SPC AC 040729

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0229 AM CDT Sat May 04 2024

   Valid 061200Z - 071200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHERN/CENTRAL PLAINS...

   ...SUMMARY...
   Numerous severe thunderstorms will likely develop and move eastward
   Monday afternoon and evening across parts of the southern/central
   Plains. Strong tornadoes, very large to giant hail, and damaging
   winds all appear possible.

   ...Synopsis...
   A negatively tilted upper trough with embedded 50-70 kt mid-level
   speed maximum will eject northeastward across the northern/central
   Plains on Monday. At the surface, the primary low should consolidate
   over the northern High Plains of eastern MT/western ND and vicinity,
   with a secondary surface low possibly developing over the central
   High Plains by Monday evening. A rather moist low-level airmass,
   with surface dewpoints generally in the mid 60s to low 70s, will
   spread northward across the southern/central Plains ahead of an
   eastward-mixing dryline. A warm front should eventually extend
   eastward across parts of NE/IA, and this boundary will probably be
   the northern limit of appreciable severe-thunderstorm potential.

   ...Southern/Central Plains...
   A severe-weather outbreak still appears possible across parts of the
   southern/central Plains on Monday, focused from south-central/
   southeast NE into central/eastern KS and much of OK. Robust diurnal
   heating of the moist low-level airmass, coupled with steep mid-level
   lapse rates overspreading much of the warm sector, will likely
   foster moderate to strong instability (MLCAPE generally ranging from
   2000-3500 J/kg) by Monday afternoon. Enhanced mid-level winds and a
   favorably veering/strengthening wind profile with height through
   mid/upper levels will support around 40-55 kt of effective bulk
   shear, stronger with northward extent in KS/NE.

   Current expectations are for scattered supercells to erupt along the
   length of the dryline in south-central NE and western/central KS by
   mid to late Monday afternoon, coincident with stronger large-scale
   ascent overspreading this region. Given the rather favorable
   thermodynamic and kinematic parameter space, very large to giant
   hail (2-4 inch diameter) will likely be a threat with these initial
   supercells. The threat for tornadoes should quickly increase through
   the late afternoon and early evening in tandem with a strengthening
   southerly low-level jet. Ample 0-1 km and effective SRH shown in
   various NAM/GFS forecast soundings suggest a threat for strong
   tornadoes with any supercell that can remain discrete. With time
   Monday evening and into early Tuesday morning, upscale growth into
   multiple linear structures is probable, with an increased threat for
   severe/damaging winds, along with embedded tornadoes given the
   forecast strength of the low-level shear.

   The southward extent of the substantial severe risk into OK and
   north TX remains somewhat uncertain, as better forcing for ascent
   will tend to remain across the central Plains. Still, modest
   mid-level height falls should encourage isolated to perhaps widely
   scatted supercells developing along the length of the dryline into
   the southern Plains. Very large hail and strong tornadoes will be
   the main threats with any supercell that can develop and persist
   across this region Monday afternoon/evening. Model trends will also
   be monitored for a more favorable corridor of strong tornadoes and
   giant hail, which may necessitate greater severe probabilities for
   Monday in a later outlook.

   ..Gleason.. 05/04/2024

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z