SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Tue Jun 10 2025 Valid 110100Z - 111200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE RIO GRANDE VALLEY... ...SUMMARY... Severe storms associated with isolated large hail and damaging wind gusts are expected this evening across parts of the Rio Grande Valley. Marginally severe storms will be possible in parts of the southern Plains, central Gulf Coast states, and northwestern U.S. ...Rio Grande Valley/Southern Plains... A shortwave trough is evident on water vapor imagery over New Mexico. Ahead of the trough, a moist airmass is present over much of the southern Plains. The RAP suggests that moderate instability is confined to the Texas Coastal Plain and lower Rio Grande Valley, where surface dewpoints generally range from the upper 60s to mid 70s F. A severe convective cluster is located near the northwestern edge of moderate instability in the vicinity of Del Rio. This area of convection will continue to move southeastward across southwest Texas this evening. The WSR-88D VWP at Del Rio has 0-6 km shear near 25 knots. In addition, the RAP suggests that 700-500 mb lapse rates are between 7 and 7.5 C/km. This environment should be sufficient for an isolated severe threat. Organized line segments could be capable of isolated large hail and wind damage. The severe threat in the Rio Grande Valley may persist into the mid to late evening. Further to the east into parts of the southern Plains, convection associated with warm advection may develop later this evening into the tonight. This convection could pose a threat for hail and marginally severe wind gusts. ...Central Gulf Coast... A mid-level trough is evident on water vapor imagery over the Tennessee Valley and central Gulf Coast states. At the surface, a moist airmass is located from the lower Mississippi Valley eastward to the Atlantic Seaboard. Within this airmass, the RAP has an axis of moderate to strong instability analyzed from south-central Mississippi into central Alabama and central Georgia. Surface dewpoints near this axis are mostly in the lower 70s F. Although deep-layer shear is relatively weak along and near this instability axis, low-level lapse rates are steep. This could contribute to a marginal wind-damage threat early this evening. ...Northwestern States... A mid-level shortwave trough will approach the northern California coast this evening. Ahead of the trough, a somewhat moist airmass is present from northern California into southeastern Oregon, where scattered thunderstorms have developed this afternoon. Within this airmass, the RAP is estimating MLCAPE in the 250 to 500 J/kg range. Deep-layer shear appears to be relatively weak, with 0-6 km shear estimated to be between 20 and 30 knots. In spite of this, low to mid-level lapse rates are very steep. This could support a marginal wind-damage or hail threat for a couple more hours. ..Broyles.. 06/11/2025