National Weather Service United States Department of Commerce
SVR/TOR Warnings Flash Flood Tornadoes Winter Storms High Wind

SVR (severe thunderstorm warnings): The number of severe thunderstorm warnings issued.
TOR (tornado warnings): The number of tornado warnings issued.
TOTAL (total of severe and tornado warnings): The total number of severe thunderstorm and tornado warnings combined.
FFW (flash flood warnings): The number of flash flood warnings.
WARN (warnings): The number of warnings issued.
VERIF (verification): The number of warnings that verified.
EVENTS (events): Total number of actual severe weather events.
UNWARN (unwarned): The number of unwarned events.
WATCH (watches): The number of watches that were in effect before warnings were issued.

FAR (false alarm ratio): The percentage of warnings where the particular weather event did not occur.
POD (probability of detection): The percentage of events that were warned for and the conditions occured.
CSI (critical success index): The number of warned events divided by the sum of the total number of events and the number of the unverified counties.
LT (lead time): The average lead time before the first reported instance of the particular event.


 

SVR/TOR Warnings

YEAR
SVR
TOR
TOTAL
EVENTS
FAR
POD
CSI
LT
1994 133 36 169 166 .503 .620 .381 12.1
1995 125 9 134 104 .590 .606 .324 13.2
1996 89 5 94 76 .436 .868 .519 18.2
1997 224 36 260 204 .388 .882 .565 21.9
1998 330 52 382 386 .343 .904 .614 27.1
1999 125 16 141 131 .362 .924 .606 23.6
2000 240 14 254 260 .276 .919 .681 22.4
2001 184 14 198 216 .228 .931 .730 19.1
2002 170 28 198 214 .192 .879 .727 17.4
2003 118 8 126 135 .254 .859 .665 15.4
2004 165 27 192 191 .375 .848 .562 19.9
2005 132 22 154 172 .305 .779 .580 14.9
2006 211 6 217 243 .226 .901 .714 18.8
2007** 226 17 243 261 .347 .808 .565 16.3
2008 168 26 194 318 .428 .792 .497 18.7
2009 78 24 102 158 .363 .876 .585 21.7
2010 114 11 125 213 .312 .749 .559 17.2
2011 104 23 127 246 .252 .845 .658 17.2
2012 124 3 127 226 .220 .780 .639 14.4
2013 123 21 144 164 .451 .767 .470 15.7
2014 136 5 141 203 .369 .837 .562 18.9

** Storm Based Warnings began 10/1/2007

Flash Flood

YEAR
FFW
EVENTS
FAR
POD
CSI
LT
1997 14 8 .357 1.000 .643 18.8
1998 48 32 0 1.000 1.000 31.3
1999 38 18 .447 .778 .477 54.0
2000 76 45 .092 1.000 .908 48.9
2001 15 7 .553 1.000 .467 41.4
2002 20 15 .250 .813 .639 49.3
2003 4 2 .500 1.000 .500 0
2004 82 49 .098 .980 .886 70.0
2005 9 7 .222 1.000 .778 12.7
2006 3 3 .333 .667 .500 0
2007 52 59 .231 .949 .739 66.8
2008 39 35 .179 .749 .664 12.7
2009 15 20 .200 .863 .710 68.9
2010 30 23 .633 .332 .211 21.6
2011 22 13 .591 .671 .341 54.3
2012 6 2 .833 .492 .142 4.4
2013 39 50 .179 .826 .700 73.2
2014 20  32  .300 .887  .643  69.4 

 

Tornadoes

YEAR WARN EVENTS UNWARN FAR POD CSI LT
1994              
1995 9 6 4 .778 .333 .154 4.3
1996 5 2 1 .800 .500 .167 11.5
1997 36 7 2 .861 .714 .132 5.9
1998 52 9 3 .885 .667 .109 5.6
1999 16 5 1 .750 .800 .235 22.4
2000 14 6 3 .786 .500 .176 9.2
2001 14 9 2 .357 .778 .543 18.1
2002 28 9 3 .750 .667 .222 7.8
2003 8 1 0 .875 1.000 .125 18
2004 27 20 7 .593 .650 .334 13.2
2005  22  17  7  .545  .588 .345   4.9
2006  6  1  1.000  0  0  0.0
2007 17 7 4 .882 .429; .102 6.1
2008 26 8 2 .769 .739 .213 11.7
2009 24 8 2 .750 .708 .227 15.2
2010 11 9 4 .545 .436 .286 7.1
2011 23 14 2 .565 .728 .374 10.9
2012 3 2 1 .667 .215 .150 0.2
2013 21 5 5 1.000 0 0 0.0
2014 5 3 2 .800 .333 .143 0.3

 

Winter Weather

 

YEAR
WARN
VERIF
EVENTS
PRECEDED
BY WATCH
FAR
POD
CSI
LT
1998-99
55
41
54
35
.255
.759
.603
8h/7m
1999-00
61
21
29
8
.656
.733
.306
9h/10m
2000-01
185
142
148
107
.232
.959
.743
11h/33m
2001-02
69
33
34
18
.522
.971
.471
14h/56m
2002-03
73
34
44
10
.534
.773
.410
8h/37m
2003-04
90
49
55
46
.456
.891
.510
22h/27m
2004-05
105
98
112
91
.070
.888
.820
15h/42m
2005-06
92
58
63
- -
.370
.921
.598
23.3 hrs
2006-07
169
147
162
- -
.130
.907
.800
21.6 hrs
2007-08
210
145
141
- -
.310
.940
.660
13.9 hrs
2008-09
142
92
96
- -
.352
.958
.630
20.1 hrs
2009-10
91
68
56
- -
.253
.893
.686
26.5 hrs
2010-11
146
108
111
- -
.260
.937
.705
20.2 hrs
2011-12
6
2
5
- -
.667
.400
.222
13.3 hrs
2012-13
201
141
136
- -
.299
.882
.641
24.2 hrs
2013-14
116
62
54
- -
.466
.889
.501
23.3 hrs

 

 High Wind

 

YEAR
WARN
VERIF
EVENTS
WATCH
FAR
POD
CSI
LT
1998-99
0
0
0
0
 
 
 
 
1999-00
10
5
5
0
.500
1.000
.500
1 hr
2000-01
26
25
25
0
.038
1.000
.962
12 hr/15 min
2001-02
0
0
0
0
 
 
 
 
2002-03
0
0
0
0
 
 
 
 
 
2003-04
8
4
8
0
 
 
15 min
 
 
2004-05
12
10
11
0
.170
.910
.770
7 hrs/42 min

 

Last Updated 4/3/15 - tjs