Jun 28, 2017 0600 UTC Day 2 Convective Outlook
Updated: Wed Jun 28 05:56:44 UTC 2017 (20170628 0600Z Day 2 shapefile | 20170628 0600Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170628 0600 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 50,995 2,405,764 Omaha, NE...Lincoln, NE...Topeka, KS...St. Joseph, MO...Council Bluffs, IA...
SLIGHT 204,939 19,476,262 Kansas City, MO...Cleveland, OH...Wichita, KS...Toledo, OH...Fort Wayne, IN...
MARGINAL 219,477 29,848,971 Chicago, IL...Detroit, MI...Indianapolis, IN...St. Louis, MO...Pittsburgh, PA...
Probabilistic Graphic
20170628 0600 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
SIG SEVERE 51,224 2,303,534 Omaha, NE...Lincoln, NE...Topeka, KS...Council Bluffs, IA...Bellevue, NE...
30 % 52,098 2,368,595 Omaha, NE...Lincoln, NE...Topeka, KS...Council Bluffs, IA...Bellevue, NE...
15 % 199,135 19,049,942 Kansas City, MO...Cleveland, OH...Wichita, KS...Toledo, OH...Fort Wayne, IN...
5 % 225,908 31,202,966 Chicago, IL...Detroit, MI...Indianapolis, IN...St. Louis, MO...Pittsburgh, PA...
   SPC AC 280556

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1256 AM CDT Wed Jun 28 2017

   Valid 291200Z - 301200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
   NE AND KS...SOUTHWEST IA...AND NORTHWEST MO...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF NE
   AND KS AND EXTENDING EASTWARD TOWARD THE LOWER GREAT LAKES....

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
   HIGH PLAINS EASWARD INTO UPSTATE NY...

   ...SUMMARY...
   Scattered significant severe thunderstorms are most likely Thursday
   across the central Plains, with areas of hail and damaging wind.
   Isolated strong storms are also possible across the Midwest eastward
   into western Pennsylvania and New York with localized severe wind
   gusts.

   ...Synopsis...
   A shortwave trough will move from the central Rockies Thu morning to
   the lower MO Valley by Fri morning, with relatively strong flow
   aloft for the time of year. At the surface, a diffuse boundary
   (possibly aided by storm outflow) will extend from the upper MS
   Valley southwestward into KS, with eventual deepening of a low over
   KS later in the day. Moderate instability will develop across much
   of the central Plains, which when combined with strengthening wind
   fields aloft, will result in severe storms most numerous from NE/KS
   into IA and northern MO.

   ...Central Plains...
   Early day storms are expected to be ongoing from eastern NE into
   northern IL, near the trailing front extending from the upper Great
   Lakes low. Some marginal hail risk may exist Thu morning, as lapse
   rates aloft will be steep, and storms may be elevated.

   Capping will be eroded near the stationary front by around 21Z from
   near the KS/NE border into IA as the moist boundary layer deepens.
   Indications are that numerous storms could form in this region, and
   this would also suggest some MCS potential. Conditionally, a few
   early supercells are possible given the increasing low-level jet and
   increasing cyclonic flow aloft. Activity could form a bit earlier
   across northern MO or IA if early storms produce any substantial
   outflow boundaries.

   To the west, strong heating will occur from central NE/KS westward,
   with low pressure developing over central KS. Here, low-level
   convergence will be on the increase, with a cold front eventually
   overtaking the area late in the day. Models such as the NAM show
   initial development over eastern CO or western KS where MUCAPE will
   be marginal but lapse rates very steep. This suggests an eventual
   MCS developing with damaging winds during the evening. 

   ...Midwest into western PA and NY...
   Southwesterly 850 mb flow in excess of 30 kt will help transport
   moisture toward the lower Great Lakes by late afternoon, with a warm
   front lifting northeast across western NY. Midlevel winds will be
   relatively strong, on the order of 40-50 kt, which will favor
   forward-propagating storms capable of gusty winds. The most
   favorable area for severe storms is likely to be coincident with the
   strongest instability which will extend from IL/IN toward Lake Erie,
   with storms moving mostly in an eastward direction.

   ..Jewell.. 06/28/2017

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z