May 27, 2017 0100 UTC Day 1 Convective Outlook
Updated: Sat May 27 00:56:30 UTC 2017 (20170527 0100Z Day 1 shapefile | 20170527 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170527 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 85,319 5,753,425 Indianapolis, IN...Cincinnati, OH...Bloomington, IN...Muncie, IN...Hamilton, OH...
MARGINAL 180,966 14,214,025 Denver, CO...Tulsa, OK...Colorado Springs, CO...Wichita, KS...Aurora, CO...
Probabilistic Tornado Graphic
20170527 0100 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 % 105,683 9,775,165 Indianapolis, IN...Cincinnati, OH...Lexington-Fayette, KY...Louisville, KY...Dayton, OH...
Probabilistic Damaging Wind Graphic
20170527 0100 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 % 86,118 5,731,406 Indianapolis, IN...Cincinnati, OH...Bloomington, IN...Muncie, IN...Hamilton, OH...
5 % 157,043 12,001,571 Denver, CO...Tulsa, OK...Colorado Springs, CO...Wichita, KS...Aurora, CO...
Probabilistic Large Hail Graphic
20170527 0100 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 % 85,417 5,759,521 Indianapolis, IN...Cincinnati, OH...Bloomington, IN...Muncie, IN...Hamilton, OH...
5 % 179,007 12,474,339 Denver, CO...Tulsa, OK...Wichita, KS...Aurora, CO...Lexington-Fayette, KY...
   SPC AC 270056

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0756 PM CDT Fri May 26 2017

   Valid 270100Z - 271200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE CENTRAL HIGH PLAINS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE OHIO VALLEY...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM
   SOUTHEASTERN WYOMING TO THE OZARKS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
   ILLINOIS TO NORTHERN KENTUCKY...

   ...SUMMARY...
   Widely scattered thunderstorms with hail and damaging gusts will
   continue this evening over parts of the central high Plains.
   Overnight, isolated strong/severe storms may develop over parts of
   the Ozark Plateau. Farther east, severe storms capable of damaging
   winds, large hail, and a brief tornado will continue this evening
   into the early overnight across parts of the Ohio Valley.

   ...Central Plains...
   Strong to severe convection has organized across the high Plains of
   eastern Colorado and southeastern Wyoming this evening, with large
   hail and damaging winds being the primary severe hazards so far.
   Within a regime of modest east/southeasterly surface flow and steep
   mid-level lapse rates (as sampled by the 00Z DDC sounding), these
   cells will likely continue east/southeast through the evening into
   the early overnight, with a persisting threat for large hail,
   damaging winds, and perhaps a brief tornado. Uncertainty exists with
   regards to the eastward extent of this severe threat, as convective
   inhibition increases slightly across central Kansas. However, any
   semi-discrete/embedded rotating updrafts and/or strong cold pools
   from upscale growth may supply enough forced ascent such that
   vigorous updrafts are sustained across central Kansas. Furthermore,
   an amplifying southerly low-level jet may further support convective
   maintenance. As such, the Marginal Risk is expanded eastward.

   ...Ozark Plateau...
   Although considerable uncertainty exists regarding development of
   deep convection late tonight, multiple large-scale and hi-res models
   suggest a few thunderstorms are possible after approximately 05Z.
   This scenario does not appear unreasonable, as an impulse noted in
   water-vapor imagery over the southern high Plains will approach the
   region overnight. Therefore, as forcing for ascent increases,
   mid-level inhibition (noted in the 00Z SGF sounding) may weaken
   sufficiently overnight, allowing for isolated/widely scattered
   convection. Considering ample effective shear and steep mid-level
   lapse rates, the potential exists for large hail and damaging winds
   with any stronger core. Additionally, if parcels can become rooted
   at the surface, a non-zero tornado threat would be present. The
   Marginal Risk is expanded eastward to account for this conditional
   severe threat late tonight.

   ...Ohio Valley...
   Ongoing vigorous convection has transitioned into a more linear mode
   over Indiana this evening, with a broad precipitation shield to its
   northeast. While deep-layer shear remains strong, parcel buoyancy
   wanes with eastward extent into Ohio (observed in the 00Z ILN
   sounding). Therefore, propagation into higher buoyancy to the south
   may drive stronger convection more southward towards far northern
   Kentucky, with an attendant threat of damaging winds and large hail.

   ..Picca.. 05/27/2017

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z