News DetailMAJOR derecho event expected today across IA-northern IL!
Posted At: July 18, 2007 @ 10:40 AM
Posted By: Reed Timmer
Related Categories: General
A major derecho or long-lived linear mesoscale convective system (MCS) event is expected today from eastern IA through northern IL from late afternoon through late evening, respectively. Extreme instability and good deep-layer shear in a classic northwesterly-flow situation will prevail over this region today. While the initial storm mode will likely be supercells over central IA, with the threat of VERY large hail, strong straight-line winds, and isolated brief tornadoes, the cells should quickly congeal into a monster MCS, which will rapidly propagate southeastward towards northern Illinois by late evening. Stay tuned for updates!
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Hey Reed i am currently in Peoria IL, Mostlikely gonna head NW on I74 to I80 and then near the IA border, maybe into IA, whats your thoughts? I dont wanna go to far into IA.
Does anyone have a idea where i might want to set up? Im open to all opinions.
Or can you atleast gimme some sort of opinion on its timing.?
Hey Ben,
I would probably target somewhere between Ames and Waterloo...you can always cheat towards the east and catch anything that develops west of you easily.
I would say discrete storms will probably initiate somewhere around Ames and Des Moines north to the MN border, and will track southeast. The RUC is showing initiation between Ames and Waterloo just after 4:00 pm. You definitely will have to intercept the cells early because they will have a tendency to congeal into an MCS.
I'll be around the computer all day and will keep you updated.
Good luck!!!
Geez, I wish these storms that develop would be further north like near the Mankato New Ulm, MN areas. We need
the rain so bad here, corn crops will die within the next week
without rain. Has not rained here since since June. All around us gets it but us.
Well that is a bit to far west for me to travel, due to funds and fourth, i may still head toward the border, and try to catch the system, in its early stages(first hr or 2), I'll make a decision by 1-2p.m.
I have a oppurtunity to sit and wait here, but i question the strength by the time it makes its way to Central/Northern IL.
On the other hand we do have a conference call with Emergency services at 2p.m. And i will see what is said.
Hey Jim don't count them out today you have a good chance of seeing something that far south in MN. Actually a pretty good chance. Notice where the 15-30% area is on the SPC outlook. They always seem to be conservative so 30% is a good chance and 45% is almost a sure thing. And those are just chances for severe weather, not rain. It's just that Iowa/Illinois might get the real widespread damaging stuff.
Hey Reed, what are the chances of the cold front spawning any severe storms for Oklahoma Friday?????????
I see stuff starting to pop a little already out in South Dakota. I wonder if this will be the stuff that goes nuts as it moves into Iowa later this afternoon? Looks like a decent area of something trying to get going out there.
wow what a t-storm last night.. so much lightning...great show.cant wait for tommorow here... looks like the dakaota/iowa again too eh?
guys, take a look at this mesoscale discussion the SPC just sent out!!!
MESOSCALE DISCUSSION 1517
NWS STORM PREDICTION CENTER NORMAN OK
1217 PM CDT WED JUL 18 2007
AREAS AFFECTED...MN...WI...MI
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 181717Z - 181915Z
ISOLATED TO WIDELY SCATTERED THUNDERSTORM DEVELOPMENT IS EXPECTED
OVER PARTS OF NRN WI...AND PERHAPS ERN MN...THROUGH THIS AFTERNOON.
A FEW SEVERE STORMS WITH LARGE HAIL AND DAMAGING WINDS APPEAR
POSSIBLE AND A WATCH MAY BE NEEDED.
