A-L-E-K Posted July 12, 2011 Share Posted July 12, 2011 getting OT, but does anyone know the record for straight line winds? Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 130+, that's just so crazy, I had no idea straight line winds without any weird topographic enhancement or something could get that high, so wicked. This was really a case where you had classic conditions for a strong cold pool that was balanced by low level shear (>25 kt). The process of advecting convective cells rearward in the system develops the rear inflow jet (RIJ), which can be enhanced by the development of bookend vorticies. We know this was occurring not only due to the wind speeds observed but the development of a nice rear inflow notch on radar (the relatively weak echo region behind the bow). The longer the RIJ stays elevated the more rapidly it descends near the updraft and the stronger the wind speeds due to buoyancy and dynamic effects. That's how you can have 50 kt mid level winds turn into 100 kt surface winds. Similar in a sense to how dynamics drive RFD winds to over 100 mph. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 getting OT, but does anyone know the record for straight line winds? In the U.S. it is 231 mph atop Mount Washington, NH in April 1934 (elevation 6288 ft). Hardly convective in nature though. Link to comment Share on other sites More sharing options...
A-L-E-K Posted July 12, 2011 Share Posted July 12, 2011 In the U.S. it is 231 mph atop Mount Washington, NH in April 1934 (elevation 6288 ft). Hardly convective in nature though. yeah i guess i should have been more specific, I'm talking straight line, convective winds without any topographic enhancement. Link to comment Share on other sites More sharing options...
A-L-E-K Posted July 12, 2011 Share Posted July 12, 2011 This was really a case where you had classic conditions for a strong cold pool that was balanced by low level shear (>25 kt). The process of advecting convective cells rearward in the system develops the rear inflow jet (RIJ), which can be enhanced by the development of bookend vorticies. We know this was occurring not only due to the wind speeds observed but the development of a nice rear inflow notch on radar (the relatively weak echo region behind the bow). The longer the RIJ stays elevated the more rapidly it descends near the updraft and the stronger the wind speeds due to buoyancy and dynamic effects. That's how you can have 50 kt mid level winds turn into 100 kt surface winds. Similar in a sense to how dynamics drive RFD winds to over 100 mph. Thanks for the info and sorry you weren't still in the area. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 yeah i guess i should have been more specific, I'm talking straight line, convective winds without any topographic enhancement. Off the top of my head I know Washington, IA (AWG) recorded a 123 mph gust in the June 1998 derecho. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 Thanks for the info and sorry you weren't still in the area. You're telling me, I arrived just after July 2008 and left just before July 2011. Environment looking pretty juicy again for the southeastern DVN CWA and for eastern EAX and LSX. Nice supercell (likely producing significant hail (70 dBZ to over 35 kft)) is tornado warned near Kirksville. It will probably grow upscale into an MCS with time, as conditions look pretty good for wind again. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 Nice supercell (likely producing significant hail (70 dBZ to over 35 kft)) is tornado warned near Kirksville. It will probably grow upscale into an MCS with time, as conditions look pretty good for wind again. 2" hail reported by the public in Novinger, with a 60 mph gust from IRK. Link to comment Share on other sites More sharing options...
Stevo6899 Posted July 12, 2011 Share Posted July 12, 2011 anyone get any pics/find a source from the approaching line back in illinois, iowa where the 100+ winds were attained? Link to comment Share on other sites More sharing options...
TimChgo9 Posted July 12, 2011 Share Posted July 12, 2011 I think the strongest straight line winds I ever witnessed was right around 75mph. The strongest one I was ever caught in was a 67mph gust during a thunderstorm about 20 years ago.... As to how I got caught outside in it, well, there's a "stupid ex-wife" story behind it.. Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2011 Share Posted July 12, 2011 anyone get any pics/find a source from the approaching line back in illinois, iowa where the 100+ winds were attained? Probably wont find much, as it was going through those areas predawn. Link to comment Share on other sites More sharing options...
andyhb Posted July 12, 2011 Share Posted July 12, 2011 I can only imagine the roar that the thing created... Even many of our major windstorms here in the Pacific Northwest don't even come close to that. Link to comment Share on other sites More sharing options...
