Table 4: The comparison between the GEFS model BI versus observed blocking BI during the validation period of all 10, seven, four, and one-day forecasts for all four blocking events. N/A: no GEFS model block present. The difference is OBS - MODEL. Dates of comparison are shown below the BI.

BI Comparison
Forecast / Blocks Model BI Observed BI Difference
10 day
WWA
0000 UTC 13 Jun
N/A N/A/ N/A
WWP
0000 UTC 17 Aug
N/A N/A N/A
SCA
0000 UTC 23 Sep
N/A N/A N/A
SCP
0000 UTC 13 Feb
N/A N/A N/A
7 day
WWA
0000 UTC 16 Jun
1.13
(00/23-00/26)
2.32
(12/23-12/26)
1.19
WWP
0000 UTC 20 Aug
1.74
(00/30)
2.69
(12/30)
0.95
SCA
0000 UTC 26 Sep
N/A N/A N/A
SCP
0000 UTC 16 Feb
N/A N/A N/A
4 Day
WWA
0000 UTC 19 Jun
1.38
(00/23-00/27)
2.43
(12/23-12/27)
1.05
WWP
0000 UTC 23 Aug
1.82
(00/28-00/01)
2.18
(12/28-12/01)
0.36
SCA
0000 UTC 29 Sep
2.38
(00/05 - 00/09)
3.87
(12/05 - 12/09)
1.49
SCP
0000 UTC 19 Feb
3.12
(00/23-0/28)
4.93
(12/23/12/28)
1.71
1 Day
WWA
0000 UTC 22 Jun
1.49
(00/23-00/02)
2.45
(12/23-12/02)
0.96
WWP
0000 UTC 28 Aug
1.73
(00/27-00/02)
2.05
(12/27-12/02)
0.32
SCA
0000 UTC 02 Oct
3.51
(00/04-00/12)
4.06
(12/04-12/12)
0.55
SCP
0000 UTC 22 Feb
4.47
(00/23-00/28)
4.93
(12/23-12/28)
0.46