Chase Case #4

[Scott Weberpal]

I'm still in Twin Falls, Idaho, on the west side of town near the junction of US 93 and US 30. I'm getting a little nervous watching the convection fire off the mountain ranges to the south and west, but there is also a nice storm in open country to my south and east and heading right toward me. It's the southern most cell in a line of storms stretching in an arc from Owyhee County into Northeast Oregon. I'll play this junction in case the storm right-moves. There is a decent grid of roads in the agricultural Snake River Plain to my south. If all else fails and I need to move fast, I-84 isn't too far to the north.

Wish my nowcaster *ahem Scott* could get me more detailed surface obs to work with. I'm basically visual here.

Couldn't seem to get a hold of Gerrit (the only chase I know in Idaho), so I got a lunchable from a gas station. I accidentally left part of the wrapper on the Andes mint and it came in contact with one of my fillings. Woo! That was a surprise.

Here you go, Dann 19z Northwest SFC

 

[Corey Sloan]

TARGET: Miner, MO near the intersections of I-55 and I-57 in SE MO. This affords me a good location to go any direction based on the forthcoming data. In all actuality I would not chase this event other than an arm chair chase.

Having said that, I like this position as it relates to the 12Z surface front positions and on-going MCS over eastern MO. The KSGF sounding is the best, IMO, of all of the soundings examined.....I am not overly impressed with the moisture return in my target area but will wait for later data to have this be a true "fly in the ointment". The atmosphere will recover and there will be outflow boundaries...just not real impressed at this time with the possibilities. Most likely a high BUST potential for this chaser!

St. Louis sounding would be nice if it were available on next data runs.

I believe there will be severe weather in East Central, SE MO and IL. I think this will be a linear event with some embedded supercells capable of producing brief tornadoes...I do not look for this event to be a prolific severe weather/tornado outbreak. Possibly a good linear line straight line winds the main threat.

All in a rookies humble opinion! The whole reason I have been working on these case studies is to study and learn....thanks for all who work on getting them prepared and presented!

Now to find the 18Z data to see how bad I did!

EDIT: Staying in the same general area after looking at 18Z data....Dp's are ok...still a high bust potential IMO....still a linear event with straight line winds as the predominant severe threat.....

 

[Tim Segraves]

I totally forgot how fast a strong NW flow would move things along so I now find myself too far to the west. I'll be racing southeast towards Madison, WI and if I'm lucky catch up to a developing squall line. I'm not expecting any tornadoes for me today.

 

[John Farley]

I am getting some work done at home in Edwardsville, IL and keeping an eye on the weather. I am not going to make the trip to northern IL, beucase I think with the forcing there will be mainly a squall line. Not to say there couldn't be a tornado or two from embedded mesovortices, but those are hard to find.

I think it is possible, though not terribly likely, that some strong storms might form along the poorly-defined warm front in the MO Ozarks. If this happens, there is a little more directinoal shear and a little less forcing (though also perhaps weaker upper support), so I think that the chance for supercells, though small, is a little better here. The warm temperatures and relative lack of clouds just to the southwest of this area are also a plus for the possibility of firing strong storms later. If I see something firing decently north of I-44, say near Columbia or Jeff City, I might head out for an intercept. Too marginal a situation to face the jungles south of I-44, though. My hunch is that with the northwest flow, the chance of strong storms is better southeast of I-44, but this is terrible chase country, and this setup is not good enough to mess with it.

 

[Dann Cianca]

Here you go, Dann 19z Northwest SFC

Thanks!!! Golly, can't believe how humid it is here in Idaho. Nothing like huge towers in the sky and huge mountains for a backdrop!

 

[Jim Tang]

Don't like this setup at all. Looks like high-based sups or multicells for the upslope, so I'll focus my attention on the Plains. Don't like the moisture quality and instability prospects up north; 12Z soundings indicated a shallow moist layer (even though this IS summer so I guess the corn will help). I will pick Montgomery City, MO near the WF/stationary front. The winds are slightly more backed in this area and there is some moisture pooling apparent invof I-70 on the sfc ob plots. Any discrete cell that can initiate further west might be able to produce as it crosses the front. Further north looks like a linear mess.

