06/29/2005 TALK: MIDWEST

Hey, maybe Illinois can get that first supercellular tornado of 2005.

Oh, yeah, who am I kidding.

But I do work Wednesday so the mere fact that I wont be chasing might be enough to get the job done.
 
After a very long day (and not done yet) of continuous editing for my DVD, I finally decided to check the models over for WED. Needless to say, I do not have a car to chase in on WED, and by the looks of everything - it looks to be a biggie.
 
Word out of southern Wisconsin offices ( MKX, ARX and WISCWX ) is that we may be looking at a classic derecho type setup. Look for storms to develop Wed. afternoon in IA/MN with supercells/tornadoes possible early, evolving into a very large forward-propagating MCS with damaging winds likely, some in excess of 80-90 MPH, across WI/N IL/MI.

If this pans out as such I will be stowing away the patio furniture and making sure the chainsaw is in working order. :wink:
 
Im currently waiting on word as to whether or not I can get the day off to chase or not. Hopefully that phone call/email will arrive soon so I can start preparations. I didnt look too extensively on the 12Z run, as its still fairly far out...but I did like NE Iowa...maybe around the Waterloo area. I guess I'll narrow it down more after the next run, and even more so if I am available to chase.
 
Word out of southern Wisconsin offices ( MKX, ARX and WISCWX ) is that we may be looking at a classic derecho type setup. Look for storms to develop Wed. afternoon in IA/MN with supercells/tornadoes possible early, evolving into a very large forward-propagating MCS with damaging winds likely, some in excess of 80-90 MPH, across WI/N IL/MI.

If this pans out as such I will be stowing away the patio furniture and making sure the chainsaw is in working order. :wink:

The 00Z NAM just increased the threat and intensity of the derecho, by quite a bit. If it pans out, a pretty widespread area would definitely need their chainsaws. This system has the dynamics of a winter storm and the moisture of a tropical rainforest. It's a dream come true :lol:
 
It's a dream come true :lol:

Not yet, i'm somewhat worried about possible convective feedback issues the models maybe having, which would mess up thier idea of how strong the low will be, wind fields, etc.

That said, it should be a pretty decent event. The tornado threat in MN/IA kinda reminds me of 5-30-98 and we know what happened overnight that day.
 
Originally posted by Jeremy Lemanski+--><div class='quotetop'>QUOTE(Jeremy Lemanski)</div>
<!--QuoteBegin-rdewey
It's a dream come true :lol:

Not yet, i'm somewhat worried about possible convective feedback issues the models maybe having, which would mess up thier idea of how strong the low will be, wind fields, etc.

That said, it should be a pretty decent event. The tornado threat in MN/IA kinda reminds me of 5-30-98 and we know what happened overnight that day.[/b]

Well, it could be convective feedback, BUT - The NAM is actually the weakest of the models right now. The GFS, GEM, and others are in basic agreement that a very deep system will result from this energy digging into the west.

The biggest forecast problems seem to be placement of the various jets, exact position of the system, and of course timing. It would seem that with such a strong system, the system would be moving slower than actually forecast.

The overall setup still appears favorable for a rather intense and significant hybrid derecho (strongly forced + high instability). I am just having doubts as to how far east it will track before outrunning the best dynamics and thus falling apart.
 
Well, after reviewing models since I live in Southern WI, I believe tomorrow is going to be VERY similar to the 6/23/04 tornado outbreak that hit S WI (timing maybe VERY similar also). Seventeen tornadoes hit S WI that evening. In fact I believe it looks frighteningly similar.... Here's what happened on 6/23/04:

A warm front was stalled across S WI throughout the majority of the day, and as evening approached, the warm front surged north into C WI and brought warmer air at the surface, while cold air resided aloft. A cold front moved in from the west in the evening and supercells fired up along the WI/MN border and developed SW as they moved east. When they encountered stronger shear due to the E winds north of the warm front and S winds south of the front, they began to rotate and dropped numerous tornadoes on their progression eastward across WI. As they neared the eastern part of the state, they started to bow and produced 60-80 mph winds and large hail.

Now back to 6/29/05.... everything is nearly IDENTICAL to 6/23/04. Nearly too perfect I believe. Warm front in perfect location, cold front moving in, 3000-3500 cape, 500 m2/s2 helicity and an EHI of 5 to 6 all in the same area!!!! In conclusion, SW/SC WI is my target for initiation around 5 to 6 pm!!!!!

Also, this nice little quotation from the SPC:
POTENTIAL FOR A CONCENTRATED CLUSTER OF TORNADOES ALSO APPEARS TO EXIST ATTM -- PARTICULARLY ACROSS PORTIONS OF MN / WI AHEAD OF SURFACE LOW / INVOF WARM FRONT...WHERE BACKED / SELY LOW-LEVEL FLOW IS ANTICIPATED.

