Datasets/UK Climate/Lamb Weather Types

Datasets/UK Climate/Lamb Weather Types

(Last updated 27 March 2000)

One of the most widely used daily synoptic classifications for the British Isles is that developed by the late Professor H.H. Lamb. The full original Lamb Catalogue runs from 1 January 1861 to 3 February 1997, the last day classified by Professor Lamb before his terminal illness brought the catalogue to a close (Professor Lamb died on Friday 27 June 1997). The original Lamb Catalogue was published in full in 1972 in Geophysical Memoirs (London), vol. 16 (116), 85pp. Values for 1972 to 1995 inclusive appear in the book Climates of the British Isles, edited by Mike Hulme and Elaine Barrow and published by Routledge in April 1997. The original Lamb Catalogue for the years 1996 and 1997 is reproduced below. In addition to the eight directional components (NE, E, SE, S, SW, W, NW and N), there are the two vorticity components (A, anticyclonicity, and C, cyclonicity) and also an unclassifiable type (U). The full original Lamb Catalogue may be obtained by ftp from the Climatic Research Unit (click on the icon below):

The Climatic Research Unit, in conjunction with the Hadley Centre, has established a real-time objective 'Lamb-type' classification to continue the data series. This objective classification is based on the original suggestion of Arthur Jenkinson and extends from 1st January 1880 onwards. The objective Lamb Catalogue is updated monthly by the Hadley Centre. For a comparison of Lamb circulation types with this objective classification scheme see the paper by Jones et al. (Jones,P.D., Hulme,M. and Briffa,K.R. 1993: A comparison of Lamb circulation types with an objective classification derived from grid-point mean-sea-level pressure data Int. J. Climatol., 13, 655-664). The objective Jenkinson 'Lamb' Catalogue for 1997 onwards can be viewed below and the full Catalogue (from 1880 through February 2000) may be obtained by ftp from the Climatic Research Unit (click on the icon below):

In these two data files, each day is allocated a code, corresponding to one of the 28 categories of the Lamb Catalogue. The data file is arranged one line per month (starting in January 1861, original Lamb, or January 1880, Jenkinson Lamb), thus containing between 28-31 valid codes per line. The coding system is as follows:
0 anticyclonic ............ 20 cyclonic
1 ANE 11 NE 21 CNE
2 AE 12 E 22 CE
3 ASE 13 SE 23 CSE
4 AS 14 S 24 CS
5 ASW 15 SW 25 CSW
6 AW 16 W 26 CW
7 ANW 17 NW 27 CNW
8 AN 18 N 28 CN

-1 unclassifiable
-9 non-existant day (eg 31 February!)


Original Lamb Catalogue for 1996

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 SE AE AN A NE W CNW CW A W W ANW 1
2 A ANE N A NE A W AW A NW W W 2
3 S A N A NE SW C A A AW CW NW 3
4 S A AN A A ASW C A AE W C C 4
5 S SW A A U SW NW CS AE W C C 5
6 SE C A A NE A NW C AE NW CW U 6
7 S C AE A A A N C AE W CNW A 7
8 S C E SW ANE AW W C ANE A CW A 8
9 S S SE ASW NE ASW W CS N ANW W A 9
10 S C ASE S NE SW W C N A C ASE 10
11 CSE C ASW S E W W C NW SW C A 11
12 C C U ASE A A W CN N U NE U 12
13 CS ANE SE U A A W N AN S N A 13
14 S A SE ASE ANE A A A A U A W 14
15 S A SE ASW NE A A A A C A U 15
16 AS NW C U NE A A A ASE C U S 16
17 S W SE SW NE AN A ASW SE SW N S 17
18 S C E CSW CNE A A S E SW U S 18
19 SE NE E SW C A A C E SW C E 19
20 E A E S C CNE A C E SW CN E 20
21 E A CE C C N ASW C AE AW CNW E 21
22 E NW E CS CS N C S A AS CNW E 22
23 E W A C C AN C C A S CN E 23
24 E CS A W CW A N C SW S C AE 24
25 E C AE W CW AW A C CSW CS C A 25
26 E CW NE AW C A A C SW C ANE A 26
27 E U A W U AW A CN W C U A 27
28 E A ANW N AW W U N SW C A AE 28
29 E A ANE C W CW C AN W N A ANE 29
30 E A C S W CW NW W AW CNW E 30
31 E A W CW A CW E 31



