Archive for May, 2009

Posted on: May 18th, 2009 by Jonathan Merage No Comments

Finally got a chance to get the mesonet rack mounted! After considerable difficulty in finding the Yakima rail clamps & getting everyone on the same schedule (mounting this thing alone would’ve been impossible), we got her done!

We already drove through a tremendous rain & wind storm that barreled through OKC the next day and the system held up perfectly. Initially, I was concerned that any rain or moisture might leak between the clamps’ rubber grip & roof rail causing the whole thing to slip, but that wasn’t the case at all. Next step: get all wires connected & a gel-based car battery to power the rig (or power it thru the car’s battery), then get the software installed that will analye the raw data and display it in real-time on my laptop screen.

The system was designed to instantly measure & display local atmospheric variables such as temperature, moisture & humidity, air pressure, and precise wind speed & direction. All readings are updated continuously on a computer screen.

Setting up the mesonet bracket

Duct taping some sharp corners

Yeahh!! All mounted up (:-D)

Almost Ready to go!!

Posted on: May 15th, 2009 by Jonathan Merage No Comments

Went on an incredible storm chase in north-central Oklahoma, starting the day in Enid with low tornado potential overall. Tracked a couple storms that erupted over west-central part of the state & quickly became awesome lightning producers but very high-based with almost nil tornado potential. After enjoying those, we headed north/east to Enid then to I-35 hoping to intercept a couple of tornado warned supercells, only one actually produced before we caught up to it, so we shot south on I-35 to Guthrie (just north of OKC) & intercepted an INCREDIBLE massive lightning storm with some rotation but mostly powerful positive CG lightning with cannon-fire thunder!
The lightning gradually became constant around/after sunset & we were treated to one of the most powerful and highly visible lightning super-storms we had witnessed in a long time.
Photos are minimally post-processed to enhance visibility & contrast. ENJOY!

Positive CG strike beneath rotating storm at Guthrie, OK

Gorgeous Curling Lightning

Just east of Edmond, OK

Powerful double strike not far away

TRIPLE Cloud-Ground Strikes!!!

Posted on: May 11th, 2009 by Jonathan Merage No Comments

Notwithstanding a highly conditional chase day tomorrow (parameters look fantastic, but a strong CAP might prevent anything from happening), Wednesday starting to look interesting.
As of this point, I won’t be posting any details on locations or target areas until up to several days after the fact, but will continue to post pictures and even short video clips from any successful chases, time permitting of course.

Today is a down day (i.e. no storm chasing). The crews are working on installing specialized software that will collect all data from each of the mesonet vehicles & display it in real time on the FC’s (Field Coordinator’s) computer screen. The name of the game for this project is keeping as many facets of the operation (especially redundant tasks) running as smoothly & automated as possible. The technology behind this is really amazing! Anyway, here’s another cool tornado picture from my collection (click for larger image)…

More info soon…

VORTEX2 Media Day, TX/OK Red River Gentleman’s Chase

Posted on: May 9th, 2009 by Jonathan Merage No Comments

The Naval Post-Graduate School’s CIRPAS Radar
(NASA funded, used to coordinate Unmanned Autonomous Systems
i.e. self-guided aerial vehicles, in adverse weather)

Yesterday presented us with an awesome local chase after the fun & informative media day at the National Weather Center, with storms forecast to go up within the extreme instability/moisture axis across south-central OK by mid-late afternoon. For once, the forecast models verified with HUGE supercells forming shortly BEFORE sunset with tops shooting up to 70,000 feet within an environment characterized by 5,500 CAPE!! Many pictures to sort thru, so here’s a few of the best:

Howie Bluestein’s UMASS Close-Range Tornado Radar

CSWR (Center for Severe Weather Research) Support Vehicles

NSSL mesonet minivans fully equipped & ready to go

Cloud-ground lightning just north of Thakerville, OK (far south-central OK).
It was around 11:15pm & the lightning became constant, with flashes to our north & east.

Norman Trip

Posted on: May 7th, 2009 by Jonathan Merage No Comments

Staying in Norman, OK over the past week into this weekend. Gearing up for VORTEX2 & a potent local storm chase tomorrow. Oklahoma City NWS mentioning giant hail & tornadoes–not at all surprising considering the progged 7500 SBCAPE into tomorrow afternoon/evening with SBCIN almost completely eroded. Dewpoints pooling to upper-70s over a wide swath from DFW-Wichita Falls-southern OK.

Only concern is the almost total lack of helicity & rapid movement of the cold front (outflow dominant storms?). Mesoscale (storm-scale) interactions in such a strongly mixed atmosphere might be the only real hope for severe wx.