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Chase Week 2010 Update. It Needs a Name!

7:59 am in Storm Chase VToo.2, Storm Chasing by Ted Keller

 I realized this morning that this chase needs a name.  So playing off of our reference to last year’s MSU chase as Vortex Too, I think I’ll call this year’s VToo.2.  Catchy? Well, maybe not but it’s shorter to type!

The morning SPC forecasts are somewhat encouraging in that they back up my late night post with regard to the overall set up early next week.  Of course, forecasters and storm chasers always take any longer range forecast with a grain of salt.  Having said that, the usual due dilagence will apply as the situation unfolds over the next couple of days.

I will be giving Annette from Artbeats a meeting point later today for the Sunday chase.  Sunday isn’t the best chase day according to conventional wisdom but I think it will hold some surprises!  Besides, the day will also be spent getting logistics worked out for the days afterward.

I’ve added to my chasing arsenal this type around.  I bought a suction-cup camera mount from Filmtools to help with live streaming.  I’ll be using my old JVC SD camera for that purpose. Also, my grateful thanks to Bart Comstock for helping be aquire high speed internet access earlier this week.

I am trying out Corel VideoStudio Pro X3 for video editing in the field.  I have been a long-time user of Pinnicle Studio 12 but it is slow and cludgy when compared to VSPX3.  I’m hoping for good things from this software!

More updates later!

VToo.2. Outlook for Chase Week

11:16 pm in Storm Chase VToo.2, Storm Chasing by Ted Keller

The 18z and 00z  model runs have been consistent in setting up a quasi-stationary zonal flow pattern across the central Plains Sunday-Tuesday.

For Sunday, our best bet would likely be along the northwest nose of a tongue of higher moisture and instability coming from the southeast into Colorado.  The placement of the western end of a cool front will have to monitored carefully.  Surface winds will be backed and deep shear sufficient for storms.  One drawback will be a strong cap in some locations or one which will strengthen quickly after dark.  I still like Lamar, CO as a starting point.

Monday and Tuesday are quite interesting.  Experience has shown that this type of pattern where a strong, nearly zonal jet stream flow is just north of unstable air suggests that storms cells will initiate in a narrow zone between a strong cap and favorable shear during the late afternoon and early evening and then become nocturnal MCS’s traveling ESE overnight.

Wednesday and Thursday have been all over the board.  Some model runs have really amplified a ridge over the western plains.  The 00Z run of the GFS tonight is quite a bit more optimistic in digging the trough coming ashore out west more to the south.  This remains a mystery and of course the handling of troughs coming off of the Pacific into the western U.S. is always a crap shoot.  We, of course, remain hopeful!

Annette from Artbeats made it to Utah last night.  We will be giving her an update on the road on Saturday.

The final preparations for streaming through Severe Studios were made today.  I spent quite some time at Radio Shack on Friday buying adaptors to make my duel-band external antenna plug into my recently-acquired Sprint USB modem card.

More updates later on!

Severe Weather Monday

10:27 am in Forecast Discussion, Severe Storms, Storm Chase Discussion, Storm Chasing by Ted Keller

Severe Outlook for Monday

This has been holding together for a few days now in the computer model forecasts so confidence is running higher that an outbreak of storms will occur over the central Great Plains Monday.

There has been some fluctuation in the position of the dry line which defines the western edge of the threat area,  If it ends up over central portions of Oklahoma and Kansas, the Ozarks would see whatever supercell thunderstorms do develop move into the area later that evening.

One computer model  (NAM) from 12z Friday has pushed the dryline back westward after trending more east the past few runs.  The GFS model is sticking with an “I-35″ (or thereabout) solution which is more east.

Since the event is still 78-84 hours away, there will likely be more adjusting of the position east or west.

The differences are arising because the speed and position of the shortwave trough are radically different between the NAM and GFS computer model!  I posted the images below.  This will make a HUGE difference in where the threat area ends up!  This position will shore up as soon as we get closer to Monday and the shortwave “comes ashore” to be sampled better by upper air measurements.

My friends Matt Gingery and Jill Gilardi will be out chasing on a special project starting Monday.  What a way to kick things off!  I wish them luck and safe travels!

I will be doing a special “Upstream” broadcast on Sunday evening, most likely after the 00z NAM comes out which will be after 9 pm sometime.  I’ll keep you posted!

NAM 500 mb 7pm MondayGFS 500mb at 7pm Monday

Storm Chase Results from May 1st

10:05 am in Storm Chasing, Storm Summaries by Ted Keller

A high risk for severe thunderstorms and long-tracked tornadoes existed for much of central and eastern Arkansas the afternoon of May 1st, 2010.  I went down there to chase this event.  When storms started firing, there were lots of them, most ended up tornado-warned.  Folks were anticipating the worst.  But in the end, very few tornadoes were produced.

Here’s my account of the chase and a bit about why so few tornadoes occurred on this day despite much anticipation.

