IGC Spy

Glider VW Thermal Info (Task 6-Open)

		Thermal Time			Thermal Alt					Orbits Speed			Orbits Diam			Orbit Time			Climb Rate			Other
ID	Type	Start [hms]	End [hms]	Duration [hms]	Start [ft]	End [ft]	Delta [ft]	Lost [ft]	Lost [%]	Avg (stab) [kts]	Min (stab) [kts]	Max (stab) [kts]	Avg (stab) [m]	Min (stab) [m]	Max (stab) [m]	Avg (stab) [sec]	Min (stab) [sec]	Max (stab) [sec]	Avg (stab) [kts]	Min (stab) [kts]	Max (stab) [kts]	Direction	Track Length [km]	Count
0	All			00:49:36			20720	1796	8.7 %	67.1						23 00:00:23 blah			4.1					17
1	Thermal	03:15:58	03:18:15	00:02:17	3558	4568	1009	37	3.7 %	65.8 66.1	41.2 64.2	79.4 68.2	246 241	230 231	281 251	22.8 22.3	21 22	27 23	4.3 5.1	1 4.1	6.2 6.2	Right	4.6	6
1	Orbit	03:15:58	03:16:25	00:00:27	3558	3773	215	14	6.7 %	63.6			0			27			4.7			Right	0.9
2	Orbit	03:16:25	03:16:47	00:00:22	3773	3962	188	4	2.6 %	64.2			0			22			5.1			Right	0.7
3	Orbit	03:16:47	03:17:09	00:00:22	3962	4192	230	4	2.1 %	65.6			0			22			6.2			Right	0.7
4	Orbit	03:17:09	03:17:31	00:00:22	4192	4374	181	0	0 %	68.2			0			22			4.9			Right	0.8
5	Orbit	03:17:31	03:17:54	00:00:23	4374	4534	159	0	0 %	66.6			0			23			4.1			Right	0.8
6	Orbit	03:17:54	03:18:15	00:00:21	4534	4568	33	13	40.2 %	67			0			21			1			Right	0.7
2	Thermal	03:27:29	03:30:46	00:03:17	1770	3028	1257	68	5.5 %	67.1 66.9	51.7 65.5	86.5 70.2	271 276	221 245	345 345	24.6 25.2	20 22	30 30	3.8 3.9	1.8 2.7	5 4.8	Left	6.8	8
8	Orbit	03:27:29	03:27:55	00:00:26	1770	1991	221	0	0 %	67.7			0			26			5			Left	0.9
9	Orbit	03:27:55	03:28:19	00:00:24	1991	2178	187	0	0 %	66			0			24			4.6			Left	0.8
10	Orbit	03:28:19	03:28:44	00:00:25	2178	2381	203	0	0 %	66.6			0			25			4.8			Left	0.9
11	Orbit	03:28:44	03:29:07	00:00:23	2381	2561	179	4	2.5 %	65.5			0			23			4.6			Left	0.8
12	Orbit	03:29:07	03:29:29	00:00:22	2561	2683	122	11	9.8 %	68			0			22			3.3			Left	0.8
13	Orbit	03:29:29	03:29:56	00:00:27	2683	2832	149	17	11.6 %	65.5			0			27			3.3			Left	0.9
14	Orbit	03:29:56	03:30:26	00:00:30	2832	2968	135	20	15.2 %	70.2			0			30			2.7			Left	1.1
15	Orbit	03:30:26	03:30:46	00:00:20	2968	3028	59	14	24.3 %	67.5			0			20			1.8			Left	0.7
3	Thermal	03:39:06	03:43:06	00:04:00	1545	3804	2258	20	0.9 %	66.4 66.1	48.9 64.9	79.1 67	237 233	214 214	280 280	21.8 21.6	20 20	26 26	5.7 6.2	1.9 2.5	7.7 7.7	Right	8.2	11
16	Orbit	03:39:06	03:39:32	00:00:26	1545	1752	206	0	0 %	63.8			0			26			4.7			Right	0.9
17	Orbit	03:39:32	03:39:54	00:00:22	1752	1959	207	0	0 %	66			0			22			5.6			Right	0.7
18	Orbit	03:39:54	03:40:15	00:00:21	1959	2215	255	0	0 %	66.8			0			21			7.2			Right	0.7
