04/13/2006 NOW: North Plains/Great Lakes

[Sam Sagnella]

Surprised there isn't a NOW thread yet, considering the impressive cluster of supercell thunderstorms moving eastward across eastern Iowa at this time. Multiple tornado warnings are out around and including the Cedar Rapids area, with an SVS indicating a spotter-reported tornado on the ground ~10 miles west of the city. SRV shows two impressive velocity couplets, one west of Cedar Rapids, and the other west of Iowa city.

 

[mikegeukes]

Tornadoes in Iowa, Johnson County is currently warned, and Iowa City
is mention in the warning

0710 PM TORNADO 5 NE TOLEDO TAMA COUNTY
0742 PM TORNADO MARION LINN COUNTY
0750 PM TORNADO 2 W WHITTIER LINN COUNTY
0758 PM TORNADO NEWHALL BENTON COUNTY
0802 PM TORNADO OXFORD JOHNSON COUNTY
0831 PM TORNADO 5 SE HILLS JOHNSON COUNTY
0833 PM TORNADO IOWA CITY JOHNSON COUNTY
0836 PM TORNADO TIFFIN JOHNSON COUNTY

Mike
http://www.chaseseason.blogspot.com/

 

[Jeff Miller]

Official NWS Text now wording "Large and Extremely Dangerous Tornado". and referencing the Iowa City storm. Also saying significant structural damage possible. I have no other information of a large tornado on the ground ATTM.

 

[mikegeukes]

http://kamala.cod.edu/offs/KDVN/0604140111.wwus53.html is the statement that Jeff mention

Mike

 

[Sam Sagnella]

With a radar presentation like this, I wouldn't be surprised if it has a large tornado on the ground:
--Time is 812CDT--

EDIT
debris knob at 820?

 

[Sam Sagnella]

that little storm behind the two main ones has developed an appendage in the last scan or two and velocity couplet is looking good. and the Iowa City storm continues to produce tornadoes "AT 829 PM CDT...TRAINED SPOTTERS INDICATED A DANGEROUS TORNADO JUST WEST OF HILLS...MOVING EAST AT 20 MPH. ANOTHER TORNADO WAS LOCATED NEAR IOWA CITY MUNICIPAL AIRPORT...OR ABOUT OVER IOWA CITY...MOVING EAST AT 20 MPH. "

 

[mikegeukes]

A report of a tornado in Iowa City (2004) Population of just over 63,000
and the home of the University of Iowa over 29,000 students

0833 PM TORNADO IOWA CITY 41.66N 91.54W
04/13/2006 JOHNSON IA EMERGENCY MNGR

TORNADO NEAR THE WAL MART IN SOUTHWEST IOWA CITY

Mike

 

[Sam Sagnella]

Near continuous lightning is visible on the webcam posted above, so the tornado should continue to be easily tracked by spotters in the area.

 

[Dan Robinson]

Doug K. is reporting a lightning-backlit stovepipe tornado with numerous power flashes in south Iowa City.

 

[Sam Sagnella]

Storm approaching the southern half of Linn County is apparently producing 4"+ hailstones per the latest SVS.
"THIS STORM HAS ALREADY PRODUCED SOFTBALL SIZED LARGE HAIL...AND IT REMAINS A THREAT."

 

[Dustin Wilcox]

Wow these storms went nuts, the storm that moved over muscatine was huge and it continues to move ESE and is regaining some of its rotation. The town of muscatine has had multiple reports of a large tornado on the ground the Storm itself is beggining to take on a coma shape look and currently has 7 TVS on GR

 

[MatthewCarman]

SPOTTER REPORTED THREE TORNADOS ON THE GROUNF ON THE EAST END OF MUSCATINE...CONFIRMED

WOW 3 tornados on the ground at the same time? I hope everyone in muscatine is alright. I was going to post a NOW thread around 6:00 as the first severe storm poped up north west of my area. I had to leave to pick someone up at the outumwa trainstation in south east iowa so I had no time. I saw the huge swelling cumlus start to form nice towers but I could not chase and was drving away from the storms The sky was mostly clear the way home. Not to step on anyone's toes here but this forum is more texas/oklahoma/kansas biased so you get less people to reply to the north states but still with how bad the storms was you would think someone would have posted to this thread sooner. Anyways I hope everyone in Iowa City and Muscatine are all right. If anyone chased these storms I would love to see some pictures.
-Matthew Carman.

 

[Jeff Snyder]

From Stormtrack Rules:

(4) Chase Forecasts forum. In the Chase Forecasts forum, we allow two types of messages, as follows.
* FCST is for discussing forecast aspects of severe weather that has not occurred yet
* NOW is for discussing forecast aspects of severe weather that is occurring right now.

(5) Chase Reports forum. In the Chase Reports forum, we allow two types of messages, as follows:
* REPORTS is for your firsthand chase report, along with photos and graphics.
* DISC is for making any non-forecasting post about an event. You may use it to make third-party reports or discuss media coverage.

Please continue any third-party or media reports over in a 4/13 DISC thread.

If you do want to post a tidbit from another chaser, an LSR, or media snippet, you must also include other comments that would qualify the post for a NOW thread -- brief synopsis of storm activity, etc.

 

[J.B. Dixon]

Big time rotation right now just north of Aledo, IL. If you look at the latest scan just base reflectivity, you'd think Muscatine IA was getting rocked right now, but I don't see rotation with that "hook". Interesting. THe first cell seems to have ingested the trailing cell, making that meso extremely large.

 

[nickgrillo]

Wow... That tornadic supercell continues to push southeast at a easily chaseable 30mph. Quite nice rotational velocity in the lowest SRV tilts near Albedo (Illinois) -- with a well defined inflow notch (and intense reflectivities)... SPC mesoanalysis shows >1500j/kg mlCAPE in the inflow sector of that supercell [with LCLs of about 1400m~ AGL, per mesoanalysis] albeit strengthening mlCIN invof the supercell as well -- although the shear-induced vertical PGF associated with the supercell will probably allow it to feed off boundary layer inflow for a solid hour or two, as it continues to move through a favorable thermodynamic and kinematic environment (e.g. large mlCAPE and very large 0-1km SRH owed to strengthening low-level flow)... I guess I somewhat regret not chasing today...