On 19 April, the VORTEX armada operated in NW and north-central
Texas. Convection repeatedly fired along the dryline. Based on
WSR-88D information, it appeared that storms rotated strongly
just as they crossed the warm front, which extended from near
Lubbock to Mineral Wells to south of DFW. Only one or two
storms persisted with supercell structure in the cold air north
of the warm front. In the late evening, a squall line developed
along the advancing dryline/cold front. At the intersection of
the warm front and dryline, a storm with a mesocyclone formed
(near dusk) and persisted as it moved across the Dallas/Ft.
Worth metro area, producing some weak tornadoes.
The VORTEX armada did not intecept any storms. We were not
interested in the storms that moved north of the warm front into
the stratus and cold air; these rarely produce tornadoes. As
the situation became clearer during the afternoon, the decision
was made to try to target storms that had been in existence in
the warm sector for 1-2 hours prior to reaching the warm front.
The only storm meeting this criterion did not survive long
enough before it was overtaken by the squall line. Thus, the
armada intercepted zero tornadoes out of the zero significant
tornadoes available to be intercepted.
Erik Rasmussen
Jerry Straka