Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat May 13 2023 01:03:05 ACUS01 KWNS 130102 SWODY1 SPC AC 130101 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0801 PM CDT Fri May 12 2023 Valid 130100Z - 131200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSOURI VALLEY... ....SUMMARY... Strong to severe thunderstorms, associated with large hail, wind damage and a few tornadoes will continue this evening across parts of the mid Missouri Valley. An isolated severe threat will also continue this evening from the central and southern Plains. ....Mid Missouri Valley/Central Plains... An upper-level low, evident on water vapor imagery, will continue to move slowly northeastward across central and northeastern Nebraska this evening. At the surface, a low is analyzed over east-central Nebraska, with an occluded front extending southeastward from the low across eastern Nebraska. A dryline and cold front is analyzed southward into eastern Kansas. To the east of these boundaries, a moist airmass is present with surface dewpoints in the upper 60s and lower 70s. The RAP has moderate instability across much of this airmass. Strong to severe thunderstorms are ongoing along the western edge of the moist sector from far eastern Nebraska into eastern Kansas. A severe threat is expected to continue across much of the mid Missouri Valley this evening and into the early overnight period. The Omaha 00Z sounding is sampling the instability axis well, with MLCAPE near 2000 J/kg and 850-500 mb lapse rates near 7 C/km. 0-6 km shear is near 40 knots, with 0-3 km storm relative helicity around 350 m2/s2. This will continue to be favorable for supercells with all severe weather hazards this evening. A 30 to 40 knot low-level jet is located over far eastern Nebraska. Supercells within and near the low-level jet, from near Omaha southward into northeastern Kansas and far northwest Missouri, will have a threat for tornadoes for a few more hours this evening. Supercells will also likely be associated with large hail. Hailstones of greater than 2 inches in diameter may occur with the stronger updrafts. A wind-damage threat will also likely continue with supercells and along the leading edge of multicell line segments. Further south into southeastern Kansas, low-level shear is considerably weaker. This suggests that the primary threats will be large hail and wind damage, associated with supercells and the more intense multicells. ....Southern Plains... Flow at mid-levels is generally weak across most of the southern Plains. At the surface, a cold front is located from central Oklahoma southwestward into west Texas. Ahead of the cold front, surface dewpoints are generally in the lower to mid 70s F. This is contributing to strong instability across much of the southern Plains, where the RAP is analyzing MLCAPE in the 3500 to 4500 J/kg range. The 00Z soundings at both Oklahoma City and Dallas/Fort Worth have MLCAPE between 4000 and 4500 J/kg. In spite of the relatively weak mid-level flow, steep lapse rates near 8.0 C/km are evident in the 700 to 500 mb layer, suggesting large hail will be possible with the more intense storms. Further southwest into northwest Texas, a line segment has organized. Wind-damage will be possible as this line moves eastward across north-central Texas this evening. The severe threat is expected to become more isolated late this evening. ...Broyles.. 05/13/2023 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .