Ed Lizard Posted December 8, 2011 Share Posted December 8, 2011 I don't know how well winds in excess of 80 knots at 850 mb will mix down, but I bet it'd be something to see. My AccuWeather PPV Euro 10 meter winds for the UK show of 75 (mph, knots?) offshore, 50 knots on the Southwest coast, and up to 40 (knots, mph) in much of the interior. 10 meter gusts will exceed 60 (mph, knots?) over much of SW England. Link to comment Share on other sites More sharing options...
OHweather Posted December 8, 2011 Share Posted December 8, 2011 Here is a free Euro screen shot off of Wunderground.com Surface winds, in knots, valid the same time as Ed's image...ouch... Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 8, 2011 Author Share Posted December 8, 2011 The UK is having a rough time of it... http://www.dailymail...rn-Britain.html Link to comment Share on other sites More sharing options...
PottercountyWXobserver Posted December 8, 2011 Share Posted December 8, 2011 I'm jealous Wish I could be in Wales. Link to comment Share on other sites More sharing options...
icebreaker5221 Posted December 9, 2011 Share Posted December 9, 2011 165 mph gust atop Cairn Gorm mountain (Scotland), just shy of the UK all-time record of 173 mph in 1986, which also occurred at Cairn Gorm. You can watch the storm deepen explosively on this GFS forecast from 12Z on the 7th (which verified quite nicely). http://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2011120712&field=Sea+Level+Pressure&hour=Animation A pressure drop of 44 mb in 24 hrs verified, down to about 950 mb. Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 9, 2011 Author Share Posted December 9, 2011 Looks interesting around the Low Countries... Link to comment Share on other sites More sharing options...
HurricaneJosh Posted December 10, 2011 Share Posted December 10, 2011 The news media is having a field day with that 165-mph gust. An important point left out of all the articles is that the gust occurred on a mountain peak several thousand feet above sea level. Coastal towns didn't see winds anywhere near these speeds, with max gusts in the 70-90-mph range. I'm sure based on the news stories that many residents who experienced 65-mph winds now think they experienced 165. Ah, the news media. Link to comment Share on other sites More sharing options...
wxmx Posted December 10, 2011 Share Posted December 10, 2011 Yeah, Emiliano Zapata's residents now think they experienced a cat 5. Link to comment Share on other sites More sharing options...
HurricaneJosh Posted December 10, 2011 Share Posted December 10, 2011 Yeah, Emiliano Zapata's residents now think they experienced a cat 5. Yes, 73 ft and nearly 4,000 ft is the same thing. lolz Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 10, 2011 Author Share Posted December 10, 2011 The news media is having a field day with that 165-mph gust. An important point left out of all the articles is that the gust occurred on a mountain peak several thousand feet above sea level. Coastal towns didn't see winds anywhere near these speeds, with max gusts in the 70-90-mph range. I'm sure based on the news stories that many residents who experienced 65-mph winds now think they experienced 165. Ah, the news media. Anyone with any knowledge recognizes the Mount Washington wind gust measurement isn't representative of winds in New England. (Now, that distinction isn't quite as clear, re Blue Hill and 1938). Still looks on for the UK... Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 10, 2011 Share Posted December 10, 2011 Getting into weenie land but the day 5 storm would be even more impressive with that type of rapid intensification. Both the ECMWF/GFS bomb it near 932 hpa. Link to comment Share on other sites More sharing options...
baroclinic_instability Posted December 10, 2011 Share Posted December 10, 2011 Wicked. Link to comment Share on other sites More sharing options...
icebreaker5221 Posted December 11, 2011 Share Posted December 11, 2011 Getting into weenie land but the day 5 storm would be even more impressive with that type of rapid intensification. Both the ECMWF/GFS bomb it near 932 hpa. Yeah, the storm at 72 hrs is a biggie, but the pressure gradient is even more impressive with the storm at 120 hrs. +NAO ftw? Link to comment Share on other sites More sharing options...
Roger Smith Posted December 11, 2011 Share Posted December 11, 2011 At the moment, the Tuesday storm looks bad enough in some parts, but the Thursday-Friday monster on the charts looks like a historic severe storm that could do enormous damage in both Ireland and the United Kingdom. The weather forums over there are running on overdrive with discussions of the coming week. By their standards, the cold and windy period between the storms is also a concern. The Thursday event could be broadly compared to the Daniel Defoe storm of (OS) Nov 26-27 (NS) Dec 7-8, 1703, which was strong enough to destroy large buildings in London, created a deadly tidal surge into the Severn estuary near Bristol, and killed thousands in shipwrecks on the south coast. Although the track of this predicted storm is somewhat further north, the intensity looks about the same (there are even some accounts of central pressures near 950 mbs with the Defoe storm). Going back to the first storm, it only looks severe for parts of northwest Ireland which is used to seeing strong winds on a regular basis, so to do a lot of damage there would require gusts of 90-100 knots, this one looks more like 70-80 knots, something they get about once a month anyway. The storm does not look quite as strong as last week's storm in Scotland (for Scotland). It will bring moderately severe winds to more populated regions further south, but if the Thursday storm is still on the charts by then, I imagine that the Tuesday storm will be almost shoved to the sidelines as the public try to prepare for the hurricane force storm to follow. There won't be much let up in the winds between the two events, in fact there's some suggestion of a third wind max developing in a hang-back trough between the two. Thursday's storm from today's charts (which seem to follow trends from past two days) could easily generate winds of 70-100 knots across large parts of Ireland and the U.K. and these could do enormous damage there. A storm in Jan 1990 that had slightly less severe winds was able to do considerable structural damage even in London which is not an especially wind-prone location. I keep waiting for the models to lose their intensity on this Thursday-Friday storm, but they keep cranking out maps that you have to go to the 400% mag button to count the isobars, and each time it comes out around 930 mbs. Storms of exceptional intensity are not unknown in Ireland either. The night of Jan 6-7, 1839 is known as the "Big Wind" and produced westerly hurricane force winds in parts of Mayo and Galway on the northwest coast there, estimated to be 90-120 knots. This storm had a very low central pressure as is known from observations made in northern Scotland (around 927 mbs). It may be a fairly similar event to what is about to unfold later this week. Of course, the damage with that 1839 storm was massive and there were severe coastal effects despite the low astronomical tides (the storm occurred about 6-7 days after a full moon, so near the tidal minimum). The Defoe storm on the other hand occurred at new moon and gave the greatest recorded tidal surge on the southwest coast of Britain (2-3 metres but funnelled into 5-10 metre floods in some estuaries). Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 11, 2011 Author Share Posted December 11, 2011 Edited thread title. Be fascinated to here from the heavyweights why such a closely packed sequence of intense storms is occuring. Link to comment Share on other sites More sharing options...
