####018004019#### ACUS01 KWNS 241938 SWODY1 SPC AC 241937 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0237 PM CDT Wed Apr 24 2024 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TEXAS SOUTH PLAINS INTO THE PERMIAN BASIN... ...SUMMARY... Isolated large hail and severe gusts will be possible this evening from the Texas South Plains into the Permian Basin. ...20Z Update... ...TX South Plains into Permian Basin... Forecast outlined in the previous discussion (appended below) remains valid. Isolated thunderstorms still appear possible within the destabilizing air mass from the TX South Plains into the Permian Basin. Moderate buoyancy (i.e. MLCAPE from 2000 to 2500 J/kg) and vertical shear (i.e. 0-6 km bulk shear from 40-50 kt) support the potential for supercells within any sustained/mature convection. Primary risk with any supercells would be large to very large hail up to 2.5" in diameter and strong gusts up 70 mph. Tornado risk still appears low, although non-zero given the increasing low-level moisture and shear expected this evening. ...OK into Central/Eastern KS... Thunderstorms are expected to develop tonight from central OK into central and eastern KS as warm-air advection increases throughout the warm sector. A few stronger storms capable of marginally severe hail around 1" in diameter are possible through Thursday morning. ..Mosier.. 04/24/2024 .PREV DISCUSSION... /ISSUED 1120 AM CDT Wed Apr 24 2024/ ...West central TX this evening... Water-vapor imagery this morning shows a midlevel low/shortwave trough west of the southern CA/Baja California coasts and it will move into the lower CO Valley by tomorrow morning. A mid-level ridge situated over the southern Rockies will gradually move east over the southern High Plains today. A lee trough will become more pronounced throughout the day and act to maintain southerly low-level flow across much of TX south of a warm front. The warm front initially analyzed this morning near the Red River will slowly move northward. Late morning surface observations over the Permian Basin/Concho Valley indicate low to mid 60s dewpoints. The 12z MAF raob showed a 7.9 deg C/km 700-500 mb lapse rate, indicative of an elevated mixed layer. Weak forcing for ascent at best is expected beneath the mid-level shortwave ridge, thereby limiting potential storm coverage. Despite the associated forcing/capping concerns, convective inhibition will erode considerably by 21-00z. Uncertainty remains regarding storm development, but additional heating this afternoon --perhaps delayed a bit due to considerable low cloud cover-- will result in moderate buoyancy (2000-2500 J/kg MLCAPE). Relatively weak but veering winds in the low levels beneath 65-kt westerly 250-mb flow will support a conditional threat for supercells. Deeper mixing over the Permian Basin may be enough to overcome and lead to a couple of storms by late afternoon/early evening along the dryline. Isolated very large hail up to 2.5 inches in diameter and severe outflow gusts of 60-70 mph are possible. There will be an increase in low-level shear this evening and low-level moisture will be greater compared to yesterday, so an isolated tornado will also be possible in a narrow time window this evening before inhibition increases and storms weaken. ...OK into KS through tonight... Elevated thunderstorms near the OK/KS border late this morning are likely the result of low-midlevel warm advection and weak buoyancy rooted near 700 mb. Some of this convection could persist this afternoon but it is uncertain whether intensification will occur with this activity and whether a marginal hail threat develops. The more probable risk for elevated storms will occur tonight coincident with strengthening warm advection and increasing low-level moisture. $$