19	Orbit	03:40:15	03:40:36	00:00:21	2215	2459	244	0	0 %	66.8			0			21			6.9			Right	0.7
20	Orbit	03:40:36	03:40:57	00:00:21	2459	2731	272	0	0 %	66.6			0			21			7.7			Right	0.7
21	Orbit	03:40:57	03:41:18	00:00:21	2731	3005	273	0	0 %	67			0			21			7.7			Right	0.7
22	Orbit	03:41:18	03:41:38	00:00:20	3005	3251	246	0	0 %	65.4			0			20			7.3			Right	0.7
23	Orbit	03:41:38	03:41:59	00:00:21	3251	3457	205	0	0 %	66			0			21			5.8			Right	0.7
24	Orbit	03:41:59	03:42:20	00:00:21	3457	3629	172	0	0 %	64.9			0			21			4.9			Right	0.7
25	Orbit	03:42:20	03:42:46	00:00:26	3629	3740	110	16	15.3 %	65.8			0			26			2.5			Right	0.9
26	Orbit	03:42:46	03:43:06	00:00:20	3740	3804	63	3	5.8 %	71.2			0			20			1.9			Right	0.7
4	Thermal	03:49:01	03:53:04	00:04:03	2887	4461	1574	139	8.9 %	67.1 67.3	54.1 66.3	81.8 68.4	243 240	220 220	266 261	22.1 21.8	20 20	25 24	3.8 4.3	-1.2 2.2	5.6 5.6	Left	8.4	11
28	Orbit	03:49:01	03:49:26	00:00:25	2887	3080	193	3	1.8 %	65.1			0			25			4.6			Left	0.8
29	Orbit	03:49:26	03:49:50	00:00:24	3080	3261	180	0	0 %	66.3			0			24			4.5			Left	0.8
30	Orbit	03:49:50	03:50:12	00:00:22	3261	3417	156	0	0 %	66.3			0			22			4.2			Left	0.8
31	Orbit	03:50:12	03:50:35	00:00:23	3417	3605	187	1	0.7 %	67.7			0			23			4.8			Left	0.8
32	Orbit	03:50:35	03:50:56	00:00:21	3605	3777	172	0	0 %	68.4			0			21			4.9			Left	0.7
33	Orbit	03:50:56	03:51:16	00:00:20	3777	3926	148	0	0 %	67.2			0			20			4.4			Left	0.7
34	Orbit	03:51:16	03:51:37	00:00:21	3926	4124	197	0	0 %	66.9			0			21			5.6			Left	0.7
35	Orbit	03:51:37	03:51:58	00:00:21	4124	4265	141	0	0.5 %	67.6			0			21			4			Left	0.7
36	Orbit	03:51:58	03:52:20	00:00:22	4265	4422	156	0	0 %	67.2			0			22			4.2			Left	0.8
37	Orbit	03:52:20	03:52:42	00:00:22	4422	4505	82	15	19 %	68.3			0			22			2.2			Left	0.8
38	Orbit	03:52:42	03:53:04	00:00:22	4505	4461	-43	118	-274.1 %	67.2			0			22			-1.2			Left	0.8
5	Thermal	04:05:09	04:06:46	00:01:37	3150	3871	721	2	0.4 %	64.7 64.9	42.2 63.9	84.7 65.9	257 244	241 241	284 248	24.3 23	23 23	27 23	4.3 4.2	2.8 3.9	6.1 4.6	Left	3.2	4
42	Orbit	04:05:09	04:05:36	00:00:27	3150	3428	278	0	0 %	64.2			0			27			6.1			Left	0.9
43	Orbit	04:05:36	04:05:59	00:00:23	3428	3579	151	0	0.2 %	65.9			0			23			3.9			Left	0.8
44	Orbit	04:05:59	04:06:22	00:00:23	3579	3757	177	0	0.2 %	63.9			0			23			4.6			Left	0.8
45	Orbit	04:06:22	04:06:46	00:00:24	3757	3871	114	2	1.9 %	64.9			0			24			2.8			Left	0.8
6	Thermal	04:09:49	04:11:07	00:01:18	3372	3812	440	49	11.4 %	68.6 65	49.7 64.9	81.7 65.1	211 256	78 234	277 277	19.5 24	6 22	26 26	2.4 3.4	-1.6 3	4.6 3.7	Mixed	2.7	4
46	Orbit	04:09:49	04:10:13	00:00:24	3372	3559	187	0	0 %	65.2			0			24			4.6			Right	0.8
