Well, I wasn’t plussed yesterday afternoon when I checked the Storm Prediction Center (SPC), and they spoke of today as a wind and hail threat. I prepped the vehicle (set up all radios), cooked food for several days, did a ton of laundry and packed bags, then loaded everything in the car, knowing full well that I could wake up this morning and call the thing off.
The SPC has kept an Enhanced Risk in place today for parts of the northern Great Plains.
Associated with this Enhanced Risk is a 10% Tornado Threat Ring.
The chase is on!
It is too early for soundings, and all I have is the 0Z NAM run from last night. At the 300 mb level, there is a trough developing over the western states with a speed max pushing its way into the northern Great Plains by 0Z Thursday (tonight).
At the 500 mb level, there is a small pocket of vorticity over central Colorado that is advecting northeast. This Positive Vorticity Advection (PVA) will amplify storm potential over northeastern Colorado by this afternoon.
At the 700 mb level, there is strongly rising air over the Kansas and Nebraska border. However, there may be too much in this region, with little capping inversion, as the SPC is calling for a large Mesoscale Convective System (MCS) in this region, rather than discrete supercells.
The forecasted surface plot for 0Z Thursday shows surface winds from the south and southeast, versus winds from the southwest for other layers. Perhaps the shear is better than the SPC thought it would be yesterday, and that is the reason for the 10% ring.
According to the 18Z RAP model, the deep-layer shear will be enough to support rotating storms, exceeding 40 kts in a corridor along and just north of I-76.
Such is the life of a storm chaser. April through June are spent in a state of not knowing where you will be in a few days, and putting “normal” life on hold during this season. Every appointment that must be made in May, you cringe and reluctantly put on the calendar, knowing that particular day could be the massive tornado outbreak of the year, and that you’ll miss it because of a dishwasher installation or a dentist appointment.
I am excited to return to the northern Great Plains. I have done a lot of chasing in Texas and Oklahoma over the past few years. I think the 2013 chase put us in southwestern Nebraska for an evening, and before that, it was 2011.
Right now, I am targeting somewhere in Northeastern Colorado or southwestern Wyoming. I don’t know yet exactly, and it is too early to tell. I won’t have to make a decision on that until the I-76/I-25 interchange.
Most people don’t understand storm chasing; they think that you wait for a tornado to be on the ground, and then drive to it. That will almost never work. The way to catch a tornado is to make a forecast, drive there, and arrive under sunny skies. After I’ve been at the threat area for a little while, the SPC will issue a Tornado Watch, meaning favorable conditions could develop into tornadic storms. Then, after a while longer, a few cumulus clouds turn into cumulonimbus clouds, and then perhaps into supercells. Those supercells have around a 5% chance of producing a tornado.
So here we are at sunrise, scrambling to get a cooler packed, showered, and breakfast eaten (while I type on a blog), so that we can drive 700 miles for storms that may develop, and if the storms develop, for the 5% chance that a tornado will form. It’s a huge gamble, but it’s what I live for.
Stay tuned, as I will update this as often as I can.
Thank you for reading my prediction.
The Severe Weather Outlook is from the Storm Prediction Center website.
The satellite imagery is from the NOAA Satellite and Information Service.
The surface observation and upper level charts are from Unisys Weather.