I may be shooting myself in the head, but I believe SW and possibly SC WI will be outlooked HIGH risk on the DAY 1 outlook.

-Tim
 
I wish i could go that far north, but will stay in NW MO, south IA and play the later-southern storms that are hopefully more isolated in nature.
 
Originally posted by Tim Gonyo

Now back to 6/29/05.... everything is nearly IDENTICAL to 6/23/04. Nearly too perfect I believe. Warm front in perfect location, cold front moving in, 3000-3500 cape, 500 m2/s2 helicity and an EHI of 5 to 6 all in the same area!!!! In conclusion, SW/SC WI is my target for initiation around 5 to 6 pm!!!!!

Also, this nice little quotation from the SPC:
POTENTIAL FOR A CONCENTRATED CLUSTER OF TORNADOES ALSO APPEARS TO EXIST ATTM -- PARTICULARLY ACROSS PORTIONS OF MN / WI AHEAD OF SURFACE LOW / INVOF WARM FRONT...WHERE BACKED / SELY LOW-LEVEL FLOW IS ANTICIPATED.

I may be shooting myself in the head, but I believe SW and possibly SC WI will be outlooked HIGH risk on the DAY 1 outlook.

-Tim

There is one key difference, Tim-moisture and instability will be MUCH better than they were on 6/23/04. T/Td was only about 75/60 on that day compared to 90/70-75 forecast for tomorrow! :shock:
 
Originally posted by Andy Wehrle
There is one key difference, Tim-moisture and instability will be MUCH better than they were on 6/23/04. T/Td was only about 75/60 on that day compared to 90/70-75 forecast for tomorrow! :shock:

Wow... yeah I missed that comparison. Can you say Armaggeddon????? :shock: :shock:

-Tim
 
6/23/04 was more northwest flow although the low was more wound up. 5/30/98 was a classic coupled jet and cape/thk gradient type event but still does not compare to what we are seeing here. I tested a bunch of potential analog events today while I was at WFO MKX and nothing really lined up too well.

I will say that the setup fits very well with the "average setup" for wind events across the MKX CWA (S WI). Still some negating factors to overcome though...it certainly is not a slam dunk.

...Alex Lamers...
 
It's just awesome to see such a deep low (i.e. 850mb heights down to 1290 meters/129dkm) this time of year. I'm always leery of very intense storm systems combined with very high instability. Typically, it results in quite a line of severe thunderstorms. There will be plenty of forcing, but I think the initial activity will be supercells. Then, things will most likely go linear. As Alex Lamers said, no event really lines up, but there are some similarities. One thing is for sure, the main ingredients, synoptically, are there for a massive derecho - It's the mesoscale aspects that will need to be worked out.
 
Greetings...first post in this area.

I'm also in SE Wisconsin, and I would agree that this setup looks close to last June's event. I has out of the state for that one, but I'll be here tomorrow. I hate cyber-chasing when it's in your own back yard.

If this event materializes, I think the best chance of seeing a tornado-producing supercell will be west of Madison, about 1800 hrs (6 pm). As it gets dark and the storms are moving east towards the lake, the overnight derecho will sweep over. I also anticipate at least one tornado somewhere between Madison and Fond Du Lac, as that valley always seems to light up during events like these.

I won't be able to chase tomorrow due to work, but good luck to those who can.
 
Wow

I am anticipating an HIGH risk will be issued tomorrow for portions of MN, IA, WI, etc. I will be chasing in Iowa (where I live :D ) and am targeting the I-35 area for supercells with very large hail and a few tornados tomorrow, mainly after 4 pm.
 
Nobody is concerned about capping? The GFS fails to generate much QPF over the currently hyped areas. Hopefully this gets resolved shortly.

...Alex Lamers...
 
Originally posted by Alex Lamers
Nobody is concerned about capping? The GFS fails to generate much QPF over the currently hyped areas. Hopefully this gets resolved shortly.

I believe....the cap will break at about 4-5 pm over S WI, and supercells will rapidily develop after that and I agree the best tornado potential will be just west of Madison up towards Fond du Lac in that valley. They always seem to form there. We don't want a weak looking cap, otherwise the thing will be linear by 5 pm and it will be over with a marginal hail/wind threat.

Lets be optimistic, especially since its a backyard chase for a lot of us!!

-Tim
 
Well i think the main show would be with a squall line overnight. Based on GFS/NAM leading edges of QPF in 6-hourly intervals I have the following timeline.

