Synthesis for June 20, 2000

This cell is moving to the south, southwest. The last lightning from this cell was at 2107. At 2118 it looks like it is putting out a small anvil towards the southwest, but motion at 4,7 and 10 km is similar. As the debris drifts and decays, a new cell appears at ~2200 under what was the small anvil. Other cells then develop nearby and become electrified to produce lightning by 2228.



The aircraft is flying near and in convection for most of this time. There might be a few minutes (230120 - 230340, 230800 - 230940 and 231130 - 231230) where the aircraft is actually flying through some small anvil, but always near convection. These times are NOT in the accepted anvil times.

Summary for June 20, 2000

Investigator: (None)

The following summary is from the notes that Jim Dye and Eric Defer put together. Probably early in 2001 (before the May/June 2001 Field Campaign).

There were two cells studied by the aircraft. The aircraft took off at about 21:30. It went after a cell that appears on the radar at about x= -75, y=-25 (Cell 1). This cell is moving in the WSW dirction. Look at the 10 km level. It reaches the anvil/debris at 22:00 at x= -110, y=-50. If we step backwards we see why I am not sure if it is anvil or debris. Step back to 2100. It is the primary cell in the frame. It looks to be a cell at about x=-75, y=-25 with an anvil to the west, or SW. The next radar frame is at 21:15; here it looks to be completely reversed. The cell is at the western edge and the anvil looks to be to the east or NE. At 21:45 the higher reflectivity region is in the middle and appears to be associated with a band that extends to the SE. When the aircraft arrived at about 22:00 it proceeded to do a spiral. There are three cells in a band, and the aircraft went SE to the next cell (Cell 2) after doing the spiral. The aircraft followed this cell for about half an hour before returning. On the way back it went by another cell that had formed behind the bank that was studied. This cell pattern is confirmed at the 7 km level.

Cell 1 does not look to be a simple cell the formed, blew off an anvil and decayed. If you watch it threw time there appear to be several cells that formed within that same air. This is also true for Cell 2 which the aircraft spent more time in.

Initially flew in anvil of small storm roughly 255 to 260 deg and 60 to 100 km from WSR74C (a litle south of BOW ??) Anvils were blowing off to SW. The storm produced first LDAR sources ~1950 and first CG at 1958 and continued to produce lightning until ~2110 for LDAR and last CG probably 2047. Spiral at 2158 to 2204 from 7 to 8.5 km (-15 -30 C). Ez first +30 as setting up for spiral then +40 at lower part of spiral, then Ez of only few kV/m for 2+ min. followed by -40 kV/m. 2D-C shows strong variability and periodicity suggesting changes in Ez might be horizontally variability as much as vertical.

After the spiral from 2205 to 2230, apparently moved south [another anvil or same anvil, I can?t tell] and made 4 passes at 8.5 km . Ez in all passes <2-3 kV/m. N>30 was 100/L or less and N>1mm was <0.1 to 0.5 /L. From 2230 to 2320 made a series of passes at 8.5 km with Ez as large as -75 kV/m. When Ez was larger, N>30 was ~500-1000/L and N>1 was ~or>1 /L.

Without radar plots cannot tell what happened very well.