Day 1 Outlook Day 2 Outlook Day 3 Outlook Days 4-8 Outlook

Day 1 Outlook Convective Tornado
Hail Wind
Categorical Day1 1300Z Outlook
  
Images courtesy of the NWS Storm Prediction Center
 Forecast Discussion

  
000
ACUS01 KWNS 191236
SWODY1
SPC AC 191234

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0734 AM CDT Tue Oct 19 2021

Valid 191300Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
MIDDLE MISSOURI VALLEY...

...SUMMARY...
Strong thunderstorms posing a risk for isolated severe hail are
possible late tonight (early Wednesday morning) across parts of
northeastern Nebraska and southeastern South Dakota into
northwestern Iowa.

...Middle Missouri Valley including portions of NE/SD/IA...
A closed low centered over Utah/western Colorado this morning will
continue eastward and reach the central High Plains by evening. The
progression of this system will influence modest surface
cyclogenesis across Kansas/Nebraska in tandem with the sharpening of
an eastward-moving cold front that will cross the region tonight
into Wednesday. Pre-frontal moisture advection into the region will
be modest overall given limited source region availability, but
middle 50s F surface dewpoints could develop into the middle
Missouri Valley late tonight. 

These forcing for ascent/moisture trends are likely to influence a
nocturnal maximization of thunderstorms, with initial isolated
development across northern Nebraska/southern South Dakota becoming
a bit more numerous (scattered) into the overnight in areas near the
front and near/north of the surface low, including northeast
Nebraska/southeast South Dakota and northwest Iowa. Steepening
mid-level lapse rates atop stable but moistening low-levels could
support MUCAPE near/above 1000 J/kg. Owing to strong deep-layer
southwesterly winds, very strong shear through the cloud-bearing
layer could support some elevated supercells capable of isolated
severe hail overnight.

..Guyer/Leitman.. 10/19/2021

$$