Tuesday, June 9, 2009

06/07/09 NE-to-MO Supercell Mayhem

Picturesque supercell at sunset in Maysville, MO

On Sunday, I targeted Fairview, KS (northeast Kansas) after busting the previous day in western Iowa. At least I was in good company with hundreds of chasers that busted along with myself. A stout cap held tough throughout the day ruining our hopes for tornadic supercells on Saturday. Sunday, the cap didn't seem so stout along the Nebraska-Kansas border and along the warm front in Iowa. In other words, the chase was on! After rooming in Atlantic, IA I had a tough decision I had to make. Abandon a warm front play in Iowa or head south where a weak low would possibly kick off some tornadic supercells as well. I decided to abandon the warm front play in Iowa and drive south into Kansas. I arrived in Fairview, KS around 3:00pm to grab some data before initiation within the next 2 hours. This area looked very favorable for supercells with 0-6km shear near 50kts and instability running 2,500-3,000J/kg. SPC outlooked this area for a MDT risk for severe weather as well. Soon after grabbing some data the first storm initiated just to the southwest of Pawnee, City, NE ahead of a weak surface low. One thing I've learned over the years is sometimes you have to jump on the first storm that goes up con-tray to some other chasers beliefs that you should wait in case the best storm hasn't developed yet. Yes, it may put you out of position for the next storm that goes up, but if you keep it in the back of your mind and leave yourself with good road options you can back-track effectively. For instance, if you're dealing with storm speeds roughly less than 40mph or like yesterday less than 35mph you should jump on the first storm immediately. Yesterday, was a great example of such this since I was able to jump on the first supercell and later catch the second one in Missouri with ease. Doubling-down on the day! Back to the chase, after jumping on the first cell that initiated I quickly noticed on the short-intercept a pronounced hook developing on GR. As I get a bit closer I get a good visual of a beautiful mesocyclone and wall cloud forming. At this time the storm had just become severe-warned. This is when the "crappy" part of the chase day happens. While watching an "area of interest" with fellow chasers the storm shifts south all of a sudden on us. A hailstone (golf-ball size) hits the ground and everyone runs for there vehicles including myself knowing there are more where that came from. Quickly more stones begin to follow with big "thuds" on our vehicles and the ground. I quickly make a decision to nose my truck into a row of trees to try to save my windshield, but it didn't work according to my plan as much as I would have hoped. The top-left corner takes a big hit cracking it. A few dents on the hood follow, but as quickly as it began it stopped. I believe what happened was the supercell started to recycle itself at this point as it went tornado-warned and this hail got chucked unexpectedly farther south (our location). Regardless, ugh...this annoyed me the rest of the day! My first cracked windshield definitely left me saying "What the hail"?! especially when no core-punching took place. However, after looking at what happened to other chasers later in the evening I consider myself fortunate since those were not baseballs or even grapefruits being chucked out of that updraft. Anyhow, trying to get out of the hail put us out of position rather quick, but it did allow me to get a view of the circulation from a different vantage point as I was behind the mesocyclone. This was very interesting to observe since you're usually viewing these storms out in front rather than from behind. The storm continued with good rotation all the way to the Missouri River before weakening as a new supercell formed to its immediate south. After giving up on that supercell I headed east into Missouri to catch up with the second flying-V supercell. Chase convergence yesterday was unreal. I think at one point we had to have 50 cars at least drafting (nascar-style) on the highway trying to catch that storm. I saw Reed Timmer and the SRV pass by at one point as we were grabbing some photos. TIV2 was riding two cars back as we headed east for the supercell that was dropping baseball-to-grapefruit size hail. Driving through the towns even 20min after the storm went through hail as big as golf-balls could still be seen. That's amazing since in that time those hail stones were melting so they were much bigger 20 min prior. Furthermore, we catch back up being careful not to run into more hail and add to the damage that was already done. Finally, near sunset I was able to work my way around the hook-echo of the second supercell getting in front of the storm without core-punching. Got a crazy-view with a rainbow in the RFD and preceded east stopping outside the towns of Oak, MO and Maysville, MO and observing a beautiful inflow band. This storm was just spectacular at sunset. I than worked my way east to I-35 for one more taste of the supercells rotation before calling it a chase with darkness near. Met up with a D.O.W. (Doppler-On-Wheels) unit with Vortex2 at a gas station along I-35 with many spectators on hand. I than began the long 5-hour drive home. Thus far, this day featured the best supercells of the year at the expense of many chasers wind shields!

After the "hail experience" we found this rapidly rotating circulation

Portrait-view of the circulation
Amazing supercell structure (looking northwest)
A great example of a supercells tilted updraft
Closer-view of the pronounced lowering below the mesocyclone
After briefly dissipating it begins to get its act together again
Simply a beautiful supercell
Picturesque beast continues east toward the Missouri River
Battle scared chase vehicle (left) and mesocyclone (background)

The first supercell that formed starts to weaken (notice how mesocyclone is less pronounced/high-base and starting to lack inflow (left))
Attention turns to the southern-most supercell (above)
Rainbow in the RFD of the second supercell (notice RFD rain curtains) Click to enlarge...
Rainbow beginning to fade at this point
Inflow band (right) as supercell is going nuts before sunset
Inflow band tail and funnel protruding (Click to enlarge)...
Tornado-warned all evening, wall cloud (center-right)
The supercell back-lit with the setting sun was amazing
 A cool perspective!
Rotation weakens briefly here with an eerie orange shade to the sky
Circulation as it crosses I-35 at sunset
The D.O.W. scanning the area of interest (center)
A short time lapse (above)

A very productive chase that didn't feature a tornado, but I wasn't disappointed in the storms however. What was a little disappointing was hearing of a tornado being reported along the warm front 3 miles WSW of Anita, IA Sunday. That was maybe 20 minutes where I roomed the previous night. Jeeze...