47	Orbit	04:10:13	04:10:35	00:00:22	3559	3697	138	0	0.2 %	64.9			0			22			3.7			Right	0.7
48	Orbit	04:10:35	04:11:01	00:00:26	3697	3828	131	16	12.7 %	65.1			0			26			3			Right	0.9
49	Orbit	04:11:01	04:11:07	00:00:06	3828	3812	-16	33	-205.5 %	79.4			0			06			-1.6			Left	0.2
7	Thermal	04:19:12	04:27:41	00:08:29	1583	5265	3681	251	6.8 %	67.9 67.3	48 61.2	92.2 70.7	244 250	113 210	327 327	22.1 22.7	8 20	29 29	4 4.5	-8.9 1.4	6.6 6.6	Left	17.6	23
50	Orbit	04:19:12	04:19:36	00:00:24	1583	1815	231	0	0 %	61.1			0			24			5.7			Left	0.8
51	Orbit	04:19:36	04:19:57	00:00:21	1815	1979	164	0	0 %	63			0			21			4.6			Left	0.7
52	Orbit	04:19:57	04:20:18	00:00:21	1979	2105	126	7	5.6 %	64.4			0			21			3.6			Left	0.7
53	Orbit	04:20:18	04:20:38	00:00:20	2105	2253	148	0	0 %	64.1			0			20			4.4			Left	0.7
54	Orbit	04:20:38	04:21:04	00:00:26	2253	2419	165	4	3 %	61.2			0			26			3.8			Left	0.8
55	Orbit	04:21:04	04:21:32	00:00:28	2419	2529	110	13	12.3 %	64.9			0			28			2.3			Left	0.9
56	Orbit	04:21:32	04:22:01	00:00:29	2529	2775	245	1	0.5 %	68.8			0			29			5			Left	1
57	Orbit	04:22:01	04:22:23	00:00:22	2775	2968	193	0	0 %	67.2			0			22			5.2			Left	0.8
58	Orbit	04:22:23	04:22:46	00:00:23	2968	3133	164	4	2.5 %	67.8			0			23			4.2			Left	0.8
59	Orbit	04:22:46	04:23:09	00:00:23	3133	3358	225	0	0 %	67.4			0			23			5.8			Left	0.8
60	Orbit	04:23:09	04:23:30	00:00:21	3358	3565	206	0	0 %	69.8			0			21			5.8			Left	0.8
61	Orbit	04:23:30	04:23:51	00:00:21	3565	3800	235	0	0 %	69.4			0			21			6.6			Left	0.7
62	Orbit	04:23:51	04:24:12	00:00:21	3800	3967	167	0	0 %	69.5			0			21			4.7			Left	0.8
63	Orbit	04:24:12	04:24:33	00:00:21	3967	4126	158	0	0.5 %	70.7			0			21			4.5			Left	0.8
64	Orbit	04:24:33	04:24:54	00:00:21	4126	4328	202	0	0.2 %	70.3			0			21			5.7			Left	0.8
65	Orbit	04:24:54	04:25:18	00:00:24	4328	4504	176	0	0 %	69.8			0			24			4.4			Left	0.9
66	Orbit	04:25:18	04:25:40	00:00:22	4504	4691	187	0	0 %	67.8			0			22			5			Left	0.8
67	Orbit	04:25:40	04:26:02	00:00:22	4691	4849	157	9	6.3 %	69.3			0			22			4.2			Left	0.8
68	Orbit	04:26:02	04:26:24	00:00:22	4849	5066	217	0	0 %	68.1			0			22			5.9			Left	0.8
69	Orbit	04:26:24	04:26:47	00:00:23	5066	5200	133	12	9.6 %	67			0			23			3.4			Left	0.8
70	Orbit	04:26:47	04:27:10	00:00:23	5200	5331	131	12	9.6 %	66.8			0			23			3.4			Left	0.8
71	Orbit	04:27:10	04:27:33	00:00:23	5331	5385	53	64	120.3 %	66.3			0			23			1.4			Left	0.8
72	Orbit	04:27:33	04:27:41	00:00:08	5385	5265	-119	119	-100 %	86.3			0			08			-8.9			Left	0.4
8	Thermal	04:38:12	04:42:53	00:04:41	3181	5305	2123	186	8.8 %	69.2 68.1	52 66.7	102 69.8	243 246	198 232	278 278	21.6 22.1	14 21	25 25	4.2 5.1	-6.7 4	6.3 6.3	Left	9.9	13
