Tornado outbreaks this weekend - outside of the Plains!

SPC severe storm risk (left) and tornado risk (right) for Saturday

The first true 'big' tornado event of the spring 2008 season looks to commence today and continue into tomorrow - but only a sliver of it within the traditional 'tornado alley'. The mid-Mississippi valley and southern US states instead will be under the gun, something that has been common so far this year. Today's pattern favors a significant tornado outbreak from Arkansas to the Gulf Coast, with strong upper-level winds and deep moisture at the surface. The outbreak should move into the southeast states of Georgia and Alabama on Sunday as the system moves offshore into the Atlantic.

The setup looks great and the chances of seeing tornadoes are fairly high - but I decided to sit this event out. First of all, I would have needed to make the call to go no later than yesterday afternoon, in order to make it in time. I hesitated too long to make the 15-hour drive to the AR/OK border. Second, while this may turn out to be a two-day event across the south, its wide footprint between the two days means that one would likely not be able to cover both days (with sufficient sleep in between) due to the long distances between them. I figured a probable path that I would have ended up taking would have been starting in western Arkansas along I-40 this morning, then working my way eastward through Memphis and ending up in Nashville, TN or Birmingham, AL. From there, I may have had time for 3 or 4 hours of sleep before trucking on to Georgia for Day 2, then ending up in Raleigh to round out the trip. That would end up being over 3,000 miles total - and at 400 miles per tank of gas, that would end up being a $550 fuel expense.

Now I'm an advocate of chasing outside of the Great Plains, because success can be had wherever a good setup materializes. But I've only got funding to make one solo trip this year, so I have to choose wisely. While there will be chaseable tornadoes this weekend, my budget dictates a choice to wait for another setup in better territory.

The models have seemed to line up in agreement of a big east coast trough forming later next week, after another round of southern US severe weather events. So, it's looking like any trip will be at least well into the later half of the month.

Based on the current outlook, this probability table charts the chance of our trip starting on a particular date:

2008 Chase Expedition - Departure Date Probability as of May 10 May 10-25 15% May 26-June 15 40% No trip 45%