SPC MD 2390

MD 2390 CONCERNING TORNADO WATCH 688... FOR CENTRAL AND EASTERN ARIZONA Mesoscale Discussion 2390 NWS Storm Prediction Center Norman OK 0605 PM CDT Wed Oct 21 2026 Areas affected...Central and Eastern Arizona Concerning...Tornado Watch 688... Valid 212305Z - 220100Z The severe weather threat for Tornado Watch 688 continues. SUMMARY...Large hail, severe wind gusts and a tornado threat will be possible across parts of central and eastern Arizona this evening. DISCUSSION...The latest surface analysis has a 1006 mb low over the Lower Colorado River Valley, with a trough extending east-northeastward across south-central Arizona. Low-level convergence is maximized near this surface trough and will be a potential location for cell initiation. Further to the north, low-level convergence is maximized along the Mogollon Rim due to upslope flow. To the south of the rim, surface dewpoints across much of central Arizona are in the upper 50s to lower 60s F, with the RAP showing SBCAPE from 1000 to 2000 J/kg. Over the top of this moist and unstable airmass, a mid-level jet is analyzed by the RAP over west-central Arizona. Large-scale ascent is likely maximized to the east of this feature over ...