SPC AC 290730

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0230 AM CDT Mon Jun 29 2020

   Valid 011200Z - 021200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
   MONTANA VICINITY...ACROSS PARTS OF THE EASTERN DAKOTAS AND INTO
   MINNESOTA...AND PARTS OF THE MID SOUTH/SOUTHEAST AND VICINITY...

   ...SUMMARY...
   A few strong/locally severe storms will be possible over the Montana
   vicinity, across portions of the eastern Dakotas and Minnesota, and
   from the Mid MS/lower OH Valley area across the Mid South and
   Southeast on Wednesday.

   ...Synopsis...
   As negatively-tilted short-wave troughing shifts northward out of
   the northern Plains into the Canadian Prairie, longer-wavelength
   upper troughing will remain over the western U.S. on Wednesday. 
   Meanwhile, a second area of troughing will remain over the East,
   with sharp ridging across the central U.S. in between the two
   troughs.

   At the surface, a baroclinic zone is forecast to linger from Montana
   to the Great Basin/northern California, while a weak low lingers of
   the Kansas/Oklahoma vicinity.  A weak cool front is also forecast to
   shift southeastward across the Southeast U.S. through the period.

   ...Parts of Montana and vicinity...
   As diurnal heating leads to modest destabilization across Montana
   and vicinity, isolated afternoon storm development is expected to
   occur, aided by a vort max progged to pivot east-northeastward
   across the area within a belt of enhanced cyclonic flow.  Given
   ample shear, a couple of stronger cells may evolve, capable of
   producing locally damaging wind gusts during the afternoon and early
   evening hours, prior to the onset of diurnal boundary-layer
   stabilization.

   ...Eastern ND/northeast SD into northern and western MN...
   Though stronger ascent, and stronger deep-layer wind field, will be
   in the process of shifting north of the International border early
   in the day Wednesday, a few storms may redevelop over the eastern
   Dakotas and into Minnesota during the afternoon, near the
   weakening/remnant surface boundary.  Sufficient mid-level flow is
   expected across the area, contributing to shear sufficient for some
   storm organization, particularly given steep mid-level lapse
   rates/moderate CAPE expected.  As such, will maintain a 5%/MRGL risk
   area across this region, given some lingering potential for damaging
   winds and/or hail.

   ...Mid MS/lower OH Valleys to the Southeast...
   As disturbances aloft -- within broad/background cyclonic
   west-northwesterly flow -- shift across the Mid South and Southeast
   once again Wednesday, another day of scattered, southeastward-moving
   storms/storm clusters is expected to evolve as the airmass diurnally
   destabilizes.  With moderate/nearly unidirectional flow through the
   lower and middle troposphere sufficient for convective organization,
   locally gusty/damaging wind will be possible with more vigorous
   storms.  Storms will likely continue well into the overnight hours
   -- moving off the Carolina Coast while sagging southward across the
   Tennessee Valley and southern Appalachians -- but with a gradual
   decrease in wind risk.

   ..Goss.. 06/29/2020

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