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SPC Mar 2, 2025 2000 UTC Day 1 Convective Outlook

6 months ago

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Mar 02 2025 Valid 022000Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE EASTERN TEXAS PANHANDLE INTO SOUTHWESTERN OKLAHOMA AND WESTERN NORTH TEXAS... ...SUMMARY... Isolated severe thunderstorms appear possible from the eastern Texas Panhandle into western Oklahoma and western north Texas this afternoon and early evening. Large hail and severe wind gusts should be the main threats, but a couple of tornadoes are also possible. ...20z Update... The latest surface analysis and satellite imagery show an arc of low-topped convection developing along a convergent dryline within the clear slot of the strong upper low ejecting eastward over the southern Plains. Recent surface obs show moisture increasing into the low to mid 50s F from roughly Childress, TX eastward into far southwestern OK and south to Interstate 20. Roughly 250-500 J/kg of MUCAPE is expected within a confined warm sector from the southeastern TX panhandle to the Red River vicinity of western north TX and southwest OK. Despite limited surface moisture, convection should intensify and strong veering wind profiles may support a few supercells. Steep low and mid-level lapse rates will favor a risk for damaging gusts and hail with the more robust storms. Large low-level buoyancy (0-3km MUCAPE of 75-150 J/kg), ample vertical vorticity and strong shear could also support a couple of tornadoes. Contingent upon storms remaining semi discrete, this may occur within a localized corridor near the surface warm front over the southeastern TX Panhandle to far southwest OK and western north TX, where shear and surface moisture are maximized. Have extended the MRGL south where convection is developing along the dryline near I-20. Have also shifted the SLGT southward toward the deeper moisture and stronger buoyancy. See MCD#0121 and the prior outlook for additional details. ..Lyons.. 03/02/2025 .PREV DISCUSSION... /ISSUED 1020 AM CST Sun Mar 02 2025/ ...Southern High Plains... Elevated thunderstorms have developed this morning across parts of the TX Panhandle and northwest TX, as an upper low continues eastward over the southern High Plains. This activity may pose an isolated small hail risk in the short term with weak MUCAPE present, but greater severe potential remains evident later this afternoon and early evening. A very strong (80-100 kt) mid-level westerly jet is present in the base of the mid/upper-level low. Strong large-scale ascent associated with the left exit region of this jet will overspread the TX Panhandle/northwest TX and parts of western OK by this afternoon, encouraging robust thunderstorm development by 20-21Z. This activity will likely form along or just east of a weak surface low and attendant dryline that will be present over the eastern TX Panhandle and northwest TX. The primary limiting factor for the severe threat across this region still appears to be rather modest low-level moisture, with latest surface observations showing low to mid 50s surface dewpoints confined well south to parts of central/south TX. Even so, there is a chance for modest moistening though this afternoon, as ongoing elevated precipitation may help saturate low/mid levels to some extent. Mid-level lapse rates are also expected to quickly steepen through the day as the upper low moves eastward, and as cold mid-level temperatures gradually overspread the narrow warm sector. There may be a small/mesoscale corridor of greater severe threat this afternoon/early evening across southwest OK/western north TX and vicinity, where greater low-level heating appears possible behind the morning activity, and where somewhat better low-level moisture and related instability should be present. Current expectations are for the afternoon/early evening convection to pose a threat for mainly large hail and severe/damaging winds, as favorable lapse rates aloft and sufficient deep-layer shear support supercell structures initially. But, there is some veer-back-veer signal in the 2-5 km layer from various NAM/RAP forecast soundings, and convection may grow into a small bowing cluster fairly quickly (as shown by several HREF members). The severe threat will likely be limited in space and time by the narrow/small warm sector, with a more isolated/limited severe threat with eastward extent into central OK and north-central TX this evening due to weaker instability. Finally, the tornado potential remains a bit unclear, as low-level moisture will be quite limited. Still, a small zone of sufficient 0-3 km CAPE and ambient boundary-layer vorticity along the northward-developing warm front may support a couple of tornadoes given otherwise favorable low-level shear. Read more