Thundersnow12 Posted August 10, 2011 Share Posted August 10, 2011 Decided to start this thread and Joe and Tony and Chi Town Wx will also be helping me out with other events but I thought I would start off with 5/18/97, an event that I still remember to this day that scared me to death in Batavia that evening and one of the storms that really got me interested in weather when I was 7 years old. This day started off like alot of severe weather days around here...we had convection fire in northern IA in the early morning hours around 12z and develop into a nice storm complex as it headed into southern WI and northern IL but began to weaken as the LLJ faded and mid-level temps warmed. Although the convection died off, we still had clouds leftover to deal with before we began to destablize later in the afternoon. And just an FYI, there aren't any sfc maps from this day...only go back to 1998 on Plymouth's site which is kind of a buzzkill. 14z sat image Around 15z or so we began to slowly clear the clouds and have the almost June sun doe its job in heating up the atmosphere and it didn't take long before we had some real progress going on. 18z sat image We continued to destablize and by 20z, we got our fist hint of CI in central/eastern IA with a very strong mid-level jet pushing eastward and into the area creating more than enough shear for supercells later in the day. Quite the jet for late May...a 65kt weserly H5 jet at 0z that evening Here is the 700mb chart, decided to contour some of the H7 temps to show you the thermal ridge/EML and also put the main jet over the area. H7 temps of 8 degrees C in the area were good until to hold off convection till just the right time in the afternoon. Storms very going up like crazy in central/eastern IA that eventally pushed into WI/IL by late afternoon and looked very healthy on radar with a tornado watch already issued for that area with a new one likely further east. As these storms pushed further eastward into IL, more storms fired further to the east along the WI/IL border and with the strong mid-level jet overhead and strengthening LLJ near 0z, the environment became very favorable for supercells and tornadoes as low-level shear increased. The hodograph taken off the KLOT VAD was impressive as well by around 23:30z we got our first legit supercell near Woodstock IL with a strong meso but there wasn't a tornado reported with this storm, even though it was very impressive for awhile. At the same time, we had the second supercell and associated meso beginning to get going further east. About 30 mins later or so the 2nd supercell to the east become dominant and really took off as the LLJ continued to strengthen and the low-level rotation beginning to really increase as it approached to town of Lindenhurst. This is about at the time right after the tornado dropped just west of town This tornado went on to produce F2 damage in Lindenhurst. The storm that sparked my interest was a weak supercell that went up ahead of the line down in southern kane county that was tornado warned. Link to comment Share on other sites More sharing options...
cyclone77 Posted August 10, 2011 Share Posted August 10, 2011 Wow, this makes me feel old. 7yrs old? LOL. Anyway, I was living on the east side of the QC at the time, in Silvis. A large HP supercell moved into the QC and dropped large hail. There were also several reports of funnel clouds. All I really remember was the golf ball sized hail that fell and damaged my car that I had just waxed a few days before. Link to comment Share on other sites More sharing options...
Stebo Posted August 10, 2011 Share Posted August 10, 2011 Nice start to this thread, although the fact that you were 7 back in 1997 makes me feel old lol. I see I concur with cyclone. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 10, 2011 Author Share Posted August 10, 2011 Almost forgot to put up the DVN soundings from that day Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 11, 2011 Author Share Posted August 11, 2011 not doing a whole write up on this day but wanted to do this....the day that ALMOST got out of hand in chi metro.. SURFACE ANALYSIS AND RADAR IMAGERY FROM CHICAGO INDICATES A E-W ORIENTED BOUNDARY EXTENDING FROM NEAR ORD EWD TO JUST NORTH OF ARR. THREE SEPARATE SUPERCELLS WILL MOVE ALONG AND JUST NORTH OF THIS BOUNDARY. RECENT LOT VWP DATA SHOWED A STRONGLY CURVED LOW LEVEL HODOGRAPH WITH O-1 KM SRH AROUND 350 M2/S2. THREAT FOR TORNADOES...POSSIBLY SIGNIFICANT...WILL OCCUR WITH THESE SUPERCELLS AS THEY MOVE EWD ALONG AND INTERACT WITH THE AFOREMENTIONED BOUNDARY. Link to comment Share on other sites More sharing options...
cyclone77 Posted August 11, 2011 Share Posted August 11, 2011 Here's a few links to supplement T-snow's 5/18/97 analysis. BTW, very nice job with that. The brief writeup/storm reports from DVN. http://www.crh.noaa.gov/dvn/?n=ev19970518svr A local chaser also did a short chase summary. http://www.severewx.com/ChaseReports/chase51897.shtml Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 11, 2011 Author Share Posted August 11, 2011 Here's a few links to supplement T-snow's 5/18/97 analysis. BTW, very nice job with that. The brief writeup/storm reports from DVN. http://www.crh.noaa....n=ev19970518svr A local chaser also did a short chase summary. http://www.severewx....hase51897.shtml Dang wish I would of known about that sfc map/vis sat image! lol thanks for posting that man. Link to comment Share on other sites More sharing options...
