TornadoVideos.net

Posted By Joel | July 25, 2007 @ 7:53 PM #

Hey everyone,

Keep in mind that CAPE is only one of the things to look at. High CAPE is not always necessary for strong tornadoes. In fact, tornadoes can occur with capes from 250-500 J/kg. A lot of the eastern US outbreaks occur with CAPE's around 1000 J/kg. It is always necessary to look at the combination of CAPE and shear. High CAPE can many times balance out low shear and vice versa in forming tornadoes.

Also, when looking at CAPE, the most important part for tornadogenesis is that which is located in the lowest 3 km of the atmosphere. Shear is most important in the lowest .5 - 1km.

Posted By Andrew | July 25, 2007 @ 8:28 PM #

That CAPE value just blows me away. Also the zero hour ehi value is 6.5 just east of Winnipeg. Lots of other indicators really high too. Too bad it all didn't pan out for you guys up in Canada tonight.

Posted By Andrew | July 25, 2007 @ 8:37 PM #

Sorry for the double post, I didn't see my earlier one, looks like the site is out of space or something!

Posted By derek | July 25, 2007 @ 9:44 PM #

i live in winnipeg and the skys are black. i geuss we have severe thunderstorms coming tonight

Posted By zack | July 25, 2007 @ 10:35 PM #

Hey, Me posting again..... That was an extremely high cape value over SE MB earlier this evening!!! As far as I'm concerned, I have never seen it that high! Well I checked the EC radar and nothing interesting is showing up as of right now.

Well it's late and I just got done mowing the lawn earlier... It felt nice this evening w/ the temp at 78 degrees when I did the lawn!! The temp is now currently 74 over my region. (yawn) I'm tired so I'm heading to bed. See you tomorrow...lol.

Posted By zack | July 25, 2007 @ 10:38 PM #

Oops... double post.

Posted By BMB | July 25, 2007 @ 11:00 PM #

Simon E - I have photos of the abandoned yardsite that was demolished on June 22nd by the tornado that was south of Oakville/north of Elm Creek. I am familiar with the area and know the windbreak was healthy before the tornado. I believe the trees were willows - definately mature trees. The bark was stripped off the trees and they were sheared off. There was a steel quonset on the yard that is gone. There were steel grain bins that are gone too. Even the concrete for the grain bins was sent flying.

Posted By Rob | July 25, 2007 @ 3:22 PM #

Reed: Mind movin all that lil. further west it would be appreciated LOL It has is the last hour here in SW Manitoba really started to bank up with clouds and is slowly starting to cool down I am hopin we may see somethin here! I am watchin radar waitin to see somethin pop then I am off. Will keep a eye on the ND. border hope somethin will show there only a hour and half drive if it does. Lemme know if ya see somethin please !! Have a good one be safe all !

Posted By Simon E. | July 25, 2007 @ 3:25 PM #

8500 Joules!? Now we're just getting ridiculous...

Posted By Amanda | July 25, 2007 @ 3:31 PM #

Should i be running for cover?:=P

Posted By Matt | July 25, 2007 @ 3:31 PM #

ya is it the higher the better or lower the better for CAPE.

Posted By Matt | July 25, 2007 @ 3:35 PM #

Alright i see so with the CAPE this high if storms produce there going to be huge????

Posted By Simon E. | July 25, 2007 @ 3:37 PM #

Yep... CAPE is measured in joules per kilogram. It's the amount of energy that would be released by a parcel of air if it were lifted (in this case) from the ground to the equilibrium level (the top of the troposphere).

Even in the absence of any strong wind shear, storms environments of very high CAPE (lets say 4000+) can still be quite dangerous.

I'm also a little bothered by the RUC showing the higher values of DBCAPE in SE Manitoba, which implies that there is a substantial dry layer that could generate some downburst activity (but I can't see anything on any of the closest soundings... problem is they're from far away and 8 hours ago. Stupid upper air network!)

Simon E.

Posted By Connor | July 25, 2007 @ 3:43 PM #

I asked this on the last post before I realized this one had been added.

This is a little off topic, but does anyone know when conditions are forecasted to become more favorable for tropical development in the Atlantic?

Posted By Matt | July 25, 2007 @ 3:53 PM #

I just did some research on CAPE on the internet. And i found something very interesting.

Two notable days for severe weather exhibited CAPE values over 5,000 J/kg. Two hours before the Oklahoma Tornado Outbreak occurred on May 3, 1999, the CAPE value sounding at Oklahoma City was at 5,885 J/kg. A few hours later, an F5 tornado ripped through the southern suburbs of the city. Also on May 4, 2007 CAPE values of 5,500 J/kg were reached and an EF5 tornado tore through Greensburg, Kansas. On these days, it was apparent that conditions were ripe for tornadoes and CAPE wasn't a crucial factor.

So with CAPE this high if storms produce it could geet nasty.

Posted By Gus | July 25, 2007 @ 3:56 PM #

It hit 53 with the humidex in carman 45 miles SE of winnipeg. We better get some good storms

Posted By zack | July 25, 2007 @ 3:59 PM #

Amanda don't be so hard on yourself...lol. The CAPE values are very high, but sheer is lacking.

Posted By Amanda | July 25, 2007 @ 4:00 PM #

I wont get really worried till I actually see something...and knowing my luck because im sitting here melting i probably wont see a drop of rain...lol

Posted By Simon E. | July 25, 2007 @ 4:01 PM #

One thing to think about is convective mode; if you get discrete supercells (that's storms that are seperated from each other, not stuck together in a squall line) in this kind of environment, almost any low-level interactions could set off a tornado. Watch out for outflow from neighboring storms as well as lake breezes. Interacting boundaries in a high-CAPE, weakly sheared (in the low-levels) environment might have been what caused (or at least played a major role in) the Elie and Oakville tornadoes in June.

I can't find any very high resolution sat images for the lakes, so I don't know if there's a substantial lake boundary there today. (Anyone have an opinion on that?)

Simon E.

Posted By Simon E. | July 25, 2007 @ 4:03 PM #

Well, I've hear of 'em...

The big July 15th, 1995 derecho in Ontario and New York was preceded by +8000 plus capes, and the Plainfiled, Illinois tornado (August 28, 1990) I think was over 9000.

Posted By Amanda | July 25, 2007 @ 4:05 PM #

LOL no problem Matt just bugging ya...its pretty interesting...can you imagine mantioba with an F5? scary thought

Posted By Don G. | July 25, 2007 @ 4:06 PM #

rene,

CAPE is an acronym for Convective Available Potential Energy, and as Simon E. noted is measured in J/kg. The energy is realized in a thunderstorm as the air rises, causing the pressure to fall, the air to expand and cool, and moisture to condense from the air, which then releases latent heat stored by the water vapor and warms the air inside the cloud. This then serves to enhance the air's upward motion (similar to a hot-air balloon), which moves the air higher, causing the pressure to fall more, and so on. This process continues until the air reaches the tropopause, a layer of high in the atmosphere where the temperature begins to warm with height, preventing the air from rising any further, and breaking the cycle. We can visually see where this occurs in the atmosphere, as air from the thunderstorm spreads out laterally there and creates an anvil.

This is all well and good, but doesn't tell us much about how much energy is really stored by water vapor in the atmosphere. By way of comparison, the energy released in a thunderstorm by a blob of air 10x10x3 m (the size of a large living room) having CAPE of 8500 J/kg is enough to power a 60W light bulb for 12 hours. Given that a strong thunderstorm can easily process ten million times this much air in about five minutes, it becomes easy to see why they can be so dangerous!

Posted By Gus | July 25, 2007 @ 4:07 PM #

Yes a warning for carman boy its comin

Posted By Amanda | July 25, 2007 @ 4:09 PM #

Matt i sometimes use the weather networks radar...just follow the links

Posted By Andrew | July 25, 2007 @ 4:11 PM #

Yes that cell west of Winnipeg has blown up so fast, and it's early, and it's out ahead of everything. If I were chasing I would be on that one fast.

Posted By Don G. | July 25, 2007 @ 4:12 PM #

rene,

Sorry, instead of ten million in five minutes, I should've said ten million in one second...my bad.

Posted By Gus | July 25, 2007 @ 4:13 PM #

I live where the warning is big clouds west of us i will keep u updated if a funnel cloud is spotted

Posted By zack | July 25, 2007 @ 4:16 PM #

Urrrrrrrg!!!! I wish I was on that storm!!!

