Sunday, April 15, 2012

High risk in Oklahoma, 4/14/12



"Do you know how the clouds hang poised, those wonders of him who has perfect knowledge?" (Job 37:16)  This video frame from just outside Cherokee, OK, pretty well describes northern Oklahoma on Saturday.  It was by far the most successful chase anyone in our group has had--thanks to Tim and Branden for driving.

   With all the day 2 high risk hype for Saturday, Friday was overlooked as a tornado day.  I left work about 2:30 as the Norman supercell took form out across I-44 near Chickasha, since I was planning to leave for a church retreat in Madill at 4:15.  I called our campus minister at the Westside church of Christ as the hook echo became well-defined and learned he had already decided to delay leaving Norman.  In disbelief that this large right-turning supercell with a velocity couplet was not tornado-warned, I went to Hwy 9 on the west side of I-35, to spot as much as to chase.  A foray right up to the precip core, followed by a speedy retreat eastward, brought me to the Sonic across the highway from Riverwind Casino.  I watched curtains of rain wrap from south to north into the circulation, increasing in speed, and realized a tornado was spinning up less than a mile in front of me.  I ran back to the car and the college-age guy in the spot next to me casually asked, "Are there gonna be any tornadoes today?"  "I think that's one RIGHT OVER THERE," I said and drove off, calling NWS Norman as I dropped south on I-35 to avoid the outer edges of the rain-wrapped tornado.  Just as I got out my description of the forming tornado, I got the "call failed" tone, and that was the last phone call I got through to anybody for a half hour or more.  It's unclear whether my report was what earned Norman a tornado warning, but I like to think it had a part.  My video from Sonic is so shaky and dark that it isn't worth posting, but that wasn't my main concern at the time.

   I turned around and headed back north to Norman once it was clear the danger had passed, and saw damage up 24th from Hwy 9.  Taking 9 eastward out into rural parts of Cleveland County, I watched various areas of rotation and ascent at the back of the storm, catching a brief funnel on the far eastern outskirts of Norman.  Little Axe was a convenient and necessary stop for a couple gallons of gas before closing on the storm near Pink.  I met up with three friends and fellow chasers/met students in another car and we chased together from there, drawing extremely close to two areas of rapid rotation on Lake Road west of Shawnee.  We followed the storm west to Shawnee and saw a brief tornado several miles to our north, so far away and short-lived that nobody has a good photo of it.  It was about that time I finally got through to our campus minister, who told me the Norman tornado had struck the church building with a group of people inside waiting to leave for the retreat.  Thankfully, everyone there was uninjured, but the building's roof was peeled off in places and trees outside were uprooted or broken.  The decision had been made not to hold the retreat due to the damage and the expectation of more storms.  First and above all, I was relieved that my friends there were kept safe.  We were all a little disappointed that the weekend was canceled, but it was a small matter in comparison.  Pretty quickly after that, though, I started thinking about Saturday.  It had never occurred to me that I wouldn't be in Madill during the weekend outbreak, but now I was going to be chasing my first high risk day.  How often is road tripping to the atmospheric display of the year your backup plan?

   On to the exciting part with pictures.  Saturday was a circus in northern Oklahoma, and it was typical of the day that our little caravan comprised two cars with five people in each.  Our jumping-off point was Fairview, OK, a small town that we later realized was not all that small compared to others in the region.  It was my first trip to northwestern Oklahoma and the area is just as remote as it appears.  Cell service is spotty at best, and data is available maybe a third of the time.  There was a Sonic in Fairview where our group spent an hour or so watching storms blow up on radar, unwilling to run to the dryline if there was a chance of anything initiating ahead of it and becoming dominant.  Finally, we headed through Seiling to Woodward on the first tornado-warned storm that came close to Woodward.  Chaser traffic became evident in Woodward and was present for the rest of the day.  The car I was in, with Tim driving, got north of Woodward on OK-34 and turned east onto back roads to cut over to OK-50.  Back roads turned to dirt, and dirt turned to sand, but Tim managed to keep the car both on the road and on pace with the storm.

   OK-50 took us north to the Cimarron River at Freedom, OK.  Coming across the river and into town, a long, skinny funnel may have touched down briefly north of town.  This storm remained tornado-warned as we turned east on US-64 toward Alva to follow it.  We saw several rotating wall clouds and lowerings on the road to Alva, stopping to watch twice, but the storm was moving off to our north and was not producing at the time.  Confident that we could catch another tornadic storm by staying south, we let the first storm go and dropped from Alva southwest to the outskirts of Waynoka on US-281.  A Woodward radio station was giving the play-by-play account of the new tornado-warned supercell approaching Waynoka, and we watched from a hill east of town as it tried and failed to drop a tornado.  There may have been a rain-wrapped twister in there somewhere, but at that distance we couldn't say.



