SPC Mar 18, 2025 0600 UTC Day 1 Convective Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1239 AM CDT Tue Mar 18 2025

Valid 181200Z - 191200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
NEBRASKA INTO IOWA...

...SUMMARY...
Isolated, marginally severe hail is possible later tonight from
eastern Nebraska across much of Iowa.

...NE/IA...

Seasonally strong upper trough is progressing inland across CA into
the Great Basin early this morning. This feature is forecast to
advance across the central Rockies into the High Plains by early
evening as 90+kt 500mb speed max translates across NM into OK by the
end of the period. This evolution warrants a lee cyclone
repositioning itself over western KS by 19/00z with subsequent
movement into northeast KS/northwest MO by sunrise. LLJ will
increase markedly across eastern OK/KS during the late evening, and
strong low-level warm advection will focus along a corridor from
eastern NE into northern IA. Increasing large-scale ascent and
steepening mid-level lapse rates will aid buoyancy along this
corridor as profiles moisten and saturate near 2km. Forecast
soundings exhibit MUCAPE in excess of 700 J/kg and this should
support robust elevated convection ahead of the approaching short
wave. However, due to the limited instability, it appears the
primary risk with this activity will be isolated, marginally severe
hail. Greatest risk for strong storms will be across eastern
NE/western IA along the nose of the LLJ.

..Darrow/Moore.. 03/18/2025

Read more