Posted By Gus | July 25, 2007 @ 4:18 PM #

Lots of thunder and lightning right now

Posted By Gus | July 25, 2007 @ 4:20 PM #

Its dying near carman CRAP

Posted By Simon E. | July 25, 2007 @ 4:25 PM #

Yep... I don't know nearly enough about boundaries, but when storms hit them (ofb, lake breezes, etc.) they do tends to go ape-sh*t. I know that boundaries generate enhanced lift and convergence, and I guess orientation might play into enhanced shear along the boundary...

I was looking at the radar loop, and I could swear I can see a hint of some kind of boundary or gravity wave moving NE, perpendicular to the cold front. Am I seeing stuff here?

Posted By Jonathan Strike | July 25, 2007 @ 4:28 PM #

4:24 PM CDT WEDNESDAY 25 JULY 2007
SEVERE THUNDERSTORM WARNING FOR
CITY OF WINNIPEG ISSUED

Persons in or near this area should be on the lookout for adverse weather conditions and take necessary safety precautions. Watch for updated statements.
Please refer to the latest public forecasts for further details and continue to monitor the situation through your local radio and television stations or Weatheradio.

I'm staying here for now. It's headed this way.

Posted By Jonathan | July 25, 2007 @ 4:31 PM #

HERE THEY COME!!!!!!!!

City of Winnipeg
4:24 PM CDT Wednesday 25 July 2007
Severe thunderstorm warning for
City of Winnipeg issued

Persons in or near this area should be on the lookout for adverse weather conditions and take necessary safety precautions. Watch for updated statements.
Please refer to the latest public forecasts for further details and continue to monitor the situation through your local radio and television stations or Weatheradio.

Posted By Simon E. | July 25, 2007 @ 4:33 PM #

Heads up north of Winnipeg! Looks like two towers just north of the city. All this convection looks like it's behind that cold front (at least, I think it's the cold front on radar), so not sure if it's surface based.

Thanks for the info, Don; was there ever any work written up on that one? We had a pair of tornadoes in Ontario back in '96 that I'm sure were capable of EF-4 damage; also CAPEs about 1000.

Posted By Andrew | July 25, 2007 @ 4:34 PM #

Simon I definitely see a distinct wave of something that just passed over Winnipeg, if so the one cell is blowing up just behind it. I took a look at sattelite and I don't see any gravity waves, doesn't mean they aren't there, from what I know they are not always visible.

Posted By Andrew | July 25, 2007 @ 4:35 PM #

Simon must be the cold front I saw on radar

Posted By YFZ43 | July 25, 2007 @ 4:38 PM #

I am in Steinbach and a large mushroom like cloud is building and rolling in pretty quick. 20 mins ago the sky was clear. I am off to Beausejout in an hour for a meeting, taking the camera along.

Posted By Simon | July 25, 2007 @ 4:44 PM #

I would say marble size and a bigger---its letting up a little now and will go outside and check it out, I can see branches all over the yard.

Posted By dj_onur | July 25, 2007 @ 4:47 PM #

Winipeg weather, the mushroom structure is evident. We're under the anvil and some dark clouds passing by. It is HOT. The storms are coming here!

Posted By Matt | July 25, 2007 @ 4:57 PM #

Thanks Simon E.

Posted By Andrew | July 25, 2007 @ 5:01 PM #

Just me rambling on again.

The tail-end charlie in the line approaching Winnipeg/Steinbach is just on the Grand Forks radar, and it looks really interesting. Close to the high ehi area on the model map.

Posted By PB | July 25, 2007 @ 5:09 PM #

Nickel sized hail reported in Starbuck, ~20 miles SE of Winnipeg.
55,000ft+ cloudtops
Nice!

Posted By Matt | July 25, 2007 @ 5:12 PM #

There looks like a storm headed right for Winnipeg. But it doesnt look to bad at this time.

Posted By Jonathan Strike | July 25, 2007 @ 5:16 PM #

For all of you not experiencing the storms in S Manitoba. It is as dark as 10pm here win Winnipeg. Very strong winds and lightning and thunder approaching from the west. Cool!

