Feb 23, 2018 1300 UTC Day 1 Convective Outlook
Updated: Fri Feb 23 12:53:30 UTC 2018 (20180223 1300Z Day 1 shapefile | 20180223 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180223 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 31,424 7,038,336 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
Probabilistic Tornado Graphic
20180223 1300 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
20180223 1300 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
20180223 1300 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
5 % 31,228 7,020,553 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
   SPC AC 231253

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0653 AM CST Fri Feb 23 2018

   Valid 231300Z - 241200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS A PORTION
   OF THE CENTRAL AND NORTHERN TEXAS VICINITY....

   ...SUMMARY...
   A couple of rounds of thunderstorms will likely affect the southern
   Plains today and tonight.  Very limited risk for an elevated severe
   storm or two may evolve over portions of central/northern Texas just
   prior to -- but more likely after -- the end of the Day 1 period
   (Saturday morning).

   ...Synopsis...
   Some progression of the upper flow field over the U.S. will occur
   this period, as the western U.S. trough advances out of the Great
   Basin and across the Four Corners/southern Rockies through the
   period.  Meanwhile, ridging will persist over the southeast U.S. and
   offshore.

   At the surface, a baroclinic zone will be maintained from the
   Tennessee Valley vicinity to Texas, focusing showers and
   thunderstorms from the Ohio Valley to the southern Plains through
   the period.

   ...Parts of central/northern Texas into adjacent parts of far
   southern Oklahoma...
   A fairly widespread cluster of showers and thunderstorms will affect
   central and northern Texas today, as the center of a short-wave
   trough now crossing the Rio Grande (per the latest WV loop) shifts
   northeast across the southern Plains.  In the wake of this feature,
   after weak/brief short-wave ridging, large-scale height-falls are
   forecast to commence -- particularly during the second half of the
   period -- as the larger-scale western U.S. trough advances
   into/across the Four Corners and southern Rockies.

   As low-level warm advection increases across the southern Plains in
   response, isentropic ascent atop a still-stable boundary layer will
   eventually fuel development of elevated storms.  While most -- if
   not all -- of this convective initiation will likely occur after the
   end of the Day 1 period, a storm or two could develop during the
   last 1-2 hours of the period over the central/northern Texas
   vicinity.  Any such development would pose some risk for hail, given
   steepening lapse rates aloft and strengthening mid-level flow --
   both spreading eastward in conjunction with the advance of the main
   upper system.  Therefore, will maintain the current/conditional 5%
   risk for hail given the end-of-period potential for convective
   initiation, though greater severe probability will evolve later
   Saturday morning/afternoon.

   ..Goss/Marsh.. 02/23/2018

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z