   Our mistake came here.  None of us could get radar on our cell phones (we're just college students, no satellite connections or anything) so we were unaware of the strengthening supercell catching up to that one from the southwest.  To stay with that storm, we rushed into Waynoka--where there was a rattlesnake festival going on and thousands of people had had to take shelter in town--and north from there on OK-14. We went through heavy precip, but managed to avoid hail.  On 14 we found cell service somehow, and realized the southern supercell was the only reasonable choice.  Turning east on 64 toward Alva once again, we drove through more intense rain and gusty winds as the northern storm sucked in precip-laden outflow from the strengthening southern one.  Tornadoes were being confirmed on our new target as we made a quick gas stop in Alva, then headed east on US-64 and south on 8 to intercept at Cherokee.

   Driving through Cherokee was a surreal experience.  We were seriously concerned that this town full of mobile homes and other tiny houses could take a direct hit.  The sky was orange in the west as we rolled through the heart of the town, Addison hanging out the window of the lead car yelling at residents to take cover.  Most continued to gawk on the sidewalk, even those in front of a trailer park.  Tornado sirens sounded just before we made it out of town and into the chaser convergence just to the south.

  We pulled off the wide shoulder of OK-8 there, at the end of a long, long line of chase vehicles.  A well-defined lowering, clearly rotating, came into view over an open field to our west just as we climbed out of the car and set up.  The show began immediately, as a funnel emerged, flirted with the ground for a few seconds, then touched down definitively.




   The first tornado dissipated, although it's entirely possible a circulation remained on the ground until the next touchdown moments later.  This new tornado quickly took on a mature stovepipe shape.




   As if this spectacular tornado wasn't thrilling enough to the chasers lining the roadway, a second funnel dropped, pencil-thin at first.  Twins!  It intensified as the first one began to fade and slowly rope out.  The latest tornado appeared to pose a threat to Cherokee, and chasers waited to see whether help would be needed in town.  Thankfully, the tornado passed northwest of most of the town, knocking out power and reportedly destroying a barn (we saw something lofted, probably the barn roof) but doing little else.








  By the time we headed back north through town, we had seen the entire life cycles of three tornadoes from one location.  This storm went on to produce several large, likely violent tornadoes after dark on its way to southern sections of Wichita, where significant damage was reported.  We left the storm at the intersection of OK-8 and US-64 north of Cherokee and headed home for the night.  About the time we returned to Norman, a tornado slammed parts of Woodward, killing at least 5 and changing the face of the outbreak.  Sirens reportedly did not sound, maybe due to the storm itself.  The daytime chase was exhilarating but for the second straight April 14th, the event will be remembered for a tragedy in a small Oklahoma town.  Thoughts and prayers are with Woodward residents today.

Friday, February 24, 2012

February appetizers for spring

   Although there's been no sign of anything like the blizzard that ushered in February 2011, this month has been eventful enough to tease chasers all over Oklahoma with the prospect of an active spring.  A poor chase day on the 3rd led me all the way to Fort Worth--we didn't chase that far, but we were close enough that I was told I had to try In-N-Out for the first time.  Totally worth it.  Thanks to Branden for driving and Sydney for introducing me to animal-style fries.  As far as the storms, we closed in on what looked like it would be a discrete, long-lived supercell in far N TX just as it began lining out like all the other storms in this low-CAPE environment.  Here's some of what we saw:

Supercell from north of Bowie, TX:


Other side of the storm:


Outflow boundary on the west side of Bowie:


Linear storms approaching Bowie:


Updraft trying to strengthen along the squall line, near Chico, TX:



   That about does it for that day.  On the night of the 12th into the morning of the 13th, Norman picked up about 2" of snow.  The lack of moisture near the surface prevented higher snowfall totals but also allowed the surface to cool enough, via the wet-bulb effect, for snow to accumulate.  Though all the snow was gone within 24 hours, roads were dangerous overnight.  A couple shots from OU:



  On the 20th, central OK through S KS was impacted by a round of marginally severe thunderstorms associated with a low up in KS.  Cold-core action around Wichita was limited, but a nice cell managed to get going from OKC to points just northeast.  We caught it as it passed over the city, produced a downburst (Mesonet in W OKC recorded 69 mph gust), and began looking like a solid supercell as it lost us in city traffic.  Tim, who was driving, managed to keep it in view until the far eastern suburbs.

