...
In Denmark the highest ever wind gust (for Denmark) was measured on Kegnäs on Als (53 m/s).
On the 24 October, UKMO issued an amber warning (see figure above) for southern England for wind speeds. They classified classifed the potential impact as the highest category and the likelihood of the event as 2 out of 4. In their warning matrix it resulted in an amber warning. The Section 3.3 (ensemble forecasts from other centres), we see that all the centres agreed about a high probability for extreme winds in this area.
2. Description of the event
...
Analyses for MSLP and Eady Index (showing baroclinic zones) from 26 Oct 0 UTC to 28 Oct 12 UTC, every 12 hours. Here we see the baroclinic zone over the Atlantic . A deep low north of the zone moved towards east over this period and a wave in the surface pressure developed and also moved eastwardsfield moving to the east. A rapid development happened after 28 Oct 00 UTC over Britain and the North Sea, and the high wind speed appeared in connection to this low0 UTC.
Satellite images from yr.no valid 9,12 and 18 UTC on the 28 October.
...
The figure above shows the maximum reported wind gusts (coloured numbers) for the 28 October and the MSLP for every 6th hour (contours). Here we see the band of the highest wind gusts from Brittany along the North Sea coast to Denmark and over southern Sweden. The highest wind gusts is found over Denmark.
This figure shows the same as the figure above but zoomed in over Denmark. Two stations measured more than 50 m/s in gusts and several coastal stations measured more than 40 m/sfigure above but zoomed in over Denmark.
3. Mesoscale Structure of the Storm
...
The figures above shows time-series of the mean wind from Kegnaes Lighthouse in the south-west of Denmark and Drogdens Lighthouse located in the east (a little bit south of Copenhagen). The time-axis is in Central European time. For both stations we see a rapid increase in the wind speeds, probably connected to the arrival of the SJ. The increase happened above 2 hours later in the east than the west.
For hour by hour plots of MSLP and wind gusts from SMHI surface analysis (MESAN), see http://www.smhi.se/klimatdata/meteorologi/vind/storm-okt-2013 .
4. Predictability (including 40r1 E-suite evaluation)
-2013 .
4. Predictability (including 40r1 E-suite evaluation)
4.1 HRES
4.1.1 O-Suite
Strip of forecasts below (left column) shows 48h maximum gusts from successive HRES forecasts from DT 00UTC 21st through to 00UTC 27th (right click, view image to get full resolution), for VT period 06UTC 27th to 06UTC 29th. Note how the early forecasts jumped around, as one might expect. Later on very extreme gusts were forecast for areas SW of the UK, and as the event approached this zone of extreme gusts migrated its way eastwards, which is perhaps not what one would expect. End of period mslp is also shown.
By 'adding together' equivalent plots from two very short range forecasts we can provide a model-based pseudo-verification to compare the above with. These are provided below in rapid animation and two-up formats (covering the period 18Z 27th to 06Z 29th). No gusts of note were forecast for the 06Z-18Z 27th period.
Forecasts |
Model-based verification  |
Model-based verification |
|---|
4.1
...
.2 O-Suite vs E-suite
The figures below shows forecasts of MSLP valid for 28 Oct 12 UTC and maximum wind gust during the 28 October. The o-suite is plotted in the left column and the e-suite in the right.
...
The figure above shows forecasts initialised 25 Oct 0 UTC (+84h).
...
.
4.2 ENS
The sequence of figures above shows the strike probability of cyclone with maximum wind speed (mean) over 60 kt (31 m/s) at 1 km height. The plots are valid for the 28 October (24-hours). The first forecast is from 28 Oct 0 UTC and one day is added for each plot. With longer lead time the feature is delayed (too slow) in the model, but the path of the cyclone seems very consistent up to 6 days before the landfall.
...
The figures below show the probability of wind speeds above 33 m/s on the 850hPa level, for forecasts valid 28 October (0,6,12,18 plus 0 UTC on the 29th). The results are for ECMWF, UKMO, NCEP and CMC. The area of the highest wind speeds on 850 hPa does not necessarily coincides with the highest wind speeds at surface. I have chosen the 850 hPa to see the more general pattern of the high wind speeds and to not be affected by the surface conditions (land vs. sea).
The figures above show forecasts from 28 October 00 UTC (0 to 24 hour forecasts). Here all four centres agrees so this pattern could be seen as the outcome of the event.
...