5/24/11 Chase

Very disappointing chase!  Left Fort Worth around 12:30 and headed north to Gainesville.  Noticed that a large cu field was already developing (earlier than thought) in SW OK by 19Z and figured that we better head W on 82 towards the SPS area.  We came up to US81 and headed north towards Waurika.  Waited there for a while while storms were firing north along I-40 in WC OK.  We stayed put hoping that other storms to the south would fire and move in our direction.  In retrospect, we should have headed N and positioned for storms as 2 tornadic supercells were dropping large tornadoes north of us.  We eventually hopped on the storm that eventually produced the Dibble tornado.  We played catch-up the entire time.  Partly my fault for waiting to long to intercept and aided by the 50mph NE storm motions, we never were able to see the tornado.  I also made a terrible decision in Lindsay to head west for a mile and then north to view the tornado.  The storm was moving so fast that we fell behind it and then had to move north to Dibble and then east.  We passed two damage paths.  From what I saw, damage was at least EF3 and the path was probably 1/4 mile or wider.  It was the most intense damage that I have ever witnessed before.  I will never forget the smell of the fresh pine from all the snapped trees and the completely destroyed homes with families all huddled together in shock.  I will upload some images when I get a chance. 

We made it to Purcell and decided to head south to intercept a storm headed for Pauls Valley.  Never made it in time but saw a mid-level funnel from the weakened storm along I-35.  More storms were to the south, so we continued heading south into Ardmore and followed another tornadic storm through town.  After playing around in the rain curtains of the RFD for about 15 minutes, we headed back to 35 and decided to just head for home.  For the remainder of the drive, we had to witness several supercells just to the east of 35.  It was excruciating to see these rock-hard updrafts and know that we werent able to intercept because we were too late.  Brought back memories of 4/14/11. 

When we made it into the DFW area, we noticed an incredibly structured supercell directly to our south in the Benbrook area.  It had an incredible back-sheared anvil and continuous lightning illuminating the updraft.  It was about 9pm, but we decided to intercept.  We headed around the east loop of 820 and intercepted the storm near the intersection of I-20.  Followed it east and witnessed a large wall cloud and funnel but the RFD eventually wrapped around the meso and we were forced to stop the chase.  We made it home around 11:30.

So, to sum it up.  An 11 hour chase with several intercepts of tornado-warned cells and 0 tornadoes.  It was an epic fail in that regard.  However, I learned a lot about chasing on these "major outbreak" days.  Position well to the NE and get on the first storms that fire if you can.  If you play it right, you can drop off and get the next NE moving storm coming your way.  It lloks like several veteran chasers did that and I definitely won't make that mistake again.  Also, I need to make sure that I don't become so radar-dependant.  I found myself treating the updated radar images as they were in real time with respect to the storm.  This put us out of position near Lindsay as I went against my gut and headed west instead of east.  If I would have just went with my original plan, we would have had one hell of an intercept of the Dibble-Washington-Goldsby long track strong tornado from close range! 

As Marc put it well........"Shoulda gone east!"

Oh well.  There will be more tornadoes to chase soon :)

Here are the reports from today:

5/21/11 Reading tornado

Looks like a tornado caused damage in Reading, KS.  The tornadic supercell had a strong velocity couplet and a noted BWER directly over the city.  Here are a couple screengrabs from GR3:

I'm sure that some damage photos will pop up tomorrow.  Interesting to see how strong this tornado was.

5/21/11 Storms

Looks like today will be another active severe weather day for parts of North Texas.  Right now, storms have fired off of a well delineated N-S dryline. 

LUD is 84/70 while RPH is 95/28!

The right entrance region of a 50kt H5 jet streak is over the area and is helping parcels lift to their LFC's.  MLLCL's are 3500+ J/kg and 0-1 SRH values will increase as the afternoon wears on.  Could see a tornado report from one of these storms as the night continues.

Looks like the first tornado warning of the day just issued for storm near Evant!

5/19/11

Well, convection has fired in SW OK along the dryline.  Here is the screengrab from GR3 at 19Z:

Unfortunately I won't be able to make it up there tonight due to work but I'm hoping to catch some tubes on the streams. 

Models did well with dryline placement; not too well with convection though.  I think the HRRR showed precip firing a little earlier than this closer to the SPS area.  The storms are all rotating and are moving NE into a good environment.  The dews are in the middle 60's with even 70 dews creeping up from SC OK.  Backed sfc flow of 20+ kts and MLCAPE values of over 2500 J/kg, also LCL's below 1200 m all look enticing.  0-1 km shear is pretty weak (10-15 kt) but the environment to the NE of these does get better and the SPC's mesoanalysis shows 0-1 SRH values of 150 in WC and NW OK.  The northern-most storm may be the good play at this point if these all stay discrete over time.

We will see.

Need to refocus

Haven't posted in a while.  Been extremely busy with school stuff and field trips and along with an active April season, i haven't posted chase reports nor posted anything else.  So, with potential chase days this week, I better get refocused and get back into the forecast mindset!  I will have the opportunity to chase both on the 19th and 20th. 

It's 3Z, Wednesday the 18th and here's the synoptic breakdown:



Strong H5 trough along west coast.  Will slowly make way towards plains over next couple days.

For Thursday the 19th.  Here are the model differences as of 18Z models.

By 18Z, the 19th, the GFS is a bit deeper with H5 low and places 70kt jet streak along W TX and OK panhandles.  The GFS is also showing a bit more meridional component to the flow and is a bit east of the NAM jet streak placement.

With the deeper H5 low solution of the GFS, a deeper H85 low is also shown.  Flow is near 20kt wwith a strong southerly component (S or SSW).  The GFS continues to deepen H85 low and thus strengthens flow to around 30-35kt. NAM is warmer with temps and also mixes these down to surface.

NAM places broad 997mb sfc low in SE CO.  A warm front extends east through SW KS and looks to not move through 0Z.  Temp gradient is strong with 60's to north and 80's to south of front.  GFS has stronger 994mb low in E CO with WF in N KS.  Also looks like GFS places meso low in SW KS by 0Z.

Dryline placement similar and placed from Hutchinson down through Wichita Falls with mid 60 dews east of line.  Backed sfc flow looks enticing on both models.  Temps in warm sector in the mid 70's on GFS and mid 80's on NAM.  If GFS is to be believed, then LCL's look good < 1000m.

Will analyze models tomorrow, but the GFS solution looks good but it has tended stronger all season long only to putter out the day before.  I believe it has showed run to run consistency though this time.  The 700-500mb lapse rates are not strong at all and I wonder what is causing this.  Other than that, I wouldn't be surprised to see a good chance for a couple tornadoes in SW OK near the LAW area and to the north.  Better shear exists north along the dryline, but I want to stay south due to work restrictions and better moisture and cape profiles.