results from vaisala’s long range lightning detection network (lldn) tropical cyclone studies
DESCRIPTION
Results from Vaisala’s long range lightning detection network (LLDN) tropical cyclone studies. Nicholas W. S. Demetriades Applications Manager, Meteorology Business Area Vaisala, Inc. Monterey, CA 24 March 2009. Hurricane Rita (2005). Demetriades and Holle (2008) Introduction - Goal. - PowerPoint PPT PresentationTRANSCRIPT
Results from Vaisala’s long range lightning detection network (LLDN) tropical cyclone studies
Nicholas W. S. Demetriades
Applications Manager, Meteorology Business Area
Vaisala, Inc.
Monterey, CA
24 March 2009
©Vaisala | date | Ref. code | Page 2
Hurricane Rita (2005)
©Vaisala | date | Ref. code | Page 3
Demetriades and Holle (2008)Introduction - Goal
• Study inner core lightning rates throughout the full lifecycle of Atlantic tropical cyclones for a large sample size
©Vaisala | date | Ref. code | Page 4
Methodology
• Full lifecycle of tropical cyclones that occurred in Atlantic basin from 2004 through 2007
• Landfall not excluded
• Subtropical storms not studied
• Tropical cyclone position and maximum sustained wind speeds obtained from National Hurricane Center best track data
• Interpolated positions and maximum sustained wind speeds between 6-hour intervals to obtain 3-hour values
• Tropical cyclone inner core lightning defined as 3-hourly CG lightning flash rates within 100 km of center of storm position
• Day/Night detection efficiency corrections were applied
©Vaisala | date | Ref. code | Page 5
MethodologyTropical cyclone intensity categories
Tropical cyclone intensity category Maximum sustained wind speeds
Tropical depression (TD) <35 knots
Tropical storm – weak (TS-W) 35-49 knots
Tropical storm – strong (TS-S) 50-63 knots
Hurricane – weak (H-W) 64-95 knots
Hurricane – strong (H-S) >95 knots
©Vaisala | date | Ref. code | Page 6
Atlantic basin resultsDay/Night, DE-corrected cumulative lightning rate distribution table
Tropical cyclone intensity category
Sample size Percentile of first non-zero
lightning count
50th percentile 75th percentile 90th percentile
Tropical depression (TD)
480 42% 3 100 585
Tropical storm – weak (TS-W)
658 35% 18 280 1248
Tropical storm – strong (TS-S)
446 29% 24 477 1765
Hurricane – weak (H-W)
512 47% 2 43 276
Hurricane – strong (H-S)
373 29% 16 76 200
©Vaisala | date | Ref. code | Page 7
Atlantic basin resultsInner core lightning with respect to landfall
0
50
100
150
200
250
300
350
400
-24 -21 -18 -15 -12 -9 -6 -3 0 3 6 9 12 15 18 21 24
Time in hours with respect to landfall (time zero)
3-h
ou
r in
ne
r c
ore
lig
htn
ing
ra
te
Median 75th percentile
©Vaisala | date | Ref. code | Page 8
Conclusions
• New finding: Atlantic tropical cyclones produce the highest inner core lightning rates during the tropical storm stage and the lowest inner core lightning rates during the hurricane stage
• High inner core (eyewall) lightning rates occur infrequently in category 3-5 hurricanes
• Appear to be related to eyewall replacement cycles (Knabb et al., 2008)
• Atlantic tropical cyclones produce more inner core lightning during the 24-hour period leading up to, and including landfall, than they do during the 24-hour period after landfall
©Vaisala | date | Ref. code | Page 9
Hurricane Katrina (2005)Eyewall replacement & Continuous eyewall lightning
0
100
200
300
400
500
600
700
800
900
1000
8/2
3/2
00
5 1
80
08
/23
/20
05
21
00
8/2
4/2
00
5 0
00
08
/24
/20
05
03
00
8/2
4/2
00
5 0
60
08
/24
/20
05
09
00
8/2
4/2
00
5 1
20
08
/24
/20
05
15
00
8/2
4/2
00
5 1
80
08
/24
/20
05
21
00
8/2
5/2
00
5 0
00
08
/25
/20
05
03
00
8/2
5/2
00
5 0
60
08
/25
/20
05
09
00
8/2
5/2
00
5 1
20
08
/25
/20
05
15
00
8/2
5/2
00
5 1
80
08
/25
/20
05
21
00
8/2
6/2
00
5 0
00
08
/26
/20
05
03
00
8/2
6/2
00
5 0
60
08
/26
/20
05
09
00
8/2
6/2
00
5 1
20