Hoosier Posted August 11, 2011 Share Posted August 11, 2011 When can we expect posts on 5/30/03 and 4/20/04? Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 11, 2011 Author Share Posted August 11, 2011 When can we expect posts on 5/30/03 and 4/20/04? I'm working on 5/30/03 and already did a nice sfc map for that day and have the radar data to go through along with some other stuff. Tony got data for 4/20/04, and Joe is looking at an event in May of 1995 I believe. Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 11, 2011 Share Posted August 11, 2011 I'm working on 5/30/03 and already did a nice sfc map for that day and have the radar data to go through along with some other stuff. Tony got data for 4/20/04, and Joe is looking at an event in May of 1995 I believe. Just got started, so it will be up eventually... Link to comment Share on other sites More sharing options...
tornadotony Posted August 11, 2011 Share Posted August 11, 2011 I'm working on 5/30/03 and already did a nice sfc map for that day and have the radar data to go through along with some other stuff. Tony got data for 4/20/04, and Joe is looking at an event in May of 1995 I believe. Yeah 4/20 may not come until like Sunday, but it will come...I promise. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 11, 2011 Author Share Posted August 11, 2011 Yeah 4/20 may not come until like Sunday, but it will come...I promise. 5/30 should be up by friday night. Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 11, 2011 Share Posted August 11, 2011 Just got started, so it will be up eventually... Both May '95 'nader events will be delayed until I figure out how to load level3 data (I have been using level2 for the other thread)...and if I don't figure it out, what I have will still be posted at some point in time. Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 11, 2011 Share Posted August 11, 2011 Both May '95 'nader events will be delayed until I figure out how to load level3 data (I have been using level2 for the other thread)...and if I don't figure it out, what I have will still be posted at some point in time. ILX data for L2 only goes back to 9/8/95 and L3 to 8/9/95. F*ck me. I guess what I have will be posted tomorrow. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 11, 2011 Author Share Posted August 11, 2011 Besides 5/30/03....I'm thinking of also doing 5/23/04. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 12, 2011 Author Share Posted August 12, 2011 tonights weather has been distracting me from my 5/30/03 write up but im getting there lol Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 12, 2011 Share Posted August 12, 2011 5/13/95... While not really a N. Illinois event, this was a fairly significant C. Illinois event. As the below maps will show, the was a strong flow aloft at 500, 700, and 850. Thhere was great turning with height, along with winds at the surface from the S/SE. The nevironment featured CAPE in excess of 1750 J/KG, SRH and HEL over 150, LCL's under 1000m, and an ample amount of moisture. Soundings: 12z DVN 12z ILX 0z DVN 0z ILX Here are 500, 700 & 850mb maps with added features: An initial mess of severe showers/storms pushed through much of the area during the morning hours, north of a warm front. Clouds quickly eroded allowing for rapid destabilization as the warm front rapidly pushed northward. Initiation occured around around 18z across N. Missouri, in the form of one discrete cell. This cell pushed northeast and quickly became severe. As it pushed into the IA/IL/MO border area along the Mississippi River, it became tor warned as other diecrete cells quickly developed and were quickly severe/tor warned. This cluster of 3-4 discrete cells pushed into Western and then Central Illinois, producing 9 tornadoes along the way. As the cluster of cells pushed into East-Central Illinois, further development occured and activity grew upscale into broken bowing line segments. Activity continued into Indiana, OH, PA, and WV before weakening. Five other tornadoes were also reported in Indiana. Radar Loop Tornado Count: Illinois - 9 F0 - 3 F1 - 2 F2 - 1 F3 - 1 F4 - 2 Indiana - 5 F0 - 1 F1 - 2 F2 - 2 Note: The Niota F4 had an approximate track length of around 50 miles. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 12, 2011 Author Share Posted August 12, 2011 5/30/03 I always wanted to really look into this day ever since I did a case study on it. This day was driven by a strong s/w trof digging southeastward from the northern plains into the great lakes region during the afternoon/evening. As usual and just like my previous discussion...we had morning convection to deal with (like clock work around here) early on in eastern IA/western IL downstream of the potent wave coming down aided by the LLJ from the overnight and indicative of the low level moist axis. 12z satellite imagery showing the early convection along the miss. river Also the 12z DVN roab sounding from that morning As the morning pressed on, these faded off to the east. With the help of colder mid-level temps moving into the area associated with the strong trof and mixing going on in the boundary layer, mid 60 dew points were on their way northward. And thanks to some sfc heating, low-level lapse rates steepened and MLCAPE values around 1000 j/kg were forecasted by late afternoon/evening as the moisture continued northeastward up to the sfc low pressing southeastward. As I said, the jet dynamics with this setup were very impressive both in the upper and mid levels of the atmosphere. map from SPC showing the 0-6km shear at 0z that evening along with the impressive helicity values. 