SPC AC 031952

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0252 PM CDT Mon Jul 03 2017

   Valid 032000Z - 041200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS WESTERN
   AND CENTRAL OKLAHOMA...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   ENHANCED RISK FROM SOUTHERN KANSAS SOUTH TO WESTERN NORTH TEXAS AND
   THE EASTERN TEXAS PANHANDLE...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS A LARGE
   PART OF THE CENTRAL AND SOUTHERN GREAT PLAINS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN
   MISSISSIPPI...NORTHERN ALABAMA...MIDDLE TENNESSEE...AND SOUTHERN
   KENTUCKY...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE CAROLINAS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NORTHERN
   INDIANA EASTWARD TO PORTIONS OF NEW JERSEY...

   ...SUMMARY...
   Widely scattered severe thunderstorms are expected across portions
   of the central and southern Plains, especially over portions of
   southern Kansas into Oklahoma. Isolated marginally severe storms are
   possible across the Ohio Valley into the northern Middle Atlantic,
   from northern Mississippi into Middle Tennessee, and over parts of
   the Carolinas.

   ...20Z Outlook Update...
   Portions of the Marginal, Slight, and Enhanced risk areas were
   expanded southward for this update based on latest high-resolution
   guidance, which depicts an appreciable wind risk developing in these
   areas after 00Z as a linear complex organizes in western Oklahoma. 
   Latest observations/objective analyses indicate that although deep
   shear is marginal, strongly unstable thermodynamic profiles are in
   place, further supporting the wind risk.  The MCS should approach
   western Arkansas and portions of north-central Texas late tonight,
   and marginal wind probabilities have been expanded slightly to
   account for a continued (although lessened) wind risk.

   In Iowa, eastern Nebraska, and northeastern Kansas, ongoing storms
   will pose a marginal hail/wind risk over the next several hours
   given moderate to strong instability in those areas.  Shear profiles
   are fairly weak, however, mitigating any widespread threat.

   Farther east, the Marginal risk area across the Mid-South has been
   re-configured to account for eastward progression of an MCS
   migrating through that region.  Storms in the region will pose an
   isolated damaging wind threat through the early evening, before
   weakening after dark due to stabilizing low-levels.

   ..Cook.. 07/03/2017

   .PREV DISCUSSION... /ISSUED 1112 AM CDT Mon Jul 03 2017/

   ...KS/OK...
   Morning water vapor loop shows a convectively-aided MCV over extreme
   southwest KS.  This feature is embedded in northwest flow aloft, and
   will move into OK this afternoon and evening.  Ahead of the system,
   southeasterly low level winds will help to maintain 60s and lower
   70s dewpoints along a corridor from northwest into central OK. 
   Forecast soundings also show steep mid level lapse rates and the
   potential for strong afternoon CAPE.  Current indications are that
   thunderstorms will intensify this afternoon near the MCV and
   move/build southeastward.  Strong consensus exists among 12z CAM
   solutions for a bowing complex of storms to spread across the ENH
   region this evening, posing a risk of damaging winds and some hail.

   ...Eastern TX Panhandle...
   Most model solutions indicate that the initial storms over northwest
   OK will build southwestward along the effective surface dryline.  It
   is unclear how much augmentation to mid level winds will occur on
   the southern edge of the MVC over KS/OK.  However, if sufficient
   flow develops, a few supercells will be possible with a risk of
   large hail and damaging winds.

   ...IN to PA...
   Scattered thunderstorms are expected to form along a cold front
   sagging into this region.  Deep layer shear is sufficient for a few
   organized storms.  However, mid level lapse rates are not
   particularly steep, low level winds are weak, and CAPE is not
   forecast to become very strong.  The strongest storms may produce
   some hail or gusty winds, but the overall threat appears marginal.

   ...MS/TN/AL...
   A remnant MCV over AR will continue to track slowly eastward today
   across western TN.  Scattered thunderstorms will continue to occur
   ahead of this system, with an increase in intensity and coverage
   later this afternoon.  Ample CAPE and forcing associated with the
   MCV may promote a risk of a few severe storms capable of damaging
   wind gusts.

   ...Carolinas...
   Strong instability is forecast to develop over parts of SC and
   southern/eastern NC this afternoon, resulting is a corridor of
   scattered thunderstorm development.  Weak but sufficient cyclonic
   flow aloft coupled with a decaying MCV over GA may aid in the
   development a isolated severe storms capable of gusty/damaging wind
   gusts.

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