Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 261806
SPC MCD 261805
Mesoscale Discussion 0562
NWS Storm Prediction Center Norman OK
0105 PM CDT Wed Apr 26 2017
Areas affected...central AR into northwester LA and northeast TX
Concerning...Tornado Watch 162...
Valid 261805Z - 261930Z
The severe weather threat for Tornado Watch 162 continues.
SUMMARY...Isolated severe hail/gusts are the main severe risks in
the short term (next 1-3 hours). The tornado threat may increase
later this afternoon dependent on quasi-discrete supercells
developing ahead of the cold front.
DISCUSSION...Radar mosaic shows a relatively weak squall line over
central AR with the mean flow largely parallel to the gust front of
the squall line. Severe weather is not expected in the short term
associated with this part of the convective line. Farther south,
strengthening updrafts on or immediately behind the surface wind
shift have led to the development of strong/severe storms developing
from northeast TX into far southwestern AR. Isolated large
hail/severe gusts are the primary hazards with this activity over
the next 1-3 hours.
A very stout cap was noted in the 12z SHV raob and the 18z SHV raob
exhibited much reduced convective inhibition compared to this
morning in the 850-650 mb layer. Although strengthening and veering
flow with height in the lowest 1 km was noted --resulting in some
enlargement to the hodograph-- considerable backing of flow in the
750-500 mb layer would tend to be suboptimal for tornadic low-level
mesocyclones. Nonetheless, gradual moistening in the low levels is
expected. It appears the risk for strong tornadoes may be less than
previously thought---although some risk remains.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 31889627 35059251 35039189 34869148 34529157 31959446
31659510 31629594 31889627