Mesoscale Discussion 1027
NWS Storm Prediction Center Norman OK
0746 PM CDT Mon May 27 2024
Areas affected...Middle/Lower Rio Grande Valley
Concerning...Severe potential...Watch possible
Valid 280046Z - 280245Z
Probability of Watch Issuance...60 percent
SUMMARY...Large to very large hail (2" to 2.5" in diameter) and
strong gusts up to 70 mph are possible across the Middle/Lower Rio
Grande Valley this evening. The need for a watch is uncertain, but
convective trends will be monitored closely.
DISCUSSION...Visible satellite and regional radar imagery shows an
intense left-moving supercell moving across northern Tamaulipas
towards the Lower Rio Grande Valley. Recent motion of this storm was
estimated at 30 kt, bringing it across the border around 0130Z.
Extreme buoyancy (i.e. MLCAPE around 5000 J/kg) is in place
downstream, with at least some potential for this storm to maintain
its intensity for the next few hours. Main deterrent is the building
convective inhibition and warm temperatures aloft, which, given the
intensity of the storm, are not expected to result in quick storm
weakening. Large to very large hail (2" to 2.5" in diameter) and
strong gusts up to 70 mph may impact the Lower Rio Grande Valley
within the next hour.
Farther north (about 30 miles south of LRD), convergence along an
outflow boundary has resulted in convective initiation, with much of
the activity west of the border. However, one cell has developed in
far western Webb County. Large to very large hail and strong gusts
are possible with this storm, as well as any other development that
occurs in this area.
Given the widely spaced and isolated nature of the severe threat,
the need for watch is uncertain. However, convective trends will be
monitored closely.
..Mosier/Smith.. 05/28/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CRP...BRO...
LAT...LON 27089942 27549952 28020006 28049926 26869822 26169825
26489909 27089942