Jun 23, 2017 1630 UTC Day 1 Convective Outlook
Updated: Fri Jun 23 16:40:41 UTC 2017 (20170623 1630Z Day 1 shapefile | 20170623 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170623 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 181,841 31,403,786 Philadelphia, PA...Dallas, TX...Fort Worth, TX...Nashville, TN...Arlington, TX...
MARGINAL 446,509 71,566,429 New York, NY...Columbus, OH...Memphis, TN...Baltimore, MD...Washington, DC...
Probabilistic Tornado Graphic
20170623 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 % 72,755 9,345,611 Nashville, TN...Lexington-Fayette, KY...Birmingham, AL...Huntsville, AL...Chattanooga, TN...
2 % 152,603 47,922,977 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Pittsburgh, PA...
Probabilistic Damaging Wind Graphic
20170623 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 % 180,582 31,358,347 Philadelphia, PA...Dallas, TX...Fort Worth, TX...Nashville, TN...Arlington, TX...
5 % 434,129 71,541,260 New York, NY...Columbus, OH...Memphis, TN...Baltimore, MD...Washington, DC...
Probabilistic Large Hail Graphic
20170623 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 % 229,812 16,265,956 Dallas, TX...Memphis, TN...Fort Worth, TX...Arlington, TX...Plano, TX...
   SPC AC 231640

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1140 AM CDT Fri Jun 23 2017

   Valid 231630Z - 241200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE TN VALLEY
   TO THE DELMARVA/MID-ATLANTIC REGION...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
   SOUTHERN PLAINS/ARKLATEX...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
   NM/SOUTHERN PLAINS TO APPALACHIANS/NEW ENGLAND...

   ...SUMMARY...
   Damaging wind gusts and a few tornadoes are possible this afternoon
   into evening from the Tennessee Valley toward parts of the
   Appalachians. A few severe storms with strong wind gusts and hail
   will also be possible across parts of the Northeast States and
   southern Plains.

   ...TN Valley vicinity...
   The remnants of Cindy will continue to spread east-northeastward
   through the afternoon and evening, with a corridor of low/mid-level
   winds preceding these remnants. A moist and increasingly uninhibited
   boundary layer this afternoon should allow for the intensification
   of a mixed mode of storms, including bands/clusters and the
   possibility of some cluster-preceding semi-discrete supercells.
   Given the magnitude of the low-level shear, especially from northern
   AL into middle/eastern TN and eastern KY, the potential will exist
   for a few tornadoes aside from some wind damage potential. Reference
   Mesoscale Discussion 1130 for additional short-term details.

   ...Middle/upper OH River Valley to Delmarva/Mid-Atlantic...
   As moisture continues to increase into the region, it appears that
   pockets of locally stronger heating will occur today ahead, and on
   the southern fringes, of upstream precipitation/thicker cloud cover.
   A steadily strengthening wind field will overspread the region
   through the afternoon and evening, with increasingly favorable wind
   profiles for organized storms including a few supercells/bows.
   Damaging winds should be the primary risk, but some hail and/or a
   tornado are possible as well.

   ...Southern Plains/Ark-La-Tex/Mid-South...
   Steep lapse rates and diabatic warming of the boundary layer will
   promote moderate instability in this region. Storms will likely
   develop along the south/southeastward-advancing cold front as well
   as over the higher terrain over NM/west TX. Additionally, ongoing
   storms across southwest MO may gradually increase in
   coverage/intensity as they progress southeastward into AR. The warm
   sector resides well south of the stronger winds aloft, but vertical
   shear will be supportive of multicells capable of producing a few
   strong to damaging wind gusts and marginally severe hail this
   afternoon into evening.

   ...Northern NY/New England...
   At least a few strong/severe thunderstorms are expected this
   afternoon across northeast NY into northern New England.

   ..Guyer/Gleason.. 06/23/2017

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