08
/26
/20
05
15
00
8/2
6/2
00
5 1
80
08
/26
/20
05
21
00
8/2
7/2
00
5 0
00
08
/27
/20
05
03
00
8/2
7/2
00
5 0
60
08
/27
/20
05
09
00
8/2
7/2
00
5 1
20
08
/27
/20
05
15
00
8/2
7/2
00
5 1
80
08
/27
/20
05
21
00
8/2
8/2
00
5 0
00
08
/28
/20
05
03
00
8/2
8/2
00
5 0
60
08
/28
/20
05
09
00
8/2
8/2
00
5 1
20
08
/28
/20
05
15
00
8/2
8/2
00
5 1
80
08
/28
/20
05
21
00
8/2
9/2
00
5 0
00
08
/29
/20
05
03
00
8/2
9/2
00
5 0
60
08
/29
/20
05
09
00
8/2
9/2
00
5 1
20
08
/29
/20
05
15
00
8/2
9/2
00
5 1
80
08
/29
/20
05
21
00
8/3
0/2
00
5 0
00
08
/30
/20
05
03
00
8/3
0/2
00
5 0
60
08
/30
/20
05
09
00
8/3
0/2
00
5 1
20
08
/30
/20
05
15
00
8/3
0/2
00
5 1
80
0
Date and Time (M/D/YYYY HHmm) UTC
3-h
ou
r e
ye
wa
ll lig
htn
ing
ra
te
0
20
40
60
80
100
120
140
160
Ma
xim
um
su
sta
ine
d w
ind
sp
ee
d (
kn
ots
)
Uncorrected Day/Night DE Corrected Maximum Sustained Wind Speed
©Vaisala | date | Ref. code | Page 10
Hurricane Wilma (2005)Eyewall replacement
0
100
200
300
400
500
600
700
800
900
1000
10
/15
/20
05
18
00
10
/15
/20
05
21
00
10
/16
/20
05
00
00
10
/16
/20
05
03
00
10
/16
/20
05
06
00
10
/16
/20
05
09
00
10
/16
/20
05
12
00
10
/16
/20
05
15
00
10
/16
/20
05
18
00
10
/16
/20
05
21
00
10
/17
/20
05
00
00
10
/17
/20
05
03
00
10
/17
/20
05
06
00
10
/17
/20
05
09
00
10
/17
/20
05
12
00
10
/17
/20
05
15
00
10
/17
/20
05
18
00
10
/17
/20
05
21
00
10
/18
/20
05
00
00
10
/18
/20
05
03
00
10
/18
/20
05
06
00
10
/18
/20
05
09
00
10
/18
/20
05
12
00
10
/18
/20
05
15
00
10
/18
/20
05
18
00
10
/18
/20
05
21
00
10
/19
/20
05
00
00
10
/19
/20
05
03
00
10
/19
/20
05
06
00
10
/19
/20
05
09
00
10
/19
/20
05
12
00
10
/19
/20
05
15
00
10
/19
/20
05
18
00
10
/19
/20
05
21
00
10
/20
/20
05
00
00
10
/20
/20
05
03
00
10
/20
/20
05
06
00
10
/20
/20
05
09
00
10
/20
/20
05
12
00
10
/20
/20
05
15
00
10
/20
/20
05
18
00
10
/20
/20
05
21
00
10
/21
/20
05
00
00
10
/21
/20
05
03
00
10
/21
/20
05
06
00
10
/21
/20
05
09
00
10
/21
/20
05
12
00
10
/21
/20
05
15
00
10
/21
/20
05
18
00
10
/21
/20
05
21
00
10
/22
/20
05
00
00
10
/22
/20
05
03
00
10
/22
/20
05
06
00
10
/22
/20
05
09
00
10
/22
/20
05
12
00
10
/22
/20
05
15
00
10
/22
/20
05
18
00
10
/22
/20
05
21
00
10
/23
/20
05
00
00
10
/23
/20
05
03
00
10
/23
/20
05
06
00
10
/23
/20
05
09
00
10
/23
/20
05
12
00
10
/23
/20
05
15
00
10
/23
/20
05
18
00
10
/23
/20
05
21
00
10
/24
/20
05
00
00
10
/24
/20
05
03
00
10
/24
/20
05
06
00
10
/24
/20
05
09
00
10
/24
/20
05
12
00
10
/24
/20
05
15
00
10
/24
/20
05
18
00
10
/24
/20
05
21
00
10
/25
/20
05
00
00
10
/25
/20
05
03
00
10
/25
/20
05
06
00
10
/25
/20
05
09
00
10
/25
/20
05
12
00
10
/25
/20
05
15
00
10
/25
/20
05
18
00
Date and Time (M/D/YYYY HHmm) UTC
3-h
ou
r e
ye
wa
ll lig
htn
ing
ra
te
0
20
40
60
80
100
120
140
160
180
Ma
xim
um
su
sta
ine
d w
ind
sp
ee
d (
kn
ots
)
Uncorrected Day/Night DE Corrected Maximum Sustained Wind Speed
©Vaisala | date | Ref. code | Page 11
Hurricane Felix (2007)Eyewall replacement
0
100
200
300
400
500
600
700
800
900
1000
8/3
1/2
00
7 1
20
08
/31
/20
07
15
00
8/3
1/2
00
7 1
80
08
/31
/20
07
21
00
9/1
/20
07
00
00
9/1
/20
07
03
00
9/1
/20
07
06
00
9/1
/20
07
09
00
9/1
/20
07
12
00
9/1
/20
07
15
00
9/1
/20
07
18
00
9/1
/20
07
21
00
9/2
/20
07
00
00
9/2
/20
07
03
00
9/2
/20
07
06
00
9/2
/20
07
09
00
9/2
/20
07
12
00
9/2
/20
07
15
00
9/2
/20
07
18
00
9/2
/20
07
21
00
9/3
/20
07
00
00
9/3
/20
07
03
00
9/3
/20
07
06
00
9/3
/20
07
09
00
9/3
/20
07
12
00
9/3
/20
07
15
00
9/3
/20
07
18
00
9/3
/20
07
21
00
9/4
/20
07
00
00
9/4
/20
07
03
00
9/4
/20
07
06
00
9/4
/20
07
09
00
9/4
/20
07
12
00
9/4
/20
07
15
00
9/4
/20
07
18
00
9/4
/20
07
21
00
9/5
/20
07
00
00
9/5
/20
07
03
00
9/5
/20
07
06
00
Date and Time (M/D/YYYY HHmm) UTC
3-h
ou
r e
ye
wa
ll lig
htn
ing
ra
te
0
20
40
60
80
100
120
140
160
Ma
xim
um
su
sta
ine
d w
ind
sp
ee
d (
kn
ots
)
Uncorrected Day/Night DE Corrected Maximum Sustained Wind Speed