Severe Storm Outlook Narrative (AC)
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815
ACUS11 KWNS 222256
SWOMCD
SPC MCD 222256
SDZ000-NDZ000-NEZ000-COZ000-MTZ000-WYZ000-230100-

Mesoscale Discussion 0495
NWS Storm Prediction Center Norman OK
0556 PM CDT Tue May 22 2018

Areas affected...far north-central Colorado...central/eastern
Wyoming...western Nebraska...western South dakota...southwestern
North Dakota...and southeastern Montana

Concerning...Severe potential...Watch unlikely

Valid 222256Z - 230100Z

Probability of Watch Issuance...5 percent

SUMMARY...An isolated hail/damaging wind threat will unfold across
the discussion area through the evening.  A WW issuance is not
anticipated due to the isolated nature of the threat.

DISCUSSION...Isolated to scattered thunderstorm activity was
gradually increasing in coverage and intensity across the discussion
area.  These storms were in a weakly to moderately unstable and
uncapped environment, with steep low- and mid-level lapse rates and
low 50s F dewpoints contributing to 1000-2000 J/kg MUCAPE.
Low-level shear is relatively weak, however, with any activity
becoming loosely organized due to modestly strong effective bulk
shear.  Storms should continue to generally propagate slowly
northward across the discussion area, and some upscale growth may
occur with storms across southeastern Wyoming over time.  The
overall threat for severe wind gusts and hail is expected to remain
isolated enough to preclude any WW issuance through the remainder of
the evening - although coverage of storms should continue to expand
through at least sunset as low-level warm advection increases.

..Cook/Grams.. 05/22/2018

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

ATTN...WFO...ABR...BIS...LBF...UNR...BOU...CYS...BYZ...RIW...

LAT...LON   43110742 43180763 44290767 45650677 46610412 46870260
            46920112 46670066 45940030 44890096 43630165 42570249
            41540319 40660391 40220466 40210522 40450560 40650575
            41410621 42330694 43110742




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