74	Orbit	04:38:12	04:38:36	00:00:24	3181	3393	211	3	1.7 %	63.5			0			24			5.2			Left	0.8
75	Orbit	04:38:36	04:38:58	00:00:22	3393	3559	166	1	1.1 %	66.7			0			22			4.5			Left	0.8
76	Orbit	04:38:58	04:39:20	00:00:22	3559	3740	181	0	0 %	67.8			0			22			4.9			Left	0.8
77	Orbit	04:39:20	04:39:42	00:00:22	3740	3910	170	0	0 %	67.6			0			22			4.6			Left	0.8
78	Orbit	04:39:42	04:40:03	00:00:21	3910	4051	141	6	4.7 %	67.5			0			21			4			Left	0.7
79	Orbit	04:40:03	04:40:25	00:00:22	4051	4268	216	0	0 %	68.5			0			22			5.8			Left	0.8
80	Orbit	04:40:25	04:40:46	00:00:21	4268	4491	223	0	0 %	67.9			0			21			6.3			Left	0.7
81	Orbit	04:40:46	04:41:07	00:00:21	4491	4652	160	4	2.8 %	67.9			0			21			4.5			Left	0.7
82	Orbit	04:41:07	04:41:30	00:00:23	4652	4828	176	0	0 %	68.4			0			23			4.5			Left	0.8
83	Orbit	04:41:30	04:41:52	00:00:22	4828	5058	229	0	0 %	69.8			0			22			6.2			Left	0.8
84	Orbit	04:41:52	04:42:14	00:00:22	5058	5285	227	0	0 %	69.1			0			22			6.1			Left	0.8
85	Orbit	04:42:14	04:42:39	00:00:25	5285	5462	176	7	4 %	68			0			25			4.2			Left	0.9
86	Orbit	04:42:39	04:42:53	00:00:14	5462	5305	-157	162	-103.5 %	86.4			0			14			-6.7			Left	0.6
9	Thermal	04:48:09	04:49:27	00:01:18	4342	4458	115	193	166.6 %	68.8 65.9	54 65.9	99.1 65.9	290 291	215 291	364 291	26 27	18 27	33 27	0.2 3.9	-4.5 3.9	3.9 3.9	Mixed	2.7	3
87	Orbit	04:48:09	04:48:42	00:00:33	4342	4419	76	44	58.4 %	67.4			0			33			1.4			Left	1.1
88	Orbit	04:48:42	04:49:09	00:00:27	4419	4596	177	1	0.6 %	65.9			0			27			3.9			Left	0.9
89	Orbit	04:49:09	04:49:27	00:00:18	4596	4458	-137	147	-107.2 %	73.1			0			18			-4.5			Right	0.7
10	Thermal	04:52:48	04:54:32	00:01:44	4282	5031	749	32	4.4 %	71.2 66.9	42.1 64.4	89.1 69.2	230 277	58 261	306 306	20.8 25.3	4 23	29 29	3.5 4.1	-0.9 3.3	5.7 4.6	Right	3.6	5
92	Orbit	04:52:48	04:53:12	00:00:24	4282	4514	232	3	1.3 %	67			0			24			5.7			Right	0.8
93	Orbit	04:53:12	04:53:35	00:00:23	4514	4691	176	16	9.3 %	69.2			0			23			4.6			Right	0.8
94	Orbit	04:53:35	04:53:59	00:00:24	4691	4878	187	0	0.4 %	67			0			24			4.6			Right	0.8
95	Orbit	04:53:59	04:54:28	00:00:29	4878	5037	159	6	4.1 %	64.4			0			29			3.3			Right	1
96	Orbit	04:54:28	04:54:32	00:00:04	5037	5031	-5	5	-100 %	88.2			0			04			-0.9			Right	0.2
11	Thermal	05:08:47	05:14:00	00:05:13	2155	4234	2079	77	3.7 %	66 65.3	49.4 63.2	81.5 67.2	259 263	179 248	305 286	24.1 24.5	15 23	28 26	4 3.9	2.8 2.8	4.7 4.7	Right	10.6	13
99	Orbit	05:08:47	05:09:15	00:00:28	2155	2330	174	3	1.9 %	66.4			0			28			3.7			Right	1
100	Orbit	05:09:15	05:09:40	00:00:25	2330	2450	120	13	11.4 %	66.9			0			25			2.8			Right	0.9
