So we picked an ultra tough day to forecast out of the gate: guilty as charged.

But to start the chase case challenge off we went exceptionally difficult with a day that would confuse us even today with real-time data. It was a true needle in the haystack type of day: May 16, 2002. Some of you guys and gals were close in your thinking, but just couldn’t quite pick a far enough west target.

First off, the two tornado reports in Kansas are not included in this event as they occurred before the main afternoon convection. For the most part most people were having issues with the dryline location and automatically assumed it was along the Oklahoma/Texas border it appears — which wasn’t the case. With such a huge gap in the old surface obs sites in the eastern Texas panhandle, it was certainly a challenge to pin down the location of the dryline and front for afternoon, but you can use the winds behind the front to judge how strong of a push southward it is getting.

Another thing you might have noticed were the very warm 700mb temperatures across Oklahoma. This was leading to a strong cap which prevented thunderstorms through most of the day while to the Northeast along the front in Missouri, ongoing storms in the morning radar image promised trouble for that target through the day. A secondary option was the outflow boundary in Northeast Oklahoma, but the capping was strong enough to suppress thunderstorm development. When looking at upper-air charts, you can certainly tell a lot without the need of a skew-t — and when combined with surface charts in the morning you can anticipate a few things.

Weather forecasting isn’t easy after all.

Where the magic happened was along and behind the front initially, in a moist upslope environment. There was a shortwave trough visible on upper charts in the morning on the 500mb chart, notice the dip in the isobars back towards the Great Basin. The approach of shortwaves typically leads to winds backing, so winds that were northeast actually became east and southeast, leading to solid upslope flow and thunderstorm development in conjunction with lift from the shortwave. This enhanced area of shear created an environment favorable for supercells along the front in the Texas Panhandle.

After dark, storms fired all along the front and a large marginally severe MCS tracked through the region.

 

The Winners

No one ‘hit’ on this forecast. So we can’t declare an outright winner. Jeremy Degenhart was probably the closest with his start in SW Oklahoma, perhaps he would’ve made it to the Panhandles in time with the help of his trusty weather radio and perhaps a phone call to some friends from a payphone in the old days!

Next Challenge

We will be providing a bit more detail in the next challenge, but not enough to give away too much. You’ve become a more resourceful chaser and will have some limited access to NOAA products — Be sure to stay tuned for it!