We drove down via Willow Springs, MO to see the damage caused by an EF1 tornado Friday evening.  The Hillbilly Junction sustained roof damage as did an antique store just up a hill and to the east.  This was the last of five tornadoes produced by a supercell which started in Boone County, Arkansas.

We were a caravan of three with Dustin Elkins and Bo Hessee also driving.  We eventually wove our way down to White Hall which is just north of Pine Bluff.  Here, other chaser friends of ours had gathered including Dena Sanders and Brian DePriest.  The Tornado Intercept Vehicle (TIV) was there as were other chasers.

Boundary Moving Slowing North This Day

Of much interest early on was the very obvious boundary visible on radar stretching WSW/ENE south of Little Rock.  It was thought that this boundary would be able to supply more focused and localized storm relative helicity to storms forming along it.  Indeed several storms west of Little Rock did appear to have an increase in rotation while crossing this boundary.  But the storm motion was taking them across and not along this feature.  If a storm could have traveled along it, it might have produced the longer-track type of tornado which was feared on this day.

Storms became very numerous in southern Arkansas by the 6 o’clock hour.  In fact, too numerous really.  It became difficult to know which storm to chase!  We initially decided to get northeast of the Arkansas River toward the flat rice lands in and around Stutgartt.  But as supercells became tornado-warned in southern Arkansas, we decided to change the plan, back track a bit and try to get one of the southern storms.  While on the way, storms started firing north and south of Pine Bluff which eventually became tornado-warned.  The decision of the day was to not chase these storms and instead press on to the most southeast of all of the supercells which was going to cross highway 65 near Gould, AR.  The reasons we didn’t pursue the Pine Bluff storms were 1) we would have to travel back through the city of Pine Bluff, 2) the river crossing were limited and 3) there was too much rain, drizzle and just plain bad visibility east of these storms.

Radar Image w/Mesocyclone Indicator at 7:46 pm

So, on down highway 65 we traveled.  We were racing against dark really.  We got into position ahead of the well defined cell which had a great hook echo.  One more adjustment southeast to Gould was required due to the slight right turn the storm (and many supercells) started to take.

We saw some great formations and a likely wall cloud but as the storm passed just to our west, no tornado ever formed.  Reed Timmer and the Dominator crew was coming though Gould and we followed them briefly north chasing the same storm but eventually the chase was abandoned.

I’m waiting on the archived SPC data for this day to appear but I suspect that the reason more tornadoes were not generated on this day were due to low values of low level rotation and generally weaker than needed low level winds.

I am compiled a video log of the chase which should be finished by Thursday.

Major Outbreak Again!

8:19 am in Forecast Discussion, Severe Storms, Storm Chase Discussion by Ted Keller

High Risk Today!

The southeastern U.S. has taken a beating with the storms last Saturday and last night.  Now, another high risk has been posted for the area pictured. 

There is a tremendous amount of moisture as measured by the dew points (colored areas) on the inserted map.  This is poised and ready in the high risk area.  What will likely happen is an increase in south to southeasterly wind flow near the surface later this afternoon and evening.  Another jet stream “max” is coming up out of Texas which will help with the development of a low pressure area over the western portion of the threat area. The winds should respond to this feature.

The computer models have been showing this for a few days but with slightly different results.  The GFS has always been more aggressive with the low development.  The morning run of the NAM has come around on the winds a bit more.  This model is also forecasting 0-3km SRH of 150-300 at 21z (4pm), jumping to 300-350 by 7 pm with these values then expanding over all of eastern Arkansas by after dark.  CAPE is progged at over 2000.

The ongoing cells are likely to been producing severe weather by just after noon in some areas.  This is not the main show!  This is expected by early evening over the high risk area.

I will be out with the Mobile Weather Lab today.  I’ll cross my fingers on live streaming on Severe Studios.

Ozark/Howell County Tornadoes, April 30, 2010

7:33 am in Storm Summaries by Ted Keller

The National Weather Service has completed its survey of the supercell thunderstorm which tracked over Ozark and Howell Counties Friday night and has determined that five separate touchdowns occurred with four of the twisters rated EF1 and one an EF0.  The complete report can be found here.

Rotation tightens over Bull Shoals Lake

The rotation was first detected in Boone county, Arkansas near Harrison.  The rotation really tightened up on radar while crossing Bull Shoals Lake while traveling northeast into Ozark county.  There are damage reports from near Pontiac and east of Gainesville.  The circulation passed north of Tecumseh.

Additional damage was produced in Dora and possibily near Siloam Springs.  The tornado then continued northeast and produced damage near Hillbilly Junction south of Willow Springs.

Tornado Approaching Willow Springs, MO. Photo by Jason Blum (still from video)

Storm chaser Jason Blum caught what is likely the tornado looking northwest from his position a few miles south of Willow Springs on Highway 63.

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