produce the expected severe weather. Unlike, what unfolded Friday afternoon (nothing), this time around we are on the proverbial hot seat wrt severe weather. All modes of severe weather, but a diagram we look at to determine the possibility of a tornado, called a hodograph, is very curvy in nature which suggests a significant risk for tornadoes. Certainly hail and wind damage will be possible with these storms as well, but a significant tornado outbreak could unfold later this morning. Based on the model projections and official current forecast from the Storm Prediction Center the greatest chance for tornadoes will be just to our NE. However, the environment over the forecast area is one that is conducive for supercell development ahead of the main evolving squall line. It is in this pre-frontal environment that the greatest tornado threat exists, and there could certainly be a few long-lived, long-track tornadoes across the state today. This is a very volatile situation, and I strongly urge everyone to pay attention to the latest weather developments this morning. Please have some way of receiving the latest weather information should watches or warnings be issued later today.  Everything is still on track to be over and done with by noon. Much drier and somewhat cooler air will filter in behind this system, and an offshore flow will develop in earnest by tonight. Rain chances will be in the 70-80% range for this morning, and rainfall totals should be between 1-2" for the duration of this event. I include the rain chances solely because everyone wants to know what the chances are, but in this situation rain chances are irrelevant because of the impinging severe weather.There is no audio blog for this go around, and please check back for more updates later this morning as necessary. See severe weather related graphics just below this.

That's all for now, but be sure to check back later for all the latest severe weather information. Maybe I'll catch a power nap before the storms get here.



-DM-