Aug 7, 2017 1630 UTC Day 1 Convective Outlook
Updated: Mon Aug 7 16:30:28 UTC 2017 (20170807 1630Z Day 1 shapefile | 20170807 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170807 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 27,936 4,724,527 Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
MARGINAL 216,069 34,824,852 Baltimore, MD...Charlotte, NC...Washington, DC...Atlanta, GA...Raleigh, NC...
Probabilistic Tornado Graphic
20170807 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 8,024 792,022 Salisbury, MD...Easton, MD...Lexington Park, MD...Cambridge, MD...Seaford, DE...
2 % 27,113 7,729,691 Washington, DC...Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...
Probabilistic Damaging Wind Graphic
20170807 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 27,926 4,724,411 Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
5 % 208,503 34,757,791 Baltimore, MD...Charlotte, NC...Washington, DC...Atlanta, GA...Raleigh, NC...
Probabilistic Large Hail Graphic
20170807 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 47,951 339,008 Roswell, NM...Clovis, NM...Hobbs, NM...Carlsbad, NM...Las Vegas, NM...
   SPC AC 071630

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1130 AM CDT Mon Aug 07 2017

   Valid 071630Z - 081200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
   MID-ATLANTIC STATES...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE TN
   VALLEY TO THE COASTAL MID-ATLANTIC/NORTHEAST STATES...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
   NM AND THE SOUTHERN HIGH PLAINS...

   ...SUMMARY...
   Severe thunderstorms are possible across the Middle Atlantic today.
   A more isolated severe risk may extend as far southwest as the
   Tennessee Valley and over parts of eastern New Mexico and far West
   Texas.

   ...Mid-Atlantic States/Coastal Northeast States...
   Scattered showers, some thunderstorms, and widespread cloud cover
   remain prevalent at midday across the region, particularly across
   northern/eastern VA and the Delmarva vicinity in association with an
   eastward-moving impulse/MCV. The ongoing convection and clouds
   contribute to continued uncertainties regarding the overall extent
   and magnitude of today's severe risk, including the northward extent
   of the severe risk.

   Morning upper-air analysis featured a subtle upstream impulse and
   mid-level speed max over the southern Appalachians vicinity that
   will cross the region through the afternoon and early evening.
   Mid-level lapse rates will remain weak, but even modest
   heating/cloud breaks ahead of east/southeastward-shifting front
   should lead to minimal convective inhibition and weak to locally
   moderate buoyancy (greatest across southern VA into NC) this
   afternoon. This will be within an increasingly moist air mass with
   lower 70s F surface dewpoints. 

   At the very least, where adequate destabilization does occur, wind
   profiles will be supportive of a few supercells capable of damaging
   wind gusts and/or a tornado or two, with low-level shear expected to
   be maximized across the Delmarva vicinity in proximity to the warm
   front. For additional short-term details, see Mesoscale Discussion
   1456.

   ...Southern Appalachians/Tennessee Valley...
   Farther southwest, scattered thunderstorms are expected to intensify
   this afternoon from western NC into parts of AL/MS within a corridor
   of 20-30 kt mid-level west/southwesterly flow. Pockets of moderate
   instability will likely form in this region, with the risk of
   locally damaging wind gusts in the strongest cells.

   ...Eastern NM/Southwest TX...
   A moist air mass the influence of higher terrain/low-level upslope
   trajectories will lead to increasing and intensifying storms by
   mid/late afternoon into evening. Northwest flow aloft, atop weak
   southeasterly low-level winds will promote the potential for
   rotating storms capable of gusty winds and some hail.

   ..Guyer/Marsh.. 08/07/2017

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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