SPC AC 141948

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0248 PM CDT Sun Jun 14 2026

   Valid 142000Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MIDDLE
   OHIO VALLEY INTO THE NORTHEAST...AND ALONG THE SOUTHERN APPALACHIANS
   INTO THE MID-ATLANTIC...

   ...SUMMARY...
   Scattered severe thunderstorms capable of damaging wind gusts and
   some hail are expected this afternoon and evening from the Upper
   Ohio River Valley into the Northeast, and from the Appalachians into
   the Mid-Atlantic States.

   ...20z...
   The previous forecast remains on track with only minor adjustments
   required based on recent convective trends. As of 19:30 UTC, MRMS
   imagery depicts an intensifying squall line with a history of severe
   gusts moving eastward across northeast OH. This section of the
   squall line remains well-phased with ascent and stronger mid-level
   flow associated with the shortwave trough aloft. Downstream of the
   squall line, a recent 18 UTC RAOB from PIT sampled a strongly
   sheared and uncapped environment that should maintain squall line
   intensity through early evening and lends confidence in the ongoing
   wind forecast. 

   Further south across the Mid-Atlantic, temperatures continue to warm
   into the mid 90s with the early stages of organized convection noted
   along the Appalachians and within a surface trough in north-central
   NC. Regional 18 UTC soundings sampled a sufficiently buoyant and
   strongly sheared environment that will likely promote further
   organization and intensification through the evening hours as
   convection spreads east/northeast. See MCD #1141 for regional
   details and the previous discussion below for additional forecast
   information.

   ..Moore.. 06/14/2026

   .PREV DISCUSSION... /ISSUED 1131 AM CDT Sun Jun 14 2026/

   ...Mid/Upper Ohio Valley to the Northeast/New England...
   Morning surface analysis places a low over southeastern Lower MI,
   along an extensive cold front that arcs from northwestern Ontario
   south-southwestward into southern IL and then more southwestward
   through southern MO and central OK into the TX Permian Basin. This
   cold front and attendant low are forecast to progress eastward
   today, moving just ahead of a shortwave trough pivoting within the
   base of a larger upper trough from the OH Valley through the
   Northeast. Moderate to strong mid-level flow will accompany this
   shortwave, with mesoanalysis currently estimating 60 kt at 500 mb
   within the base of this shortwave over the IA/MO border. 

   Moderate low-level moisture is already in place ahead of this
   shortwave trough and associated cold front across the OH Valley,
   with upper 60s dewpoints currently observed over much of IN and OH.
   Low-level moisture decreases with northeastward extent, with low 60s
   dewpoints in place across much of PA and western NY, decreasing to
   the upper 50s across much of New England. Filtered daytime heating
   will contribute to airmass destabilization ahead of the cold front,
   with temperatures in the 80s and dewpoints in the mid 60s resulting
   in moderate buoyancy (i.e. MLCAPE around 800-1000 J/kg) across the
   Middle to Upper OH Valley. Modest height falls and ascent along the
   front will support thunderstorms within this moderately buoyant
   environment. Around 40 kt effective shear could support a few
   initial/semi-discrete supercells prior to more prevalent
   upscale-growing linear modes, with the primary concern being
   damaging wind gusts, particularly in the OH/PA border vicinity where
   the best overlap of better buoyancy and shear exists. A brief
   tornado and/or hail could also occur given the relative strength of
   the wind profiles. 

   Cooler temperatures and lower dewpoints will lead to more limited
   buoyancy farther northeast (i.e. from western NY into New England).
   However, the airmass is still expected to destabilize, supporting
   afternoon/evening thunderstorms along and ahead of the front.
   Effective shear around 35 to 40 kt should be sufficient for
   occasional organization and some stronger bowing segments. 

   ...Mid-Atlantic to TN/southern Appalachians/Carolinas...
   Thunderstorm development is anticipated along the modest lee
   troughing expected to extend across the region this afternoon and
   evening. This development is forecast to occur well ahead of the
   cold front mentioned in the previous subsection, resulting in a
   separate area of strong to severe thunderstorm potential from the
   Carolinas into the Mid-Atlantic. 

   Dewpoints across the region currently range from the upper 60s
   across the central MD and VA to the low 70s across the central
   Carolinas. Heating of this airmass will result in moderate to strong
   surface-based buoyancy. Shear will be weaker than areas farther
   north but still sufficient for organized clusters and/or perhaps a
   few supercells. Primary risk will be damaging gusts, with this
   potential maximized from eastern PA and NJ southward through the VA
   Tidewater region. 

   Also worth noting is the trend within the recent guidance for a
   modestly organized convective line to progress from Middle
   TN/northern AL through northern GA. This line appears to result from
   upscale growth of a relatively higher concentration of multicells
   initially over the western TN vicinity near a weak surface low.
   Consistency within the guidance is high enough to extend 15% wind
   probability back into middle TN/northern AL to cover this threat.

   ...Southern Rockies into the Southern High Plains...
   Afternoon thunderstorm development is anticipated across central NM
   amid persistent westerly flow aloft and modest mid-level moisture.
   Deep-layer shear is strong enough to support a few organized
   updrafts capable of hail with any of the early, more cellular
   development. Thereafter, a trend towards a more outflow-dominant,
   linear structure is anticipated, and a few damaging gusts are
   possible with any stronger bowing segments.

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