Mesoscale Discussion 0571 NWS Storm Prediction Center Norman OK 0942 AM CDT Thu Apr 27 2017 Areas affected...Southeast AL...West-central GA Concerning...Severe potential...Watch unlikely Valid 271442Z - 271645Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe threat of primarily damaging wind gusts is expected to persist for the next several hours. A brief tornado or two is also possible. Current expectation is for the severe threat to remain too isolated for watch issuance but trends across the region will be monitored closely. DISCUSSION...Line of storms extends from LGC (in west-central GA) to GZH (in southern AL) has shown supercellular characteristics over the past few hours. Recent radar suggest the rotating storm about 30 miles east of MGM has produced a tornado. Radar data also indicate a few more persistent updrafts within the line of storms. Downstream thermodynamic environment is characterized by a deep, moist boundary-layer (as evidenced by the 12Z VPS sounding), surface dewpoints in the low 70s, and MLCAPE around 1000-1500 J/kg. These parameters are favorable for storm persistence. Downstream kinematic environment is also favorable for a continued isolated severe threat with recent mesoanalysis suggesting the effective SRH is around 300 m2/s2. Recent EOX VAD sampled 0-1 km SRH greater than 250 m2/s2. Expectation is for occasionally rotating storms capable of isolated damaging wind and a tornado or two to persist throughout the next several hours. Isolated nature of the threat is expected to preclude the need for a watch but trends across the region will be monitored closely. ..Mosier/Hart.. 04/27/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FFC...TAE...BMX...MOB... LAT...LON 31238672 33048486 32788415 31798492 31098587 31238672Read more
from SPC Forecast Products http://ift.tt/HXqQxn
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