WPC Mesoscale Discussion

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SPC MD 1823

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Mesoscale Discussion 1823
NWS Storm Prediction Center Norman OK
0122 AM CDT Wed Aug 21 2019

Areas affected...Central into southeast NE

Concerning...Severe potential...Watch unlikely 

Valid 210622Z - 210815Z

Probability of Watch Issuance...20 percent

SUMMARY...Storms capable of large hail will be possible overnight.
Watch issuance for the ongoing storms is currently not anticipated.

DISCUSSION...Elevated convection that rapidly developed across
portions of central NE around 05Z has evolved into more of a
discrete mode as of 06Z, with a couple of potentially severe cells
noted just west and southeast of Grand Island. This activity is
likely being sustained by low-level warm advection, given the
strongly veering wind profiles noted in area VWPs. Steep midlevel
lapse rates (noted on 00Z soundings) and relatively rich low-level
moisture are supporting strong elevated buoyancy across the region,
with MUCAPE in excess of 3000 J/kg per recent mesoanalyses. 

With generally weak midlevel flow across this area, effective shear
is generally in the 20-30 kt range, so longevity of any one
particular cell may be relatively limited. However, given very
favorable instability noted above, a large hail threat will continue
with the strongest storms. The coverage and duration of the hail
threat should remain relatively limited, so watch issuance is
currently not anticipated for the ongoing storms. However, watch
issuance may be needed later this morning if the ongoing MCS across
the NE Panhandle begins to threaten this area.

..Dean/Edwards.. 08/21/2019

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


LAT...LON   41489914 41319814 40739603 40329603 40189686 40199732
            40269781 40349838 40539877 40869915 41489914 

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