822
ACUS01 KWNS 061956
SWODY1
SPC AC 061955

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0255 PM CDT Sat Jul 06 2024

Valid 062000Z - 071200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
PLAINS...

...SUMMARY...
Scattered severe thunderstorms are expected across the central
Plains this afternoon into evening, including central/eastern
Nebraska and western/northern Kansas. Large to very large hail and
severe wind gusts are the primary hazards.

...20Z Update...

...Central Plains...
Strong to severe thunderstorms, including several intense
supercells, continue to evolve across southwest/south-central NE and
northwest KS, just to the east/southeast of a surface low centered
about 30 miles east of IML (in southwest NE). Moderate westerly flow
and associated vertical shear in the presence of moderate to strong
buoyancy will continue to support robust storm development into
south-central/southeast NE north-central/northeast KS. Large to very
large hail has been the primary risk so far, but a trend towards a
more outflow-dominant structure is still anticipated with severe
gusts then becoming the dominant hazard.

...Eastern CO/Western KS into far northwest NM and the western TX/OK
Panhandles...
Thunderstorm development is still possible this afternoon and
evening amid modest low-level convergence across the region. High
storm bases and steep low-level lapse rates should result in
outflow-dominant storms capable of a few damaging gusts.

..Mosier.. 07/06/2024

.PREV DISCUSSION... /ISSUED 1134 AM CDT Sat Jul 06 2024/

...Central/Southern Plains to Upper Midwest...
A shortwave trough over the western Dakotas will continue
southeastward, with a cyclonically curved belt of seasonally strong
westerlies (40+ kt) from the north-central High Plains to the
central Plains and middle/lower Missouri Valley. A weak area of low
pressure will migrate slowly eastward from northeast Colorado toward
the Nebraska/Kansas border vicinity as a weak front advances
southeastward across the central High Plains.

Moderate destabilization is expected near a surface trough across
western Kansas into southwest/south-central Nebraska, to the south
of ongoing showers/thunderstorms at midday generally I-80 and
northward. These initially elevated storms will probably
increasingly interface with a warming and modestly moist boundary
layer and trend increasingly surface-based this afternoon on their
southern periphery.

Steep 700-500 mb lapse rates from 7-8 C/km and a relatively strong
wind profile will support storm organization, potentially including
a couple of supercells capable of large to very large hail.
Relatively quick upscale growth into a couple of
southeastward-moving clusters is expected towards early evening.
Severe gusts will likely become more prevalent during this evolution
towards more outflow-dominant storms.

Further west, isolated thunderstorms will also be possible behind
the front from the central High Plains northeastward into southern
South Dakota. In this area, lower surface dewpoints and weaker
instability should keep the severe threat more isolated and
marginal. Some severe risk is also expected to develop southward
across parts of the southern High Plains, where a small or cluster
or two capable of strong/potentially severe wind gusts could occur.

...Northeast States...
Widely scattered thunderstorms are expected to develop and increase
this afternoon from the lower Hudson Valley and especially into
upstate eastern New York and northern New England, influenced by
higher terrain/differential heating as well as a wind shift/weak
eastward-moving front. Pre-convective MLCAPE may reach 1250-1500
J/kg, with relatively long/semi-straight hodographs with 50+ kt
effective shear. Sustained multicells are expected with some
possibility of a few transient/weak supercells. Localized 50-60 mph
gusts capable of wind damage are possible with the stronger storms
this afternoon through early evening.

$$