Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 242147
SWOMCD
SPC MCD 242146
MNZ000-242345-

Mesoscale Discussion 1670
NWS Storm Prediction Center Norman OK
0446 PM CDT Sun Sep 24 2017

Areas affected...Portions of Minnesota

Concerning...Severe potential...Watch unlikely

Valid 242146Z - 242345Z

Probability of Watch Issuance...5 percent

SUMMARY...Isolated severe hail and/or damaging wind reports are
possible late this afternoon into this evening. However, watch
issuance is not expected.

DISCUSSION...Widely scattered thunderstorms have developed this
afternoon near a cold front pushing east across Minnesota. Surface
heating ahead of the front and sufficient boundary-layer moisture
have promoted modest mixed-layer buoyancy (e.g., values generally
around 500-1000 J/kg), tempered by relatively poor mid-level lapse
rates. However, mid/upper southerlies around 40-50 kt are offering
adequate effective shear for occasional updraft organization, in
turn yielding a threat of isolated severe hail. Moreover, dry
mid-level air, well-mixed boundary-layer profiles, and
small-scale/localized bowing segments may foster a few stronger wind
gusts prior to substantive nocturnal cooling this evening. Despite
this wind/hail potential, a lack of more robust buoyancy is expected
to keep most storms below severe limits, likely precluding watch
issuance.

..Picca/Guyer.. 09/24/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DLH...MPX...FGF...FSD...

LAT...LON   44129530 45829511 48119357 48249265 47719222 46449245
            43969393 43609459 43709509 44129530




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