242
ACUS01 KWNS 210100
SWODY1
SPC AC 210059

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Mon May 20 2024

Valid 210100Z - 211200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN THE CENTRAL
HIGH PLAINS ACROSS SOUTHERN NE...

...SUMMARY...
Scattered severe thunderstorms are expected through tonight from the
central High Plains to parts of the Upper Midwest. The greatest
concentration of tornadoes, large hail, and severe wind is expected
over northeast Colorado into southern Nebraska, and far northwest
Kansas. This will include potential for a strong tornado, very large
hail, and significant severe gusts.

...01Z Update...
Primary concern is with ongoing convection developing across
northeast CO into the southwest NE Panhandle. With a current of east
to southeast 0-1 km winds expected to increase during the next few
hours, afternoon CAM guidance along with recent WoFS runs are
insistent on long-lived supercell development along the southern
flank of the thunderstorm plume. This appears likely to emanate out
of the Akron, CO vicinity and move east towards the CO/KS/NE border
area. With low 60s surface dew points across northwest KS marking
the northwest extent of MLCAPE in excess of 1500 J/kg, a supercell
or two impinging on the increasingly buoyant airmass downstream, may
become intense. In addition to the risk for very large hail,
enlarging low-level hodographs will support potential for cyclic
tornadogenesis, especially in the 02-05Z time frame. Transition from
tornadic supercell to a bow will likely occur during the late
evening to early morning, with probable movement along the
pronounced MLCAPE gradient into at least south-central NE.
Increasingly large MLCIN is anticipated overnight across KS,
suggesting that the severe wind swath will remain latitudinally
confined. Downstream convection, ongoing across southeast NE,
suggests the upstream severe wind threat may wane somewhat near dawn
as the MCS approaches the Mid-MO Valley. But the potential for a
well-organized MCS to persist across much of southern NE is apparent
and warrants expansion of the level 3-ENH risk.

Elsewhere, scattered large hail and sporadic severe wind gusts
should occur this evening into the early overnight from southeast NE
to southeast MN. A lower-end QLCS across Lower MI into northwest IN
may produce locally damaging winds with strong gusts through the
rest of this evening. But this convection will likely diminish
overnight.

..Grams.. 05/21/2024

$$