00Z - approximately along a line from superior to red wing to mason city into SC IA.

06 Z - approximately from calumet mi to clintonville wi to madison wi to near davenport ia

12 Z - into western lower michigan...extreme east illinois and northern indiana.

This looks like a 01-07Z event for S WI beginning around La Crosse and ending around Kenosha. It looks likke more of a 4Z-10Z event across far E IA and into N IL.

Edit although the NGM from tonight pivots a rather extensive squall northeast around the low. Kinda screws N IL but Wisconsin would get absolutely raked with winds.

...Alex Lamers...
 
:shock: After being away for a while, this evening was the first chance I've had in a few days to look over the models...appears like a very nice setup will come together tomorrow evening over WI and IA. Looks like an excellent tornado/wind damage potential to me. CAPE and windshear values look excellent over that region, so long track supercells look like a strong possibility in my opinion. It wouldnt surprise me if the SPC places that area under a high risk in later outlooks considering all of the factors that are expected to be in place. If I can get the day off tomorrow, I'll probably be headed up to northeastern Iowa. :D
 
Keep a CLOSE eye on TAMDAR data http://www.crh.noaa.gov/tamdar

It was critical to several busts so far this year, and there are a few powerpoints showing how it helped some forecasters keep the dry forecast in place when many others were going gangbusters.
 
Re: Wow

Originally posted by Craig Maire II
I am anticipating an HIGH risk will be issued tomorrow for portions of MN, IA, WI, etc. I will be chasing in Iowa (where I live :D ) and am targeting the I-35 area for supercells with very large hail and a few tornados tomorrow, mainly after 4 pm.

This is where I will likely be as well... Targeting the Mason City area for now. But, that can always change of course.

I'm going to play that cold front and hopefully get an outflow boundary out there (hopefully from the northern MCS that is forecasted) moving south. That would enhance shear considerably in my opinion. Or dependent on the warm front location I may hop on that. Mornings observations are going to be big in my decision process. But, either way I wouldn't mind meeting up with some other chasers if you are in the Mason City area. Pueter jeep grand cherokee... ;)

EDIT - Anybody know of a good wifi spot in Mason City??
 
I'm wondering just how far east things will make it before dying out. Since derecho's generally move alot faster than the parent cyclone, are they still able to sustain themselves once they move away from the stronger shear (provided the atmosphere is sufficiently unstable)? The NAM has things blasting into western lower MI at 12Z (as Alex said), but then it quickly weakens things...
 
I'm still maintaining my tornado forecast for SW/SC WI on WED evening.... MKE area forecast discussion does a nice job summing it up:

ANY STORMS DEVELOPING OVER THE WRN CWA DURING LATE AFTERNOON AND OVER THE ENTIRE AREA FROM EARLY TO MID EVENING WOULD MOST LIKELY BECOME SUPERCELLULAR GIVEN STRONG CLOCKWISE CURVATURE TO HODOGRAPHS IN LOWEST 3 KM AND ASSOCIATED HELICITY VALUES OF 300-500 M2/S2. BRN SHEAR...VGP... EHI AND BRN ALL HAVE VALUES INDICATING SUPERCELLS AND TORNADOES AS WELL.

Another snip from the HWO:

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST MINNESOTA...NORTHEAST IOWA...AND SOUTHWEST INTO CENTRAL WISCONSIN...

...IF ENOUGH INSTABILITY CAN BUILD DURING THE DAY...SOME OF THE THUNDERSTORMS COULD BECOME SEVERE. THE MAIN SEVERE WEATHER THREATS SOUTH OF THE WARM FRONT WILL BE LARGE HAIL AND DAMAGING WINDS. MEANWHILE ALONG THE WARM FRONT...THERE WILL ALSO BE THE POSSIBILITY OF A FEW TORNADOES. EVENTUALLY THE THUNDERSTORMS WILL EVOLVE INTO A SQUALL LINE WITH THE MAIN THREAT BEING DAMAGING WINDS. AT THIS TIME...THE BEST CHANCE OF SEVERE WEATHER WILL LIKELY OCCUR BETWEEN 3 PM AND 11 PM.

The Green Bay HWO indicates an outbreak:

THE STORM WILL PROVIDE THE LARGE SCALE INGREDIENTS NECESSARY FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK ACROSS THE UPPER MIDWEST AND WESTERN GREAT LAKES REGION. EARLY ESTIMATES ARE THAT THE OUTBREAK WILL BE CENTERED ACROSS MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN.

Lets hope I'm right.

-Tim
 
Attm. I am targeting Lacrosse, WI perhaps farther north. I would like to be on that warm front, given its not too far north. Anyone who wants company give me a PM.
 
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