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.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z