Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 301113
SPC MCD 301112
Mesoscale Discussion 0610
NWS Storm Prediction Center Norman OK
0612 AM CDT Sun Apr 30 2017
Areas affected...Southern to eastern LA...far southeast AR...and
Concerning...Tornado Watch 180...
Valid 301112Z - 301245Z
The severe weather threat for Tornado Watch 180 continues.
SUMMARY...The tornado threat and potential for damaging winds and
hail persists across WW 180, along and ahead of the cold front
advancing east across LA early this morning. Although a new watch
will likely be needed to the east of WW 180 this morning, a parish
and/or counties may need to be added across part of LA and southwest
MS in the short term. Meanwhile, local WFO clearance of
counties/parishes can continue with the cold front passage.
DISCUSSION...The 11Z surface analysis showed an area of low pressure
located in vicinity of KLIT with a cold front trailing southward
into northeast LA, and then south-southwestward through southwest LA
(east of KLCH). The pre-frontal environment remains moderately
unstable (MUCAPE 1500-2000 J/kg) with strong effective shear per
strong unidirectional deep-layer winds per area VADs. This will
tend to favor linear mode, though given the strength of the
effective shear (40-60 kt) and low-level shear (surface-1 km of
35-50 kt), embedded supercells with a tornado threat persists this
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 29619306 30449248 31759179 32349182 33349183 33529080
32779060 31509061 31079060 30309098 30069126 29699108
29449129 29379140 29429209 29619306