DESPITE SOMEWHAT WEAK/AMBIGUOUS SURFACE FEATURES OVER THE REGION
THIS AFTERNOON...LARGE SCALE ASCENT IS EXPECTED TO INCREASE AHEAD OF
STRENGTHENING SHORT WAVE IMPULSE DIGGING SEWD OVER NRN MN ATTM. A
WEST-EAST WIND SHIFT/CONVERGENCE AXIS EXTENDS EWD ACROSS NCNTRL WI
FROM A WEAK LOW OVER ERN MN. THESE FEATURES APPEARS TO BE
CONTRIBUTING TO SUFFICIENT LOW LEVEL FORCING FOR RECENT CONVECTIVE
DEVELOPMENT ACROSS RUSK...PRICE...AND LINCOLN COUNTIES. AIR MASS
ACROSS THE REGION IS GENERALLY UNCAPPED AND BECOMING INCREASINGLY
UNSTABLE WITH LATEST OBJECTIVE DATA INDICATING MLCAPE AROUND 2000
J/KG. IN ADDITION...ENTIRE AREA LIES BENEATH 40-50KT NWLY MID LEVEL
FLOW RESULTING IN MORE THAN ADEQUATE DEEP-LAYER SHEAR TO SUPPORT
STORM ORGANIZATION AND PERSISTENCE.
CURRENTLY LIMITED/WEAK LOW LEVEL FORCING MECHANISMS ACROSS THE
REGION LEAD TO UNCERTAINTY REGARDING AREAL COVERAGE OF CONVECTIVE
DEVELOPMENT THIS AFTERNOON. HOWEVER...GIVEN WEAK INHIBITION AND
OTHER PARAMETERS IN PLACE OVER THE REGION...A WATCH MAY BE NECESSARY
IF IT APPEARS THAT MORE WIDESPREAD STORM DEVELOPMENT IS BEGINNING TO
OCCUR.
Hey Dale...are you planning on chasing tomorrow in Alberta?
It looks like things could be active through the weekend up there as well.
I'll be adding a post about today in Alberta once the storms begin to fire on the foothills.
wow this looks like something interesting to follow! Ill be keeping an eye on this! btw NY took a hit too..good luck to all the chasers going after this beast!
Reed: What area is it lookin like would be the best place to be in alberta for thursday? I am thinkin Red Deer looks good to start from. I am decidin right now whether to make the drive or not 14hrs from here to there so would be there is lots of time but UGH ton of drivin LOL shorter to hit Iowa storm but not enough time now :(
you bet cha reed... got the batteries charged and both cameras going. ive been doing this for over 15 years...we only got dopplar radar in ab in 91 lol. i strted with a weather radio , a few books, driving way too fast, and getting myself a few to many times close lol. i sent you some of my pics , hope ya like em.
rob: im in edmonton and im thinking red deer is a good start too.
Looks like things are cooking up in South Dakota...
What do you guys think?????
Dale: Found a flight that leaves here at 6:30 get into edmonton at 10:45 for only $400 soundin real good to me !! much nicer than the 14hr drive so now gotta convince the wife I should go to Alberta and play with upcoming monster storm LOL
Hey Rob!...Red Deer is a good place to start on Thursday. The recent models are trending further north with the best instability/shear...so maybe between Edmonton/Red Deer.
All you need is an isolated storm up there and it will have a good chance of producing a tornado.
Dale...Did you email the pictures to reed@tornadovideos.net?
How many tornadoes have you intercepted in AB?
hey jim do you live in wisconsin because i know here it has been dry but around us they have been getting so much rain
Hey everybody, The SPC is monitering northern Iowa for poss. weather watch! Here is the latest mesoscale discussion....
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 181747Z - 182015Z
CLUSTER OF STG TSTMS OVER SERN SD MAY CONTINUE TO INTENSIFY AND
ACCELERATE ESEWD ACROSS NRN IA/FAR SRN MN OVER THE NEXT FEW HOURS
WITH THE ATTENDANT THREAT FOR DMGG WINDS AND MARGINALLY SVR HAIL.
AREA WILL BE MONITORED FOR A POSSIBLE WW IN THE NEXT HOUR.
