Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
710 ACUS48 KWNS 190857 SWOD48 SPC AC 190856 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Thu Sep 19 2024 Valid 221200Z - 271200Z ...DISCUSSION... Some severe potential is evident on both D4/Sunday and D5/Monday. But both regimes appear to be focused on the mesoscale, rendering insufficient predictability at this time frame for a 15 percent highlight. A combination of both low predictability and potential is apparent mid-week next week. A southern-stream shortwave trough is expected to progress from the Southwest into the central Great Plains on D4. A confined belt of enhanced mid-level southwesterlies overspreading a corridor of rich boundary-layer moisture just ahead of an attendant weak surface cyclone may yield a severe-storm threat on Sunday afternoon. Per consensus of latest guidance, the most favored area could be centered around the Lower MO Valley. This shortwave trough may continue northeastward towards the Upper MS Valley into D5. Guidance spread increases with the degree of forward speed, along with potential weakening of the flow fields surrounding the trough. Still, a similar setup may occur on Monday in parts of the Midwest, centered on the southwest Great Lakes region. Mid-level lapse rates on both days are uniformly depicted to be weak, suggestive of lower-end severe potential. ..Grams.. 09/19/2024