Chase Case #15

[Mike Umscheid]

I did actually chase this day. I recognized the event shortly after my post on Page 10. Here was my actual morning forecast written about 9am that morning (starting point Dodge City):

Subject: Sidney NE/Julesburg CO... or Matador, TX?

Where to go... where to go. I am leaning north for several reasons:
The hordes won't be up there, and I have a good shot at playing eastern
Nebraska Sunday since I would be up there already. There should be a
maximized area of convergence in the Sidney-Sterling-Julesburg area by
late afternoon. This area is at the nose of a 100kt 300mb speed max, so
deep layer shear for significant rotating storms looks good. The latest
RUC shows a maximized area of thermodynamics around this corridor up to
Scottsbluff, NE. Mid level temps will certainly be cooler up here, with
dewpts in the lower to mid 50s. This area concurs with the latest Day
One by Roger Edwards.

Final decision within the hour... but 70/30 that I'm going north...
departure by 10am.

Mike U

 

[Mike Umscheid]

Actual chase account from 3 May 2003, chasing in the Nebraska Panhandle:

I'm spent! Didn't see any "for sure" tornadoes, but finally
intercepted the supercell that came out of the Scottsbluff area
after producing the large tornado sequence that Anton witnessed
near Minatare... then another significant supercell thunderstorm
about 25 miles west of the first supercell that took nearly the
same track before dark.

My original target was Sidney, NE, but on the way out there, I
was suckered to towering Cu in the Akron area along the dryline.
I felt that, based on the info I was provided, this area would
also go nuts with 140 sfc winds and influx of mid 50s dewpoints.
It never went down there. I had to blast north to Sidney and
continue on 385 to get to the show. I finally intercepted the
first supercell north of Broadwater in the sand hills. On the
way up there, I had a great view of the convection. Even with
100kts impinging on the summit of the storm, it still tried to
backshear. Incredible evacuation of the updraft. Unfortunately,
given my angle of attack, the sunshine killed my chances of
seeing under the storm until I was right there... quite scary
actually. It was like entering a dungeon.

What I had entered was a very dark storm, of which I was
entering the rear flank of I think. The best rotation was off
to my north wrapped up in rain, but the rotation this storm had
was vast. There was probably a large tornado wrapped in the
rain (oh, roughly 2330 zulu? I have to check my times)...but I
was in the sand hills on a sand road, and I had to make due with
the horrible road network in northern Morril County. I tried to
get east as far as I could before I dead ended into a ranch
driveway. I looked north and noticed an incredible, rather wet,
RFD cut. Back in the occlusion, wrapped in rain, was an
incredible tornado cyclone, with decent electrical activity.

I was unable to see an actualy "tornado" because of the hills
and the wrapping of pcpn. At this time, I was on the outskirts
of the rear flank gust front, which was just flying in a
cyclonic sense around the back side of the storm. I had to let
this amazing storm go because of the terrain.

On the heels of this storm was another supercell, and after a
couple logistical decisions, decided to intercept this storm
rather than drive east and continue with the 1st supercell. For
awhile, I was unimpressd with the 2nd Morril County supercell,
however there were reports of tornadoes in the Minatare/McGrew
area once again with this 2nd storm. I planned a second
intercept on the same sandy county road that goes north out of
Broadwater. After talking with Fritz Kruse about what was going
on, the storm really started looking good. A large, hard
updraft was evident to my northwest, and at times, it was
generating weird condensation stuff at the gound underneath a
rotating area of the rear flank gust front. I told Fritz at the
time that I might be seeing a weak tornado, but further
inspection of my video is doubtful, as this was not the actual
area of strong rotation... but just a smaller scale feature on
the RFGF. I drove north and..whoa.. major tornado cyclone now
evident to my north. I continued north to get closer to this
area that was severely occluded, but with tons of cyclonic shear.
There were a couple of instances where I thought a big tornado
may plant out of this occluded updraft, but it was without a
doubt, rotating like a son of a gun. I'll have to review my
video on a large screen. The severely occluded cyclonic shear
was incredible!! No tornado. I then got blasted by 50-60mph
NNW rfd winds and heavy rain, and this storm moved off to the
east. This would have occured roughly 15-20 miles due east of
Angora in northeastern Morril County during the 0100z hour
(exact times unsure yet).

shot some decent lightning video of the developing linear severe
complex around the Oshkosh area 0300z, then arrived at the Super
8 in Kearney... A good day, but didn't get lucky. I still think
I used all my luck for the year on March 17th.

My thanks to Jay Antle, Fritz Kruse, and Jon Finch for great
nowcast support throughout!!

Mike U

 

[Bob Hartig]

Mike, thanks for providing that writeup. You've just helped take some of the sting out of getting snookered by that cu field in NE Colorado, and reinforced some of my reasoning for choosing the northern target, even if I did bust. Maybe I wouldn't have busted in real life--hard to tell with a virtual chase. But my point is, having learned a few things about forecasting but not yet having acquired a great body of field experience, I find it really helpful to compare notes with a lead forecaster who actually chased that day, and to see that my thinking wasn't way off in left field, particularly regarding the jet max.

 

[Andrea Griffa]

Did anyone take some picture of the Tx large tornado?

 

[Matt Gingery]

I agree Andrea. . .The word is that the cells will start out as supercells, and merge into a squall line. I honestly think if it is played right, one could get lucky and get some early season footage of a rope. Ted Keller and I are wanting to chase on Sunday due to our very busy schedule. Ted is the Senior Meteorologist at one of the local T.V. Stations, and probably the best local chasers in this area. I am going to wait and see what his input is before I decide to go. Tomorrow will tell the story. I am seriously interested in going though.

 

[Dann Cianca]

Definitely did NOT see a tornado. Not even sure I would have made it to the storm in OK.

 

[Paul Austin]

Thanks for sharing your account, Mike. That was a great write-up. I like your description of the actual storm. It helps to visualize the nature of these particular upslope setup cells. Sorry you didn't score anything definite, but nice call on the forecast. It's interesting you chose the southern target in the virtual scenario, and your initial position was quite good. I'll see you in Denver in a few days

 

[Paul Austin]

Great pics, Tim, and nice call! I like the one that clearly shows the condensation funnel. Undoubtedly without it many would consider the tubes gustnadoes, since many of these pics don't give a broad view of the rotating updraft base. Excellent work!

 

[Sarah Austin]

I didn't get to finish posting after 0z, since I was on the southern cell in TX, most likely I would have seen the other tornadoes or at least come close to them.

Thanks Paul for the chase case. It was a lot of fun! Sorry Marc, I'm sure you got some good night thunders!!! LOL!

Thanks to all for sharing their official experience on that day!!! Interesting to read!!

 

[Matt Gingery]

I personally am not going to take credit for seeing a tornado either, I would have headed out early and chased the next day. . .

 

[Paul Austin]

I personally am not going to take credit for seeing a tornado either, I would have headed out early and chased the next day. . .

Small consolation, perhaps, but you probably caught some decent hail up in SD. Certainly, May 4 made up for it