IMADreamer Posted July 12, 2011 Share Posted July 12, 2011 Nice severe storm to the northwest of me. Beautiful looking. Hopefully 4pm gets here soon so I can go shoot some photos of it, but I think it will be nearly overhead by then. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted July 12, 2011 Share Posted July 12, 2011 If anyone has access to the Euro instability values...look the CAPE forecast and checkout the values being printed out from friday to next weds in the northern plains to the upper miss valley. I wouldn't be shocked at all to see another textbook derecho event diving southeast at somepoint during that timeframe. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 That is the ECMWF valid at 00z on the 20th (so Tuesday evening). The shaded is MUCAPE (>4000 is white), and maximum values are pushing 5000 J/kg. The thin black lines with numbers is precip (to give an idea of expected convection) and as one might guess the Euro is developing something north of the strongest instability and cap. Black barbs are 850 mb winds, with a decent 30 kt LLJ already at 00z. Light blue barbs are roughly 0-2 km storm relative winds, and you can see values near the convection in excess of 35 kt, indicating the potential to balance the motion of the cold pool as well as its likely rapid movement if it does develop. Finally, tan barbs are 0-3 km shear values, in excess of 30 kt, which again is good for wind producing MCSs. Conditions as they stand at 180 hours on the Euro would appear favorable for some wind events. The usual caveats still apply of course, as these are mesoscale processes they are highly changeable. But strictly on an overviews, you would think with that kind of heat and humidity that the northern periphery of the high will see some big complexes. Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2011 Share Posted July 12, 2011 That is the ECMWF valid at 00z on the 20th (so Tuesday evening). The shaded is MUCAPE (>4000 is white), and maximum values are pushing 5000 J/kg. The thin black lines with numbers is precip (to give an idea of expected convection) and as one might guess the Euro is developing something north of the strongest instability and cap. Black barbs are 850 mb winds, with a decent 30 kt LLJ already at 00z. Light blue barbs are roughly 0-2 km storm relative winds, and you can see values near the convection in excess of 35 kt, indicating the potential to balance the motion of the cold pool as well as its likely rapid movement if it does develop. Finally, tan barbs are 0-3 km shear values, in excess of 30 kt, which again is good for wind producing MCSs. Conditions as they stand at 180 hours on the Euro would appear favorable for some wind events. The usual caveats still apply of course, as these are mesoscale processes they are highly changeable. But strictly on an overviews, you would think with that kind of heat and humidity that the northern periphery of the high will see some big complexes. I'd love to nudge that instability axis a touch East more, for personal storm reasons. Although I think in this pattern MN/N WI/ MI should do well with storm complex potentials. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 I'd love to nudge that instability axis a touch East more, for personal storm reasons. Although I think in this pattern MN/N WI/ MI should do well with storm complex potentials. Well I will be flying back to Iowa for a little vacation and county fair action next Wednesday, so I'm rooting for the ridge to get beaten back a bit. Definitely not rooting for the 95+/80 stuff. Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2011 Share Posted July 12, 2011 Well I will be flying back to Iowa for a little vacation and county fair action next Wednesday, so I'm rooting for the ridge to get beaten back a bit. Definitely not rooting for the 95+/80 stuff. Yeah especially if its sunny, then that sun just beats you into submission. Link to comment Share on other sites More sharing options...
TimChgo9 Posted July 12, 2011 Share Posted July 12, 2011 That is the ECMWF valid at 00z on the 20th (so Tuesday evening). The shaded is MUCAPE (>4000 is white), and maximum values are pushing 5000 J/kg. The thin black lines with numbers is precip (to give an idea of expected convection) and as one might guess the Euro is developing something north of the strongest instability and cap. Black barbs are 850 mb winds, with a decent 30 kt LLJ already at 00z. Light blue barbs are roughly 0-2 km storm relative winds, and you can see values near the convection in excess of 35 kt, indicating the potential to balance the motion of the cold pool as well as its likely rapid movement if it does develop. Finally, tan barbs are 0-3 km shear values, in excess of 30 kt, which again is good for wind producing MCSs. Conditions as they stand at 180 hours on the Euro would appear favorable for some wind events. The usual caveats still apply of course, as these are mesoscale processes they are highly changeable. But strictly on an overviews, you would think with that kind of heat and humidity that the northern periphery of the high will see some big complexes. That is just ugly.... 180 hours out...yeah it can change. Better? Worse? going to keep an eye on this one. Supposed to be a hot weekend..... Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 Yeah especially if its sunny, then that sun just beats you into submission. I really don't miss those 80 dewpoints, but that's why they make beer cold. Just a monster ridge the Euro builds into the heart of the country. Nearly 600 dm at 500. Link to comment Share on other sites More sharing options...
hm8 Posted July 12, 2011 Share Posted July 12, 2011 Headin' on a road trip next week to Indianapolis and then St. Louis...ideally I'll avoided the worst of the heat but still be in the perfect spot for MCS's coming around the ridge... Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2011 Share Posted July 12, 2011 I really don't miss those 80 dewpoints, but that's why they make beer cold. Just a monster ridge the Euro builds into the heart of the country. Nearly 600 dm at 500. What is the record 500 height for DVN area, I want to say DTX's is something like 597dm. Link to comment Share on other sites More sharing options...
