The Long Range Forecasters
Delta House, 175-177 Borough High Street. London SE1 1HR Tel +44(0)20 7939 9946
E: piers@weatheraction.com From: Piers Corbyn 07958713320 (or office above)
www.weatheraction.com or for Europe
www.lowefo.com
URGENT AND IMPORTANT SEVERE WEATHER WARNING
You are welcome to circulate this warning as you may require
Our apologies if for circulation list reasons you receive this document twice
25th/26th Nov 2007
To Emergency Services, Local Authority Risk managers, media and WeatherAction forecast users.
UPDATE on forecast period 23-28th Nov (original central highest risk period for dangerous events) - now extended to 1st/2nd Dec
[This is a 'superstorm' period in English & US usage of the word meaning it is likely to include in the most exposed parts of main storm tracks winds gusting to over 100mph (160kph) - ie resulting from Hurricane (Beaufort Force 12 ) winds]
The period is on the 304th anniversary of the devastating Tempest of 26th/27th (modern calendar) Nov 1703 in which thousands died mainly in Bristol, the South coast of England and London, and Portsmouth was destroyed. Although there are some similarities concerning solar forcing factors of storms developments, events of that magnitude are NOT forecasted for this period.
At the time of writing (25th Nov 22.00hrs), deep low pressures are developing -as forecasted - over the Atlantic and short range standard forecasts show 'dartboard' (exceptionally deep - eg 955mb*) lows. Predicted solar effects make the present period one of rapid and accelerating weather change for the whole of the north Atlantic region from Greenland to St Petersburg and from North Norway to Belgium which will often get ahead of standard meteorology forecasts.
We continue to forecast the British Isles and the North Sea area are likely to be hit (90% confidence) by a major storm(s) and associated substorms including possible tornado type events - particularly in England - starting to show from Weds/Thursday Nov 28th/29th onwards and this or these storm systems to then move into Scandinavia in an now extended period to 1st/2nd December (for reasons for extension see below) and have important impacts in, in order of danger: Scotland, Northern Ireland, Ireland, Wales, England, Norway, Sweden, Denmark, NW Germany, North Netherlands, North Poland and the Baltic States. (This is the same order of danger as in all previous issued forecasts and updates)
(*This pressure and situation puts the potential storms comparable with the most damaging storms of 1990 and 1987 in the UK and Europe)
WeatherAction's warning for this period of likely storm events to begin from November 23rd was confirmed by the significant Low with gales in Scotland and the North Sea on 23rd November and continuing gales or strong north winds in the North Sea and Norway, Sweden, Denmark, Netherlands, Belgium, Germany and Poland in the following days as that low tracked/tracks through Norway and Sweden into the Baltic and Baltic States along the storm track shown in WeatherAction's update map issued 15th Nov.
The raised sea levels in the North Sea from the storm surge driven by this North wind have given (24th / 25th Nov) Coastal gale / severe gale warnings and flood warnings / Watches in England and Holland
In England there is one flood warning and 21 flood watches on the east coast (24/25 Nov) - see:
http://www.environment-ag...jects/flood/floodwarning/
In Holland warnings of gales and severe gales and flood watches (from 23:00hrs Sat 24th
http://pietpaulusma.sbs6....tormkansen-nemen-toe.html
Embarrassingly for Dutch meteorologists leading forecasters on TV (channel1) on Saturday 24th had been rudely denouncing the WeatherAction forecast as 'nonsense' and barely 6 hours later Dutch meteorologists announced a flood watch for the Dutch coast and gale/severe gale warnings!
The most dangerous events associated with this now extended period 23Nov to 1st/2nd Dec are set to come
=> The warnings of dangerous weather stands: bringing serious wind damage and disruption of travel by land, sea and air - as advised in forecasts issued 11 months ago and updated in detail 29 Oct and 15 Nov particularly for Britain but anywhere in the core storm tracks especially Scandinavia, and threats to sea defences in the Severn estuary and parts of the South coast of England.
=> A North Sea storm surge is also likely on the tail of these storm events - ie early December. The lunar tides will be lower then so their contribution to the threat to sea defences in eastern England and the Netherlands will be lessened - but should NOT be ignored.
=> Standard Meteorology forecasts as on TV will UNDERESTIMATE the intensity and speed of developments in this period even from 24 or 12 hours ahead
=> WHY? There is no change in the basic weather events and dangers in the forecast issued 11 months ago and subsequent updates of detail but the present weather period is combining with the next weather period which was also forecast to include vigorous Lows. For this reason the main action now looks set to appear around the end of the original 24-28th period and into the next one - 28/29th to 1st Dec (or just beyond). The reasons for this are probably to do with merging of solar wind (charged particles coming from the sun) effects as they are modulated by magnetic linkages with the Earth.
{Note on time periods and timings. WeatherAction weather periods refer to periods of a general weather type within which weather events referred to have the highest probability (85%) of occurring. There will be a proportion of occasions (about one in 6) when the main events happen just outside these time periods. As an example see November British Isles main forecast page 4 (for Atlantic Tropical Storms and WestNorth Pacific Typhoons). There the October Typhoon Formation and Active Development (FAD) forecast was assessed. Of the 7 forecast FAD periods all 7 gave typhoons; and with DATE defined as the date of the lowest pressure (deepest, date D)., 6 were within the defined FAD periods and one had D one day early.
For what this forecast means for countries on the continent please visit WeatherAction's LOng range WEather FOrecast site
www.lowefo.com . For information specifically for the |Netherlands see below.
THE NETHERLANDS IN THE COMING WEEK
At the time of writing 25th November 22:00 hours GMT.
For the (90% probability) 'superstorm' period in two waves we forecast for 23rd-28th (which is now extending to the start of December - see note above) which has Netherlands not in the first core track and 80% probability that much of the Netherlands (ie the north particularly) would be on the edge of the second core storm track.
This means in forecasting terms that the advance probability of much of the Netherlands (with the North coast at highest risk) being hit by the second wave is (80% of 90%) 72% and given it is on the edge of the core projected track the most likely highest gusts are at the lower end namely around 70mph = 110kph with a small chance (say 10%) of 90mph = 145kph or above occurring in some exposed coastal places. For details see the map issued on 15Nov on
www.lowefo.com .
Contact piers@weatheraction.com or magnus.hagelstam@asiakashallinta.com directly for copies - if you do not have them - of the full November forecasts and maps or for latest news visit
www.lowefo.com (and use Netherlands subsite for English text).
Thank you,
Piers Corbyn