JUNE 12, 1997

SHAMROCK, TEXAS CHASE
Tim Marshall, Chuck Brazell

12:59 250 FLOWER MOUND - Leaving NW towards Wichita Falls. There is an outflow boundary along the Red River left over from last nights convection. Also, there is a dryline in the Texas panhandle. There are two areas I like for convection today. One is the moist axis intersecting the outflow boundary near Wichita Falls. The other is the outflow boundary/dryline intersection near Shamrock. SPC has issued a Moderate Risk for Oklahoma today. Rt 287 NW.

1:58 300 DECATUR - Rt. 287 NW

2:59 370 WICHITA FALLS- Western edge of strato-cu. Everything seems to be pretty capped right now. Ate lunch and headed up to Rt. 70 just across OK border.

4:07 394 Rt. 70 W. Stopped for a weather channel update. Dryline is still pretty far back in west Texas. Short wave is firing off storms in eastern Colorado extending down to Clayton, NM. SPC has issued the first T- box for eastern Colorado.

4:31 421 Still westbound on Rt. 70. Line of small cumulus extending NW-SE to our west. Looks like boundary cu to me. S-SW winds 15-20. Clear skies elsewhere. CI distant west.

4:37 437 DAVIDSON, OK - Stopped near Rt. 183/70 under a shade tree. Watched the weather channel. No storm development yet.

5:43 429 DAVIDSON, OK- Leaving town. Heading S on Rt. 183 towards Vernon. No storm development yet.

5:56 440 OKLAUNION - Rt. 287 NW. Small anvil distant SW. More CI NW. Towers developing along the outflow boundary now.

6:06 449 VERNON - Stopped at Braums. Also, set up satellite dish to monitor radar. Towers continue to build to our east along the outflow boundary at the same time that cirrus thickens to the northwest. No echoes on weather channel radar's!

6:35 449 (Severe Thunderstorm Warning for Wheeler Co. says Weather Channel) Also, T-Box just issued for eastern TX panhandle and western OK. Heading NW towards Childress to intercept Wheeler Co. storm. Three clusters of towers begin to glaciate to our east along the outflow boundary. Decisions, decisions. Winds are now backed to SE. Best convergence looks like eastern Tx panhandle.

6:40 455 Cb NW is in site.

6:41 456 Cb has overshooting top now NW. Three towers some glaciating SE. Crisp towers NW and SE.

6:56 474 Knuckles forming on anvil beginning to backshear.

6:59 477 QUANAH - (Severe Thunderstorm Warning for Hutchinson and Moore Cos. Storm is over Dumas and another over SE Moore.) Two Cbs now SE.

7:12 Tornado Warning - Doppler Radar indicated a possible tornado 8 W of Wheeler in Wheeler Co.)

7:21 504 CHILDRESS- SE winds

7:24 506 CHILDRESS- Rt. 83 N. Cb N and two Cb's SE. Southern Cb of pair is dominant.

7:31 514 Cb NW with mushy anvil. Cb distant NW. Two Cb's SE. Northern cell has low top and is sheared. Southern cell has large overshoot, higher anvil and has a split on its north side.

7:33 517 1 pict N of Cb.

7:38 Large overshooting top N-NW.

7:40 1 pict of overshoot, two trees one on each side of road. Pair of Cb's south: northern one is low topped and is shearing over. Southern one is going to town with large updraft, no backshearing in anvil.

7:56 549 1 pict N of large overshoot, mid-level banding also noted.

8:01 555 Bell shaped rain free base now in view. Lots of Cgs.

8:04 Entering Wheeler Co. Mid-level bands wrap around south and east side of updraft. There is even a small beavers tail extending off to the southeast.

8:13 563 SHAMROCK- Wall cloud in view NW of town. Stopped north side of town on hill and took several pictures of the wall cloud.

8:22 567 Winds switched to NW -outflow from RFD. Storm SE has dome on it and anvil is backshearing. Meanwhile, dirt starts rising as RFD precip kicks up dust to our northwest. Dust crosses the road to our north.

8:30 Cb Se has an overshoot with large, vertical updraft, new tower rising up.

8:40 572 I-40 E. Southern Cb has a nice overhang on south side of anvil. Stopped at FM2168 exit east of Shamrock to watch storm/sunset. Saw Doppler on Wheels. Took pictures SE of storms and NW of sunset/clouds. Cb NW has flank with scud beneath base. End of chase.

9:00 583 SHAMROCK - Rt. 83 Southbound. NE winds

9:47 638 CHILDRESS - Pit stop. Food stop.

10:08 642 CHILDRESS - Heading SE on Rt. 287.

10:36 (Tornado Warning issued for storm near Archer City)

10:54 695 VERNON - Frequent lightning SE.

11:35 744 WICHITA FALLS- Cb south of us has great structure. Chunky anvil with good overhang. Lots of in cloud and cloud to ground bolts. Illuminated cerebral look to updraft.

12:42 821 DECATUR- Moderate rain.

1:04 845 I-35S.

1:43 874.8 FLOWER MOUND - 597 miles in 12.8 hours. TRW+

Summary: Spent a little to long at Vernon. Tough call on whether to go for Shamrock storm or the one that later developed near Jacksboro.