Rainbow over Devon Tower:


Downburst over downtown:


Wall cloud (?) high over OKC.  This should give you an idea of what it's like chasing in a metro area.



  Sadly, one woman was killed in Ada when straight-line winds destroyed a mobile home on this day.

Monday, January 30, 2012

Another offseason storm day (2/3/12) in S OK?

   I'm pretty excited to be writing this discussion right now.  Whether the current forecast verifies or not, it's good to have a potential severe weather day on the horizon at the beginning of February.  Friday is going to be another one of those touch-and-go offseason days like November 7th.  The last 3 GFS runs suggest a surface low forming Thursday into Thursday night up around NW OK into the Panhandle region.  The 00z NAM tonight is hinting at the same thing, though daytime Friday remains out of its range.  If that low can form and deepen a little, it's a classic severe weather setup.  Model guidance suggests modest CAPE, sufficient shear, and plenty of helicity.  Moisture advection will have to occur rapidly as the low develops, but it appears 60F dew points have a good chance to cross the Red River.  NAM is a little more promising with moisture.  An upper-level trough, which the GFS tries to turn into a cutoff low through the day, will provide lift.  The SPC has noted the possibility already in its day 4-8 outlook.  That's really all I have to say about it right now--at four days out, numerical prediction is about all there is to go on when it comes to relatively localized severe weather events.  But just for fun, my target for Friday:  Ardmore, OK.  (I wish I had an obscure little wide-spot-in-the-road town to make me cool, but Ardmore's really where I would head if things didn't change.)

EDIT:  00z GFS obscures things a little, moving the surface low SE slightly, toward Euro solution which would mean no chase.  Just based on current guidance, I wouldn't go, but the setup will change a dozen times between now and then.

EDIT:  It's Wednesday morning now, and the 06z NAM is insisting the low will be farther east in SE KS, too far to go after such a mediocre setup.  NAM has been indicating a cold-core setup in S KS for several runs, with parameters sufficient for such an event.  The SREF this morning is beautiful for N OK cold-core or warm-front stuff, placing the surface low far WSW of Wichita, out closer to Liberal.  While this would be a huge stroke of luck, meaning we could start with Enid as a target and go from there, I'm only hoping for a compromise between the NAM, GFS, and SREF, putting a chance for cold-core storms around Wichita Friday afternoon.  SPC has gone Day 3 slight risk for a small area around the DFW metro, but shear is not as good down there and it appears one might have to take off eastward from there to actually chase--east Texas is both iffy terrain and a long way from Norman.  So it looks like cold-core or nothing for Friday.

EDIT:  Per 00z NAM and GFS, whole setup's gone to crap.  Going to do my p-math and intro homework and forget about chasing...

EDIT:  Chased it.  Everything lined out.  Was introduced to In-N-Out in Fort Worth so the whole thing was worthwhile.

Tuesday, January 10, 2012

11/7/11: Tornadic supercells in SW OK

  November 7--where do I even begin with this day?  I wasn't aware it was possible to be so pleased and so disappointed with a chase.  It was apparent from a couple days out that this Monday had potential.  In OU's student-run Oklahoma Weather Lab, I'd forecasted severe storms in the target area on my Saturday shift.  The only question was whether instability would be sufficient for any tornadoes within our range, given that we had morning classes.  Three of my friends, also OU SoM sophomores, formed our chase team for the day, and we headed southwest on I-44 just after one, bound for Lawton.  Coming up to the Chickasha exit, we made a unanimous mistake.  We could see supercells off to our west, though our target was still far to the southwest.  A photo posted to Facebook by Joel Taylor of Stormchasers fame confirmed a tornado in Elk City, farther north than we imagined a storm could produce.  With only this information, we took off on OK-9 toward Hobart.  After an eternity of small towns and their associated speed limits, we closed in on the first storm of the day, picking up an occasional radar scan via smartphone wherever service allowed.  We stayed with this storm just east of Hobart only a few minutes, watching its once-promising wall cloud grow less and less defined.  (I'm strangely inclined to call the inflow tail in the first photo "cute."  I don't know why.)



  On to the next one.  We dropped west and south on OK-9, skirting the precip core of our new target supercell--driving a Cobalt I'd like to keep through a good chunk of my adult life, I've begun to pride myself on avoiding even the possibility of severe hail.  The land here, just south of Hobart, was the flattest I had ever seen, except for mountains on the southwestern horizon.  This storm was fierce-looking, with a shelf cloud looming over its outflow and dominating the scene.  It dwarfed a short train that rolled past our location.  The mesocyclone was understated, nearly unnoticeable, until it tightened up and produced a wall cloud just up the road to our north-northwest.





