New Mexico Tech Interferometer/Sferic System
Notes for June, 2000

Universal Date/Time
JDay Date Time Comments
153 01-Jun 0:48 Severe thunderstorm warning for Cheyenne County. Severe storm near Cheyenne Wells indicated by measured wind gusts >65 mph. All storms are at ~low elevation (<=10 degrees). There is a line of storms to SW and a closer, more recent (formed ~0:30 UT), line to NE.
0:58 Severe thunderstorm warning for Dundy County. NEXRAD radar indicates severe thunderstorm over Max.
1:56 Severe thunderstorm warning for Dundy County (again). NEXRAD radar indicates severe thunderstorm ~10 mi. N of Max.
2:05:30 -BP (negative bipolar) with strong RF
2:15 Lightning continues to be at low elevation angle. Storm to SSW appears to have died. Storm to NE continues to be very active, but is receeding. Additional distant lightning to NW.
2:19 Phase offsets (HEX codes from raw oscilloscopes): XS: cos-70 sin-70 XL: cos-75 sin-75 YS: cos-75 sin-91 YL: cos-75 sin-71
2:19:33 Upward SA. +CG?
2:30 High wind warning for Wallace County. ~0 mi. visibility reported by police all around Goodland.
2:50 New lightning activity frequent to ~S, but at/below ~10 degrees elevation.
3:19 Winds increasing. Blowing dust is causing SA (slow antenna) to be erratic.
5:09 Check of phase offsets (HEX): XS: cos-71 sin-72 XL: cos-78 sin-76 YS: cos-75 sin-90 YL: cos-76 sin-74 (~same as at 2:19 UT)
Disconnected phase cables (2-6) at grounding box before adjusting to 80h (offsets from receivers may be real: galactic 274 MHz??)
New offsets with cables reconnected: XS: cos-79 sin-70 XL: cos-7c sin-75 YS: cos-79 sin-88 YL: cos-78 sin-7c
155 03-Jun 23:05 Flash rate: ~1 per 10 sec. Severe thunderstorm watch for E CO, NW KS, and SW NE
23:58 Flash rate: ~1 per 5 sec.
23:59 Severe thunderstorm warning for Cheyenne County (indicated by radar) in NW KS. Storm is travelling SE and is 16 mi N of Wheeler.
156 04-Jun 0:11 Balloon launch into updraft of storm.
0:28:18 Turned off raw oscilloscope display on Sun IPC (slightly increases data rates). Raw data display was on since 22:57 UT.
1:10 Storm has dissipated. No more lightning.
? Began adjusting phase detector board offsets when XL(x-long) suddenly went completely dead (see repair log).
158 06-Jun ? Placed Radar Technology Inc. Model RTPL-6010, SN 1082018, in place of previous #2 Antenna c.phase IF limiter. Also removed 10 dB attenuator (since output is ~0 dBm, not ~10 dBm)
159 07-Jun 1:12:54 Shut off power to INTF racks due to (potential?) problem with log-RF? Log-RF connector is flaky and needs repair.
<1:30 Repaired bad log-RF connector.
1:32 Targeting: Storm 20 mi. NE of Wray is producing 80% +CGs. The +CGs are single-strokes according to spotters. Another storm 10-15 mi. S of Wray is not producing any CGs at all.
2:05 +CG out of anvil seen to N by Paul Krehbiel while he was driving on I-70
2:20:44 +CG (saw visually)
~2:33 +CG
2:38:30 +CG?
160 08-Jun late Replaced rain shield on top hat of Slow Antenna. Note: For good contact with bellows, want 7-8 turns of screw thread exposed on top.
161 09-Jun ? Adjusted phase detector offsets so that all averages were 7Fh/80h when disconnected. Phase detector shifts were also measured (see repair log).
21:50-22:55 Severe thunderstorm warning for Logan County based on NWS radar
~22:10 Power lines downed by severe storm
23:15 Ballooning crew targeting storm near Gove in Gove County, Kansas (far to East of INTF)
23:33-0:45? Severe thunderstorm warning for Sheridan County
23:45-0:55 Severe thunderstorm warning for Gove County (2 severe storms in Gove County)
163 11-Jun ~5 Receiver #6 went "dead". Will diagnose after sunrise...
? Checked phase detector offsets: no change (see June 9). Also checked phase detector shifts (see repair log)
? Repaired receiver #6: power cord bitten by rabbit
? Checked antenna pair gains. Most were OK, though YL (mainly cosine) had to be adjusted (see repair log)
21:43 Spotter in Joes, CO reports 3/4" hail
21:47-22:50 Severe thunderstorm warning for Yuma County. Storm is 2 mi. NE of Joes
22:05 Spotter report of 3/4" hail in Flagler, CO
22:09-23:10 Severe thunderstorm warning for Kit Carson CO. Storm is SE of Flagler
22:27 Status report: Balloon ascended into anvil and is now on descent. Successful T-28 penetration earlier; now heading back to airport. Lightning is currently at a good elevation angle for interferometer.
