The
Wheatland Storm from GO to WHOA!! Report: Clyve Herbert
After overnighting at Ogallala, we decided to head
west for our target area of southeast Wyoming searching for clear sunwarmed areas. The
synoptic setup showed a complex arrangement of a trough and a small vorticity max moving
through eastern Wyoming / western Nebraska panhandle through the afternoon. Approaching
Wheatland from the south, we noted a dissipating multicell and just to its southwest an
alignment of deep cumulus persisted and appeared to be generating lee of or near to high
ground.
We pulled over about 15 miles south of Wheatland
and watched the Cu alignment throw up a tower to glaciate. Sometimes you can be lucky and
be in a position to study the evolution of a storm to start to finish. From the first
narrow tower the alignment lingered, not doing much for 10 - 15 minutes...and then a
larger updraft really got the storm going. At first it was a picturesque classic Cb with a
flanking line...but we noticed as the storm shifted east-northeast, it was starting to
draw a clear inflow of warm moist air from the south. The area to the south of Wheatland
was almost cloud free, and no doubt influenced the intensity of the storm as its flanking
line dug into an increasingly better inflow. The storm continued to put up successive
pulses which rapidly expanded its anvil. We moved north along I-25 and approached the
Wheatland township..we struck a brief amount of large hail (finally got a dent in the
bonnet!) near the infeed edge of the storm...estimate size from 4 - 6cm (1.75 -
2.75"), however, most hail was pea to marble size.
The sight that greeted us at Wheatland was
virtually chaos...as the torrential hail and rain quickly flash flooded the town! The
amount of precipitation would be difficult to estimate but would have been between 1 and
2" (25 - 50mm) falling within 30 minutes...virtually all streets became rivers. The
water was washing hail into drifts along the front yards of houses, and at times,
visibility was almost a whiteout. We escape north and watch the storm slowly weaken into a
linear multicell.
Report: Clyve Herbert
Photography: Jane ONeill / Clyve Herbert |