LATEST RADAR/IR IMAGERY SHOWS COOLING CLOUD TOPS/INCREASING RADAR
ECHOES TRENDS WITH ACTIVITY NEAR FSD. DOWNSTREAM AIRMASS ALONG AND
JUST NORTH OF A STATIONARY BOUNDARY OVER SRN MN/NRN IA WAS
MODERATELY TO VERY UNSTABLE WITH MLCAPE VALUES FROM 2500-3500 J/KG.
RECENT RUC FORECAST SOUNDINGS INDICATE MINIMAL CINH REMAINS OVER
THIS AREA. DESPITE MODEST CLOUD COVER...IF INCREASING ORGANIZATION
OF TSTMS OVER SERN SD OCCURS...MODERATE UNIDIRECTIONAL MID LEVEL
WIND FIELDS /35 KTS FROM 3-6 KM/ COUPLED WITH THE INSTABILITY WOULD
FAVOR A SVR WIND THREAT WITHIN THE NEXT 1-2 HOURS OVER NRN IA/FAR
SRN MN.
Could I get the Coles Notes version Zack ?
Newbee...
Posted By Greg | July 18, 2007 @ 1:03 PM #
hey jim do you live in wisconsin because i know here it has been dry but around us they have been getting so much rain.
Greg, I live in New Ulm,MN and many parts of this state
have been extremely dry. the hit and miss storms soak
some areas but leave others bone dry. My lawn is history
and the trees are dropping leaves due to stress already in
town. Just watched the latest radar loop out of SD and it
looks like this batch wil miss us again as it slides to the
SE of us. Maybe only a sprinkle here to raise the humidity
even higher then the 77f dewpoint we already have.
Can only hope more develops later this evening around here.
Severe T-Storm warnings have been issued w/ the cluster of strong storms in SD....
Anything going up in canada yet?? Just wondering.
yes reed i e-mailed them there...hope you like em bud.
between red deer amd edmonton...its almost a repeat of 20 years ago... same conditions ..same everything.
Zack, click on my name to view radar stations across Canada.
As for the storms coming out of SD they seem to be loosing
strength.
The system moved from Alberta into British Columbia now
reed: not to many tordadoes...we get an average of only 14-20 a year in all of alberta... and given alberta is 3 times the size of texas...you get skunked more than anything on a chase...thats why this year seems so far so monmentious... we hover at usually 30% humidity and popcorn thunderstorms. ive gotten in front of only 8 in my all my 15 years. and the first was the edmonton one... before that nobody even new they exsisted here believe it or not.
thats the mother low off the coast rene... beside it what you can see is a low pressure area sitting just benieth alberta waiting to come up here. be side that is a high pressure area so it has no where to go but up given the air currents.
Thanks Dale, I need to learn all of this stuff.
What's a good place to learn beside School hahahah
Thanks Jim..... Gosh its getting really hot at my place!! Im still wondering if the cold front that is expected Friday will kick off any severe storms. Taking a look at the latest models, it seems that the rain chances are beginning to look a little more impressive.
rene...the collective knowledge and pure instincts on the sight are second to none. gald to see ppl taking more interest.
Hi Dale ....
My interest started a few years ago. It happened at my cottage. We were getting severe T-storm, Lighting like there's no tomorrow. Our dock got hit by lighting 3 times. Parents left the gazeebo and entered the cottage. My brother and I stayed.. the winds have pick up and notice 500 yrds from a funnel rotation. I pointed to my brother thta's a Tornado. I was so exited. It touched down later (10 miles from the cottage).
Just last year we had a microburst at the cottage. It damanged 6 of our 100+ years Pine trees. toppled them over.
So ya I want to learn this stuff and witness again another tornado. I'm willing to chase with someone who's experienced
where do you live rene? and do you have nerves of steel lol?
That isolated cell approaching Green Bay may have just produced.
Nerves of steel....yup..
I currently live in Mississauga Ontario. We get to see lots of wicked stuff, but all wind up disipating for some reason..really disapointing..
