Feb 17, 2018 0830 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Feb 17 08:25:17 UTC 2018 (20180217 0830Z Day 3 shapefile | 20180217 0830Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0830 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Graphic
20180217 0830 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 170825

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0225 AM CST Sat Feb 17 2018

   Valid 191200Z - 201200Z


   Showers and occasional/embedded lightning will again be possible
   over parts of the West Monday, while showers and thunderstorms are
   expected from portions of the southern Plains north-northeast toward
   the Upper Great Lakes region.

   Continued amplification of the upper flow field across the U.S. is
   expected Monday, as additional expansion -- and some slow eastward
   progression -- of the western U.S. trough is expected.  In response,
   intensification of the upper ridging over the southeast U.S. and
   adjacent western Atlantic and Gulf of Mexico is expected.

   At the surface, a baroclinic zone over the central portions of the
   country is forecast to re-orient to a more northeast-to-southwest
   alignment, as cold air spreads southward across the west and warm
   advection continues across central and northeastern portions of the

   Showers -- and occasional/embedded lightning -- will likely continue
   to spread south across the interior West, including portions of the
   Great Basin.  Meanwhile, some decrease in early-period convection --
   lingering from the overnight hours -- may occur during the day, only
   to redevelop/expand nocturnally through the end of the period.  This
   convection will remain elevated, with a general lack of CAPE likely
   to hinder any severe potential.  With that said, hints exist at the
   possibility for some small hail across portions of the
   Kansas/Oklahoma regions and vicinity during latter stages of the
   period, pending ample elevated CAPE development, given background
   shear sufficient for organized updrafts.

   ..Goss.. 02/17/2018