Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 200012
SPC MCD 200011
Mesoscale Discussion 0077
NWS Storm Prediction Center Norman OK
0611 PM CST Thu Jan 19 2017
Areas affected...eastern Alabama through west central GA
Concerning...Severe potential...Watch unlikely
Valid 200011Z - 200215Z
Probability of Watch Issuance...20 percent
SUMMARY...Thunderstorms will continue to pose a marginal risk for
isolated damaging wind and a brief tornado through 02Z as they move
through the remainder of eastern Alabama into far western Georgia.
Overall threat does not appear sufficient for a WW.
DISCUSSION...A line of thunderstorms with embedded bowing segments
and meso-vortices extends from northeast through south-central GA.
The line is moving east at 15-20 kt, while individual elements
within the line move more rapidly northeast. Objective analysis
indicates a marginally unstable warm sector with MLCAPE below 500
J/kg. The weak thermodynamic environment should remain the primary
limiting factor for a more robust severe threat especially as storms
continue east into GA as evidenced by the 00Z Atlanta raob. Based on
the VWP from Montgomery AL, low-level hodographs are not
particularly large with unidirectional deep-layer wind profiles.
However, effective bulk shear up to 40 kt is sufficient for storms
to organize with embedded bowing segments and weak supercell
structures. Some increase in the low-level jet is expected this
evening in response to the ejecting upper trough. However, storms
will begin to move east of the more unstable portion of warm sector
beyond 02Z, suggesting an overall diminishing trend by that time.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 32008649 32748614 33288591 33698578 34038556 33748505
33268476 32478474 31878549 32008649