Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0256 PM CDT Fri Jul 19 2024
Valid 192000Z - 201200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHWEST
NEBRASKA INTO PORTIONS OF WESTERN/CENTRAL KANSAS...
...SUMMARY...
Scattered to numerous severe gusts (60-75 mph) are possible this
afternoon into tonight across portions of the central Great Plains.
...20Z Update...
Primary adjustment to the ongoing forecast was to shift the northern
bound of the Enhanced risk slightly farther south to account for the
progression of convection in southwest Nebraska/northwest Kansas. An
area of agitated cumulus have developed in south-central North
Dakota. The environment and some CAM guidance suggest some potential
for large hail and severe gusts should storms develop. The Marginal
risk area has been expanded to account for this possibility.
..Wendt.. 07/19/2024
.PREV DISCUSSION... /ISSUED 1126 AM CDT Fri Jul 19 2024/
...Central/southern Great Plains...
Visible-satellite imagery late this morning shows several clusters
of sub-severe thunderstorms over central/northern NE into SD ahead
of a southeastward-migrating mid-level shortwave impulse. The
disturbance is evident in water-vapor imagery and approaching the
Black Hills vicinity. The mid- to upper-level anticyclone over the
Great Basin/Desert Southwest will move little during the period, and
aid in allowing the aforementioned disturbance to move southeastward
into eastern NE/western IA later tonight.
Morning surface analysis places a moist axis from western KS
northward into west-central NE and SD with lower 60s deg F surface
dewpoints. This adequately moist airmass will become moderately
unstable by mid afternoon across southwest NE southward into extreme
eastern CO and western KS (2000-2500 J/kg MLCAPE). It seems
plausible a southward-moving cluster will emerge from the midday
ongoing thunderstorm activity over central NE and move into a
boundary layer featuring steep 0-3 km lapse rates. Veering flow
with height will support 35-45 kt effective shear and promote storm
organization. Large hail and severe gusts will be possible with the
stronger storms over mainly parts of NE and SD. As additional
storms develop, a coalescing into one or more clusters will likely
evolve by late afternoon over the central Great Plains.
Additionally, scattered storm development is expected near/east of
the Front Range with coverage forecast to increase as storms move
into a more moist environment over eastern CO. Upscale growth into
one or more linear clusters is expected before an MCS evolves
(perhaps from a merging of thunderstorm clusters) over western KS by
this evening. Severe gusts will be the primary hazard later this
afternoon through the late evening. As storms move farther
southwest into central KS and parts of northwest OK/TX Panhandle
later this evening, weaker instability and greater CINH will likely
lead to a gradual decrease in storm intensity and severe risk.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/T9qYQH