300mb 500mb By mid-afternoon the better upper support was moving overhead and after awhile a heating/moistening of the boundary layer, thunderstorms began to go up in central/southwest WI by 21z near the dryline/warm front intersection near the sfc low (YES i said dryline) and on the nose of the moisture axis (60 degree dew points) This is at 23z so the storms have already fired and became supercells with one of them putting down a tornado just before this time in green county in southern WI. A second supercell then took over and decided it would ride the WI/IL border and put down several tornadoes in Winnebago county north of RFD and about 20 minutes later...another one As this was all going on, discrete supercells were developing further south in a SSW-NNE line from Ogle county down to Princeton to north of PIA with the supercell west of DKB showing a nice TBSS on it for a few scans. About 10 minutes after this it produced a tornado near West Brooklyn in Lee county. I didn't post a image of the velocity because you can't tell much with it. By about 00:40z the supercell that put down a tornado in Lee county reorganzied and moved along rt 34 and towards Kendall county, just before it crossed the county line it put down a tornado northwest of Millington It continued into Kendall county where it was at its strongest north of town with 125kts of shear over a mile and a half at 3500kft. The supercell then continued east towards Joliet and decided "hey what the heck, I'll put down another one" and it did just that. It won't let me upload a image of the couplet of that tornado. here is another sfc map I did for 1z just before the JOT tornado, these storms were right near the warm front and ingesting the better shear, you can also see moisture did increase some from 2 hours before hand and the movement of the sfc low and dryline. The orange outlined area is where most of the tornadoes were this day, besides the two in southern WI. map of tornadoes that day A supercell south of the JOT storm also produced a tornado in Will county near Wilmington about 5-10 minutes later. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted August 12, 2011 Author Share Posted August 12, 2011 Mine isn't done yet but for some reason it isn't letting me upload some other images so stand by lol Link to comment Share on other sites More sharing options...
Hoosier Posted August 12, 2011 Share Posted August 12, 2011 5/13/95... While not really a N. Illinois event, this was a fairly significant C. Illinois event. As the below maps will show, the was a strong flow aloft at 500, 700, and 850. Thhere was great turning with height, along with winds at the surface from the S/SE. The nevironment featured CAPE in excess of 1750 J/KG, SRH and HEL over 150, LCL's under 1000m, and an ample amount of moisture. Soundings: 12z DVN 12z ILX 0z DVN 0z ILX Here are 500, 700 & 850mb maps with added features: An initial mess of severe showers/storms pushed through much of the area during the morning hours, north of a warm front. Clouds quickly eroded allowing for rapid destabilization as the warm front rapidly pushed northward. Initiation occured around around 18z across N. Missouri, in the form of one discrete cell. This cell pushed northeast and quickly became severe. As it pushed into the IA/IL/MO border area along the Mississippi River, it became tor warned as other diecrete cells quickly developed and were quickly severe/tor warned. This cluster of 3-4 discrete cells pushed into Western and then Central Illinois, producing 9 tornadoes along the way. As the cluster of cells pushed into East-Central Illinois, further development occured and activity grew upscale into broken bowing line segments. Activity continued into Indiana, OH, PA, and WV before weakening. Three other tornadoes were also reported in Indiana. Radar Loop Tornado Count: Illinois - 9 F0 - 3 F1 - 2 F2 - 1 F3 - 1 F4 - 2 Indiana - 3 F1 - 2 F2 - 1 Note: The Niota F4 had an approximate track length of around 50 miles. You might've noticed this but there were 2 other tornadoes in Indiana which occurred just after midnight (the F2 you listed started just before midnight and continued after midnight). Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 12, 2011 Share Posted August 12, 2011 You might've noticed this but there were 2 other tornadoes in Indiana which occurred just after midnight (the F2 you listed started just before midnight and continued after midnight). Fixed...for a total of 5. Link to comment Share on other sites More sharing options...
Chicago Storm Posted August 13, 2011 Share Posted August 13, 2011 5/9/95... This was another significant event across E. Iowa and Northern/Central Illinois...leading up to the second event on 5/13/95, which was covered on the last page. This event featured a nice closed low, in a low CAPE/moisture and strong upper flow/high shear environment. Soundings and 500/700/850mb maps are below. Development first occured around 17z in C. Iowa and N. Missouri. As this area of non-severe showers and storms worked northeast, further discrete development took place in E. Iowa into W. Illinois. This activity quickly became tornadic as it continued to push northeast. This line of severe/tornadic activity pushed into SW. Michigan down into S. Illinois by about 5z before weakening. There were about 22 tornadoes in Illinois, including 4 F3's. There were also about 18 tornadoes in Iowa. Soundings: 12z DVN 12z ILX 0z DVN 0z ILX Radar Loop Tornado Count: Illinois - 22 F0 - 11 F1 - 7 F3 - 4 Iowa - 18 F0 - 13 F1 - 3 F2 - 1 F3 - 1 Link to comment Share on other sites More sharing options...
cyclone77 Posted August 13, 2011 Share Posted August 13, 2011 5/9/95... This was another significant event across E. Iowa and Northern/Central Illinois...leading up to the second event on 5/13/95, which was covered on the last page. This event featured a nice closed low, in a low CAPE/moisture and strong upper flow/high shear environment. Soundings and 500/700/850mb maps are below. Development first occured around 17z in C. Iowa and N. Missouri. As this area of non-severe showers and storms worked northeast, further discrete development took place in E. Iowa into W. Illinois. This activity quickly became tornadic as it continued to push northeast. This line of severe/tornadic activity pushed into SW. Michigan down into S. Illinois by about 5z before weakening. There were about 22 tornadoes in Illinois, including 4 F3's. There were also about 18 tornadoes in Iowa. Soundings: 12z DVN 12z ILX 0z DVN 0z ILX Radar Loop Tornado Count: Illinois - 22 F0 - 11 F1 - 7 F3 - 4 Iowa - 18 F0 - 13 F1 - 3 F2 - 1 F3 - 1 Nice! Here's some archived level II radar images I put together from the LOT 88D. Unfortunately level II wasn't available from DVN and ILX. Link to comment Share on other sites More sharing options...
cyclone77 Posted August 13, 2011 Share Posted August 13, 2011 A closer look at two of the better couplets from the LOT archives from 5/09/95... Link to comment Share on other sites More sharing options...
Chicago Storm Posted September 23, 2011 Share Posted September 23, 2011 The following will come in two posts... 4/19/96... This is my new favorite Illinois tornado event. Meso analysis is not avaliable this far back. ILX soundings would suggest this event had ample instibility/moisture/shear/and a strong flow aloft. Soundings: 12z ILX 0z ILX 12z 500mb, 700mb, and 850mb maps: 0z 500mb, 700mb, and 850mb maps: Wide View Radar: Tornado Reports/Ratings: Link to comment Share on other sites More sharing options...
Chicago Storm Posted September 23, 2011 Share Posted September 23, 2011 Continued... Tornado Count: Illinois: 39 F0: 20 F1: 10 F2: 4 F3: 5 Indiana: 13 F0: 5 F1: 5 F2: 3 Kentucky: 9 F0: 1 F1: 6 F2: 2 Missouri: 6 F0: 2 F1: 1 F2: 2 F3: 1 Iowa: 2 F0: 2 Texas: 2 F0: 1 F2: 1 Tennessee: 3 F2: 3 Radar: Jacksonville, IL - F2: Bath, IL - F2: Easton, IL - F1: Armington, IL - F2: Niantic/Harristown, IL - F3: Bath/Easton, IL Supercell Loop: Link to comment Share on other sites More sharing options...
Thundersnow12 Posted September 23, 2011 Author Share Posted September 23, 2011 I believe Gilbert from NIU got one or several tornadoe that day. Link to comment Share on other sites More sharing options...
Thundersnow12 Posted September 23, 2011 Author Share Posted September 23, 2011 The only thing you chase more than IL warm fronts are IL drylines lol Link to comment Share on other sites More sharing options...
Chicago Storm Posted September 24, 2011 Share Posted September 24, 2011 The following will be spread across two posts... 5/10/03... Mesoanalysis not avaliable this far back. ILX soundings a strongly unstable/moist/sheared/strong flow aloft environment. Given the amount of visuals provided, everything is pretty self-explanatory. Soundings: 12z ILX 0z ILX 12z 500mb, 700mb, and 850mb Maps: 0z 500mb, 700mb, and 850mb Maps: 18z, 21z, and 0z Surface Maps: Link to comment Share on other sites More sharing options...
Chicago Storm Posted September 24, 2011 Share Posted September 24, 2011 Continued... Tornado Count: Illinois: 24 F0: 11 F1: 7 F2: 5 F3: 1 Missouri: 12 F0: 8 F1: 1 F2: 2 F3: 1 Iowa: 7 F0: 4 F1: 2 F2: 1 Kentucky: 6 F1: 2 F2: 2 F3: 2 Tennessee: 6 F1: 4 F3: 2 Wisconsin: 2 F1:2 Indiana: 1 F0: 1 Arkansas: 1 F1: 1 Radar Images: Rushville, IL - F2: Astoria, IL - F1: Havana, IL - F1: South Pekin, IL - F3: Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.