I departed NIB around 8:30pm CDT on Thursday evening to travel to MLU to meet with Cooper for what would be a slight risk chase across the western parts of Dixie Alley. A new challenge for myself in forecasting this system was the fact that there were multiple target areas, including the NW Arkansas and the Ozark region of Missouri which is mostly bad chase area (with the exception of a few areas in Missouri). In addition, storm motion was going to be far faster than what is ideal to chase in these areas. Fast storm motion and poor road networks usually spell disaster. Taking all of this into account, we decided to play the southern scenario and initially target East Central Mississippi between Vicksburg and Jackson.
After a few hours of sleep, we awoke to semi discrete supercells racing across NW Arkansas producing several tornadoes in its wake. Being sorely out of position and having no desire to be playing catch-up with these fast moving storms, we decided to stick with our target area of East Central Mississippi. Cooper and I departed MLU around 9 am on Friday with an initial target of Vicksburg, MS. However, with storms already developing in the favorable thermodynamic environment that was present over SE Louisiana, I decided to target Jackson initially due to more road options.
We arrived at our target area around 11:30 CDT and began staging. The storms that formed over SE LA were tracking further east toward the jungles of West Central MS and were going into HP mode as expected. Meanwhile, a weak storm cluster formed just to the northeast of Lake Charles, LA. Based on the thermodynamic and dynamic environment that was present across all of South Louisiana, we decided to drive back toward Vicksburg and monitor the situation from there with viable road options to take us south and west.
In Vicksburg, Cooper and I noted the increasing temperature and moistness of the air. The SREF and RUC models were both indicating that a Theta E ridge (see http://www.theweatherprediction.com/habyhints/324/ for more info) was building north toward the I-20 corridor, with the main axis building in between Tallulah, LA and Vicksburg, MS. I noted that the storm cluster that formed NE of LCH was following the theta e ridge to the northeast, and it was only a matter of time before these storms were going to intensify and go severe. Therefore, Cooper and I decided that it would be best for us to reposition further west to cross the Mississippi River to have a change to intercept these storms before they merged into a squall line.
As we mobilized, the southernmost storm in the targeted broken line of storms went supercellular prompting a tornado warning from the NWS LCH, as this storm was in the extreme northeastern part of their CWA. Noting the track of these storms to the northeast and considerably slower storm motion (25-30 mph at this time), Cooper and I took Highway 65 south to attack a cell in the middle of the broken line the was beginning to show signs of forming a mesocyclone. As we began moving south, the storm that was targeted went supercellular and was warned on by the NWS in Jackson, MS. Around this time, we were inconvenienced by the loss of mobile internet. However, with the help of several nowcastors and visual knowledge, we were able to put ourselves in position for a good intercept 4 miles west of Newellton, LA along State Highway 4.
After sitting for about 20 minutes watching to storm, we were rewarded for our patience as the wall cloud associated with our storm appeared out of the rain. Very weak rotation was observed with this wall cloud. After calling it in to WFO JAN as well as capturing stills and photos of it, we decided to move north on Hwy 65 and parallel the wall cloud rather than sitting and waiting for the next storm. This decision was made in an attempt to 1) stick with that particular storm and 2) get back across the Mississippi River as soon as possible, as the severe threat was beginning to shift further east as the broken line of storms began to merge into a squall line.
On our way north, we ran into fellow chasers Conner McCrorey and David Reimer of Texas Storm Chasers and Scott Peake from OU, who were also on the same storm. As both teams continued north tracking the storm, we experienced a new wall cloud with this particular storm passing over the top of both of our vehicles. As it crossed the Highway, I noted weak vertical motion and little to no rotation associated with the wall cloud itself. The storm still retained supercell characteristics, as both teams were slammed with a very wet RFD containing ~60-65 mph winds. Due to the brief delay in the RFD reaching our location on the road after the wall cloud passed over us, I was able to infer that there was still broad rotation associated with the storm itself.
After punching through the newly developed squall line around Jackson, MS, Cooper and I targeted a discrete supercell with a confirmed tornado ahead of the main line that was translating NE toward the Jackson Metro area. With the lack of daylight left and poor terrain (lots of trees), I decided it was best to not punch the bears cage with the hope of getting a brief glimpse of the tornado. In addition, storm motion was much quicker (~45 mph) due to an increase in low level jet (850mb) wind speeds. Instead, we tracked a little further East to Highway 49, where we drove south into the town of Richland. There, we watched the rain wrapped tornado translate across the highway about 3 miles to our north noting power flashes and inflow winds well beneath the severe threshold.
Around this time, WFO JAN issued a Tornado Emergency for the city of Jackson, as this tornado was moving toward the city. After about a 5 minute wait, we decided to follow this storm toward Brandon, the next town east of Jackson on I-20. As we tracked East toward Brandon, we noted several power flashes associated with the tornado as were pushed around by winds in access of 55-60 mph in the backside of the storm. We also ran across tree limbs in the road around mile marker 50 on I-20, just a little damage associated with this EF-2 tornado.
Around this time, we noticed another cell to our southeast that was beginning to go supercellular. We managed to get ahead of this storm on I-20 before driving south on state highway 13 toward the town of Polkville. Despite the terrible terrain, we managed to find a small hill next to a clearing in the dense tree canopy to watch the storm approach our area. However, the storm gusted out before reaching our location and managed to recycle off to our Northeast. However, due to the lack of light, we decided to call it a chase.
Special thanks to Don Wheeler of LA Delta Community College and Brandon Thomas from the Alabama Storm Trackers for nowcasting assistance!
Chase Stats
Storms Intercepted: 4
Wall Clouds: 2
Highest winds: ~60 mph
Largest Hail: Dime sized (.75 in)
Miles Driven: 990
Our location relative to the rainwrapped tornado as it moved toward the Jackson area. Courtesy of Don Wheeler LDCC.
-JP
-JP
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