After initially deciding not to chase on a day where parts of the southeast and Midwest would experience the largest severe weather outbreak of the year to date; Cooper, Blanchard, Chenoweth, and myself decided to go spot around the Monroe area. Upon convective initiation shortly after 18Z (12pm CDT), I initially did not pay much attention to the storms as they formed in a linear fashion oriented from southwest to northeast along a pre-frontal boundary. At this stage, it appeared that QLCS formation was imminent. However, a fairly significant amount of CIN observed on the morning sounding from SHV was responsible for limiting convection to the area of strongest forcing (along the pre-frontal boundary). This allowed for an isolated storm mode along the boundary, thus making it conducive for some storms to exhibit supercellular characteristics despite the lack of 0-1 km directional shear in the area.
12Z KSHV Sounding courtesy of the SPC.
One storm north of Ruston, LA piqued my interest around 2045Z. Although hail was the main threat with these isolated storms, this storm in particular was one of the first storms to exhibit rotation at upper levels on radar (due to radar beam properties as the beam travels away from the radar). With this storm being so close to our location, Cooper and I rounded a few people up and departed MLU for Sterlington, LA around 21Z to check the storm out.
Convection across the Southeast ~21Z. Note the isolated nature of the cells in Northern LA. Image courtesy of UCAR image archives.
Upon our arrival to the Sterlington area, Cooper spotted a wall cloud to the west of Sterlington associated with our storm of interest. As expected, this wall cloud was not rotating at all due to lack of directional shear at the lower levels of the atmosphere, but was fairly picturesque for Northeast Louisiana. Despite its history of producing up to golfball sized hail in Union Parish, no hail was observed in the precipitation core of the storm. After spending 15 minutes observing the storm’s characteristics as it moved off to the northeast, we decided to relocate to the south of Monroe in anticipation of another storm that was exhibiting supercellular characteristics south of the Ruston, LA area.
Part of the chase party.
After a quick drive through Monroe and Richwood, we decided to stage just outside of Logtown, LA and wait for the storm to come to us. Despite our timing and excellent positioning, mother nature did not produce a repeat of what was observed in the Sterlington area. This particular storm went outflow dominant just to the southeast of Ruston, which choked off its warm inflow causing it to begin a weakening cycle as it approached the Richwood area. Several interesting undulations in the cloud deck associated with the gust front responsible for the demise of our storm were documented by Cooper. Despite the weakening trend, RFD was spotted and documented wrapping around and eventually concealing the main updraft base of our storm, providing another excellent photo opportunity. Almost immediately following this, a wind shift to the west and increase in wind speeds were experienced followed by a ~10 degree Fahrenheit drop in temperature, thus effectively marking the end of our first expedition of the new chase season.
Chase Highlights
1 Non-rotating Wall Cloud
58 Miles
