Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 170243
SWOMCD
SPC MCD 170243
ALZ000-MSZ000-LAZ000-170345-

MESOSCALE DISCUSSION 1913
NWS STORM PREDICTION CENTER NORMAN OK
0843 PM CST SUN NOV 16 2014

AREAS AFFECTED...SERN LA / SRN MS / FAR SWRN AL

CONCERNING...TORNADO WATCH 550...

VALID 170243Z - 170345Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 550 CONTINUES.

SUMMARY...THE POSSIBILITY FOR TORNADOES WILL LIKELY PERSIST BEYOND
THE 04Z EXPIRATION TIME OF TORNADO WATCH 550.  A REPLACEMENT TORNADO
WATCH WILL LIKELY BE NEEDED WITHIN AN HOUR OR SO AND WILL COVER ERN
PORTIONS OF WATCH 550 AND INCLUDE DOWNSTREAM AREAS OVER SRN MS...FAR
SERN LA...AND PERHAPS FAR SWRN AL.

DISCUSSION...THE 00Z LIX RAOB SAMPLED AN ADEQUATELY MOIST/MARGINALLY
UNSTABLE AIRMASS OVER THE LOWER MS RIVER VALLEY TO THE S OF A MARINE
WARM FRONT LOCATED OVER SRN MS AND SRN AL.  STRONG LOW-LEVEL WIND
SHEAR /270 M2 PER S2 EFFECTIVE SRH PER OBSERVED STORM MOTIONS/ AND
LOOPING HODOGRAPHS WILL SUPPORT LOW-LEVEL MESOCYCLOGENESIS AND THE
POSSIBILITY FOR A FEW TORNADOES PERSISTING FOR AT LEAST THE NEXT FEW
HOURS.

SHORT-TERM...THE AREAS DOWNSTREAM OF THE LIVINGSTON/ST. HELENA
PARISH LA TORNADIC SUPERCELL WILL LIKELY EXHIBIT THE GREATEST
NEAR-TERM TORNADO POTENTIAL COMPARED TO OTHER AREAS OF THE REGION.

LONGER-TERM...STRENGTHENING FLOW FIELDS AND INCREASING ASCENT
ASSOCIATED WITH THE APPROACHING SHORTWAVE TROUGH WILL SUPPORT THE
POTENTIAL FOR ORGANIZED STORM STRUCTURES /SUPERCELLS AND BOWING
LEWPS/ LATE TONIGHT.  THE LONGER-LIVED CIRCULATIONS WILL PROBABLY BE
MOST ASSOCIATED WITH THE THREAT FOR ISOLD DAMAGING WINDS AND A
TORNADO OR TWO.

..SMITH/MEAD.. 11/17/2014

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MOB...JAN...LIX...LCH...

LAT...LON   29159033 29259127 29619191 30359143 31828923 31958837
            31578802 31048829 29159033




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