Mesoscale Discussion 1783
NWS Storm Prediction Center Norman OK
0122 AM CST Tue Dec 05 2017
Areas affected...Portions of far eastern Texas...central/northern
Concerning...Severe potential...Watch unlikely
Valid 050722Z - 050845Z
Probability of Watch Issuance...5 percent
SUMMARY...A brief tornado could occur over the next 1-2 hours.
However, the threat should be relatively transient/confined,
precluding watch issuance.
DISCUSSION...Regional radar data illustrate a cluster of convective
cells from eastern Texas to northern Louisiana early this morning,
ahead of a cold front pushing southeast across the Arklatex.
Developing within a modest low-level warm-advection/confluent
regime, these cells are likely being aided by a weak southern-stream
impulse currently crossing the upper Texas coast. KPOE VWP data
depict some veering with height through the lowest 2 km, with 0-1km
storm-relative helicity around 150 m2/s2. Several of these cells
have occasionally exhibited weak rotation, and this trend may
continue for the next hour or two. Therefore, despite weak buoyancy
(evidenced by a lack of CG lightning), a favorably moist boundary
layer may support a brief tornado. However, as low-level flow
continues to veer this morning, this potential should diminish with
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 31039460 32039326 32109250 32019193 31709153 31339148
31169164 30769311 30589447 31039460