May 29, 2018 0600 UTC Day 1 Convective Outlook
Updated: Tue May 29 05:58:40 UTC 2018 (20180529 1200Z Day 1 shapefile | 20180529 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180529 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 39,542 865,635 Wichita, KS...Salina, KS...Hutchinson, KS...Hays, KS...Newton, KS...
SLIGHT 106,218 4,889,794 Oklahoma City, OK...Omaha, NE...Lincoln, NE...Norman, OK...Fargo, ND...
MARGINAL 390,583 26,322,351 Nashville, TN...Atlanta, GA...Tulsa, OK...Minneapolis, MN...St. Paul, MN...
Probabilistic Tornado Graphic
20180529 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
5 % 48,794 1,067,976 Wichita, KS...Salina, KS...Hutchinson, KS...Altus, OK...Hays, KS...
2 % 167,217 18,888,093 Oklahoma City, OK...Nashville, TN...Atlanta, GA...Tulsa, OK...Lincoln, NE...
Probabilistic Damaging Wind Graphic
20180529 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
30 % 39,448 863,530 Wichita, KS...Salina, KS...Hutchinson, KS...Hays, KS...Newton, KS...
15 % 105,051 4,813,841 Oklahoma City, OK...Omaha, NE...Lincoln, NE...Fargo, ND...Duluth, MN...
5 % 370,434 26,137,967 Nashville, TN...Atlanta, GA...Tulsa, OK...Minneapolis, MN...St. Paul, MN...
Probabilistic Large Hail Graphic
20180529 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
SIG SEVERE 40,070 770,416 Salina, KS...Hutchinson, KS...Altus, OK...Newton, KS...Great Bend, KS...
30 % 33,678 630,995 Salina, KS...Hutchinson, KS...Newton, KS...Great Bend, KS...Woodward, OK...
15 % 110,195 5,086,545 Oklahoma City, OK...Omaha, NE...Wichita, KS...Lincoln, NE...Norman, OK...
5 % 312,697 12,492,000 Tulsa, OK...Minneapolis, MN...St. Paul, MN...Des Moines, IA...Sioux Falls, SD...
   SPC AC 290558

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1258 AM CDT Tue May 29 2018

   Valid 291200Z - 301200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KS
   SOUTHWARD INTO WESTERN OK...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE UPPER MIDWEST AND CENTRAL AND SOUTHERN PLAINS...

   ...SUMMARY...
   Severe thunderstorms are expected across portions of the central and
   southern Plains and upper Midwest. Highest concentration of severe
   storms is anticipated from central Kansas into western Oklahoma
   during the afternoon and evening.

   ...Synopsis...
   Shortwave trough now rounding the base of the larger parent upper
   trough extending along the northern and central Rockies is expected
   to eject out into the Plains this afternoon. At the same time, a
   convectively induced shortwave trough over central Plains will
   likely progress northeastward into the upper Midwest, with some
   phasing possible with yet another vorticity maximum currently over
   eastern MT. 

   At the surface, low presently over southeastern MT is expected to
   drift northward during the next several hours before then shifting
   northeastward/eastward across ND. Another low is anticipated over
   the TX/OK Panhandle with diffuse troughing in between these two
   features. A well-defined dryline will extend from the southern low
   southward into the TX Big Bend. 

   Farther east, Subtropical Depression Alberto will continue to weaken
   as it moves from northern AL through middle TN and into the lower OH
   Valley.

   ...Southern/Central Plains...
   Thunderstorms will likely be ongoing at the beginning of the period
   across northwest KS with the resulting outflow playing a significant
   role in delineating the higher severe thunderstorm coverage. Current
   expectation is for the outflow to act as the focus for afternoon
   convection initiation, aided by large-scale forcing for ascent from
   the approaching central Rockies shortwave trough. 

   Airmass east of the boundary is expected to be characterized by warm
   temperatures, adequate low-level moisture, and steep mid-level lapse
   rates. Consequently, a moderate to strongly unstable airmass with
   MLCAPE in excess of 2500 J/kg is anticipated from central KS
   southwestward across western OK and into western north TX. A modest
   increase in mid-level flow is anticipated with the shortwave trough,
   with vertical profiles supporting 0-6 km bulk shear around 35 to 45
   kt. Numerous thunderstorms are anticipated along the effective
   frontal zone across central KS and northwest OK with thermodynamic
   and kinematic profiles supporting severe thunderstorms. Primary
   severe threat will be very large hail but strong wind gusts are also
   probable. A tornado or two is possible, particularly with any
   discrete activity. Given linear forcing and high thunderstorm
   coverage across KS, more discrete activity will likely be limited to
   northwest OK and southward where less forcing for ascent and
   therefore less convective coverage is anticipated.

   ...Upper Midwest...
   Scattered thunderstorms are expected to develop during the afternoon
   within the modest low-level warm advection and confluent surface
   flow across the region. Dewpoints will likely be in the low 60s with
   an area of mid 60s possible near an ill-defined warm front extending
   from the ND surface low. Afternoon temperatures are expected to
   reach the upper 80s and low 90s, which, when combined with the
   anticipated dewpoints, results in moderate instability (i.e. MLCAPE
   around 1500-2000 J/kg). Vertical shear across the region is weak but
   the favorable instability will still support multicell storms
   capable of large hail. Steep low-level lapse rates and seasonably
   high moisture (i.e. PW over 1.20 inches) will also support damaging
   wind gusts.  

   ...Southeast...Middle/Eastern TN...
   Alberto continues to weaken but vertical wind profiles that veer
   with height, and a very moist airmass, could still result in a few
   water-loaded storms capable of damaging downburst winds.
   Additionally, pockets of diurnal heating may contribute to locally
   enhanced instability and the potential for isolated updrafts
   organized enough to support a brief tornado.

   ..Mosier/Gleason.. 05/29/2018

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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