SPC MD 687

MD 0687 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PORTIONS OF THE CENTRAL GREAT PLAINS Mesoscale Discussion 0687 NWS Storm Prediction Center Norman OK 0332 PM CDT Sat May 09 2026 Areas affected...portions of the central Great Plains Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 092032Z - 092130Z Probability of Watch Issuance...80 percent SUMMARY...Widely scattered thunderstorm development should occur from the eastern TX/OK Panhandles into western Oklahoma and northwest Texas this afternoon. Large to very large hail and severe wind gusts will be the main hazards. DISCUSSION...Weak convection is noted along a subtle boundary extending from southwestern Kansas into northeastern New Mexico, with modest moisture return ongoing ahead of this boundary and east of a dryline across the eastern TX/OK Panhandles, western Oklahoma, and northwest Texas. A developing Cu field is evident across this region in visible satellite imagery, with forecast soundings and latest mesoanalysis depicting 500-1500+ J/kg MLCAPE amid eroding inhibition. Intensification of the southeastward moving convection as it encounters this greater moisture and additional development along a north-south oriented dryline across the eastern Texas Panhandle are both likely over the next couple of hours. Strengthening westerly flow aloft ahead of an approaching mid-level shortwave trough is expected to promote increasing effective bulk shear of 30-40 kts, which will be sufficient for high-based supercells. Coupled with steep mid-level lapse rates, this will support a risk of large to very large hail. Steep low-level lapse rates, deep well-mixed boundary layers, and DCAPE of 1000+ J/kg will also promote a threat for severe wind gusts. Watch issuance will likely be needed. ..Chalmers/Gleason.. 05/09/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN...DDC...LUB...AMA... LAT...LON 33429955 33900035 34310053 34880069 35630086 36200080 36640071 36960029 37139960 36999882 36579852 35569840 34889840 34479848 33909866 33459897 33429955 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more