22:46:40 Gust front hit
22:55 Buffer is filling often. Some lightning is lasting >1 sec. Also, some lightning is reaching up to >45 elevation (good for intercomparison). Flash rate is still very active: >1 per second!
23:05:06 +CGs?
23:11 Lightning is still at high elevation angle. Sharp recoil (fast) events continue to be evident.
23:17:00 Paused display (hoping to increase data rate). Buffer is filling every ~20 secs on DSP (when there are long flashes or multiple flashes back-to-back)
23:34:45 Saw CG (+?) to WNW. Had a rather strange loopy (up/down) nature.
23:43 Most lightning is at low elevation, though a few channels are reaching up to ~30 deg. elev.. Horizontally extensive lightning emanating from storm which is now ~E to ~ESE? or from cell SSW? Discharges spanning up to ~180 degrees of horizon.
23:47:00 +CG struck to W (visual). Discharge wrapped around the horizon to N.
23:55:10 Discharge ~overhead. Slow antenna saturated.
164 12-Jun 0:07:30 Occassional big horizontal discharges with substantial field changes (still on scale)
0:12-0:26 Data acquisition system suspended in order to transfer data off of a ~full hard drive on Sun IPC
0:29:48 Big lightning discharge; saturated slow antenna and filled DSP buffer
0:30:15 Heard thunder from discharge.
0:33:18 Another big lightning discharge
0:42:? Discharge
0:47:01 Big static field change; saturated SA
0:54:40 Big static field change
~1:02:25 Horizontal lightning discharge and +CG
1:07:56 Horizontal lightning discharge and +CG?
1:12 Update: 4 successful balloon launches earlier: 1 post core launch
1:16:28 Significant static field change. Lightning is mostly at low elevation angle
1:38:48 Static field change, +CG (saw out window to NE)
? Phase detector shifts were adjusted (see repair log).
22:50 Very active lightning to S. Good SA data at gain 7: ~1 flash every 2 secs. Recently formed and rapidly-growing cells are being scanned by both radars. Lightning is at low elevation.
22:58 Lightning is at/below ~20 deg. elevation to ESE. See a little structure
23:20 Lightning to S has ~deceased
23:30 High winds (Boundary - Gust front)
165 13-Jun 1:39 Tornado warning for NE Sheridan County
2:41 Storms extending from North Platte, Nebraska, south to Nebraska-Kansas border, then SE to Hill City, Kansas
169 17-Jun Replaced Sun Ultra 1 CPU fan (CPU had been overheating; triggering automatic shutdown)
170 18-Jun Got sferic acquisition to work on Sun Ultra! Tried to fix DSP crashing by reseating DSP board front panel.
171 19-Jun <21 Storms formed along dry-line to NE of main STEPS region. Runtime errors in interferometer data acquisition code on Sun Ultra were fixed sometime today. The Sun Ultra 1 was used to acquire data for the first time!
172 20-Jun 0:47 Lightning is very active: ~1 flash every second. Occasional big static E-field change (horizontal lightning, +CGs?)
~0:49 Took digital pictures (via Olympus C2000Z) of impressive advancing-line of storms
1:12 Sun Ultra was not responding well: could still use mouse but was slow. System was rebooted. DSP locked up after reboot. Adjusted cables...
1:44:00-50 System locked up, but came back after ~1 minute!?!? (Note: no keyboard or mouse button actions were processed in this time, but were afterwards (all at once!) )
~1:46:50 Big static field change (~1.5 V at gain of 3)
1:51:20-52:30 System locked up (had use of mouse & keyboard initially, but slowly lost use of them)
2:10:30 Checked /var/adm/messages. Sun Ultra locks up due to problems writing to 18 GB Hitachi HD. Many errors reported which don't lock up the system.
3:02 Switched to recording data on 2 GB HD
3:11:45 Onset of DSP crash was likely caused by vibration (at connectors?) when I sat down. I've noticed such a correlation before too.
3:40 Receiving occassional error messages in /var/adm/messages for 2 GB Seagate HD! Not as frequent as for 18 GB HD, though.
~5:17:50 Power-cycled VME since DSPs hung when sferics program was started.
6:10:04 Sprite in center of field-of-view (FOV)? Note: clouds blocking most of FOV for this and later sprites.
6:16 Sprite activity increasing: ~1 per minute
6:22:27 Sprite
6:54:08 Sprite halo? (or elve)
7:03:47 Sprites
7:07:15 Sprites
7:11:00 Sprites? Cloud cover continues to be thick.