 

[Doug Mitchell]

Yuck, looking linearish to me. I'll play that little puff that developed on the 2145z SAT just to the south of me

 

[Dennis Dennison]

I would be issuing some warnings for that north East sections of Colorado for High winds and hail--I also believe now there will be at least 3 touchdown in NE Colorado and Cheyenne area of Wy.
I have stayed in the Gary,IN area all day,
I think I will reposition to Lafayette, In

so I can intercept tornado's either in and either side of a line from Bloomington to Kokomo,In. I am certain to expect .34 to1.2 " hail, and a BOW echo.

 

[Andrea Griffa]

After have seen the last update I'm seeing a quite strong low on the border between Minnesota and Wisconsin, moving southestward, with a definite cold front to my west (I left 30 min ago from Des Moines,Ia).
I have to say that I don't like north flow as the major part of us even if I'm aware that sometimes it can produce something good. That's the reason why I want to chase today and as it will happen nothing in the Plains during the next days I decide to go North East in Janesville,wisconsin, ready to go east where I expect a convective development substained by a very very strong deep layes shear and a nice low level jet. I can't rule out supercells and who knows, if something remains isolated we could have also few tornadoes.
By 20Z satellite, I see the cold front pushing southestward and I can see some towers in the distance.
It sounds good for Chicago and Milwaukee today, to me.

 

[Niccolò Ubalducci]

Now, after a bad night on Motel6, I'm driving fast from Saint Louis to La Crosse Wisconsin; I think that the occlusion could will be strong and we can get some satisfaction from these nice LLJ.

 

[Andrea Griffa]

Now, after a bad night on Motel6, I'm driving fast from Saint Louis to La Crosse Wisconsin; I think that the occlusion could will be strong and we can get some satisfaction from these nice LLJ.

You'll never make it before convection: you have 8 hours of driving to La Crosse.

 

[Niccolò Ubalducci]

You'll never make it before convection: you have 8 hours of driving to La Crosse.

Doh!!!

But I'm started from Motel at 7 am and I can be on LaCrosse at 15 pm!

 

[Josh Richardson]

After having lunch in Clinton and sitting around I see some agitated CU outside now and on the 2045 SAT image, I see no reason to do anything but move with this CU field and see what develops. I have a gut feeling I should be in Muscatine for some reason but I am not going to risk, we'll probably just follow this across the river into ILL.

 

[Tom Dulong]

I would be issuing some warnings for that north East sections of Colorado for High winds and hail--I also believe now there will be at least 3 touchdown in NE Colorado and Cheyenne area of Wy.

I agree. The central high plains areas was originally my second most favorite target. Since I was starting from OKC, I had settled for SGF where the veered surface winds spell doom for any decent severe storm chances.

The nice thing about a virtual chase is that I can admit my first target will be a bust, wipe the board clean, and start somewhere else (yes - I can make the rules as I go along. So, here is my reasoning and my plan..

Surface dewpoints are still in the mid 40s to mid 50s in the northeaster CO plains. That storm popped up quickly east of the Palmer Lake Divide southeast of Denver, which is a favored region for tornadoes in late May - late June. If you squint and hold your head just right, you can see a boundary with that storm on the latest visible satellite pic.

So, I am now streaking (within the speed limit, of course) toward my new target of Limon, CO. From there, I can work north, east, or south as the storm(s) evolve.

 

[Buddy W Bradley]

I also want to thank Scott for providing these chase cases during this lull (down) time. My original thinking was to stay put here in springfield after the 12z information. But after evaluating the 18z info and satellite pics I have decided to head up to I-70 around Columbia MO and probably try to catch something along that weak boundary close to the Missouri River. The wind profilers do scream linear, but the morning convection had to put out some outflow boundaries in the area. With the approach of the front and low pressure system to the north and the weak stationary front in this area, there just might be a severe storm or two develop before the whole area of convection goes linear. I'd guess this was a SLIGHT RISK day over the N. Rockies as well as the Upper Midwest down to S. Missouri. The 5% tornado area was probably up closer to the low in Minnesota and Wisconsin and a 2% extending all the way down to central MO. Also a 2-5% area in S. Idaho and E. Colorado, SE Wyoming and W. Kansas. I would guess It was a 15% hail and wind through out the slight risk area in the Upper Midwest and Mid-Mississippi Valley. There was probably a small area of 30% wind near the low in Minnesota and Wisconsin. So my best guess is: Columbia Mo by noon and northeast toward Kirksville or Quincy after that. Good luck to All!