Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 02 2025 01:02:46 ACUS01 KWNS 020102 SWODY1 SPC AC 020100 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Mon Sep 01 2025 Valid 020100Z - 021200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS AND IN SOUTH-CENTRAL ARIZONA... ....SUMMARY... Isolated severe thunderstorms may occur across parts of northern and western Oklahoma this evening, with isolated large hail and damaging winds the main threats. A marginal severe threat will also be possible in parts of south-central Arizona. ....Northwest Oklahoma... At mid-levels on water vapor imagery, a shortwave trough is moving across the central U.S., embedded in northwesterly flow. At the surface, a moist airmass is located in the southern and central Plains with dewpoints in the lower to mid 60s F. The RAP has a pocket of moderate instability over southern Kansas and northern Oklahoma with MLCAPE estimated to be in the 1000 to 1500 J/kg range. Isolated to scattered thunderstorms are ongoing within this pocket of instability. These storms will persist for a couple more hours, moving southeastward across parts of western and central Oklahoma. RAP forecast soundings in north-central Oklahoma early this evening have 0-6 km near 45 knots. In addition, the Oklahoma City 00Z soundings has a somewhat steep lapse rates in the 0-3 km layer. This suggests that isolated severe gust will be possible with the stronger cells. Hail could also occur. ....Northeast North Dakota... Northwesterly mid-level flow is evident on water vapor imagery over parts of the northern Plains. At the surface, a moist airmass in place with surface dewpoints in the lower to mid 60s F. Isolated thunderstorms are ongoing near an axis of maximized low-level convergence in northeastern North Dakota and far northwest Minnesota. Although a strong storm will be possible this evening, any severe threat is expected to be limited due to weak deep-layer shear and poor lapse rates. ....South-central Arizona... Water vapor imagery shows a plume of mid-level moisture over south-central Arizona. A few thunderstorms are ongoing within this plume in the Phoenix area. This convection is located within a pocket of instability, where SBCAPE values are estimated in the 1000 to 1500 J/kg range, according to the RAP. The 00Z sounding at Tuscon has a surface dewpoints of 55 F, with 0-3 km lapse rates of 9.7 C/km, with a dry adiabatic temperature profile from the surface to 700 mb. This should be favorable for isolated severe gusts with the stronger cells for another hour or two. ...Broyles.. 09/02/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .