Mesoscale Discussion 0659
NWS Storm Prediction Center Norman OK
0542 PM CDT Mon May 06 2024
Areas affected...West-central into northwest/north-central
OK...extreme south-central KS
Concerning...Tornado Watch 189...
Valid 062242Z - 070015Z
The severe weather threat for Tornado Watch 189 continues.
SUMMARY...The threat for strong and potentially long-tracked
tornadoes is expected to increase into this evening. Very large hail
will also be possible with any supercell.
DISCUSSION...Three mature supercells are ongoing across northwest OK
as of 5:30 PM CDT. Initial development occurred in an environment
characterized by warm temperatures (well into the 80s F) and
dewpoints generally in the mid 60s F. However, dewpoints downstream
of the ongoing cells into north-central OK are in the upper 60s to
near 70F, supporting even greater buoyancy (MLCAPE of 3000-4000
J/kg) and a more favorable thermodynamic environment for tornadoes.
In addition, VWP data from KOUN and KVNX depict a notable increase
in low-level flow over the last hour, with some modest backing of
surface winds noted in recent Oklahoma Mesonet data. 0-1 km SRH of
around 200 m2/s2 was noted in the 21Z OUN sounding, with values
expected to increase above 300 m2/s2 into this evening. The
combination of strengthening low-level shear and strong to extreme
instability will support a rapid increase in potential for strong
and possibly long-tracked tornadoes as storms spread
east-northeastward this evening.
In addition to the tornado threat, very large hail and localized
severe gusts will also remain possible. Additional development
southwest of the ongoing supercells remains possible with time this
evening, as the low-level jet continues to increase.