May 29, 2017 1730 UTC Day 2 Convective Outlook
Updated: Mon May 29 17:13:04 UTC 2017 (20170529 1730Z Day 2 shapefile | 20170529 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170529 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 201,291 17,179,617 Kansas City, MO...New Orleans, LA...Baton Rouge, LA...Rochester, NY...Overland Park, KS...
Probabilistic Graphic
20170529 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 202,148 17,213,701 Kansas City, MO...New Orleans, LA...Baton Rouge, LA...Overland Park, KS...Springfield, MO...
   SPC AC 291713

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1213 PM CDT Mon May 29 2017

   Valid 301200Z - 311200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS
   PENNSYLVANIA AND NEW YORK...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN
   KANSAS INTO MISSOURI...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   CENTRAL OREGON AND WASHINGTON...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN
   LOUISIANA...

   ...SUMMARY...
   Marginally severe thunderstorms with hail and wind will be possible
   on Tuesday across parts of the Northeast and from eastern Kansas
   into Missouri. Isolated severe storms with hail and wind are also
   possible over Washington late Tuesday into the evening. A few strong
   thunderstorms with wind gusts will also be possible across southern
   Louisiana.

   ...Synopsis...
   A large upper low will remain situated over Ontario, with broad area
   of strong cyclonic flow aloft from the Mid Mississippi and Ohio
   Valleys across the Northeast.  A weak surface trough will move
   eastward across Pennsylvania and New York, and provide a focus for
   daytime thunderstorm development. Cool temperatures aloft along with
   50s to near 60 dewpoints should support at least a few severe
   thunderstorms there. 

   To the south, high pressure will be centered over the central Gulf
   Coast states, but substantial moisture will remain near the coast,
   especially into Louisiana and Texas which may provide enough
   instability for a few strong storms and wind gusts. Out west, an
   upper ridge axis will be maintained from Idaho into the Four Corners
   states, with compact shortwave trough gradually breaking down the
   ridge over Washington and Oregon. With a low pressure trough
   deepening during the afternoon, thunderstorms will form with at
   least isolated hail and wind threat by afternoon.

   Hail will be possible as well across eastern Kansas into Missouri
   near a weak boundary and around the southern periphery of the upper
   trough where winds aloft will remain strong.

   ...Pennsylvania, New York, Vermont...
   Storms are expected to form by around noon across western PA and NY
   along the front, and will develop and move relatively slowly
   northeastward during the afternoon, possibly reaching Vermont by
   evening. The primary storm mode is expected to be cellular, but
   small lines may eventually form with outflow mergers. Hail is
   expected to be a main threat, with strong wind gusts eventually as
   well. Long hodographs along with weak but veering winds with height
   in the low levels suggest a few supercells are possible. A Slight
   risk cannot totally be ruled out in later outlooks, although
   marginal moisture and instability along with the overall weak
   surface pattern look to temper the magnitude of this event.
    
   ...Washington and Oregon...
   Southerly midlevel flow will increase to around 50 kt by late
   afternoon with the shortwave trough and ridge breakdown. Meanwhile,
   a surface trough will deepen with daytime heating. Storms are
   expected to form over central Oregon and over northwest Washington
   during the afternoon, and will spread northeastward through the
   evening. Forecast soundings show steep midlevel lapse rates will be
   present, which when combined with daytime heating will favor strong
   updrafts with both hail and wind possible.

   ...Eastern Kansas into western Missouri...
   Heating should result in marginal instability across the area as
   dewpoints slowly begin to rise, mainly due to evapotranspiration.
   Good mid to upper level flow will remain, and heating will lead to
   around 1000-1500 J/kg MUCAPE. Hodographs will be largely straight,
   favoring some splitting cells with hail threat as storms form during
   the afternoon and dwindle during the evening. 

   ...Southern Louisiana...
   A moist air mass will remain along the Gulf coast near a weak warm
   front maintaining 1500-2000 J/kg MLCAPE throughout the day. Rain and
   storms are likely to be ongoing across the area Tuesday morning in
   association with a weak midlevel disturbance which will be exiting
   the northern Gulf. Even as this wave passes by, some heating should
   allow for sporadic clusters of thunderstorms to redevelop, with
   localized strong wind gusts the most likely threat as wind profiles
   will be weak.

   ..Jewell.. 05/29/2017

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z