  The precip wrapping around the meso was catching up, and we had to move.  In my obsession with avoiding hail, I made another mistake, this one all my own: I took off eastward into a network of dirt and gravel grid roads.  We got one last look at the updraft area and wall cloud before it lost us.


  Reaching OK-9 near Gotebo, we saw for the first time a radar image of the monster storm producing an EF-4 tornado in the Tipton-Snyder area.  Just from the hook echo, we knew we had to drop down and get on it.  We raced south toward the Wichita Mountains on OK-54, taking in a spectacular view of the back of the cyclic supercell about the time it was producing a tornado in the Wichitas.


  Turning eastward toward the storm's mesocyclone just north of the Wichitas, we saw we would have a difficult time getting any kind of position.  We could only make time going east, while the storm was moving northeastward.  Nevertheless, we slowly narrowed the gap.  The number of other chasers around increased steadily.  Stopping along a back road north of the mountains and south of the meso, we saw a rapidly rotating funnel, seemingly detached from the main area of rotation.  It momentarily looked as if it could touch down, but never did.


  Shortly thereafter, we caught a wide view of the massive flying-saucer-shaped mesocyclone and wall cloud.  It was in this area I managed to get the Cobalt mired on the shoulder.  Thankfully, with three people pushing and me nudging the accelerator, we dislodged it quickly and kept chasing.


  Though we pursued the storm as far as Binger through nightfall, the closest we came to any action for the rest of the day was south of Carnegie--a brief swirl of dust under a distant wall cloud.  Had we gone east on OK-9 from the second storm and simply waited for the storm of the day at Fort Cobb, we would have seen a tornado cross the road there, but such is the nature of chasing.  Even though we're paying our dues in terms of experience, it's undeniably exciting to see sights like this in the middle of November.  We keep getting better, and spring isn't all that far off.

10/11/11: CGs over Norman

  I needed something to make up for the disappointment of not having anything to chase over the summer, and I got it late on the night of October 11, 2011.  Seeing distant flickers out the window, I pulled up Weather Underground's lightning product and noticed quite a few CGs in some storms off to the west.  They were inexplicably holding together in a cool, uninspiring environment for thunderstorms.  I tried a couple worthless, overly lit roadside spots in northern Norman before parking in a neighborhood off Tecumseh Road and walking down to the sidewalk.  There I was treated to a rapid succession of CGs in the distance to the west, as well as a couple closer strikes just to the northeast.  I finally got something like a good lightning photo with the nearest stroke.




The highlights of summer 2011 in WV

  In the midst of the unparalleled 2011 tornado season, I returned from the heart of Tornado Alley to my home in West Virginia, one of the least tornado-prone places east of the Rockies.  I missed out on the Joplin storm and the May 24th Oklahoma outbreak by a couple weeks.  With some Plains experience, I felt prepared to run down anything resembling a supercell that might go up within a couple hours' drive.  Unfortunately, there were two problems.  First, that didn't happen all summer.  Second, I wasted a considerable amount of time searching for any kind of summer work, which I never found despite several employers' promises.  Still, I managed to see a lot of the sky shows the Mountain State served up, however mediocre they were.  I even got my girlfriend to venture out to a garden-variety thunderstorm to catch a little lightning!  Being with her, my family, and my friends at home after a year in Norman made this an unforgettable summer.  It was much less memorable meteorologically, but here are some of the highlights.

May 23:  The only CG I caught this night connected Milton, WV, with an unimpressive Cb.  Thanks to Heather for tolerating my obsession for a night :)


June 4:  It's always a good night when you can shoot anvil crawlers 50 feet up the street from your house.



June 21:  A modest squall line moved down I-64 into Scott Depot, WV; the most interesting feature was a shear funnel far in advance of the storms.  When the gust front hit (second shot), it was a bad day for trash cans up and down my street.



June 23:  Tornadic supercells in eastern Kentucky, one round early in the afternoon and another in the evening, fizzled but still brought severe winds well into West Virginia.  In order:  a panorama of Scott Depot before the evening storms; a shelf cloud begins swallowing the I-64 corridor; and an up-close view right up under the shelf in Nitro, WV.




July 11:  A weak squall line, the remnants of a derecho that struck the Chicago metro, was only a distraction from the real display--sunset mammatus like nothing I'd ever seen at home.