MAY 22, 1996

ATWOOD, KS TORNADIC LP SUPERCELL

Carson Eads, Bruce Haynie, Gene Rhoden and Tim Marshall

Time Odom Town/Heading Remarks

9:33 014 LEWISVILLE: First time this year that a half way decent trough is moving into the west. A short wave is rounding the base of the trough and should be sheared out over the plains as it lifts northeastward. A weak stationary front is along the Red River and a surface low pressure center is progged to form in the Texas panhandle. All east-southeast winds in Texas, Oklahoma and Kansas. Two target areas today are the warm front across the Kansas-Nebraska border or the dryline in West Texas. Soundings look great. 100 degree turning from Amarillo northward (160 degrees to 260 degrees). Moist axis hits the warm front in north-central Kansas. SELS has a moderate risk in northern Kansas and southern Nebraska and no risk in the Texas panhandle. I think they are questioning the 23 degree C cap over Amarillo. We've chosen northern Kansas as our destination -instead of what I would normally pick -Amarillo. I-35N.

11:52 190 NORMAN: Overcast strato-cu. Winds strong southeast.

12:15 212 OKLAHOMA CITY- N on I-35. Scattered broken strato-cu. Blue.

12:52 Stopped at the Stuckeys for a pitstop.

2:03 326 Crossed Kansas border. Broken strato-cu.

2:40 372 WICHITA, KS- Broken strato-cu. Flat bases. Strong S winds.

3:15 414 HESSTON, KS - pitstop. Strato-cu aligned in transverse rolls.

Carson pulled up data and satellite. It appears that NW Kansas and SW Nebraska are the areas to be in today. The system is a little slow in coming out. Tornado Watch Box has already been issued for that area. We will proceed west from Salina.

3:52 414 Leaving Hesston.

437 MCPHERSON - Cloudy skies.

4:41 476 SALINA - Overcast skies, strong south winds. I-70 West.

532 Mile marker 200, it has cleared out completely. Strong SE wind.

Mile marker 175. Sheared towers overhead and to the west.

5:57 574 HAYS- Mile marker 161. No towers. Cirrus now west. Fuzzy.

(Seward Co. Nebraska-Lincoln- Severe Thunderstorm moving E at 30).

6:55 624 GRAINFIELD, KS- Two Tornado Boxes in Nebraska at each end of the state. There's a Severe thunderstorm box in Texas as a severe storm has blown up near Childress. Lone supercell in NE Colorado is going to town.

7:05 636 CB west-northwest of our position. Long anvil.

7:17 Overshooting top on Cb NW. (Severe Thunderstorm Warning as spotters report 2.5 inch hail at 7:05pm 6 NW of Sparks, NE or 18NW of Benkleman.)

666 OAKLEY, KS- Supercell is to our NW. It has a backsheared anvil and somewhat of a dome. Slightly mushy anvil.

TORNADO WARNING- Doppler Radar indicates a possible tornado between Benkleman and Bird City moving SE at 20mph. Alright -a right mover. Come to Papa.

7:40 Video of backsheared anvil on storm. Another storm distant NW.

7:47 690 COLBY- Large backsheared anvil NW. Rt. 16 northbound.

7:52 (New Tornado Watch Box issued) Backsheared anvil has knuckles on it. The top half of the updraft is very crisp. There is some mid-level banding. Anvil distant NW. (Severe Thunderstorm Warning for Rawlins Co. At 7:50pm, a severe thunderstorm was located 7 miles southeast of Benkleman, NE moving southeast at 26 mph.

7:56 (TORNADO WARNING RAWLINS CO. Spotters report tornado on the ground about 4 miles southeast of Benkleman.

8:10 1 pict NW of sun behind the anvil. Flared base coming into view.

8:12 723 ATWOOD, KS-

8:14 725 Rt. 36 West

8:16 725 Stopped just west of Atwood on hill. Twenty minutes too late for the tornado. Look at this barber shop pole updraft with flared base. Wall cloud noted at north end of base.

8:18 Taking video. Wish I had a wide angle. Cool temps. Spiral bands.

8:20 1 pict. of storm NW. Tremendous rotation. Flared tail. Anvil NW.

This looks like an LP supercell. Marty Feely drives up.

8:23 725 Leaving film site to head north of Atwood.

8:24 726 ATWOOD - North on Rt. 25 Flared base supercell NW.

8:29 729 Stopped again. Set up cameras. Barber pole updraft. Strong inflow.

Some dust noted underneath the wall cloud -persistant.

Took several pictures, horizontal and vertical. RFD coming in. Rows of mammatus overhead. Cumuliform anvil extends out to the east. Dust again gathers under wall cloud. Took 24mm shot of storm. RFD wraps around the updraft. Incredible banding. Clear slot 8:35 729 occludes updraft but wall cloud does not intensify. Storm is moving to the east. Vertical shot on Cannon. Vertical shot on Ricoh, horizontal shot on the Ricoh. Winding film up on Ricoh -end of the roll. Winds went calm as flank passes over us.

8:37 729 Windshifts to the west. Lots of chasers fleeing the storm. CG NE.

8:38 729 Wind has swung to NW. RFD wrapping around updraft. Outflow dust now northwest. Bowl-shaped wall cloud. Watch for new wall cloud to form. Anticyclonic circulation overhead. Adjusting gain on 8:40 729 camera. Downward motion on back edge of updraft. Lots of rising 8:42 729 motion on the leading edge of the eastward moving flank. Close CG. Wall cloud has lifted as updraft appears as a backwards C-shape.

8:48 729 Leaving film site heading back to Atwood and Rt. 36 East.

8:53 753 ATWOOD- Rt. 36 E

9:07 751 Jct. 117N

9:17 755 Turned around and going back south. Updraft has occluded. New precip core now SW. Darkness is upon us. Rain on flank

9:22 759 Westbound on Rt. 36. East winds.

9:36 775 ATWOOD- (TORNADO WARNING- Tornado reported west of Oberlin at 9:30pm).

10:15 805 COLBY- Stopped for the night.

TRIP SUMMARY 12.7 hours, 791 miles

CHASE SUMMARY: The LP supercell we were on did produce a ropy tornado east of Benkleman that was captured by numerous spotters. Also, the Colorado supercell produced several tornadoes and large hail and was witnessed by a few chasers.