7:58:04 Huge sprite (not recorded. It was seen on real time video since camera was left outside and clouds had cleared)
7:58:06-08 Dancing sprite (also not recorded)
8:02:36 Huge dancing sprites (not recorded. Camera was subsequently taken inside since sprites were distant and I did not want to risk damaging the HDs with overheating from unneccessary sferics recording)
174 22-Jun 23:50 Using oscilloscope, discovered that SIN 4+5 was ~dead (for how long??). Fixed by adjusting card.
175 23-Jun ~0:08 Funnel cloud spotted by spotter. Tornado warning is for SE Yuma County.
~0:10 NEXRAD radar showing interesting velocity structure near S-POL
0:25 Marble-size hail at SPOL
0:26 Very high trigger rate: ~>80 MB/min!! Buffer full every ~10 seconds
0:58 Overview/update from CHILL: Large convective "blob" SSW-NNE. T28 already headed home. Hailstone van in area. 2 balloon launches.
~1:04:40 Big -SA field change (probably -CG). New cell(s) on SW side of big storm?
1:05:20 Heard thunder from discharge.
~2:30 Balloon launch. Note: field changes are >90% negative-going (inverted ICs)
2:32 CHILL: Very good case today of switch from ~all +CGs to -CGs
~2:49 CHILL: Balloon crew reports good E data. Balloon is entrained.
<4:00 Sprites observed at Yucca Ridge from an MCS to N and E of LMA
~4:13:15 Saw -CG out window to NNW. It produced a -4.3 V static field change
~4:16:00 Another -CG to NNW. It produced a -5 V static field change
~4:30 No more lightning from close cells
5:49 Big + static field change (way off scale at gain 6). Overhead IC (inverted)? Just prior to IC, a significant -DC displacement forced me to drop the SA sensitivity from gain 7 to gain 6.
5:53 Static field changes are +, even though storm appears to be within reversal distance (loud thunder).
6:58:17 Sprites (seen on video just before recording)
7:14:56 Big discharge seen on video
7:27:45 Dancing sprite
7:31:32 Bright meteor
~8:00 YRFS stopped sprite observing
20:48 DC displacement upwards on SA at gain 7. Turrets nearby.
20:49:30 Static field change. Close?
21:27:15 -2.8 V static field change
22:41:50 High elevation lightning channels (seen visually below cloud). Note: cells are in an ~E-W line with the closest cell near I-70. Cells are almost stationary.
22:45:28 +CG? Heard somewhat loud thunder and there was a big +static field change
23:07:21 Big +static field change. +CG seen to NE? (or low, bright, channel)
23:10:46 Two bright flashes (2 +CGs?). Big +static field change, slightly off-scale.
176 24-Jun 3:34:34 Dancing sprites
~3:36 Noticed that DSPs were hung
~3:38:10 GPS locked. Times before this will be off by ~15 secs (early).
4:16:11 Sprite
4:53:08 Sprite to ~east
4:57:39 Sprite to ~east
5:03:19 Sprite to ~east
5:13:46 Sprite to ~east
22:09 Isolate storm to W. It is being scanned by radars. Flash polarity appears to be normal on SA (mostly +going), but was -going prior to arm. Flash rate is slowing? Only ~1 per minute.
~23 No more lightning. Waiting for new storms to form (possibly near Wray? based on 23:30 Nowcast report)
177 25-Jun ~0:25 Flash rate: ~1 per 2 secs. All field changes are negative (inverted ICs). Storm is "just" north of S-Pol
~1:00 Most static dE's are still negative, though there are a few positives. CHILL: Left & right-moving storms. T28 will penetrate both.
~1:30 Flash rate has slowed: ~1 per 10 secs. Still mostly negative static dEs.
1:42 3/4" hail reported ~3 mi. S of Yuma
1:47 Flash rate is low: ~1 per minute based on SA. However, RF triggers are frequent since there are active ~distant storms
2:04 CHILL: Andy reports that T28 obtained its first good data on supercells
2:16 CHILL: NSSL just launched a balloon into a core from Hagler
~2:34 Combines harvesting wheat in adjacent field. Airborn particles are interfering with SA.
3:47:35 Turned on Vertical Baseline rack. Have the long 3-13 1/2 wavelength horizontal baseline running.
4:52 SA output looks like a sawtooth wave - extremely active!! (has been extremely active for a while now)
5:02:30 Discovered that COS 4+5 (YS) was bad. Fixed by wiggling board
5:03:30 COS 4+5 broke again. Fixed it again.
5:29:05 Sprite from close decaying supercellular storm (seen by YRFS)
~5:40 No more lightning from supercell to ENE
6:03 Lightning has resumed to East now (new cell just E of Goodland)
~6:52:25 Noise goes away (had increased RF threshold only moments before due to noise)
21:00 All storms are still ~distant to ~E-S (and moving further away). Cold front passage occurred well before 20 UT (winds from N)

Last Modified By: Mark Stanley ( )
Last Modified On: Monday, March 26, 2001  21:29:17