Table 7: Forecast Accuracy


UKMO Forecasts, for IOP low centres, are colour coded to show forecast accuracy:

    GOOD Forecasts: GREEN         MODERATE Forecasts: ORANGE         POOR Forecasts: RED

    Definition of Good,moderate,poor

    Supplementary comments: DARK RED

Positive pressure errors (=insufficient depth) are shown bold


Note that for IOPs 2, 6, 8 and 19 there was no real low centre to verify.


IOP T+24 (LAM) T+48 (LAM) T+72 (Global) T+96 (Global) T+120 (Global)
Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb)
1 150 -6 250 -1 No closed low No closed low No closed low No closed low - -
2 - - - - - - - - - -
3 - - - - 450 +20 350 +29 No low No low
4 100 -4 400 +1 200 +4 900 +9 1300 +4
5 440 0 990 -2 200 +3 Trough not low Trough not low Wrong structure Wrong structure
6 - - - - - - - - - -
7 140 +1 160 -6 - - - - - -
8 - - - - - - - - - -
9 130 -4 20 -8 60 0 850 +11 600 +11
10 500 -17 500 -17 600 -12 1000 -20 No appropriate low No appropriate low
11 280 0 280 -3 400 -3 700 -8 1100 +13
11a 140 +8 110 +6 350 +10 250 +14 No appropriate low No appropriate low
12 100 +7 330 +20 350 +32 650 +41 No appropriate low No appropriate low
13 500 -9 700 -1 600 +8 850 +12 1600 +14
14 300 +2 200 -3 1300 +7 200 0 150 -13
15 70 -2 0 -9 150 +5 550 -6 700 0
16 100 -5 250 -5 250 +11 No low No low 250 (different low?) +19 (different low?)
17 180 +7 800 +17 300 +25 1250 (double centre) +31 (double centre) 1150 +49
18 60 -1 170 +5 100 +3 750 +11 600 +26
19 Good Moderate Good Moderate - - - - - -
IOP T+24 (LAM) T+48 (LAM) T+72 (Global) T+96 (Global) T+120 (Global)
Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb) Position Error (km) PMSL Error (mb)


Humphrey W Lean | hwlean@meto.gov.uk