The Work Week will Begin with Unsettled Weather from the Southern Plains to the Great Lakes

Unsettled weather is forecast to continue through the first half of the work week from the Southern Plains to the Great Lakes as a frontal system moves through. Isolated to scattered severe thunderstorms and flash flooding will be possible each day. Meanwhile, scattered showers and thunderstorms are expected across the Southwest and California, with isolated flash flooding possible. Read More >

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	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

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The Work Week will Begin with Unsettled Weather from the Southern Plains to the Great Lakes

NWS La Crosse Severe Weather Verification