SPC Mesoscale Discussion
SPC MD 385
MD 0385 CONCERNING SEVERE THUNDERSTORM WATCH 95... FOR PORTIONS OF THE LOUISIANA AND TEXAS COASTLINE
Mesoscale Discussion 0385 NWS Storm Prediction Center Norman OK 0527 PM CDT Wed Apr 14 2021 Areas affected...Portions of the Louisiana and Texas Coastline Concerning...Severe Thunderstorm Watch 95... Valid 142227Z - 150030Z The severe weather threat for Severe Thunderstorm Watch 95 continues. SUMMARY...A limited threat for severe storms will remain in place for a couple more hours. Large hail would be the primary threat for any storms that manage to develop. DISCUSSION...A surface cold front is currently meandering along the east-TX coastline, with temperatures in the 80s F and dewpoints exceeding 70 F ahead of the front. Steep (8+ C/km) mid-level lapse rates overspreading the warm, moist low-level airmass have promoted 3000-4000 J/kg MLCAPE (per latest Mesoanalysis and RAP forecast soundings). Despite the favorable thermodynamic environment in place, along with 35+ kts of effective bulk shear, very limited deep-layer ascent has precluded a more robust severe threat thus far. Given that afternoon peak heating is underway, it appears that low-level lift due to diurnal mixing is insufficient for promoting organized storms/a severe threat. Some upper support is evident via the eastward propagation of a small mid-level impulse across northwest TX, however, it is unclear if the upper support will influence an uptick in convective development across southeast Texas. Should storms manage to develop and mature in close proximity to the front, especially towards the BEA/VCT vicinity, large hail would become a concern given the steep lapse rates in place. Conditions will continue to be monitored for more rigorous convective development. ..Squitieri.. 04/14/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LCH...HGX...CRP...EWX... LAT...LON 27839716 28249789 28669810 29029778 29489684 30029529 30209403 30029377 29579389 28989501 28549588 27839716Read more
SPC MD 384
MD 0384 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHWEST TEXASMesoscale Discussion 0384 NWS Storm Prediction Center Norman OK 0449 PM CDT Wed Apr 14 2021 Areas affected...northwest Texas Concerning...Severe potential...Watch unlikely Valid 142149Z - 142345Z Probability of Watch Issuance...5 percent SUMMARY...A set of splitting cells may continue to pose a damaging hail risk over the next 1-2 hours, with a general weakening trend expected as they move northeastward this evening. A watch is not expected due to limited coverage. DISCUSSION...Splitting cells exist over Taylor and Jones counties as of 21:45Z, with a very large hail core noted earlier on the southern/right-moving cell. These cells are located within the elevated MUCAPE plume, with weak warm advection occurring around 850 mb aiding lift. The theta-e gradient at 850 mb is forecast to remain quasistationary, with little increase in advection through evening. The strong deep-layer effective shear may allow these cells to persist in severe fashion for a row or two of counties east of their current location. However, a weakening trend is anticipated after 00Z as they move farther away from the instability axis. ..Jewell/Hart.. 04/14/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN...SJT... LAT...LON 32299848 32139938 32249979 32539994 32869996 33639924 33899823 33669774 33249755 32929758 32559766 32299848Read more