brody_clifton
EF1
Observed: 2 rotating wall clouds, a few short lived funnels.
Added 4/5/2005: I finally got my web hosting working from my home computer. The new address is http://24.211.196.156/ (domain registration isn't ready yet) and the link to the new firewire captured clip is
http://24.211.196.156/Chase%20logs/040205_...05_Virginia.wmv
I left my house in Goldsboro, NC at 4:30am this (Saturday) morning for an initial target area somewhere in southest VA/northeast NC. CAPE had been forecasted to be in the 250-500 J/Kg range there in the 12-15Z timeframe, and low level helicity was forecast to be well over 300 m^2/s^2 for those hours. However, after reaching the initial TA the only convection firing in or approaching there was in the form of yellow radar blobs with 30 mile diameters, so I decided to play the advancing warmfront and headed towards Richmond, VA. 30 miles north of Richmond I exited I-95 at Ladysmith, VA to stop to analyze WxWorx data and plan the next move.
At this time, about 9:50am, several initially discrete cells to my west and SW had formed together into a line. About 10 minutes later, the line split into two separate lines, with the top cell in the southern line being displaced 10 miles or so to the SE of the last cell in the northern line, with only light reflectivity echos between them. At just about the same time, low level wind shear values began to increase in an area coiciding with the extreme northen tip of the southern line. This cell looked to arrive near my location in roughly 25 minutes, so I parked and waited for it.
As the line approached I caught a view of the updraft ahead of it and saw no noticable areas of rotation, and shortly after the heavy rain hit. I checked again after the next WxWorx update, and the shear was still indicated, but this time a few miles to east. I booked east on Ladysmith Rd and after a mile or so got far enough back into the rain where I could begin to see the updraft area again, and caught a glimpse of an area to my 10 o'clock that may have had some rotation. This got my blood pumping, and after another mile I turned NE onto hwy 207.
After traveling about 4 miles on 207, I finally caught up with the suspected updraft area and saw that it was indeed a rotating wall cloud. At this point the wind really picked up and I pulled off the the side of the road to watch and film. The wall cloud was around a half mile ahead, over an area of woods between Bowling Green, Wrightsville, and Fort AP Hill Military Reservation. After 20 seconds or so, a funnel formed about 1/3 from the left edge of the wall cloud, extending about a third of the way to the ground, and persisted for 15 seconds or so, then lost its form. After another 30 seconds or so the funnel again dipped down about a third of the way, and persisted for about the same duration. After the second funnel dissipated the wall cloud seemed to occlude and lose its vertical height and alot of its rotation. I continued on NE on 207 and then NE on US 301. 10 miles or so down the road I saw that a second wall cloud seemed to have formed, but I wasn't in a good position to stop and check for rotation as I was back in the rain due to a couple of stoplights in Port Royal.
After another 15-20 miles the new wall cloud finally came into view as I was driving over the Potomac River bridge into Maryland. This one also seemed to develop/dissipate a funnel on and off every 15-30 seconds, but again the funnels would only extend 1/4 to 1/3 from cloud to ground. I couldn't really verify rotation on these due to driving over the bridge taking alot of my concentration, but am guessing since the shapes changed so rapidly it was probably not just scud. I could tell the new wall cloud was rotating, though it was a bit larger than the first one and rotation did not seem to be as intense, but that was with me driving so I couldn't be sure.
After crossing into Maryland, I made some road option mistakes and
lost the chance for another view of the cell's updraft as it raced off to the NE at 50mph. I headed back home and intercepted a few cold front cells that may have had a lightning bolt or two, but nothing really interesting.
None of the pre-cold front storm cores I passed through today had hail, even pea sized , probably due to the lack of instability. There were some hail reports from storms later in the day after the cold front passed and the upper level cold core arrived. I was really surprised to even catch a couple of funnels from the event. I guess the high 0-3000ft shear, 15kt SSE under 40kt SW winds, increased to the tornado threat even with the very low CAPE.
