|Mesoscale Discussion 712|
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Mesoscale Discussion 0712
NWS Storm Prediction Center Norman OK
0822 PM CDT Mon May 20 2019
Areas affected...much of Oklahoma and western north Texas
Concerning...Tornado Watch 199...
Valid 210122Z - 210215Z
The severe weather threat for Tornado Watch 199 continues.
SUMMARY...The severe threat continues in portions of central and
southern Oklahoma and western north Texas.
DISCUSSION...Most of the storms in central Oklahoma have been
undercut by an extensive outflow boundary located from northwest of
TUL through OKC and LTS, with the most substantial surface-based
activity now entering portions of Foard and Knox counties in Texas.
The undercutting nature of the outflow has tempered the tornado
threat across much of central Oklahoma in the near-term, though hail
and damaging wind gusts continue along and north of the outflow with
training convection moving east-northeast. In northeastern
Oklahoma, however, surface-based parcels are still being ingested
within a broken line of storms in that area, and strong
shear/instability continues to support more of a threat for
tornadoes and damaging wind gusts.
More isolated convection south of the boundary continues to struggle
against weak mid-level inhibition located at around 700 hPa on the
00Z OUN RAOB. The trend with this convection has been upward,
however, with mesocyclones noted in relatively shallow convection
just south of the Tulsa area. If storms can continue to deepen
within the pre-convective environment, the parameter space remains
favorable for all modes of severe, including significant tornadoes.
Western north Texas convection will also have an increased threat
for severe as it progresses eastward into an even more strongly
sheared and unstable environment to its east.
Over time, increased forcing for ascent associated with the longwave
trough now traversing New Mexico will foster upscale growth of
storms into one or two linear complexes. Damaging wind gusts and
hail would be the most favored severe mode with this activity,
though isolated tornadoes cannot be ruled out. It is uncertain
whether upscale growth in southern portions of the WW area will
occur with ongoing activity in western north Texas or wait for
stronger forcing aloft and redevelopment southwest of WW 199.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 35379984 35659902 36229794 36789672 36879615 36799566
36039565 35089568 34359575 33839604 33809719 33629796
33409864 33459954 33590002 34570014 35040004 35379984
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