Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS11 KWNS 192230
SPC MCD 192230
Mesoscale Discussion 0520
NWS Storm Prediction Center Norman OK
0530 PM CDT Wed Apr 19 2017
Areas affected...Southeast Nebraska...Southwest Iowa
Concerning...Tornado Watch 148...
Valid 192230Z - 192330Z
The severe weather threat for Tornado Watch 148 continues.
SUMMARY...Severe thunderstorm threat should increase across Tornado
Watch 148 over the next few hours.
DISCUSSION...Large-scale forcing for ascent appears to be increasing
across eastern NE early this evening, per visible satellite imagery
where rapid increase in elevated convection is noted. Frontal
convection should increase markedly over the next few hours and
spread/develop from southeast NE into southwest IA. With low-level
warm advection expected to increase across central IA it appears
thunderstorms will evolve along/north of the warm front as well.
Large hail and damaging winds are the primary threats with
convection along the cool side of each boundary while any meaningful
tornado threat should be confined to warm-sector supercells that
don`t get undercut by the cold front.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 41829677 41829445 39979521 39989747 41829677