Oh well, such is early April. I'm ready for the 85 degree days to get here
with those dynamics in place.
Added 4/5/2005: I finally got my web hosting working from my home computer. The new address is http://24.211.196.156/ (domain registration isn't ready yet) and the link to the new firewire captured clip is
http://24.211.196.156/Chase%20logs/040205_...05_Virginia.wmv
I left my house in Goldsboro, NC at 4:30am this (Saturday) morning for an initial target area somewhere in southest VA/northeast NC. CAPE had been forecasted to be in the 250-500 J/Kg range there in the 12-15Z timeframe, and low level helicity was forecast to be well over 300 m^2/s^2 for those hours. However, after reaching the initial TA the only convection firing in or approaching there was in the form of yellow radar blobs with 30 mile diameters, so I decided to play the advancing warmfront and headed towards Richmond, VA. 30 miles north of Richmond I exited I-95 at Ladysmith, VA to stop to analyze WxWorx data and plan the next move.
At this time, about 9:50am, several initially discrete cells to my west and SW had formed together into a line. About 10 minutes later, the line split into two separate lines, with the top cell in the southern line being displaced 10 miles or so to the SE of the last cell in the northern line, with only light reflectivity echos between them. At just about the same time, low level wind shear values began to increase in an area coiciding with the extreme northen tip of the southern line. This cell looked to arrive near my location in roughly 25 minutes, so I parked and waited for it.
As the line approached I caught a view of the updraft ahead of it and saw no noticable areas of rotation, and shortly after the heavy rain hit. I checked again after the next WxWorx update, and the shear was still indicated, but this time a few miles to east. I booked east on Ladysmith Rd and after a mile or so got far enough back into the rain where I could begin to see the updraft area again, and caught a glimpse of an area to my 10 o'clock that may have had some rotation. This got my blood pumping, and after another mile I turned NE onto hwy 207.
After traveling about 4 miles on 207, I finally caught up with the suspected updraft area and saw that it was indeed a rotating wall cloud. At this point the wind really picked up and I pulled off the the side of the road to watch and film. The wall cloud was around a half mile ahead, over an area of woods between Bowling Green, Wrightsville, and Fort AP Hill Military Reservation. After 20 seconds or so, a funnel formed about 1/3 from the left edge of the wall cloud, extending about a third of the way to the ground, and persisted for 15 seconds or so, then lost its form. After another 30 seconds or so the funnel again dipped down about a third of the way, and persisted for about the same duration. After the second funnel dissipated the wall cloud seemed to occlude and lose its vertical height and alot of its rotation. I continued on NE on 207 and then NE on US 301. 10 miles or so down the road I saw that a second wall cloud seemed to have formed, but I wasn't in a good position to stop and check for rotation as I was back in the rain due to a couple of stoplights in Port Royal.
After another 15-20 miles the new wall cloud finally came into view as I was driving over the Potomac River bridge into Maryland. This one also seemed to develop/dissipate a funnel on and off every 15-30 seconds, but again the funnels would only extend 1/4 to 1/3 from cloud to ground. I couldn't really verify rotation on these due to driving over the bridge taking alot of my concentration, but am guessing since the shapes changed so rapidly it was probably not just scud. I could tell the new wall cloud was rotating, though it was a bit larger than the first one and rotation did not seem to be as intense, but that was with me driving so I couldn't be sure.
After crossing into Maryland, I made some road option mistakes and
lost the chance for another view of the cell's updraft as it raced off to the NE at 50mph. I headed back home and intercepted a few cold front cells that may have had a lightning bolt or two, but nothing really interesting.
None of the pre-cold front storm cores I passed through today had hail, even pea sized , probably due to the lack of instability. There were some hail reports from storms later in the day after the cold front passed and the upper level cold core arrived. I was really surprised to even catch a couple of funnels from the event. I guess the high 0-3000ft shear, 15kt SSE under 40kt SW winds, increased to the tornado threat even with the very low CAPE.
Oh well, such is early April. I'm ready for the 85 degree days to get here
with those dynamics in place.