Original Lamb Catalogue for 1997

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 ANE S 1
2 NE W 2
3 E SW 3
4 AE 4
5 ANE 5
6 AE 6
7 A 7
8 A 8
9 AE 9
10 AS 10
11 S 11
12 SW 12
13 SW 13
14 SW 14
15 SW 15
16 S 16
17 SW 17
18 SW 18
19 E 19
20 A 20
21 A 21
22 C 22
23 A 23
24 A 24
25 A 25
26 A 26
27 A 27
28 A 28
29 A 29
30 A 30
31 A 31
[Data supplied courtesy of the late Professor H.H.Lamb]

Objective Jenkinson-Lamb Catalogue for 1997

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 AE AS ASW AW A AE CN W C AW A U 1
2 N SW W A A AE C AW SW ANW A N 2
3 E A AW NW ASE E C A S A ASE NE 3
4 ANE W A A C A CNW ASE SW AW SE A 4
5 ANE AW SW W C AS A ASE W AW C AW 5
6 ANE ASW A A N CSE AW AE W SW C W 6
7 A W SW A CNW C A AE NW C C SW 7
8 A AW A A C CS A ASW AW CSW C C 8
9 A SW A A C SW A W ANW C C CW 9
10 A SW A A C AS A A A C C CSW 10
11 S W A AN C SE S SE SW NW C CSW 11
12 SW CSW SW A C C S SE C N C ANW 12
13 SW C A A CSW C CS A NW N W A 13
14 ASW W W A W N W A AW A SW A 14
15 A NW W A A A SW ASW SW C SW A 15
16 AS S ASW A SE A CW A AW S S A 16
17 S CSW A A SE A NW SW NW CSW S SE 17
18 SW CSW CSW A CE SW AN A A SW S SE 18
19 CSE ASW CNW A C C A ASE AE A S SE 19
20 A W NW A C C A S A AE CS C 20
21 A W A ANW CNE C A SW A ASE C ASW 21
22 AS W A A U C AS W A A CS S 22
23 C SW C ASW AE N AS ASW A A S S 23
24 SW CSW C CW A A C A A A S CSW 24
25 A C W ASE A C C AS A A SE CW 25
26 ASW C SW S A CNE W SW A A CSE C 26
27 A A W CSE A NE NW CS A ASE SE W 27
28 A SW NW CSW A NE AW C A A C W 28
29 A A CNW A NE A C SW A C U 29
30 A A A A N SW C A SW CN SW 30
31 A A A W S A C 31
[Data supplied courtesy of Ian Macadam, Hadley Centre]

Objective Jenkinson-Lamb Catalogue for 1998 (awaiting completion)

