Severe Storm Outlook Narrative (AC)
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000
ACUS48 KWNS 210857
SWOD48
SPC AC 210855

Day 4-8 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0355 AM CDT Sat Oct 21 2017

Valid 241200Z - 291200Z

...DISCUSSION...
A significant upper trough may amplify southeastward through much of
the eastern U.S. during the early to middle portion of next week,
before losing amplitude and accelerating into the north Atlantic
late next week into next weekend, as upstream troughing amplifies
over the interior United States.  However, the medium range models
and their respective ensemble output suggest that both developments
remain characterized by low predictability, which contributes to
uncertainty regarding associated convective potential.  There does
appear at least some potential for low-topped convective development
in the presence of moderately strong southerly lower/mid
tropospheric flow, along/ahead of a surface front associated with
the lead wave advancing into and through the mid Atlantic and
Northeast on Tuesday.  The extent to which thermodynamic profiles
become conducive to lightning remains unclear, but it may not be out
of the question that convection could aid downward mixing of higher
momentum, and be accompanied by some risk for potentially damaging
surface gusts.  Even so, due to both low potential and low
predictability issues, severe weather probabilities remain below 15
percent through this period.

..Kerr.. 10/21/2017


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