Mesoscale Discussion 1579
   NWS Storm Prediction Center Norman OK
   1244 PM CDT Wed Aug 26 2020

   Areas affected...Southern LA

   Concerning...Severe potential...Watch unlikely 

   Valid 261744Z - 261915Z

   Probability of Watch Issuance...20 percent

   SUMMARY...Strong wind gusts and perhaps a tornado or two possible.

   DISCUSSION...Convective band associated with Hurricane Laura is
   currently moving northward into far southern LA. Storms within the
   band are generally moving northwestward, with shallow,
   short-duration/pulse-like updrafts thus far. Additionally, northward
   motion of the entire band suggests predominantly outflow-dominant
   storm structures. Given the strength of the low-level wind fields,
   some of these outflows could produce 40-50 kt gusts.

   Low-level kinematic environment will continue to improve across the
   region as Laura approaches. Current LIX VAD profiles and recent
   mesoanalysis suggest around 20-25 kt of 0-1 km bulk shear and
   100-150 m2/s2 of 0-1 km storm-relative helicity are already in place
   across the region. Gradual strengthening is anticipated over the
   next few hours, particularly as the stronger low to mid-level flow
   moves over the region, lengthening the hodographs. 

   Modest thermodynamics are in place, suggesting storms will continue
   to develop on the outflow, but the overall kinematic environment
   does not appear overly supportive of tornadogenesis on a large
   scale. Even so, given the strengthening of the low-level wind fields
   that is anticipated, trends will be monitored closely and a watch
   will be needed later this afternoon.

   ..Mosier/Bunting.. 08/26/2020

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...LIX...LCH...

   LAT...LON   29619255 29759365 30139378 30599346 30729200 30459067
               29978983 29188973 29039034 29439152 29569204 29619255