Severe storms possible in Virginia on Friday; storm chasers prepare for more storms in southern Plains
Reminder: Deadline for the summer prediction contest is tonight at midnight. If you want to enter, send your projected highest temperature for Roanoke and when it will occur between June 1 and August 31 to email@example.com by midnight.
There will be a significant risk of severe thunderstorms throughout Virginia (except for the far southwest tip) on Friday as a cold front and jet stream trough plow into warm and humid conditions. The primary threat will be large hail and damaging winds with the likelihood of one or more storm lines developing. The potential for supercells (storms with rotating updrafts) and perhaps a few tornadoes will be greater east of the Blue Ridge, especially near the Delmarva Peninsula where a warm front may provide a somewhat greater level of atmospheric shear (winds changing speed and/or direction with height).
The system affecting Virginia on Friday is the same one the Virginia Tech storm chasers have been tagging for a couple of days in the southern Plains. After a very busy chase day on Tuesday, Wednesday did not come off as expected. We targeted the Oklahoma-Kansas border region where there appeared to be a somewhat heightened risk of tornadic supercells, but the atmosphere had other plans. By late afternoon, severe storms had fired in hard-to-chase clusters in central Kansas, while a few tornadic supercells had developed in the southeastern part of the Texas Panhandle. We did get near a severe storm in the Oklahoma Panhandle right at sunset — a picturesque way to end the day, with glowing red sunlit mammatus clouds. We landed in Guymon, Okla., for the night — and possibly the next couple of nights as well, with a chance for scattered supercells in this general region of the High Plains (elevations above sea level here similar to western Virginia ridgetops) through the weekend, aided by Gulf of Mexico moisture banking against the even higher terrain to our west in New Mexico and Colorado. Today, we plan a sightseeing day, with a picnic at Palo Duro Canyon south of Amarillo, then a return here to Guymon for the evening.
Tuesday’s chase was an amazing success in that the students were able to watch a supercell evolve from initiation — literally when it was just sprinkling rain and had a very high base — into a grapefruit-sized hail chunking monster (we were not actually in that hail, by the way) with recycling rotating wall clouds. As we pulled off that cell both because it was near dark and running into the Oklahoma City metro area, another developed quickly just west of El Reno on Interstate 40. This is the storm we tracked into early evening, spawning a likely tornado near Union City to the south of El Reno. We were evading developing cells well into the evening, running through small hail once on Interstate 44, before landing in Lawton, Okla., for the night. As it turned out, we should have drifted a few counties west of Lawton for the best storms Wednesday, rather than heading to northwest Oklahoma. That’s storm chasing — one day positioning excellently in a setup that produced far more than expected, the next day positioning poorly in a setup that underachieved (at least where we were).