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Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.

Monday, October 25, 2021

SPC Oct 25, 2021 0600 UTC Day 2 Convective Outlook

SPC 0600Z Day 2 Outlook Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Mon Oct 25 2021 Valid 261200Z - 271200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN AND CENTRAL PLAINS... ...SUMMARY... Scattered severe thunderstorms associated with large hail, wind damage and an isolated tornado threat are expected across parts of the southern and central Plains from late Tuesday afternoon through the evening into the overnight. ...Southern and Central Plains... An upper-level trough will move eastward across the southern Rockies on Tuesday as an associated 60 to 80 knot mid-level jet moves into the southern and central High Plains. Southwest mid-level flow will be in place ahead of the system across the southern and central Plains. The approach of the system will result in strong moisture advection across the southern and central Plains during the day with a corridor of moderate instability developing by late afternoon from west-central Texas northward into west-central Kansas. A capping inversion during the day will prevent convection initiation from taking place until late afternoon along and to the east of a dryline. Initially, thunderstorm development is expected to be isolated but storm coverage should steadily increase during the evening as the low-level jet strengthens. The storms should eventually organize into a line with MCS development possible during the mid to late evening. Model forecasts are in good agreement concerning the timing of the upper-level system and position of the moist axis. During the early evening, MLCAPE is forecast to reach the 1000 to 2000 J/kg range along much of the instability corridor. Supercell wind profiles are forecast in most areas with 0-6 km shear in the 35 to 45 kt range. In addition, mid-level lapse rates are forecast to be near 7.5 C/km in the vicinity of the dryline. This will be favorable for the development of supercells with large hail. In areas that destabilize the most, supercells with hailstones of greater than 2 inches in diameter will be possible. Supercells will also be capable of damaging wind gusts and an isolated tornado threat. A more widespread wind-damage threat should develop as storms congeal during the evening and move eastward across north-central Texas, west-central Oklahoma and south-central Kansas. The severe threat will become isolated during the early overnight period. Further to the north across northern Kansas and central to eastern Nebraska, a severe threat is also expected to develop. The northern end of a convective line should be located in central or northern Nebraska during the evening. Instability is forecast to be weaker this far north but strong deep-layer shear will still be adequate for severe storms. Isolated large hail and wind-damage are expected to be the primary threats. ..Broyles.. 10/25/2021 Read more LIVE: