Jul 1, 2017 1630 UTC Day 1 Convective Outlook
Updated: Sat Jul 1 16:27:24 UTC 2017 (20170701 1630Z Day 1 shapefile | 20170701 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170701 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 164,961 33,031,060 Philadelphia, PA...Baltimore, MD...Washington, DC...Albuquerque, NM...Newark, NJ...
MARGINAL 521,712 78,377,037 New York, NY...Detroit, MI...Columbus, OH...Charlotte, NC...Nashville, TN...
Probabilistic Tornado Graphic
20170701 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 % 10,919 710,823 Saratoga Springs, NY...Rutland, VT...Glens Falls, NY...Claremont, NH...Lebanon, NH...
2 % 58,161 2,799,860 Albany, NY...Santa Fe, NM...Schenectady, NY...Utica, NY...Troy, NY...
Probabilistic Damaging Wind Graphic
20170701 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 % 153,399 32,066,948 Philadelphia, PA...Baltimore, MD...Washington, DC...Newark, NJ...Yonkers, NY...
5 % 512,557 79,200,854 New York, NY...Detroit, MI...Columbus, OH...Charlotte, NC...Nashville, TN...
Probabilistic Large Hail Graphic
20170701 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
15 % 25,093 889,975 Albuquerque, NM...Santa Fe, NM...Rio Rancho, NM...Roswell, NM...South Valley, NM...
5 % 328,782 72,778,259 New York, NY...Philadelphia, PA...Detroit, MI...Baltimore, MD...Washington, DC...
   SPC AC 011627

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1127 AM CDT Sat Jul 01 2017

   Valid 011630Z - 021200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTHEAST AND
   MID-ATLANTIC STATES...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TN VALLEY AND
   SOUTHERN APPALACHIANS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS EAST-CENTRAL NM...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EASTERN STATES
   INTO THE DEEP SOUTH AND LOWER MS VALLEY...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SOUTHERN ROCKIES
   AND HIGH PLAINS...

   ...SUMMARY...
   Isolated to scattered severe storms, primarily producing wind
   damage, will be possible this afternoon across the Northeast and
   Mid-Atlantic States, along with parts of the southern Appalachians
   and Tennessee Valley. Storms with severe hail and wind may also
   occur over parts of the southern High Plains late afternoon into
   tonight.

   ...Northeast into the Mid-Atlantic states...
   Showers and widely scattered storms are ongoing from NH to western
   PA in association with a lead mid-level disturbance downstream of a
   shortwave trough over the central Great Lakes. This lead impulse
   should track east across New England today. Cloud breaks are evident
   ahead of this morning convective activity and diabatic heating will
   result in a moderately unstable air mass with MLCAPE reaching
   750-1500 J/kg. Storms should expand in coverage and intensity during
   the mid to late afternoon. While stronger mid-level southwesterlies
   will lag to the west, 35-45 kt 500-mb flow will be prevalent.
   Low-level winds are progged to strengthen from the Hudson Valley
   eastward. In this region, the setup should yield a couple supercells
   embedded within multicell clusters, with primary hazards being
   damaging winds and a tornado or two. Farther south, multicells
   should dominate with damaging winds as the main hazard. 

   ...TN Valley into the southern Appalachians...
   A moisture-rich air mass characterized by 70s surface dew points is
   in the process of destabilizing with MLCAPE of 1500-2500 J/kg
   expected by late afternoon. A remnant MCV over the Mid-South should
   track east and promote scattered storm development over the TN
   Valley through the afternoon. On the southern periphery of moderate
   mid/upper-level westerlies (25-35 kt at 500 mb), a few multicell
   clusters may form and congeal towards the southern Appalachians with
   a primary risk of damaging winds. The Slight risk area has been
   shifted north to account for the most likely area of storm
   development centered on eastern TN.

   ...Southern High Plains...
   50s to lower 60s surface dew points are prevalent across the eastern
   two-thirds of NM amid weak low-level easterlies. Robust diabatic
   heating and steep mid-level lapse rates will promote MLCAPE of
   1500-2500 J/kg by late afternoon. Despite relatively weak flow
   aloft, directional veering with height should result in effective
   shear of 25-30 kt. Widely scattered storms will develop off the
   higher terrain and may consolidate into a cluster or two across
   eastern NM and adjacent portions of west TX this evening. The risk
   for large hail and severe wind gusts appears sufficient to warrant
   an upgrade to Cat 2/Slight.

   ..Grams/Cook.. 07/01/2017

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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