airmarci Posted December 11, 2011 Share Posted December 11, 2011 Shaping up to be a pretty wicked storm Thursday into Friday Link to comment Share on other sites More sharing options...
Roger Smith Posted December 11, 2011 Share Posted December 11, 2011 The ECM has severely downgraded the second (Thurs-Fri) storm and the 18z GFS has partially followed that trend although it keeps a storm of moderate intensity. Could be into a cycle of model flip-flop here related to how the two systems interact. I think the basic explanation for the outbreak of severe storms in the region lies in the SST anomaly pattern which features 3-5 deg negative anomalies mid-ocean around 40-50 N. This has tended to concentrate the jet stream and create a stronger than normal baroclinic environment for the storms to develop. Heights south of Greenland and Iceland are probably on the order of -30 dam this past two weeks but closer to near normal in Spain and southern France. It's pretty much the same set-up as a firehose aimed at central California. I would add the geomagnetic energy peak of full moon as the icing on the cake, but that's just to add intensity rather than a cause in itself. Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 12, 2011 Author Share Posted December 12, 2011 Later system not quite as strong, but impressive anyway. Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 13, 2011 Author Share Posted December 13, 2011 Storm 1 approaches... Link to comment Share on other sites More sharing options...
OHweather Posted December 13, 2011 Share Posted December 13, 2011 Browsing Wundergound.com, appears much of northern Ireland and Britain have gusting to 60-70MPH, with coastal areas seeing 80+ gusts. A number of stations have scene SLPs as low as about 28.3" in that region as well. This station (over extreme NW Ireland) is the most impressive I could find, max gust pushing 86MPH on the day: http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=IDONEGAL7 Link to comment Share on other sites More sharing options...
Bryan Wood Posted December 13, 2011 Share Posted December 13, 2011 I think the basic explanation for the outbreak of severe storms in the region lies in the SST anomaly pattern which features 3-5 deg negative anomalies mid-ocean around 40-50 N. This has tended to concentrate the jet stream and create a stronger than normal baroclinic environment for the storms to develop. Heights south of Greenland and Iceland are probably on the order of -30 dam this past two weeks but closer to near normal in Spain and southern France. It's pretty much the same set-up as a firehose aimed at central California. I would add the geomagnetic energy peak of full moon as the icing on the cake, but that's just to add intensity rather than a cause in itself. Sounds right to me. When you have a strong Positive NAO, you tend to get a strong zonal jet stream across the North Atlantic. It's acting like a slingshot for these storms. Winter's opening act has been very interesting across the Northern Hemisphere! Link to comment Share on other sites More sharing options...
kwt Posted December 14, 2011 Share Posted December 14, 2011 The set-up for Thursday-Friday is very close to what we call in the UK the fabled Channel low, its pretty siomilar to Noreaster, but obviously rarer due to the fact we don't often get the conditions to get it. When it does pull off though 1-2ft accumulations are the result and some places have been known to get way more then that. Still they are rare. This one hasn't quite got the depth of cold so nothing that extreme will happen. What is looking likely is the high winds will be staying mainly in the channel and instead we will have to deal with a rain-snow event. Alot of uncertainties with this set-up. Shouldn't anything as severe as the previous 2 winter snow events but with such a deep low you never can be quite sure!! Link to comment Share on other sites More sharing options...
bluewave Posted December 14, 2011 Share Posted December 14, 2011 The set-up for Thursday-Friday is very close to what we call in the UK the fabled Channel low, its pretty siomilar to Noreaster, but obviously rarer due to the fact we don't often get the conditions to get it. When it does pull off though 1-2ft accumulations are the result and some places have been known to get way more then that. Still they are rare. This one hasn't quite got the depth of cold so nothing that extreme will happen. What is looking likely is the high winds will be staying mainly in the channel and instead we will have to deal with a rain-snow event. Alot of uncertainties with this set-up. Shouldn't anything as severe as the previous 2 winter snow events but with such a deep low you never can be quite sure!! It looks to be taking the 26 December 1999 track, but is forecast to be weaker than that storm. http://oiswww.eumets...1226_storm.html Link to comment Share on other sites More sharing options...
Ed Lizard Posted December 15, 2011 Author Share Posted December 15, 2011 Amber condition (about halfway up the color scale) for rain turning to snow in London, other places just snow, from UK Met Office. Link to comment Share on other sites More sharing options...
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