I'm willing to tag along with someone
I had to talk a female chaser into heading out the door from Green Bay to the storm that is about an hour and a half west of her. Her lack of interest really disappointed me, but is now preparing for an intercept. 45-60 knots of Effective shear, small t/td depressions, and somewhat isolated, with better moisture to the south, the storm could go AWOL. Jinx.
Maybe a storm will survive over Lake Michigan for once!
Zack..The WRF is not showing nearly as much precip with the front as before in central OK. It has northwest OK receiving some good rain, though.
With that moisture in place I still think parts of central OK could get some good rain with it 72-84 hours out.
Just issued a watch over northern Iowa effective until 10pm.....
here is a portion I highlighted from the SPC.
HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
yup, its gonna be a looooong night for them!
Hey Reed, Im wondering looking and radar there are some storms entering Southern Ontario from the Detriot area. They look bad and Im also under a severe thunderstorm watch up near Georgin Bay area wonderin if Tornadoes could be possible.
yeah Reed I just noticed that.....
I hate this Severe weather around and i dont have a car to chase it SUCKS. Sorry just a little angry!!!!!!!
From the last Sever T-storms we had in the past month
. For some reason, the GTA region kills the storms. It's a voodoo curse man.
I really hope it does carry thru the GTA unaffected and go your way
My home town is Sudbury
Reed (or Zack) I live in nebraska, near the IA border *along omaha* and i wanted to know if we will get any of this? its been so boring here withought any storms :(, hopefully something will happen around the 15th when im in chicago ;o
Sorry the last post at 2:59pm is not from Matt. It's from Me
So sorry
Lake's too cold. Watch it drown slowly and painfully.
Damn! those great lakes.!!!!!
Blake, just took a quick glance at radar around your region and it appears that the cluster of storms in northern Iowa are moving southeasterly, which will miss you BUT some new development is taking place around the Sioux Falls area. To me you have a pretty good chance of seeing something around your area
I'll keep you updated if anything seems to be heading in your direction
Hey Guys,
I have the DV Camcorder and Cameras charged. If anything moves through the GTA I'll be on the run. Some severe weather warnings are starting to pop up :-)
BTW, great job with this site!
Thanks Zack =], cant wait, might go to northern IA and see some of this and right now around us isnt much, just looks like clouds that could produce very very little rain
Dave where do u live????
how's Chicago looking for this storm
strong storms right??
no more flood watch
but tornadoes are possible in Chicago
Matt,
I'm in Oshawa (20 min east of Toronto). You guys are right about the GTA, the cooler waters seem to kill all the storms. Lightning shots are no problem, but it's next to impossible to get a tornado shot....one can dream.
Reed, Corey any Michigan guys are you going to chase anything today just for fun?
The cell by Mt. Pleasant looks chaseable, starting to look good.
Again Damn those Great Lakes.
One can dream?.. so because of these Great Lakes of ours.(Canada & U.S)..it will never happen in the GTA?
Man were is Lake St. Clair because of the Weather network they have a slight chance of a Waterspout. Man i would love to see on of those. But something tells me that it is no where near were i live upin the Barrie area.
Well i just answered my own question and it is nowhere near me.
Rene,
We had an F4 in Barrie in '85. Come to think of it, that's probably a baby compared to what Reed and the guys see...I doubt a huge wedge like the one in Manitoba will ever happen. Maybe Reed can comment on the probability :-S
The London area in Southern Ontario seems to see the most action. I'm not sure if that's because it's located between the lakes???
I saw the SPC model...guess Cedar Falls is in the middle again..lol Just hope my car doesn't get hit by large hail again today..Lucked out last Monday. YEEHAH!!!!!
Nothing seems to materialize around Chicago.. Last year we had a few good storms at this time that produced some funnels at least. I seen a could storms wanting to start today but they died out quickly. Hoping for better times in the future.
Well guys. I'm dead squashed in central illinois. Ottawa being probably most recognized if i had to guess. I work midnights. So, If before dark 830pm chance or finding something nearby please keep me notified on here. From what i been looking at I'm expecting to see probably just hail.
