Clearpost.online It's your post, so post it!

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
0102 AM CDT Thu Apr 28 2022

Valid 291200Z - 301200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PORTIONS
OF FAR SOUTHEAST NEBRASKA INTO CENTRAL/EASTERN KANSAS AND
NORTH-CENTRAL OKLAHOMA...

...SUMMARY...
Severe thunderstorms capable of all hazards are possible Friday
afternoon into Friday night across portions of the southern and
central Plains into the lower Missouri Valley.

...Synopsis...

A negative-tilt mid/upper trough over the Rockies will eject
eastward into the Plains on Friday. Forecast guidance has trended a
bit further south with this system over the past 1-2 days.
Additionally, guidance is less aggressive with developing an upper
low over the northern/central Plains, maintaining an open wave at
least through early evening. These trends will result in stronger
large-scale ascent and increasing vertical shear overspreading
NE/KS/OK by late afternoon. A surface low will deepen as it shifts
eastward across western/central KS through Friday evening, before
lifting northeast toward western IA by Saturday morning. A surface
dryline will extend south/southwest from the low across central
KS/OK into west-central TX. Southerly low-level flow will maintain
strong moist advection ahead of the dryline and generally low to mid
60s F dewpoints are expected across OK/KS and into southeast NE. A
cold front will surge east/southeast during the afternoon into
Friday night, beco*ing positioned from southwest IA to eastern OK
and north-central TX by Saturday morning. 

While some uncertainty remains regarding the warm sector and
midlevel capping, the overall pattern suggests a couple of focused
areas for severe thunderstorms are possible. One area being near the
surface low/triple point across parts of northern KS into southern
NE. The second being during late afternoon/early evening along the
surface dryline from central KS into north-central OK. Finally,
additional storms are likely to develop along the eastward-advancing
cold front overnight, though this activity may be elevated. 

...Parts of southeast NE into central/eastern KS and OK...

Much of the higher-quality warm sector will be focused roughly
across the eastern half of OK/KS into far southeast NE where
southerly low-level flow to around 1 km AGL is forecast. This will
maintain a moist airmass east of the dryline. Some forecast
guidance, particularly the operational NAM, maintains rather cool
temperatures across the warm sector with cloudiness prevailing
through the day. However, this appears to be an outlier co*pared to
most other guidance, with NAM surface high temperatures perhaps 5-10
deg F too cool. This is resulting in a capping inversion that is
likely too strong. Modified forecast soundings for warmer surface
temperatures do result in erosion of the cap. Therefore, while some
capping may limit storm coverage, it is anticipated that at least a
few supercells will develop in a narrow corridor along the dryline
by late afternoon/early evening. Very steep midlevel lapse rates and
elongated hodographs above favorably-curved low-levels indicate
significant hail potential with these storms. Furthermore, steep
low-level lapse rates and moderate 0-3 km MLCAPE values amid
increasing SRH as a low-level jet increases during the evening,
indicate that tornadoes will also be possible, a couple of which may
be significant (EF 2+). Of note, most CAMs guidance appears to leave
an outflow boundary across far southern KS associated with Thursday
night/early Friday morning convection shifting east into MO. This
boundary would extend west to east, perpendicular to the dryline and
could be a further area of focus for severe thunderstorm development
during the late afternoon. 

The southward extent of higher risk probability is uncertain, but
generally will decrease with southward extent across Oklahoma as
stronger ascent will be focused to the north and the influence of
the cap will be greater.

A second round of convection may develop during the mid/late evening
along the eastward-advancing cold front. This activity will likely
be elevated and beco*e linear, though some isolated hail threat
could continue eastward into MO. 

...Portions of northwest KS into western/central NE...

Strong to severe thunderstorms are expected to develop near the
deepening surface low across northwest KS by mid-afternoon.
Boundary-layer moisture will be lower quality co*pared to further
east, with dewpoints in the 50s to near 60 F. However, very steep
midlevel lapse rates will support moderate instability. Effective
bulk shear values will support initial supercells capable of large 
to very large hail. With time, this convection may develop into
bowing line segments as convection shifts northeast into NE.

..Leitman.. 04/28/2022