101	Orbit	05:09:40	05:10:04	00:00:24	2450	2615	165	7	4.6 %	64.5			0			24			4.1			Right	0.8
102	Orbit	05:10:04	05:10:29	00:00:25	2615	2735	119	12	10.6 %	63.7			0			25			2.8			Right	0.8
103	Orbit	05:10:29	05:10:55	00:00:26	2735	2942	207	0	0 %	67.2			0			26			4.7			Right	0.9
104	Orbit	05:10:55	05:11:19	00:00:24	2942	3103	160	6	4.2 %	64.9			0			24			4			Right	0.8
105	Orbit	05:11:19	05:11:42	00:00:23	3103	3279	176	9	5.6 %	65.9			0			23			4.5			Right	0.8
106	Orbit	05:11:42	05:12:06	00:00:24	3279	3433	153	9	6.4 %	64.8			0			24			3.8			Right	0.8
107	Orbit	05:12:06	05:12:30	00:00:24	3433	3624	190	0	0 %	65.6			0			24			4.7			Right	0.8
108	Orbit	05:12:30	05:12:54	00:00:24	3624	3799	174	2	1.2 %	63.2			0			24			4.3			Right	0.8
109	Orbit	05:12:54	05:13:20	00:00:26	3799	3979	179	4	2.5 %	66.1			0			26			4.1			Right	0.9
110	Orbit	05:13:20	05:13:45	00:00:25	3979	4124	145	6	4.8 %	65.9			0			25			3.4			Right	0.8
111	Orbit	05:13:45	05:14:00	00:00:15	4124	4234	110	0	0 %	72.7			0			15			4.4			Right	0.6
12	Thermal	05:16:48	05:18:31	00:01:43	3820	4428	607	69	11.5 %	66 65.8	45.6 65.8	87.5 65.8	370 302	197 302	611 302	34.3 28	18 28	57 28	3.2 3	2.8 3	4 3	Left	3.5	3
112	Orbit	05:16:48	05:17:45	00:00:57	3820	4203	382	29	7.8 %	65.5			1000			57			4			Left	1.9
113	Orbit	05:17:45	05:18:13	00:00:28	4203	4344	141	3	2.3 %	65.8			0			28			3			Left	0.9
114	Orbit	05:18:13	05:18:31	00:00:18	4344	4428	84	36	43.3 %	66.8			0			18			2.8			Left	0.6
13	Thermal	05:24:15	05:26:33	00:02:18	3798	4488	689	287	41.6 %	65.6 64.9	43.8 62	85.8 67	295 305	225 225	427 427	27.6 29	21 21	42 42	3.1 4	-0.8 2.7	5.2 5.2	Mixed	4.6	5
117	Orbit	05:24:15	05:24:41	00:00:26	3798	3976	177	19	11.1 %	65.1			0			26			4			Right	0.9
118	Orbit	05:24:41	05:25:23	00:00:42	3976	4171	194	86	44.5 %	62			0			42			2.7			Left	1.3
119	Orbit	05:25:23	05:25:47	00:00:24	4171	4338	166	2	1.3 %	67			0			24			4.1			Left	0.8
120	Orbit	05:25:47	05:26:08	00:00:21	4338	4523	184	9	5.3 %	65.6			0			21			5.2			Left	0.7
121	Orbit	05:26:08	05:26:33	00:00:25	4523	4488	-34	168	-491.8 %	68.4			0			25			-0.8			Left	0.9
14	Thermal	05:36:20	05:38:40	00:02:20	2516	3923	1407	6	0.5 %	64.5 63.6	45.6 62.4	80.5 64.4	207 239	12 214	290 290	20 23	1 21	28 28	6.2 5.6	4.1 4.1	7.9 6.5	Left	4.6	7
123	Orbit	05:36:20	05:36:44	00:00:24	2516	2834	318	0	0 %	60.9			0			24			7.9			Left	0.8
124	Orbit	05:36:44	05:37:06	00:00:22	2834	3077	242	1	0.6 %	64			0			22			6.5			Left	0.7
125	Orbit	05:37:06	05:37:28	00:00:22	3077	3315	238	0	0 %	64.4			0			22			6.4			Left	0.7
126	Orbit	05:37:28	05:37:49	00:00:21	3315	3503	188	0	0 %	62.4			0			21			5.3			Left	0.7