-mike
A textbook bow-echo/derecho is getting going in northeast Iowa...some major wind will be produced by this thing as it moves rapidly ESE. A tornado warning has been issued for the "book-end vortex"...at the northern end of the bow.
hey everyone i am now in Galesburg Illinios...i didnt go as close to the border as i would have liked, but i do still have time to move that way...
I stopped here an hr ago, just to get the PC up and running and check out radar. I am right now poised with holding my position...But with new updates i may move Toward the Davenport, Aledo, Muscatine areas.
This this is looking awesome, i beleve the tornado warning are going out just because of the excessive winds. 80+.
Reed if you see this Post back soon.
Ben you are about a hour from my homestead location. If i were you the sun will be setting for evening in the next hour. So I would probaly move to a further north position. towards quad cities doesnt look bad, but could put you in a bad situation off 80 over there. you could always go west to burlington area and watch it goes by you to the east? the storm should be nearing soon anyways it's just about ready to come over the mississippi.
-mike
I am near the city of andover, just pulled over to check the radar, and timing, i may try to take 74 to US67, and 67 up to Princeton IA.
Making good time, there is not much west bound traffic right now, and have seen a few chasers.
Making a ditch effort to try and get in line with what is tornadic right now, though i dont see much rotation on radar.
Missed us again, all we we had here in New Ulm,MN was a
light sprinkle while all the heavy rain moved SE of us. I
guess the corn crops around here will be history before we
get any rain. This hit and miss T-storms seems to have
forgotten us and will really hurt area farms this year.
same here
Dave F: You might be interested in knowing that we've had some pretty big tornadoes in SW Ontario. It's just that a lot of the big ones happen with High Precipitation (HP) supercells, so they tend to be rain wrapped and not very photogenic. (And you're right that the Barrie tornado wasn't especially huge in physical dimensions, but it packed one hell of a punch! It did start off at about 600 meters wide, but quickly went down to about 100-200).
Off the top of my head, I can think of August 19th, 2005; both the Fergus and Conestoga Lake tornadoes reached 1 km wide at some points along their path. The Grand Valley tornado (same day as Barrie) got up to about 800 meters wide. And the biggest I can think of was Woodstock on August 7th, 1979; maxed out at 2km wide at one point!
And I'm glad to see I wasn't too far off on the Iowa derecho thing... just about a day late!
Cheers,
Simon E.
Here on the far south side of Chicago, there was a nice gust front that went through, to bad that this didnt happen during the daylight it may have looked nice. The lightning was good. Thought I was gonna get struck while driving home from work.
First time on this site and I am having an over load of information.
First I would like to say that the storm that moved through Ames, IA today was a waste of time. It looked like other violent storms that we have had in the past, but it was all show. We have had storms with shelf clouds come through in the past, but usually they pack more of a punch. All that happened here was a few sprinkles and about 3-5 minutes of gusty wind. Now there is quite a light show going on outside. Hope there was some action elsewhere.
I live in Northern Illinois and we got a line of powerful thunderstorms that were connected to that huge mesoscale from the west and we got clipped on the most northern part of it. No damage done on my home but one flash of lightning after another. I didn't get out to see if there was any flooding. I bet the park near me is flooded as it usually is after a heavy rain.
I spoke too soon. Around 12:30 Ames was pummelled with heavy rains and small gusts of wind. It rained hard for at least 2 hours and the sky was lit up constantly. The house was close to being hit by lightening a few times, but was not damaged.
Simon,
Thx for the interesting facts. I had no idea that those tornados were so big! Do you see anthing happening up this way today?
thx
Dave
i was in rock island when it happend there were a few funnel clouds but no tornados
AGAIN. the MCS storms fail to reach my homestead of streator, il. This is quite fustrating because the last time it sounded so promising to get some storms and the low level winds defeated it from happening and now this time.. it looks like it just started to go more east then south at us. =/