SPC AC 011250

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0750 AM CDT Tue Apr 01 2025

   Valid 011300Z - 021200Z

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

   ...SUMMARY...
   Rapid, intense thunderstorm development should occur this evening
   over parts of the central/southern Plains. A few supercells with a
   risk for very large hail and strong tornadoes appear possible,
   particularly across north-central Oklahoma into eastern Kansas. A
   line of thunderstorms should also develop and pose a threat for
   severe/damaging winds across eastern Kansas into western Missouri
   tonight.

   ...Synopsis...
   Upper troughing over the western CONUS will undergo amplification
   today as multiple embedded mid-level shortwave troughs move
   east-northeastward across the Southwest and into the
   central/northern Plains. A pronounced southwesterly mid-level jet
   will also overspread the southern/central Plains this evening and
   overnight. Low-level moisture centered around 850 mb has been
   streaming northward this morning across TX in association with a
   strong southerly low-level jet. Surface dewpoints have also been
   increasing across the Rio Grande Valley into south-central TX. This
   trend is expected to continue through the day, as a surface low
   deepens as it develops from eastern CO into western KS through the
   afternoon. This low is forecast to further develop/reform across
   southwest KS into northwest OK as ascent associated with the
   mid-level jet overspreads the High Plains. A dryline will extend
   southward from this low across western OK into northwest TX. A cold
   front is expected to sweep east-southeastward over much of the
   central Plains and southern High Plains overnight, as the surface
   low develops northeastward towards eastern NE/western IA by early
   Wednesday morning.

   ...Central Plains into Missouri...
   It appears likely that the cap will erode over the central High
   Plains by late afternoon or early evening. At least isolated
   thunderstorms are expected to develop near the triple point in the
   south-central KS/north-central OK vicinity, and subsequently spread
   quickly northeastward. Moderate to locally strong instability,
   coupled with 50-60 kt of effective bulk shear, will easily support
   supercells, with an associated threat for very large hail (up to 2-3
   inches in diameter). As the southerly low-level jet markedly
   increases this evening, hodographs will enlarge and become
   elongated, with ample effective SRH to support tornadoes with any
   sustained supercells. Given the strength of the low-level flow
   expected (50-60+ kt southerly jet at 850 mb) and degree of low-level
   shear forecast, strong tornadoes appear possible. A line of
   convection should also erupt along the cold front in north-central
   to northeast KS tonight, and spread eastward into parts of western
   MO through early Wednesday morning. Even with the time of night, the
   overall environment appears quite favorable for severe/damaging
   winds, including the potential for isolated 75+ mph gusts. The
   Enhanced Risk has been expanded east-northeastward some across
   eastern KS into western MO to account for this scenario.

   ...Southern Plains...
   There is somewhat less confidence in convective initiation farther
   south into central/southern OK and western north TX late this
   afternoon and early evening. While low-level moisture will be
   greater across this area compared to locations farther north, with
   related stronger instability, large-scale ascent is forecast to be a
   bit weaker/delayed. Even so, a very favorable thermodynamic and
   kinematic environment will exist across this region, with MLCAPE
   ranging generally 2000-3000 J/kg by late afternoon, and 50+ kt of
   effective bulk shear present. Any supercell that initiates along the
   dryline, and which can be sustained into the early evening, would
   pose a risk for both very large hail and a strong tornado. While
   overall thunderstorm coverage may be more isolated with southward
   extent in OK, have opted to expand the Enhanced Risk southwestward
   along the I-44/I-35 corridors to account for an intense supercell or
   two which could form. Another round of severe convection may develop
   late tonight into early Wednesday morning as the cold front surges
   east-southeastward. Severe/damaging winds should be the main threat
   with this activity if it forms. But, given the strong low-level
   shear and ample MUCAPE forecast, tornadoes and perhaps large hail
   will also be a concern with any embedded supercells.

   ...Central Valley of California...
   With cold air aloft associated with the upper trough over the
   western CONUS, weak instability could develop by peak afternoon
   heating to support isolated strong thunderstorms. These could pose a
   risk for small hail, gusty winds, and perhaps a brief tornado or two
   across portions of the Central Valley in CA.

   ..Gleason/Leitman.. 04/01/2025

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