Kokomo, IN 8/24/16
Surprise Tornado Outbreak IN/OH
On August 24, 2016, an unexpected tornado outbreak occurred across central Indiana and went unseen by forecasters and meteorologist alike. The SPC or Storm Prediction Center had issued a marginal risk for severe storms for their day one convective outlook stretching from MI to the TX Panhandle with a slight risk stretching across northern MO, southern IA, northeastern KS, and west-central IL. A 2% tornado probability was issued for that area under the slight risk issued by the SPC. It wasn't until 16:30z (12:30 PM EDT) that the SPC upgraded southern Indiana into the slight risked area and it wasn't until 20z (4 PM EDT) when they issued a slight risk for areas in northcentral Indiana, along with a 5% tornado probability.
The first tornado to touch down was an EF2 south of Crawfordsville in Montgomery County at 2:38 PM. This tornado was on the ground until 2:48 PM, followed by the EF3 that knocked down the Kokomo Starbucks in Howard County. This tornado formed just west of town at 3:20 PM and was on the ground for about 14mins before lifting just past the Kokomo reservoir at 3:34 PM. A total of 11 tornadoes were surveyed in IN with another 10 in northwestern Ohio. A few of those tornadoes as I mentioned, where considered significant tornadoes. A significant tornado is classified as a tornado with wind speeds of 111mph+whch is equivalent to an EF2 or greater tornado.
What was so challenging about this forecast? Well, morning convection had forecasters thinking it would be hard for the atmosphere to destabilize. What you need is intense sunshine to heat the ground which will allow the air to mix and become unstable. When it rains it makes it hard for that to happen, for many reasons. However, the clouds moved out and the temperatures began to rebound. The atmosphere mixed out all that stable air and began building energy (CAPE) for if a storm was to develop it had something to feed off of. CAPE is basically a measurement of instability in the atmosphere. Now besides having warm temperatures, a very humid environment, some substantial wind shear, and now energy, we didn't have any frontal systems moving through to provide the lift to get storms going. So what are some other ways of lift? Again, we can get lift by drylines, orographic features, or just reaching something called convective temperature, in which then the parcel of air will rise freely. Well, we had none of those either. But, what went unseen was an MCV (Meso-Convective Vortex) over Illinois spinning on visible satellite imagery that formed storms that died off overnight. This MCV enhanced wind shear and provided the lift needed for storms to form, thus giving us a tornado event across IN and OH.
On this day, I managed to track 4-5 confirmed tornadoes, one of which was on the ground for a little over an hour and produced a track a little over 17 miles long. It wasn't until later that day we got caught up in one of the storms where the tornado dropped on the road in front of us and went over our vehicle.
Videos are NOT FOR BROADCAST