May 30, 2017 1630 UTC Day 1 Convective Outlook
Updated: Tue May 30 15:45:02 UTC 2017 (20170530 1630Z Day 1 shapefile | 20170530 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170530 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 55,872 12,366,460 Washington, DC...Rochester, NY...Arlington, VA...Syracuse, NY...Alexandria, VA...
MARGINAL 259,743 23,913,475 Baltimore, MD...Kansas City, MO...New Orleans, LA...Raleigh, NC...Buffalo, NY...
Probabilistic Tornado Graphic
20170530 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 % 60,284 13,582,339 Baltimore, MD...Washington, DC...New Orleans, LA...Arlington, VA...Metairie, LA...
Probabilistic Damaging Wind Graphic
20170530 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 % 55,473 12,135,225 Washington, DC...Rochester, NY...Arlington, VA...Syracuse, NY...Alexandria, VA...
5 % 259,780 24,047,853 Baltimore, MD...Kansas City, MO...New Orleans, LA...Raleigh, NC...Buffalo, NY...
Probabilistic Large Hail Graphic
20170530 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 % 55,513 12,352,496 Washington, DC...Rochester, NY...Arlington, VA...Syracuse, NY...Alexandria, VA...
5 % 201,341 21,523,386 Baltimore, MD...Kansas City, MO...Raleigh, NC...Buffalo, NY...Norfolk, VA...
   SPC AC 301545

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1045 AM CDT Tue May 30 2017

   Valid 301630Z - 311200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
   VT/NY INTO THE MID-ATLANTIC REGION...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   WESTERN NEW ENGLAND AND NY INTO THE CAROLINAS...

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

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE MID-MISSISSIPPI VALLEY...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
   CENTRAL WA/OR...

   ...SUMMARY...
   Severe thunderstorms, capable of large hail, damaging winds, and
   perhaps a tornado, will be possible this afternoon and evening from
   the lower Great Lakes and Adirondacks to North Carolina. Elsewhere,
   a few strong/severe storms may occur across the central
   Plains/Ozarks, central Gulf Coast, and Pacific Northwest.

   ...NY/VT/PA/MD/VA...
   Only minor changes have been made to the ongoing forecast in this
   area.  Visible satellite imagery shows a corridor of daytime heating
   occurring from central NY into western PA, then southward into
   western MD and northern VA.  12z model guidance remains consistent
   that scattered thunderstorms will form in this region, aided by an
   approaching shortwave trough now over MI/IN/OH.  Afternoon CAPE
   values of 1000-2000 J/kg and rather strong west-southwesterly mid
   level winds will promote rather fast-moving thunderstorms capable of
   damaging winds and some hail.  The eastern extent of the severe
   threat should be strongly limited by the cool/stable environment
   over eastern NY/PA/MD/VA.

   ...LA...
   Radar loops have shown several rotating storms off and just along
   the coast of central/southeast LA.  This activity may persist for
   several more hours, posing a risk of a brief tornado or damaging
   wind gust.

   ...Southern MO/Northern AR...
   A remnant area of weak convection is tracking across southeast KS. 
   Model solutions suggest some intensification may occur with this
   activity by mid/late afternoon, with a risk of an isolated severe
   cell or two.  Gusty/damaging winds and hail would be the main
   threat.

   ...Eastern KS/Northern MO...
   A weak surface cold front is sagging southward across IA/NE.  This
   boundary may be a focus for scattered showers and thunderstorms this
   afternoon and evening.  Relatively steep low level lapse rates and
   sufficient vertical shear indicate a risk of an isolated severe
   storm or two capable of gusty winds and hail.

   ...WA/OR...
   A well-defined shortwave trough is approaching the Pacific Northwest
   coast.  Strong heating is forecast over parts of central WA/OR, with
   afternoon temperatures warming through the 80s and into the 90s. 
   Steep low and mid level lapse rates and sufficient southwesterly
   flow aloft suggest a risk of high-based showers and thunderstorms
   capable of gusty and locally damaging wind gusts.

   ..Hart/Smith.. 05/30/2017

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