April 13, 1999 - Storm Chase

Team:  Rob Ferguson and Putnam Reiter
Target Area:  Southwest Oklahoma
Departure Time:  14:00
Return Time:  22:15
Miles Driven:  300

Took off for Lawton around 14:00.  Stayed in Lawton until about 17:00 and then headed towards Hobart.  Dryline was located in far western Texas at this time and the only hope of activity was periodic storms moving out of the panhandle.  The majority of activity was near Amarillo and Lubbock.  In fact a storm moved just north of Amarillo with a beautiful hookecho signature.

Once at Hobart, measured 9mph southeast flow.  Was  somewhat discouraged, but decided to continue.  Got radar data on a storm moving into the area, so headed west to Mangum.  Reached Mangum shortly after 19:00 to see a marginally severe storm.  KFOR reported a wall cloud and 80mph winds with the storm.  This appears to be the last severe weather report regarding this particular storm.  We noted a weakening trend shortly after receiving the above report.

Sat north of Mangum for 30 minutes watching the storm cycle.  Saw three wall cloud cycles and then collapse of the updraft.  Measured only 15mph gust inflow.  Had to drive with my wind sensor out the window to get it above 30mph.  Storm had some nice cloud features, but nothing to write home about.  Left this storm around 19:30 and headed home.

Observations:

Engaged Storm:  Yes, 
1) just north of Mangum, Oklahoma.  Storm moved east-northeast from Memphis, Texas, in Hall County to our area in Greer County.
Hail (larger than 0.75 inches):  No
Tornado:  No
Wall Cloud:  Yes
Wind above 58mph:  No

Lessons Learned:
Storms in Texas can disrupt surface and low level flow into Oklahoma.  Believe that killed our storm, since there was copious activity in western Texas at the time.  Additionally, cap strength appeared to be weak allowing cluster development along and just east of the dryline.  Must be careful of early morning activity.  This apparently cooled the atmosphere and solid cloud cover resulted in weak thermodynamics.  Surface features were real complex.

Credits:
Thanks to Brad Stanley and Andy Wallace for data support.

Pictures:
Picture of updraft region of Greer County storm.  Photo taken around 19:05, about 8 miles north of Mangum.  We are looking just north of west.  This photo also shows a "beaver's tail," which extended northeast from the updraft area.