L.B. LaForce Posted July 12, 2011 Share Posted July 12, 2011 I really don't miss those 80 dewpoints, but that's why they make beer cold. Just a monster ridge the Euro builds into the heart of the country. Nearly 600 dm at 500. Yeah, unfortunately, it looks as if this ridge is going to be around a very long time Link to comment Share on other sites More sharing options...
IMADreamer Posted July 12, 2011 Share Posted July 12, 2011 Whew impressive cloud motions out. I'd say a 30mph gust and some nice lightning. Got to close for comfort so I came in. No rain yet and wind is picking back up. Main cell is still a few miles away. Link to comment Share on other sites More sharing options...
OceanStWx Posted July 12, 2011 Share Posted July 12, 2011 What is the record 500 height for DVN area, I want to say DTX's is something like 597dm. That's a good question. I don't know it off the top of my head, but it might be buried in the records at the office. I would imagine it has to be over 600 dm, due to their proximity to the ridge axis. Link to comment Share on other sites More sharing options...
IMADreamer Posted July 12, 2011 Share Posted July 12, 2011 Tor warning for this cell BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE ST LOUIS MO 444 PM CDT TUE JUL 12 2011 THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A * TORNADO WARNING FOR... GREENE COUNTY IN SOUTHWEST ILLINOIS... NORTHWESTERN MACOUPIN COUNTY IN SOUTHWEST ILLINOIS... SOUTHEASTERN PIKE COUNTY IN WEST CENTRAL ILLINOIS... * UNTIL 530 PM CDT * AT 442 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS STORM WAS LOCATED 6 MILES SOUTHEAST OF PITTSFIELD...AND MOVING SOUTHEAST AT 45 MPH. * LOCATIONS IMPACTED INCLUDE... WHITE HALL...ROODHOUSE...CARROLLTON...ATHENSVILLE...GREENFIELD... MILTON...MONTEZUMA...BEDFORD...PEARL...BEECREEK...HILLVIEW... PATTERSON...HAYPRESS...WALKERSVILLE...BARROW...BELLTOWN...BERDAN... WRIGHTS AND SCOTTVILLE. PRECAUTIONARY/PREPAREDNESS ACTIONS... TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS. Link to comment Share on other sites More sharing options...
Stebo Posted July 12, 2011 Share Posted July 12, 2011 That's a good question. I don't know it off the top of my head, but it might be buried in the records at the office. I would imagine it has to be over 600 dm, due to their proximity to the ridge axis. Yeah I would imagine something like 602-604dm would probably be close to it. Link to comment Share on other sites More sharing options...
IMADreamer Posted July 12, 2011 Share Posted July 12, 2011 local news showing pictures of damage in Barry, IL. Looks like the roof of the library sustained some damage. Link to comment Share on other sites More sharing options...
cyclone77 Posted July 12, 2011 Share Posted July 12, 2011 Off the top of my head I know Washington, IA (AWG) recorded a 123 mph gust in the June 1998 derecho. IIRC right around that same time (June '98) there was an event in Wisconsin east of Lacrosse where some airforce base measured winds over 125mph. Don't quote me on that, but I think it was something like that. I'll have to look it up when I get back, gotta head out for the evening. Link to comment Share on other sites More sharing options...
cyclone77 Posted July 12, 2011 Share Posted July 12, 2011 IIRC right around that same time (June '98) there was an event in Wisconsin east of Lacrosse where some airforce base measured winds over 125mph. Don't quote me on that, but I think it was something like that. I'll have to look it up when I get back, gotta head out for the evening. Nevermind I looked it up quick. It was only 100mph. I could have swore I read somewhere that some Air Force base recorded a gust well over 100mph. http://www.crh.noaa.gov/arx/events/june27case.php Link to comment Share on other sites More sharing options...
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