MD 2187 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR SOUTHEAST NEBRASKA INTO SOUTHERN IOWA AND FAR NORTHWEST MISSOURI
Mesoscale Discussion 2187
NWS Storm Prediction Center Norman OK
0458 PM CDT Sat Sep 23 2023
Areas affected…Southeast Nebraska into southern Iowa and far
northwest Missouri
Concerning…Severe potential…Watch possible
Valid 232158Z – 240000Z
Probability of Watch Issuance…60 percent
SUMMARY…Developing thunderstorms across southeast Nebraska will
likely intensify over the coming hours, and will pose a risk for
large hail and severe wind. Watch issuance may be needed to address
this threat.
DISCUSSION…Over the past 30-60 minutes, a cluster of cumulus has
shown steady deepening on the intersection of the cold front and a
subtle surface trough. A few deeper towers are noted in IR and
low-level water-vapor imagery, which suggests convective initiation
is probable within the next hour or so. 50-60 knot winds between 6-8
km AGL is supporting elongated hodographs with effective bulk shear
values between 40-50 knots. This kinematic environment should
support organized convection, including the potential for splitting
supercells (though the propensity for splitting cells is somewhat
uncertain given strong ascent along the front, which may foster
somewhat quick upscale growth). The thermodynamic environment
immediately downstream is becoming increasingly supportive for
robust convection as surface temperatures warm into the upper 70s;
however, cooler temperatures further east into southern IA/northern
MO in the wake of prior convection cast some uncertainty onto the
downstream intensity. Regardless, the severe threat is expected to
increase in the coming hours across southeast NE into adjacent areas
of IA and MO, and watch issuance is probable.
..Moore/Thompson.. 09/23/2023
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…DMX…EAX…OAX…TOP…
LAT…LON 39999703 40469708 40859715 41009717 41989565 41979514
41689476 41019438 40309443 39939501 39779624 39759669
39999703
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