Mesoscale Discussion 0590 NWS Storm Prediction Center Norman OK 0611 PM CDT Mon Apr 28 2025 Areas affected...Portions of western North Texas into southwest Oklahoma Concerning...Tornado Watch 182... Valid 282311Z - 290030Z CORRECTED FOR SPELLING ERROR The severe weather threat for Tornado Watch 182 continues. SUMMARY...Initial supercells will pose mainly a risk of very large hail and locally severe wind gusts. The tornado risk will increase into the evening as the low-level jet strengthens (00-01Z time frame). DISCUSSION...Initial discrete supercell has developed immediately south of the Red River in western North TX, where convergence is maximized near the dryline amid an uncapped air mass (per 21Z special NSSL sounding from Quanah, TX). Strong surface-based instability (3000 J/kg MLCAPE), driven by a warm/moist boundary layer beneath very steep midlevel lapse rates, will favor continued rapid updraft intensification. Around 50 kt of effective shear oriented oblique to the low-level convergence will support discrete/semi-discrete supercells. The initial hodograph (sampled by FDR VWP) depicts weak winds in the 1-2-km AGL layer, despite favorable deep-layer shear for supercells. This should initially favor some splitting supercells with a risk of very large hail. However, as the low-level jet rapidly increases, storms should intensify into dominant right-movers with an increasing supercell tornado risk. Current indications are that this evolution will occur in the 00-01Z time frame. The strong buoyancy, discrete/ semi-discrete mode, and increasing streamwise vorticity (around 400 m2/s2 effective SRH), will support a strong/intense tornado threat. ..Weinman.. 04/28/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OUN... LAT...LON 34099985 34499972 34979935 35139892 35119860 34949830 34619826 33899867 33669906 33649952 33809982 34099985 MOST PROBABLE PEAK TORNADO INTENSITY...120-150 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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