May 31, 2017 1630 UTC Day 1 Convective Outlook
Updated: Wed May 31 16:01:41 UTC 2017 (20170531 1630Z Day 1 shapefile | 20170531 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170531 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 75,391 6,144,031 Springfield, MA...Topeka, KS...Olathe, KS...Albany, NY...Lawrence, KS...
MARGINAL 456,207 72,099,575 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Kansas City, MO...
Probabilistic Tornado Graphic
20170531 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
2 % 33,275 5,789,956 New Orleans, LA...Mobile, AL...Springfield, MA...Metairie, LA...Manchester, NH...
Probabilistic Damaging Wind Graphic
20170531 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 % 76,963 6,223,628 Springfield, MA...Topeka, KS...Olathe, KS...Albany, NY...Lawrence, KS...
5 % 455,998 72,196,163 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Kansas City, MO...
Probabilistic Large Hail Graphic
20170531 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 % 75,317 6,008,187 Springfield, MA...Olathe, KS...Manchester, NH...Albany, NY...Lawrence, KS...
5 % 377,812 70,286,975 New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Kansas City, MO...
   SPC AC 311601

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1101 AM CDT Wed May 31 2017

   Valid 311630Z - 011200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NY
   AND NEW ENGLAND...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   KS/MO...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND
   SOUTHWARD INTO THE CAROLINAS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   THE CENTRAL GULF COAST REGION...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE
   CENTRAL PLAINS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHWEST
   TX...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
   THE NORTHERN ROCKIES...

   ...SUMMARY...
   A few severe storms capable of strong, damaging winds and large hail
   will be possible from parts of New England southward to the
   Mid-Atlantic. Another area of strong/severe storms is expected from
   the central High Plains to the Ozarks. Isolated strong to marginally
   severe storms will also be possible across southwestern Texas, the
   central Gulf Coast region, and the northern Rockies.

   ...New England/NY...
   Morning visible satellite imagery shows considerable sunshine over
   much of eastern NY, spreading eastward into VT/NH and western ME. 
   Those areas where heating occurs will see rapid destabilization and
   the likelihood of afternoon convection.  Storms are expected to form
   over central NY by early afternoon and spread relatively quickly
   eastward across the SLGT risk areas.  Surface dewpoints in the mid
   50s, coupled with cold mid level temperatures, will yield CAPE
   values of around 1000 J/kg.  Strong southwesterly flow aloft will
   also result in sufficient vertical shear for rotating storms.  Hail
   appears to be the main threat in the stronger cells, although
   locally gusty/damaging winds may also occur.  If surface winds
   remain locally backed in the Hudson River Valley, an isolated
   tornado would also be possible in that area.

   ...OH/PA/WV into VA/NC...
   Farther south, broad cyclonic flow is present from the upper OH
   Valley into the Central Appalachians and Mid-Atlantic region. 
   Scattered afternoon thunderstorms are possible throughout this area.
    Forecast soundings suggest sufficient parameters for at least a
   marginal risk of hail and gusty winds in the stronger cells over a
   relatively large area.

   ...Central Plains...
   A weak surface boundary extends across KS/MO today.  Dewpoints in
   the 50s to the south of the boundary, coupled with strong daytime
   heating, will result in a corridor of moderate afternoon CAPE from
   western NE and northeast CO into southern KS/MO.  Scattered
   thunderstorms are expected along this axis, with hail and gusty
   winds possible.  Overnight and 12Z CAM solutions suggest the area of
   highest probability of strong storm coverage is over parts of
   eastern KS and western MO, where the SLGT risk area remains.

   ...Central Gulf Coast States...
   Isolated storms capable of gusty winds or brief tornadoes are
   possible today.  Please refer to MCD #925 for further details.

   ..Hart/Mosier.. 05/31/2017

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