127	Orbit	05:37:49	05:38:11	00:00:22	3503	3716	212	0	0 %	63.9			0			22			5.7			Left	0.7
128	Orbit	05:38:11	05:38:39	00:00:28	3716	3911	195	5	2.6 %	63.3			0			28			4.1			Left	0.9
129	Orbit	05:38:39	05:38:40	00:00:01	3911	3923	12	0	0 %	72.5			0			01			7.1			Left	0
15	Thermal	05:38:46	05:40:31	00:01:45	3999	4732	733	152	20.8 %	66.4 66.9	54.6 66.6	81.6 67.1	293 235	100 231	602 240	26.3 21.5	10 21	52 22	3.6 4.9	0.3 4.7	5.2 5.2	Right	3.7	4
130	Orbit	05:38:46	05:39:38	00:00:52	3999	4370	370	75	20.3 %	70.7			1000			52			4.2			Right	1.9
131	Orbit	05:39:38	05:39:59	00:00:21	4370	4553	183	5	2.9 %	67.1			0			21			5.2			Right	0.7
132	Orbit	05:39:59	05:40:21	00:00:22	4553	4727	173	6	3.8 %	66.6			0			22			4.7			Right	0.8
133	Orbit	05:40:21	05:40:31	00:00:10	4727	4732	5	65	1282 %	61			0			10			0.3			Right	0.3
16	Thermal	05:44:29	05:45:49	00:01:20	4634	5013	379	148	39.1 %	68.3 65.6	48.2 65.6	86.2 65.6	215 258	25 247	319 268	20 24	2 23	30 25	-0.7 2.8	-12.3 1.6	4 4	Left	2.7	4
135	Orbit	05:44:29	05:44:59	00:00:30	4634	4831	197	7	3.7 %	65			0			30			3.9			Left	1
136	Orbit	05:44:59	05:45:22	00:00:23	4831	4988	156	26	16.8 %	65.6			0			23			4			Left	0.8
137	Orbit	05:45:22	05:45:47	00:00:25	4988	5055	66	73	109.4 %	65.6			0			25			1.6			Left	0.8
138	Orbit	05:45:47	05:45:49	00:00:02	5055	5013	-41	41	-100 %	77			0			02			-12.3			Left	0.1
17	Thermal	05:54:40	05:56:53	00:02:13	3736	4627	890	72	8.1 %	67.4 65.8	48.3 65.3	89.9 66.7	294 266	251 251	360 278	26.6 24.7	23 23	32 26	4 4.4	2.7 4	4.6 4.6	Right	4.6	5
140	Orbit	05:54:40	05:55:12	00:00:32	3736	3959	222	10	4.6 %	68.6			0			32			4.1			Right	1.1
141	Orbit	05:55:12	05:55:38	00:00:26	3959	4160	201	14	7.3 %	65.3			0			26			4.6			Right	0.9
142	Orbit	05:55:38	05:56:03	00:00:25	4160	4350	189	0	0 %	65.4			0			25			4.5			Right	0.8
143	Orbit	05:56:03	05:56:26	00:00:23	4350	4504	154	9	5.9 %	66.7			0			23			4			Right	0.8
144	Orbit	05:56:26	05:56:53	00:00:27	4504	4627	122	38	31.3 %	70.8			0			27			2.7			Right	1

Color of the track indicates climb rate
Width of the track indicates ground speed (not air speed)
Pink arrow indicates wind (not always reliable)
Fire indicates thermal source based on wind

IGC-SPY Gliders Competitions Flight LOG analysis (VW)

Glider VW Thermal Info (Task 6-Open)

Color of the track indicates climb rate Width of the track indicates ground speed (not air speed) Pink arrow indicates wind (not always reliable) Fire indicates thermal source based on wind

Color of the track indicates climb rate
Width of the track indicates ground speed (not air speed)
Pink arrow indicates wind (not always reliable)
Fire indicates thermal source based on wind