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 SW W SE A CSE N S C CN A 1
2 C CW CSE AN CE A C E C A 2
3 CSW CSW C AN C SW CNE AS C A 3
4 W C C A A W SE CSE N N 4
5 CW CNW C W S ANW C NE W N 5
6 AW SW C C S W S AE NW A 6
7 CSW C C CSW U AW CS AE ASW A 7
8 SW C C SW NW AW C A SW SW 8
9 SW U C C C A C CS SW 9
10 SW SW CNE NW C AS C CNW W SW 10
11 S CN NE A CN U CNW W A W 11
12 SW ANW N SE ANW C CW NW C SW 12
13 SW NW N SE S NW CN SW C W 13
14 C A CNW AS C W N W C SW 14
15 CSW A CN A CNE W NW W N AW 15
16 C A C A N AW NW AS A A 16
17 AW A CN A A W A C S SW 17
18 CS ANW AN A SW A SW AW AS W 18
19 C A S A AS AW A NW S CNW 19
20 A A C A S W A A AS N 20
21 ASW A S AN C CNW A CSW SW A 21
22 SW A S A W NW A SW SW AW 22
23 SE A CS ANW SW W A CW A SW 23
24 A W CSW NW SW N SE ASW SW W 24
25 A SW CSW NW C AW SE CNW SW W 25
26 A SW CSW C C N CE W W W 26
27 A W C CNE C A C SW W CW 27
28 A SW C CNE CW A C CW SW CW 28
29 A ASW CSE CE CNW A C NW W S 29
30 A C NE E C A C A CS 30
31 A ANW CE AS W S 31
[Data supplied courtesy of Ian Macadam, Hadley Centre]

Objective Jenkinson-Lamb Catalogue for 1999

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 CS A W S A A SW ASE A W SW NW 1
2 CS A SW SE A A A SE ASW C W NW 2
3 CSW A C SE A C SE CSE ASW C AW SW 3
4 CSW W C S A C CS SE A NW SW W 4
5 SW NW CN SW SE C C CE A A CSW ANW 5
6 C NW CN SW SE C U SE U A CN W 6
7 NW N CN NW SE CN A CSE W W AW W 7
8 C NW C A CSE CN A E ASW W AW W 8
9 N N CNE AW CS NW A CE SW NW A C 9
10 A N A SW S N A NE A W A CNW 10
11 A A SW NW C AN A A S AW A C 11
12 SW SW SW C C NE A A C A A C 12
13 NW A CSW CN C ANW A SW C A A CNW 13
14 NW SW SW C CN SW W C AW A A C 14
15 W AW SW CN AN A W CNW S A A N 15
16 SW NW SW C A ASW W CW S SE NW ANW 16
17 SW NW AW ANE A W SW CSW C SE N CW 17
18 W NW W U A A W C S SE NW NW 18
19 SW W ANW A E AW S C S SE N N 19
20 SW W A SE U CW C N CE E A A 20
21 W W CW C SW NW CW A C SE A S 21
22 A NW N C W A NW A C CSE AW SW 22
23 SW N NW C W AS A ASE C CSE W W 23
24 W C SW C W A AW SE C C SW CSW 24
25 C AW C S W A ANW SE C C W C 25
26 W W C SE SW S A C U CN SW CW 26
27 NW SW C AE ASW C A W C ASW W W 27
28 CNW W A A C C A A C W CSW NW 28
29 W SW A CN C A ASW C A CNW NW 29
30 A SW A ANE W ASE W C S SW W 30
31 A SW A AS A SW AW 31
[Data supplied courtesy of Ian Macadam, Hadley Centre]

Objective Jenkinson-Lamb Catalogue for 2000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 NW NW 1
2 W W 2
3 CW ANW 3
4 CNW NW 4
5 CNW NW 5
6 CSW NW 6
7 NW NW 7
8 W NW 8
9 W W 9
10 NW CW 10
11 NW W 11
12 W W 12
13 S SW 13
14 A CNW 14
15 A W 15
16 A W 16
17 A SW 17
18 A CW 18
19 A A 19
20 A N 20
21 A W 21
22 A CN 22
23 A NW 23
24 A W 24
25 A AW 25
26 A NW 26
27 A W 27
28 W W 28
29 W CW 29
30 W 30
31 W 31
[Data supplied courtesy of Ian Macadam, Hadley Centre]

Objective Jenkinson-Lamb Catalogue for 2001

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
17 17
18 18
19 19
20 20
21 21
22 22
23 23
24 24
25 25
26 26
27 27
28 28
29 29
30 30
31 31
[Data supplied courtesy of Ian Macadam, Hadley Centre]