Posted By Reed | July 25, 2007 @ 5:18 PM #

It looks like there is a secondary cold front surging south across the Lakes right now. Storms have tried to develop south of it but have been continually undercut by the cold air. The very southwest storms are trying to become suface based but the front may be moving too fast, and continues to undercut the updrafts.

If a storm can move off the front it will have a small chance of producing a tornado with the high EHIs in the warm sector.

Posted By Dale | July 25, 2007 @ 5:25 PM #

hey gang just got home from work...read all the postings...whats with the 8000j/km in man????? in 1999 , the big one in oklahoma the cape was at 5000j/km just before it hit.... that was an f-5.

Posted By Simon | July 25, 2007 @ 5:34 PM #

The amazing part of this storm is that it has not stopped thundering since it started here (west of Winnipeg). This has gone on for about an hour. It has been just one contanst rumble. The winds here keep shifting from the southeast then northwest. With each gust comes cold air or hot air. The rain has stopped (which was horizontal) now to a faint drizzle.

Posted By Simon | July 25, 2007 @ 5:40 PM #

hi Amanda
About 20 k west of Elie and south of Hwy 2

Posted By andy | July 25, 2007 @ 5:50 PM #

There seems to be alot of variables for storms, I think moisture is probably pretty important too.

Posted By Simon E. | July 25, 2007 @ 6:30 PM #

Just playing devil's advocate, here, but I was looking at those pics from the Linn County, KS EF-4 tornado, and just from what I see on the web site, I think that that would have been rated F-3 if it happened in Canada.

The sill plates seem to be intact with no tearing of the wood, the front porch is still there. And the tree had one branch broken, but it's still hanging there, and it doesn't look like it's lost any bark...

Don't get me wrong, I'm not saying it doesn't deserve the rating, I'm just trying to illustrate why we don't report as many significant and violent tornadoes up here.

Simon E.

p.s. Those storms don't seem to be realizing the energy out there, I'm doubting if anything really spectacular is going to materialize. How are those flash flooding reports going in Winnipeg area?

Posted By Mike R | July 25, 2007 @ 6:32 PM #

BTW
the dew point in Carman, man hit 30C(86F). That is 4C shy on the world record.
Humidex Peaked at 53C(127F)
Manitoba is one of the most humid locations on earth at the moment.

Posted By Simon | July 25, 2007 @ 6:42 PM #

Hi Amanda
I should have wrote north of Hwy 2. Draw a line between Elm Creek and Elie and smack in the middle and thats where I am. Has the storm hit there yet?

Posted By Mike R | July 25, 2007 @ 6:45 PM #

anyone know what the cape was for the Edmonton tornado

Posted By Amanda | July 25, 2007 @ 6:47 PM #

K the other simon now...has it hit oakville i dont know...here (i live north of the city) its just been thundering and odd bit of lightening....and unfortunately no freaking rain yet...

Posted By Simon E. | July 25, 2007 @ 6:56 PM #

Uhhh... Amanda, I'd really like to see some of those pictures! I spoke with Dave Carlson (he directed the damage surveys after the two events) and he called the Oakville tornado a "tentative F3." I'm thinking maybe there was evidence that it was higher than that now that you mention the tree thing.

Now I'm in investigative mode here...

We're the trees healthy? What kind of trees were they? Did anything else happen on the farm (building damage, vehicles thrown long distances, etc.)?

p.s. Both for you and other Simon, watches and warnings have been cancelled. It looks like your well on the other side of that front. Looks like weak convection (so still some thunderstorms, but nothing severe) and some stratiform rain behind that in a few hours (that the constant, gloomy stuff like you get in the fall).

Posted By Amanda | July 25, 2007 @ 7:01 PM #

Simon E....My dad left for a golf trip today but will be back sunday...ill get him to forward me the pictures and let u have a look...i know one house was left with only one wall standing...and as for the trees ...not exactly sure...pretty sure they were healthy....ohhh boy...thundering lots now...hell just give me rain to cool things down already....gonna go see if i can get a shot of lightening...

Posted By PB | July 25, 2007 @ 7:34 PM #

Edmonton f4 tornado CAPE: 2690
Pine Lake f3 tornado CAPE: 2250

CAPE over se Manitoba at 21z: 10717