Feb 18, 2018 0600 UTC Day 1 Convective Outlook
Updated: Sun Feb 18 05:49:21 UTC 2018 (20180218 1200Z Day 1 shapefile | 20180218 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180218 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20180218 1200 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20180218 1200 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Large Hail Graphic
20180218 1200 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 180549

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1149 PM CST Sat Feb 17 2018

   Valid 181200Z - 191200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   A few thunderstorms are possible from the southern Plains to the
   middle Mississippi Valley today into tonight. Showers and
   embedded/sporadic lightning may also occur along the northern
   California and Oregon coasts.

   ...Southern Plains through Middle Mississippi Valley area...

   Synoptic upper trough will amplify along the western U.S. coast
   Sunday, while a southern-stream shortwave trough off the coast of
   Baja CA deamplifies and shears ewd through the southern Rockies.
   Downstream from this feature, a low-amplitude shortwave trough will
   move newd through TX and into the Middle MS Valley region. At the
   surface a warm front will return north through TX and the lower MS
   Valley. 

   Within a broad zone of modest low-level theta-e advection and weak
   destabilization, an area of showers and a few thunderstorms will
   move from southwest through north central TX during the day in
   association with deeper forcing for ascent accompanying the lead
   southern-stream shortwave trough. This activity may diminish as it
   continues northeast toward the middle MS Valley where instability
   will be more limited. In wake of initial convection, additional
   moistening and modest destabilization associated with the
   strengthening low-level jet may contribute to elevated showers and
   possibly a few thunderstorms overnight. Coverage will probably
   remain isolated due to the marginal thermodynamic environment.

   ...Oregon and Northern CA coasts...

   A few thunderstorms are possible along the OR and northern CA coasts
   today within post-frontal region in association with cold air aloft
   and steepening mid-level lapse rates accompanying the amplifying
   synoptic trough.

   ..Dial/Jirak.. 02/18/2018

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z