August 12th, 2010 SD/MN Supercell/Tornado

Chase Stats
SPC Outlook: SLGT
States Driven: WI, MN, SD
Miles: 710
Departure City: Tomah, WI
Target City: Wheaton, MN
Ending City: Sioux Falls, SD
Outcome: Tornado (1)
Chase Pics: Gallery

This would be my final "long range" chase of the season before I headed off to CMU. Things were looking really good for Thursday in north-eastern South Dakota, and into west-central MN. Friday had looked alright, but at the time I was focused on Thursday to be the day. We headed out on Wednesday evening, and made it to our usual spot: the 90/94 split in Wisconsin. We drove all morning and early afternoon to our general target area which was the NSD/MN triangle area.

The atmosphere looked primed, as CAPE values climbed with excellent shear and helicity in place. A few things were left to be desired including a rather strong 700mb cap, and weak low level lapse rates.

7/22/10 & 7/23/10 Chase Recaps

Chase Stats
SPC Outlook: SLGT, SLGT
States Driven: MI
Miles: 215, 128
Departure City: Battle Creek, MI
Target City: None
Ending City: Battle Creek, MI
Outcome: Heavy Rain, Scud (SLC's)
Chase Pics: Unavilable

July 22nd was kind of a surprise day here in Michigan. I wasn't expecting much this day, because the main action looked to be just across the lake in extreme northern Illinois, and southern Wisconsin. For some reason or another, I stayed up pretty late, and woke up early to assess the weather situation. Not seeing any great potential for us, I ate some breakfast, and did a few things including getting my car ready for the next day. Eventually I went inside, and took a nap. Sometime around 4 o'clock or so, my weather radio went off. Having my radio set to only go off for tornado warnings, I realized our County was indeed in a tornado warning.

7/18/10 Severe Multicells in Southern Michigan

Chase Stats
SPC Outlook: SLGT
States Driven: MI
Miles: 224
Departure City: Battle Creek, MI
Target City: Grand Rapids, MI
Ending City: Battle Creek, MI
Outcome: Hail (1/8"), Shelf Cloud, Lowering/Downdraft Feature
Chase Pics: Unavailable

This setup did not look spectacular; then again, how often are Michigan setups amazing? Michigan has lately had problems with anvil blow-off, or cloud cover inhibiting surface heating which results in less instability in the atmosphere. We have also had issues with veered flow. Most setups are usually linear with surface winds from the southwest. To create more directional shear, or turning in the atmosphere, it is helpful to have southeast winds-sometimes referred to as backed winds.

Fortunately for us, the models were indicating some backed winds over towards the lakeshore area and northeast of the surface low. Mesoanalysis showed a nice theta-e axis from St. Joseph to Grand Rapids. While the most CAPE was down south, the better helicity, and moisture convergence was further north near the warm front.

Pages

Subscribe to Tornado Insanity RSS