Aug 15, 2017 0100 UTC Day 1 Convective Outlook
Updated: Tue Aug 15 00:50:09 UTC 2017 (20170815 0100Z Day 1 shapefile | 20170815 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170815 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 30,457 474,930 Amarillo, TX...Rapid City, SD...Hereford, TX...Dumas, TX...Canyon, TX...
MARGINAL 93,114 572,571 Casper, WY...Clovis, NM...Gillette, WY...Plainview, TX...Pampa, TX...
Probabilistic Tornado Graphic
20170815 0100 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
2 % 25,537 223,199 Rapid City, SD...Spearfish, SD...Rapid Valley, SD...Sturgis, SD...Belle Fourche, SD...
Probabilistic Damaging Wind Graphic
20170815 0100 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
15 % 30,492 474,968 Amarillo, TX...Rapid City, SD...Hereford, TX...Dumas, TX...Canyon, TX...
5 % 93,154 579,250 Casper, WY...Clovis, NM...Gillette, WY...Plainview, TX...Pampa, TX...
Probabilistic Large Hail Graphic
20170815 0100 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
15 % 6,240 108,985 Rapid City, SD...Rapid Valley, SD...
5 % 101,154 791,540 Amarillo, TX...Clovis, NM...Gillette, WY...Plainview, TX...Pampa, TX...
   SPC AC 150050

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0750 PM CDT Mon Aug 14 2017

   Valid 150100Z - 151200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   NORTHEAST NEW MEXICO AND INTO THE TEXAS PANHANDLE...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   SOUTHWEST SOUTH DAKOTA AND THE NEBRASKA PANHANDLE...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   SLGT RISK AREA AND COVERING A SLIGHTLY LARGER PORTION OF THE
   SOUTHERN HIGH PLAINS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
   THE NORTHERN HIGH PLAINS AREA...

   ...SUMMARY...
   Isolated strong to severe storms will continue this evening across
   parts of the southern High Plains, as well as parts of the northern
   High Plains.

   ...Southern High Plains...
   A few storms have evolved this afternoon over northeast New Mexico,
   with the strongest storm now in the process of expanding into
   Hartley County in the Texas Panhandle.  A small mesolow is evident
   with this storm, and with several of the latest CAM runs still
   suggesting upscale growth of northeast New Mexico convection into an
   east-southeastward-moving MCS, potential for a somewhat more
   widespread severe risk evolving across the Texas Panhandle vicinity
   still appears to exist.  As such, will maintain slight risk area to
   cover this potential over the next 3-4 hours.

   ...Northern High Plains...
   Isolated strong/severe storms continue across parts of eastern
   Wyoming an eastward into western South Dakota and the Nebraska
   Panhandle.  Recently, coverage has increased in the vicinity of the
   Black Hills, where the upslope component of easterly low-level flow
   is enhancing ascent.  

   With only a narrow northwest-to-southeast axis of instability
   extending into western South Dakota, severe risk will likely remain
   confined to a rather small area.  Farther south however, with the
   zone of CAPE broadening across western Nebraska, some risk for a
   southeast-moving MCS to shift off the higher terrain and linger
   through the evening is evident.  Given the favorability of the
   environment, and resulting organization within the evolving Black
   Hills storms, introduction of a small SLGT risk area to highlight
   locally greater severe risk over the next few hours will be included
   in this forecast update.

   ..Goss.. 08/15/2017

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