ZCZC SPCSWOMCD ALL
ACUS11 KWNS 181830 
SPC MCD 181830 
TNZ000-MSZ000-ARZ000-LAZ000-182000-

Mesoscale Discussion 0072
NWS Storm Prediction Center Norman OK
1230 PM CST Wed Jan 18 2023

Areas affected...northeast Louisiana...east Arkansas...west/north
Mississippi...and far southwest Tennessee

Concerning...Severe potential...Tornado Watch likely 

Valid 181830Z - 182000Z

Probability of Watch Issuance...80 percent

SUMMARY...The ongoing severe weather threat is expected to continue
eastward this afternoon. Downstream watch issuance is likely.

DISCUSSION...A broken line of convection with embedded supercell
structures is ongoing across WW 24. These storms are evolving in an
environment broadly characterized by modest MLCAPE (500-1000 J/kg)
and favorable bulk shear (50-60 kts). A steadily clearing boundary
layer ahead of the convection has yielded gradual warming, with
surface temperatures in the low to mid 70s F across the region. This
has steepened 0-3-km lapse rates slightly, which have increased to
around 6 C/km per recent 17z/18z special soundings at SHV and JAN,
respectively. Amidst broader moist advection, some boundary-layer
mixing is evident in northeast Louisiana and west Mississippi with
dewpoints dropping slightly to the low 60s F. This environmental
evolution (along with ongoing convective patterns) is expected to
yield continued, gradual upscale growth as the system progresses
eastward. The primary threats should include a few tornadoes and
isolated damaging wind gusts, mainly associated with any embedded
supercells and/or more intense mesovortices within the broader
convective line.

..Flournoy/Gleason/Grams.. 01/18/2023

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

ATTN...WFO...MEG...JAN...LZK...SHV...

LAT...LON   34228948 33228995 32029087 31539164 31509250 31639290
            31999272 32339244 32849216 33279197 33389147 33769119
            34309094 34919100 35369087 35518983 35208938 34228948 

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