COL Map Ver 4.0

2026-05-0500-000764

The daily central positions of lows are plotted with reference to the time shown at the top of the image. For a description of each column in the table, please refer to the bottom of this page.

timestamp	lat	lon	So	ro	Sb	ang	SR	ex
00Z 14 May	42.5	143.5	7.63	500	13.72	-2.9	1.8	0
06Z 14 May	40.0	143.0	9.71	400	11.69	-2.95	1.2	0
12Z 14 May	38.0	143.5	11.42	400	6.81	-2.96	0.6	1
18Z 14 May	37.0	144.0	13.56	300	3.22	2.22	0.24	1
00Z 15 May	36.0	143.0	16.22	200	8.47	1.65	0.52	1
06Z 15 May	35.0	141.0	19.81	200	13.39	1.9	0.68	1
12Z 15 May	33.5	139.0	21.51	200	14.74	2.37	0.69	1
18Z 15 May	33.0	140.0	16.36	500	2.93	2.15	0.18	1
00Z 16 May	31.5	138.5	16.08	500	3.59	-2.35	0.22	1
06Z 16 May	31.5	139.0	15.65	500	3.71	-1.98	0.24	1
12Z 16 May	32.0	140.0	17.09	500	4.27	-1.66	0.25	1
18Z 16 May	32.0	141.0	17.7	500	6.24	-1.46	0.35	1
00Z 17 May	32.5	141.5	17.13	400	7.13	-1.87	0.42	1
06Z 17 May	32.0	142.0	15.48	300	10.25	-1.99	0.66	1
12Z 17 May	33.5	146.0	11.51	400	9.76	-1.48	0.85	1
18Z 17 May	34.0	149.0	9.88	400	12.06	-1.64	1.22	0
00Z 18 May	34.5	153.0	9.85	400	15.16	-1.73	1.54	0
06Z 18 May	35.5	158.0	11.91	300	13.22	-1.92	1.11	1
12Z 18 May	34.5	162.0	9.6	300	16.66	-1.94	1.74	0
18Z 18 May	33.0	168.0	7.32	300	18.59	-1.57	2.54	0

Columns

Name	Unit	Displayed	Description
timestamp		✓	datetime
detected_id			Vortex ID that matches the detection rule.
ID			Vortex ID at the corresponding time. If a split occurs, the detected_id may not match the detected_id.
lat	deg	✓	Latitude
lon	deg	✓	Longitude
val	m		Geopotential height at the center of the vortex
So	m (100 km)^-1	✓	Optimal slope
ro	km	✓	Optimal radius
Do	m		Optimal depth
Sb	m (100 km)^-1	✓	Intensity of background slope (S_BG)
ang	rad	✓	Direction of S_BG
m	m (100 km)^-1		Eastward component of S_BG
n	m (100 km)^-1		Northward component of S_BG
SR		✓	Ratio of intensity of background slope (S_BG) to optimal slope (S_o) (S_BG/S_o)
ex		✓	COL flag 0: trough 1: COL
Merge			Merge Log 0: None -1: Vortex dissipated -2: Merged from another -3: Present at the end of analysis Vortex ID: Merged into the corresponding vortex and dissipated
Split			Split Log 0: None -1: Vortex generated -2: Split into another -3: Present at the start of analysis Vortex ID: Formed by splitting from the corresponding vortex
generation			Generation Number Set to 1 at the initial analysis time (FT = 0) and incremented when a different vortex ID is encountered as time is traced backward.