Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 222156
SPC MCD 222156
Mesoscale Discussion 0548
NWS Storm Prediction Center Norman OK
0456 PM CDT Sat Apr 22 2017
Areas affected...Central Mississippi...northwestern Alabama...and
southern middle Tennessee
Concerning...Severe Thunderstorm Watch 158...
Valid 222156Z - 222300Z
The severe weather threat for Severe Thunderstorm Watch 158
SUMMARY...Scattered to numerous storms continue in WW 158, with a
continued threat for hail, damaging wind gusts, and perhaps a
tornado or two through at least 02Z.
DISCUSSION...Scattered thunderstorms have increased in coverage and
intensity over the past couple of hours in WW 158. These storms
have a history of producing hail, damaging wind gusts, and a tornado
or two. The highest (albeit low) tornado threat appears to be
concentrated in northern portions of the WW (from northeastern
Mississippi into far southern Middle Tennessee) where a few weakly
rotating supercell structures have evolved despite mostly
unidirectional wind profiles and relatively weak low-level wind
shear. Farther south into central Mississippi, storms have
congealed into linear segments and tended to propagate
east-southeastward toward the southern edge of WW 158.
Ongoing trends suggest that far western portions of WW 158 behind
the strongest activity may be cleared soon. Southward spatial
extensions of the WW across central/east-central Mississippi may be
needed to address the evolving multicellular downburst threat in
that area. Additional sub-severe storms continue in parishes of
east-central Louisiana, and these may also pose a brief severe
threat as they move eastward into southwestern Mississippi where
moderate instability exists. Finally, spatial extensions of the
watch will likely be needed in northeastern Alabama downstream of
the watch before scheduled expiration.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 32628776 32228862 31828948 31539046 31509135 31589179
32019171 32849077 33689012 35458798 35718677 35718669
35708619 35668598 35528561 35488554 35408548 35378548
35368551 34528558 34028604 32628776