Mesoscale Discussion 1545 NWS Storm Prediction Center Norman OK 0327 AM CDT Sat Aug 22 2020 Areas affected...portions of central Texas Concerning...Severe potential...Watch unlikely Valid 220827Z - 221030Z Probability of Watch Issuance...5 percent SUMMARY...Sporadic strong gusts may accompany southward-progressing thunderstorm clusters through early morning. DISCUSSION...Scattered thunderstorms are ongoing early this morning across parts of central Texas. This activity is associated with a weak shortwave impulse near the Red River. This impulse should continue migrating south/southeast through the morning hours, and clusters of thunderstorms may persist across central Texas into the daylight hours. While moderate near-surface inhibition exists, regional VWP data shows a modest southerly low level jet around 25-30 kt over the region. Considerable veering with height noted in 06z regional RAOBs and current VWP data is contributing to 30-45 kt of effective shear as well. Downstream dewpoints in the mid to upper 60s beneath midlevel lapse rates around 7.5 C/km are resulting in MUCAPE values around 1000-2000 J/kg. As a result, an loosely-organized storm cluster should continue tracking southward the next several hours. Some CAMs guidance suggests some upward development/cold-pool induced forward-propagation is possible. Locally strong gusts could accompany this activity as it encounters greater instability with southward extent. Any more discrete cells within the larger cluster could also produce hail to near 1-inch. Given the marginal nature of the threat, and climatologically unfavorable timing for severe convection, a watch is not expected, but trends will be monitored. ..Leitman/Thompson.. 08/22/2020 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...EWX...SJT... LAT...LON 30949983 31119974 31359919 31649856 31859826 31829780 31539760 31379737 30919704 30279697 29819714 29449752 29309883 29469957 29739986 30159989 30949983Read more
from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1545.html
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