Cindy Simons
EF0
Tornado confirmed near Radcliffe, Iowa. Nice looking hook echo.
11/12/05 NOW Central Plains
- Thread starter Dick McGowan
- Start date
rdale
EF5
"Tornado confirmed near Radcliffe, Iowa."
...and somehow it happened without advanced notice, as the TOR wasn't issued until the cell was overhead!
Surprised that the activity east of DSM appears to be sputtering out.
...and somehow it happened without advanced notice, as the TOR wasn't issued until the cell was overhead!
Surprised that the activity east of DSM appears to be sputtering out.
Cindy Simons
EF0
Good Point. The TV stations have been covering the storms non-stop so hopefully most people were aware of the potential danger. No reports of injuries or fatalities yet.
Now the damage footage, tornado photos, video, and stories are coming in.
The damage in Woodward looks pretty bad.... possible F2-F3.
nickgrillo
EF5
I'm guessing it's due to increasing CINH due to nocturnal cooling... As the storms to the north still remain sustained tornadic supercells (given they developed way earlier this afternoon, and have still been able to digest surface parcels), while any new activity simply is getting cut apart or generally weak as they are rooted above the strengthening inversion. The only other activity I could see being surface-based besides the storms in IA would be the activity in southeast KS that is pushing into southwest MO (as surface-based instability is stronger and CINH is way weaker then further north -- allowing for any activity to draw in surface-based parcels -- with potential for damaging wind gusts and large hail).
mikegeukes
EF5
Record Day for Most Tornadoes in November for Iowa
Be interesting to see how many verified.
Some research I did on Iowa Tornadoes in November
11-17-52 1 Tornado
11-15-60 2 Tornadoes
11-27-60 1 Tornado
11-09-75 11 Tornadoes Note: Counted as County Segments
actually 9 tornadoes
11-11-82 1 Tornado
11-15-88 10 Tornadoes Note: Counted as County Segments
actually 8 tornadoes
11-29-91 1 Tornado
Later, I will adjust the numbers for the tornadoes that are
counted as county segments.
Des Moines TV Stations:
Channel 05 ABC WOI-TV http://www.woi-tv.com/
Channel 08 CBS KCCI-TV http://www.kcci.com/index.html
Channel 13 NBC WHO-TV http://www.whotv.com/
Channel 17 FOX KDSM-TV http://www.kdsm.com/
Des Moines Newspaper:
http://www.dmregister.com/apps/pbcs.dll/frontpage
Mike
http://mgweather.com
Moving to Norman sometime in December
Be interesting to see how many verified.
Some research I did on Iowa Tornadoes in November
11-17-52 1 Tornado
11-15-60 2 Tornadoes
11-27-60 1 Tornado
11-09-75 11 Tornadoes Note: Counted as County Segments
actually 9 tornadoes
11-11-82 1 Tornado
11-15-88 10 Tornadoes Note: Counted as County Segments
actually 8 tornadoes
11-29-91 1 Tornado
Later, I will adjust the numbers for the tornadoes that are
counted as county segments.
Des Moines TV Stations:
Channel 05 ABC WOI-TV http://www.woi-tv.com/
Channel 08 CBS KCCI-TV http://www.kcci.com/index.html
Channel 13 NBC WHO-TV http://www.whotv.com/
Channel 17 FOX KDSM-TV http://www.kdsm.com/
Des Moines Newspaper:
http://www.dmregister.com/apps/pbcs.dll/frontpage
Mike
http://mgweather.com
Moving to Norman sometime in December
nickgrillo
EF5
Per SPC storm reports, there has been 15 tornadoes reported today -- with the majority of them being reported from the southern-most supercell that passed through the Ames area. I would like to give a congratulations to Jim Bishop and any other chasers who were out in IA today. If it wasn't for work, I would have been on those storms as well. Too bad, as it would have been a great way to end this great year!
nickgrillo
EF5
There could be the possibility of some very damaging wind gusts associated with the activity ahead of the surface dryline from southwest MO into southeast OK. Quite moist surface layer (with Tds 58-63F across western MO and then back down into eastern OK) has yielded surface-based instability sufficiant enough to sustain deep convection -- with a line of severe thunderstorms now moving into western MO -- then another line segment well further south from McAlester into Coalgate, OK. Any surface-based thunderstorm which can sustain themselves will be capable of destructive winds and large hail (and likely a tornado or two across southwest MO into eastern OK given very strong low-level shear).
rdale
EF5
Tornado Potential
I'm thinking the tornado potential has taken quite a hit over IA/MN/WI - looks more like a low-topped squall line setting up with some wind or non-large hail based on the time of day (night)...
I'm thinking the tornado potential has taken quite a hit over IA/MN/WI - looks more like a low-topped squall line setting up with some wind or non-large hail based on the time of day (night)...
Gabe Garfield
EF5
The Springfield WFO has issued a tornado warning for Newton County in SW MO. This storm is the "tail-end charlie" in a short line of storms. To be quite honest, this storm does not seem to have an overly impressive velocity signature. Also, the environment it is heading into does not seem to be terribly favorable for tornadic development (other than the insane 0-1 km SRH).
Also of interest is a divergence maximum that is present over E and NE OK. Given the relative lack of CAPE, this might help the updrafts in this region a bit.
(ADMIN: Part of message pertaining to now-deleted posts has been removed... Morgan P.)
Gabe
Also of interest is a divergence maximum that is present over E and NE OK. Given the relative lack of CAPE, this might help the updrafts in this region a bit.
(ADMIN: Part of message pertaining to now-deleted posts has been removed... Morgan P.)
Gabe
Morgan Palmer
EF5
Please return to topic.
ADD: (portions of some posts in this thread have been deleted as they violate Stormtrack TOS)
MP
ADD: (portions of some posts in this thread have been deleted as they violate Stormtrack TOS)
MP
After initially heading to Neb City, I turned around at Atlantic. Turned my back on a DITOR storm north of I-80, because I would have had no chance going NE with all those N-S and E-W roads--with a storm speed of 40+ MPH! And we all know that DITOR storms never verify...
That and my camera croaked. Never had a problem with my Sony until the WSJ article came out mentioning the chip problems. Since then...!
Jeff Snyder
EF5
I was asked by a fellow chaser about my thoughts as to why convective initiation failed during the afternoon south of the central Iowa activity... Here are my thoughts:
I think the fact that the winds veered a bit ahead of the dryline resulted in less surface convergence. There aren't any upper air soundings from the area ahead of the dryline/pacific front, as TOP is too far west, OAX is west, DVN is east, MPX is too far north... SGF was in the warm sector, but too far ahead of the dryline, which explains the low instability on that sounding. Regardless, there was relatively weak surface convergence on the dryline/front. Weak instability (max of 1000 SBCAPE) created problems as well... With the very strong flow aloft, dry air entrainment was likely intense, so any updraft that tried to develop probably just couldn't survive the hostile environment (very high shear). This strong shear not only likely ripped up updrafts / TCu, but also forced try air into the updraft, leading to evaporational cooling, and thus killing the updraft. We really needed stronger convergence (to allow for more persistant initiation attemps) and stronger instability to allow an updraft to survive the high wind shear and dry air entrainment aloft.
In addition, The vort max swung through eastern Kansas in the late morning, and was located from central MO to Des Moines to northwestern IA by 0z. Differential negative vorticity advection was then occuring behind this wave, which leads to large-scale subsidence across eastern KS and western MO by afternoon. This then leads to warming mid-level temperatures, further reducing potential instability, and yielding a stronger cap. Subsidence aloft also likely diminished convergence at the surface. Meanwhile, the supercells in central Iowa formed immediately ahead of the vort max (the convection aided by strong DPVA ahead of the wave). The position of the jet streak in the upper-levels also places eastern KS and extreme western MO is the left-entrance region, which yields upper-level convergence, and creating more subsidence and weakening surface convergence along the dryline.
A weak shortwave / vort max is seen on the RUC analysis in central OK, which is likely promoting the convective development that has occurred the past few hours in southeastern OK and extreme sw MO.
I think the fact that the winds veered a bit ahead of the dryline resulted in less surface convergence. There aren't any upper air soundings from the area ahead of the dryline/pacific front, as TOP is too far west, OAX is west, DVN is east, MPX is too far north... SGF was in the warm sector, but too far ahead of the dryline, which explains the low instability on that sounding. Regardless, there was relatively weak surface convergence on the dryline/front. Weak instability (max of 1000 SBCAPE) created problems as well... With the very strong flow aloft, dry air entrainment was likely intense, so any updraft that tried to develop probably just couldn't survive the hostile environment (very high shear). This strong shear not only likely ripped up updrafts / TCu, but also forced try air into the updraft, leading to evaporational cooling, and thus killing the updraft. We really needed stronger convergence (to allow for more persistant initiation attemps) and stronger instability to allow an updraft to survive the high wind shear and dry air entrainment aloft.
In addition, The vort max swung through eastern Kansas in the late morning, and was located from central MO to Des Moines to northwestern IA by 0z. Differential negative vorticity advection was then occuring behind this wave, which leads to large-scale subsidence across eastern KS and western MO by afternoon. This then leads to warming mid-level temperatures, further reducing potential instability, and yielding a stronger cap. Subsidence aloft also likely diminished convergence at the surface. Meanwhile, the supercells in central Iowa formed immediately ahead of the vort max (the convection aided by strong DPVA ahead of the wave). The position of the jet streak in the upper-levels also places eastern KS and extreme western MO is the left-entrance region, which yields upper-level convergence, and creating more subsidence and weakening surface convergence along the dryline.
A weak shortwave / vort max is seen on the RUC analysis in central OK, which is likely promoting the convective development that has occurred the past few hours in southeastern OK and extreme sw MO.
Andrew Khan
EF5
There is a tornado warning in AR, with VERY strong low-level rotation, even up at higher levels. Based on radar signatures, and velocity scans, I would assume the tornado (if there is one, in question) would be near the city of Mena, AR.
Andy Wehrle
EF5
That Arkansas tornado-warned storm has a very HP-ish, almost bow-echo appearance to it. Any tornado is going to be extremely rain-wrapped in addition to it being dark. Uh-oh...
Gabe Garfield
EF5
The cell near Mena is in a very favorable environment for tornadic development. First of all, the storm is relatively isolated, so it should be able to maintain an unfettered inflow for a while. In addition to this, *insane* 0-1 km SRH exists in this region (300-500 m2/s2) as a result of the backed surface winds and screaming LLJ. I wouldn't be a bit surprised if a signficant tornado develops in this region, owing to the strong low-level shear combined with weak instability.
Edit: As soon as I started hyping the possibilities for the AR supercell, it begins to weaken.
Gabe
Edit: As soon as I started hyping the possibilities for the AR supercell, it begins to weaken.
Gabe
