May 22, 2017 1630 UTC Day 1 Convective Outlook
Updated: Mon May 22 16:25:26 UTC 2017 (20170522 1630Z Day 1 shapefile | 20170522 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170522 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20170522 1630 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.
Probabilistic Damaging Wind Graphic
20170522 1630 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.
Probabilistic Large Hail Graphic
20170522 1630 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.
   SPC AC 221625

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   Issued by 15th OWS Scott Air Force Base IL
   1125 AM CDT Mon May 22 2017

   Valid 221630Z - 231200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN NM
   AND WEST/WEST-CENTRAL TX...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
   CENTRAL/SOUTHERN HIGH PLAINS TO THE UPPER MIDWEST...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE GULF
   COAST TO SOUTHEAST VA...

   ...SUMMARY...
   Severe thunderstorms will be possible this afternoon and evening
   from parts of eastern New Mexico into west Texas. Other strong to
   briefly severe storms may occur across the western/central Gulf
   Coast region extending Northeastward into Southeastern Virginia, as
   well as the central Plains and Upper Midwest.

   ...Synopsis...
   A longwave trough will continue to evolve over the CONUS to the east
   of the Rockies, with multiple embedded low-amplitude disturbances
   crossing the Plains and Gulf Coast into the Southeast States through
   tonight.

   ...Southern High Plains...
   Beneath a plume of steep mid-level lapse rates noted in 12Z observed
   soundings, weak low-level upslope trajectories will maintain modest
   boundary layer moisture across west TX into eastern NM today. This
   scenario should result in as much as 1000-1500 J/kg of MLCAPE by
   peak heating especially across east-central/southeast NM into
   west/southern TX including the TX south Plains and Permian Basin
   vicinities. Storms are likely to initially develop and intensify
   through early/mid-afternoon across eastern NM. 

   In the presence of strengthening west-northwesterly mid/high-level
   winds, more than adequate buoyancy and vertical shear will exist for
   supercells capable of large hail. These storms are likely to spread
   east/southeastward into west/southwest TX by late afternoon, with a
   continued large hail risk and an increasing potential for
   severe-caliber wind gusts as storm mergers occur. These storms may
   reach parts of the Edwards Plateau and Low Rolling Plains by late
   evening.

   ...Western/central Gulf Coast region to Southeast VA...
   A cluster of persistent eastward-moving thunderstorms exist along
   and off the middle TX coast to coastal LA early this morning, with
   other showers and a few thunderstorms noted across other parts of
   east TX to the lower MS River Valley. Focused generally near a
   west/southwest to east/northeast-oriented frontal boundary
   (modulated by outflow), this convection appears to be aided by a
   weak southern-stream disturbance. While deep-layer/low-level winds
   are forecast to gradually strengthen through the afternoon and
   evening atop the frontal corridor, the widespread nature of
   near-coastal convection contributes to uncertainty regarding the
   degree of destabilization in inland areas. Even so, some potential
   for locally damaging winds, marginally severe hail and possibly a
   brief tornado (near-coastal areas) will exist today. Should greater
   inland destabilization become more apparent, areas such as southern
   LA/far southern MS could warrant a Slight Risk upgrade.

   Farther east, other more isolated strong to locally severe
   thunderstorms could occur this afternoon and evening across other
   parts of the Southeast States into the Carolinas.  A few isolated
   severe storms may develop in North Carolina through Southeastern
   Virginia associated with a slow moving MCV.  

   ...Central Plains and Upper Midwest...
   Low-level moisture will be limited in advance of a pre-frontal
   trough and weak southeastward-moving front today, although diurnally
   steepening lapse rates and modest moisture will yield weak buoyancy
   mainly across far southeast SD and east-central NE into IA/southern
   MN. Isolated to widely scattered thunderstorm development is
   expected this afternoon. While updraft intensities will be tempered
   by weak overall buoyancy, strong mid-level winds across the area
   could contribute to a few stronger storms capable of strong gusty
   winds and possibly some marginally severe hail this afternoon into
   evening. 

   Farther west, other southeastward-moving high-based storms are
   expected across the central High Plains this afternoon/evening with
   some potential for severe-caliber winds and perhaps some hail.

   ..15_ows.. 05/22/2017

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z