Can the E fields be recovered from 2158 to 2225? Are they good after 2225?

Was the Citation always following the same storm (check when radar available)?

The initial target was a storm with attached anvil North of Lake Okeechobee that was still active when the Citation arrived. During the flight the anvils expanded further North and moved East out over the ocean and were decaying. During the flight there were problems with the field mills (especially between 21:58 and 22:25 UTC when they seem unuseable). Early and other parts of the flight seem to show high electric fields. Mostly the Citation was flying East -West cuts through the cloud.

We began flying on Tuesday May 22. That flight was for shakedown and if lucky, we would find storms as well. The forecast was for possibly late convection. We waited through the afternoon for convection to develop and took off at 1700 (local). Some good storms with anvils developed out over the Atlantic, N of VRB. We sampled several storms until they evaporated and returned to PAFB at 2000. There were some problems with communications and the field mill data system (it took a power hit just before takeoff and possibly trashed some of the OS).

No flight. Fixed comm problems and worked on FM data system. Bottom mill was drifting; mill was replaced and all mills are working well.

Dry air behind front -- no storms. The plane flew to calibrate the winds system and the field mills. FM data system had more problems in flight, but Scott was able to get it working well just before the pitches & rolls maneuvers. Unfortunately later analysis showed the E measurements were contaminated with spikes and hard to work with.

2 cases, first one was active cell decaying at Vero Beach moving north-east, second case was over KSC - detached anvil (maybe connected to still active cells to the north and/or south?):

First case is an attached anvil (first to an active core - then decaying and getting detached later then maybe connected to new developing cells again) out over the ocean just North of Vero Beach. The Citation made a few East-West passes and North-South passes through the anvil between approximately 18:50 UTC and 20:30 UTC. There were strong electric fields between 18:50 UTC and 19:01 UTC - the Citation was doing a South-North pass close to the core. After that new cells were developing just North of the previous cell. The Citation was sometimes also flying through their anvil (e.g. see 19:46-19:48 UTC). All cells seemed to be in a stage of decay when the Citation was leaving them at around 20:30 UTC.

Second case was above KSC from 20:39 UTC to end of flight. Detached or attached ????? anvil(s). Active cores around it. First passes showed moderate fields growing weaker on later passes.

For both cases the Citation did not get clearance to fly where we wanted.

Efield data of Citation missing between 20:54 and 21:00 UTC.

-FM data system: Scott re-installed the OS and it has been rock solid ever since. Plane took off at 1430. Air traffic was very heavy due to Memorial Day weekend, so operating was difficult. There were storms with anvils over KSC. We were able to make passes over KSC, but were not allowed to loiter there. So we were able to take some "snapshots" but not follow development and decay. On the way home, the plane made some passes through an anvil near PAFB. The Plane landed at 1810.

There were cells developing on land between Vero Beach and Melbourne producing an anvil to the East. The cell(s) showed some lightning until.???..., during the flight. New cells developed besides or behind the old ones but fed into the overall anvil. First passes were through the East 'tip'of the anvil - low fields were reported. Towards the last part of the flight the Citation made some East - West passes and from 23:22 UTC on there were some stronger electric fields in higher reflectivities.

Storms developed along the east coast north of VRB. The plane took off at 17:30 UTC. We made several passes through the anvil, following it until it disappeared. The plane landed at 20:35 UTC.

Several passes through an attached anvil cloud above KSC from a core near TCO. The anvil moved east over the ocean. Strong Efields were recorded between 19:20 and 19:27 UTC. Between 20:23 UTC and the end of flight passes were made through decaying anvil in roughly E-W directions. Cell was moving out to the ocean. Weak Efields were recorded between 19:35 UTC to 20:30, then intervals of stronger Efields between:

20:32 - 20:41 UTC and

20:45 - 20:55 UTC and

20:59 - 21:03 UTC and

21:06 - 21:11 UTC and

21:12 - 21:15 UTC and

21:23 - 21:26 UTC and

21:29 - 21:21:31 UTC)

due apparently to the plane being in the higher reflectivity remnants of the storm/anvil.

Several cells developed west of and then moved over KSC. We made several passes through the anvil cloud over the KSC FM network. We were able to follow the cloud out east over the ocean, and were able to get clearance to go high enough to get over the anvil and follow it down.

The storm with a short attached anvil moved from west of KSC, over KSC and then out over the water until out of radar range. It became more coherent and unicellular as it moved more off shore maintaining coherence for several hours. The continuity was probably a result of a short

wave which moved through the area.

Many good passes across the anvil in roughly E/W directions. E fields in stronger reflectivity regions maintained strength throughout the study.

