7 January 2008 Tornado at the Rolla-Vichy National Airport John Gagan NOAA National Weather Service...
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Transcript of 7 January 2008 Tornado at the Rolla-Vichy National Airport John Gagan NOAA National Weather Service...
7 January 2008 Tornadoat the Rolla-Vichy National Airport
John GaganNOAA • National Weather Service
Springfield, Missouri
Outline
• Event overview• Focus on tornadic supercell affecting KVIH
– Reflectivity, SRM and Base Velocity Imagery– Warning decision process– Role of Heuristics (“gut feelings”)
• KVIH observations (1 min, 5 sec) – direct hit!• Pics from Survey
Event Overview
• 12 hours of tornadoes, hail, wind and flooding• Watches: 3 Tornado Watches (1 PDS), 1 Severe• Warnings: 62 Tornado, 33 Severe, 4 Flash Flood• 161 Severe Weather Reports• 33 Tornadoes• 3 Fatalities, Numerous Injuries• In previous Januaries from 1950-2007, only 5
Tornadoes were reported in SW Missouri
Event Overview
Event Overview250 mb
00z January 8th
Event Overview500 mb
00z January 8th
Event Overview850 mb
00z January 8th
SGF
RAO
B00
z Jan
uary
8th
Loop of Event
33 Tornadoes in January!
Only 5 tornadoes reported in January from 1950-2007!
LSX
SGF
• KLSX WSR 88D• KVIH is ~5200 ft AGL• Rank 5-6 Meso
• non continuous• No TVS• Warning decision
~0325 UTC
From IEM COW – Iowa State University
Warning Decision
• Quickly transitioned from coordinator role to warning operator– Bathroom breaks!!!!– Warning operator fatigue
• Assigned to Sector 3 (central MO)• Meso was weakening• No recent (<30 min) reports from the storm• Why continue to warn?
Warning Decision• Ultimately, the warning decision hinged on a
heuristic (gut feeling)– Meso began to reorganize/strengthen– Reflectivity structure in tact– Not much info < 8000 ft– Past history – numerous reports of damage – cyclic
• “Warn on a cyclic supercell until it’s someone else’s problem.”
• Great reference– “Gut Feelings: The Intelligence of the Unconscious”– Gerd Gigerenzer
KVIHVichy Tornado Track
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
400
401
402
403
404
405
406
407
408
409
4100
10
20
30
40
50
60
70
80
90
10 9 8 7 6 64 5 6
811 12 13
16 17
27
4442
29
2117 16 15
1210 11 11
9 8 7 7
12 11 118 7 7 7 8
1113
1714
18
2422
67
84
48
30
2219 19 19
14 13 1412 12
9 911
KVIH Station 2-min and 5-sec Wind Speed Plot340 to 410 UTC 8 January 2008
2min Wind Spd 5sec Wind Spd
Hour UTC
Knot
s
2 Minute Wind 5 Second Wind
KVIH Takes a Direct Hit!
0347 UTCTo
0400 UTC
• Wind direction switched from ESE to WNW
• Wind speed changed from 5 to 44 knots
• Wind direction switched from ESE to NW
• Wind speed changed from 8 to 84 knots
KVIHDouglas DC-3WWII Era Planes
KVIH
EF Rating
• Main casualty was trees– A few hard and soft wood trees uprooted– DIs 27 and 28, highest DOD was 3
• Most extensive damage was to the destroyed mobile home– Not tied down well – Pushed and rolled– Debris field scattered over 200 yds– DI 3 (single wide), DOD 9 (lower bound)– Damage consistent with high end EF-1
• VIH ASOS ~ 1-1.5 mi west of mobile home damage– 5 second wind speed well within EF-1 range
• 13 mile path, max width 100 yds, max winds 110 mph
Acknowledgements
• Ron Przybylinski – LSX radar• Kelsey Angle – Prior work on event• The SGF office for a job well done
Thank You