Severe Storm Outlook Narrative (AC)
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ACUS48 KWNS 220713
SPC AC 220711

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0111 AM CST Wed Nov 22 2017

Valid 251200Z - 301200Z

The mid-upper-level flow will continue to be dominated by a
west-to-east, ridge-trough pattern across the United States. The
continued northwest flow across the eastern United States will
maintain/reinforce the already dry airmass. By late weekend the
mid-level pattern should break down with the arrival of a more
substantial trough moving across the country. As this trough moves
into the Plains during the Day 6-8 time frame, surface cyclogenesis
in the central Plains will allow low-level moisture to be drawn
northward ahead of a surface cold front. Despite the likely presence
of strong tropospheric shear associated with this trough, concerns
abound regarding the depth and quality of moisture return. This
leads to considerable uncertainties regarding thunderstorm
initiation, timing, duration, and even location. Thus predictability
of any severe potential remains too low.

..Marsh/Smith.. 11/22/2017 is the U.S. government's official web portal to all federal, state and local government web resources and services.