Periods of stronger E fields corresponding to higher reflectivities (~25 to 30 dBZ) were:

20:16 - 20:17 UTC

20:21 - 20:23 UTC

20:27 - 20:30 UTC

20:32 - 29:34 UTC

20:40 - 20:45 UTC

20:52 - 20:57 UTC

21:00 - 21:06 UTC

21:12 - 21:18 UTC

21:35 - 21:40 UTC

We flew another mission on Tuesday. Convection appeared over much of the FL. By mid-afternoon it reached us on the east coast; the plane took off around 1540. We were able to get in position to catch cells forming over the KSC FM network, which developed anvils and then moved out over the Atlantic. The storm maintained a single cell that persisted the whole flight. We suspect it was long-lived due to the short wave that passed through. The anvil was too short to fly toward the core, so we made several passes across the anvil at various distances from the active convection. The plane landed around 1845.

The system of convective cells was between Vero Beach and Melbourne moving to the East out over the ocean again. The Citation was flying through convective debris or outflow from cell to the north, but new cells were also developing at lower altitudes at certain times.

Between 19:18 and 20:53 many passes were made in the large system, there was one dominant cell in the North part of it and had a large stratiform region to the south. For most passes E field was higher, but also some passes with transition from strong to weak Efield probably when leaving higher reflectivities.

Two spirals were made. One at around 20:53 to 21:08 UTC with descent and ascent in strong Efield with a lot of variations and the other spiral was at 21:18 to 21:36 UTC on the edge of the reflectivity (first time Efield was very weak then increasing a bit. Both spirals were a long way from the core).

For the whole flight: complex but interesting Efield measurements!

Weak Efield 19:25 - 19:27; Stronger Efield: 19:18 - 19:20, 19:28 - 19:33, 19:40 - 19:50,

20:00 - 20:15!!, and 20:20 - 20:34

weak 20:34 - 20:38 then strong from 20:38 - 20:45

weak 20:45 - 20:51 then stronger 20:50 - 21:14

weak 21:14 - 21:30 then stronger 21:30 - 21:53

weaker 21:53 - 22:00 then stronger 22:00 - 22:24 (passing core)

The plane took off about 1445. Storms developed south along the east coast, near VRB. We were able to make several passes through the anvil(s) and followed them out over the ocean. We were also allowed to spiral down AND back up in the anvil (twice!). The plane landed about 1900.

First case was a detached anvil between MLB and Vero Beach. Flight passes were made between 19:04 and 19:28 UTC (first pass at FL 170, then long time gap and later passes at FL 270). Weak fields. The measurements were not very continuous.

Second case was a small single cell with anvil between Vero Beach and Fort Pierce. It decayed quickly, Efield seemed to decrease from first pass through it to last pass through it. Times where there were flights through it: 19:30 UTC to 20:05 UTC (passes at FL 270, maybe FL 230, there were strong fields between 19:32 - 19:38 UTC and became weak after that).

Third case is complex of 2 – 3 cells along line initially west of Fort Pierce and to the South. The anvil moved to the ESE eventually reaching the range limit of the 74C radar. The Citation flew in it approximately between 20:10 UTC to approximately 22:50 UTC.

From 20:10 to 21:10 UTC made N-S passes at different distances from core (~30, 60 and 75) at FL 290 and 310. From 21:10 to 22:30 UTC E-W passes were made through anvil debris from earlier, strong surge, but debris still connected to the cores. Did bank maneuvers in Ez of ~30kV/m which were pretty steady. Periods where the Efield was stronger but changing were:

20:10 - 20:25 UTC; 20:30 - 20:34; 20:40 - 20:45; 21:11 - 21:25; ; 21:28 - 21:50; 21:59 - 22:05; and 22:08 - 22:14

Between 22:30 and 22:42 UTC ) before RTB made a spiral down from 27 to 17 kft (~8.5 to 5.5 km in moderate to weak reflectivity at the edge of the anvil. Should be excellent case to examine changes of E with reflectivity.

When the first cumulus of the day occurred, we filed for take off. The plane took off about 1445. Cells developed southward along the east coast seabreeze. We sampled several anvils as they decayed into dissipation. We finished by sampling an anvil that stretched 100 mi from its parent convection. The plane landed about 1900.

The first case the Citation flew between 18:22 to 18:45 UTC. It was an anvil of a maritime cell in its late stages of decay, almost not visible on radar. Weak E field was measured in the beginning then no enhanced field.

The second case was an attached anvil of active, intensifying cells with strong variable fields at the time the Citation flew (19:03 to 19:27 UTC, mostly the edge of the anvil). Left this case because of intense lightning activity.

The third case was a decaying, detached anvil which was flown between 19:50 to 20:45 UTC. Weak E fields decreasing to near zero were measured in the anvil – very good case!!!

The Fourth case was an attached anvil of an active core between Orlando and KSC flown between 20:50 to 21:13 UTC. E fields changed from weak to strong E during the passes as the Citation flew into and out of higher reflectivity; fields were stronger between 20:49 to 20:51 and 20:57 to 21:04.

Then from 21:30 to 21:45 UTC the Citation flew over the KSC for measuring E field changes to be compared with the surface network.

The plane took off around 1415. A maritime storm put out an anvil east of KSC. We sampled the remnant then flew several anvils from active and dying storms. On the way back to base, the plane made passes over the KSC FM network with a distant storm making lightning -- this will aid in calibrating the airborne FMs. The plane landed about 1800.

Complex of cells between Daytona and just north of KSC putting out a kind of anvil or debris to the south. Gradually the cells became more pronounced to the north and west of original activity. Between 18:00 to 18:10 Citation made passes in/near some of these weak cells. Strong E associated with cores. Later made NNW to SSE passes in large elongated debris cloud (stratiform-like) region. 18:17 to 19:20 UTC worked debris decaying in place produced by the cells near Daytona. E field went from stronger fields in the north to weak fields in the south. Some chance to look at E versus dBZ in these passes, but there was precipitation which itself violates the rules, so this case not of great interest for ABFM.

19:25 to 20:00 UTC worked another similar convective debris decaying in place, situated further North along the coast than the previous one.

20:10 UTC flew over the U of Arizona mobile situated under a small but very active cell. The Citation passed through the core south of them.

The plane took off around 1330. We sampled two dying storms, both in attached and detached anvils. When most of the state started to convect, the weather was too confused to interpret, and the plane landed about 1630.

The first case (~1740 to 1820) was a decaying cell with debris north of KSC which becomes attached to new developing cells over KSC -- a messy situation. Around 17:40 first few passes were made at FL 230 with stronger convection to the south.

Lightning strike to the Citation at 17:46:25 on the south end of a growing line of cells.

First case was followed by a spiral down to 5 kft from 18:20 -18:40 for passes over the KSC network for E change comparisons with the surface E mill network. However, cells over SLF made it hard to fly over the network. 18:55 started to climb to FL 230. Between approx. 18:20 to 19:32 a number of flashes for possible E-mill calibration.

Second case: From 19:10 to ~1935 started with passes from NNW to SSE at 23 kft in and over stratiform debris with embedded convection, strong Efield. May be somewhat useful for studies for comparison with reflectivity but not decay. Reflectivity gradients usually pretty sharp.

The third case was a decaying detached anvil east of KSC with excellent measurements between 19:38 - 20:03 UTC. The last lightning from this storm was approximately 90 minutes earlier. Made N-S passes first at FL 250 and then at FL 210. E field was very weak.

The plane took off around 1320. A storm north of KSC was developing an anvil southward. The plane headed for the anvil, but was held just short and just below by ATC. The anvil came toward the plane

and we made some passes through the cloud over the KSC FM network. We then sampled an anvil from a dying storm between KSC and Orlando. The plane landed about 1630.

A line of severe thunderstorms moved north of KSC out over the ocean putting out extensive debris to the NE. Initially was more like a stratiform region but part of this area produced an anvil to the SE. The Citation followed this stratiform debris/anvil from 20:25 to 23:20 UTC. Initially 5 passes NE to SW across debris (anvil??), but then ~12 passes (beginning ~2125) along the anvil axis from NW to SE and back. An excellent case to compare transitions from weak to strong E fields with reflectivity both aloft and below the aircraft, but is a little complex meteorologically.

Extensive convection with copious lightning from severe thunderstorms (with a probable tornado north of KSC).

At take off "A/C crew could see the wall cloud near Patrick.

First case was the anvil of a severe thunderstorm extending 125 to 150 km to the NE of the cores. There were two active cores SE of KSC. The Citation made passes from ~2130 to 2240 from SW to NE and vice versa following the anvil and debris as it drifted to the SE. In early passes E fields were very strong but after about 2215 the fields decayed in this anvil remnant and were weak. This should be a very good case to follow decay and also to relate E to reflectivity.

During the second case from ~2255 to ~2400 the Citation made E-W passes from KSC out over the ocean some of which were over the U of Arizona mobile. These passes appear to be in stratiform-type debris with embedded convection, but were pretty near regions to the west with very active lightning. This debris which seems to merge with the remnants of the first case. At times there was radar attenuation from cells north of PAFB (some time from 21:30-22:00 UTC to perhaps the end of flight). The E fields during this part of the flight were generally large. Because of overflights of the U of A mobile this is a medium priority case for ABFM