Severe Storm Outlook Narrative (AC)
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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