Feb 28, 2017 1630 UTC Day 1 Convective Outlook
Updated: Tue Feb 28 16:30:27 UTC 2017 (20170228 1630Z Day 1 shapefile | 20170228 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170228 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MODERATE 80,322 10,245,409 Indianapolis, IN...St. Louis, MO...Louisville, KY...Springfield, IL...Evansville, IN...
ENHANCED 94,255 10,312,326 Cincinnati, OH...Dayton, OH...Springfield, MO...Joliet, IL...Peoria, IL...
SLIGHT 136,659 23,243,650 Chicago, IL...Columbus, OH...Memphis, TN...Lexington-Fayette, KY...Fort Wayne, IN...
MARGINAL 193,965 29,017,413 Milwaukee, WI...Nashville, TN...Kansas City, MO...Cleveland, OH...Atlanta, GA...
Probabilistic Tornado Graphic
20170228 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
SIG SEVERE 155,902 18,811,005 Indianapolis, IN...St. Louis, MO...Cincinnati, OH...Louisville, KY...Springfield, MO...
15 % 33,529 3,247,771 Louisville, KY...Evansville, IN...Owensboro, KY...Columbus, IN...New Albany, IN...
10 % 122,417 15,600,745 Indianapolis, IN...St. Louis, MO...Cincinnati, OH...Springfield, MO...Joliet, IL...
5 % 92,705 17,442,966 Chicago, IL...Columbus, OH...Memphis, TN...Lexington-Fayette, KY...Fort Wayne, IN...
2 % 85,078 12,730,457 Nashville, TN...Kansas City, MO...Cleveland, OH...Toledo, OH...Akron, OH...
Probabilistic Damaging Wind Graphic
20170228 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
30 % 155,614 18,058,954 Indianapolis, IN...St. Louis, MO...Cincinnati, OH...Louisville, KY...Dayton, OH...
15 % 138,297 22,245,885 Chicago, IL...Columbus, OH...Memphis, TN...Lexington-Fayette, KY...Fort Wayne, IN...
5 % 196,437 29,636,004 Nashville, TN...Kansas City, MO...Cleveland, OH...Atlanta, GA...Tulsa, OK...
Probabilistic Large Hail Graphic
20170228 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
SIG SEVERE 166,962 19,116,603 Indianapolis, IN...St. Louis, MO...Cincinnati, OH...Louisville, KY...Dayton, OH...
45 % 80,093 10,232,575 Indianapolis, IN...St. Louis, MO...Louisville, KY...Springfield, IL...Evansville, IN...
30 % 86,421 8,698,874 Cincinnati, OH...Dayton, OH...Springfield, MO...Joliet, IL...Peoria, IL...
15 % 126,708 22,450,389 Chicago, IL...Columbus, OH...Memphis, TN...Lexington-Fayette, KY...Fort Wayne, IN...
5 % 110,928 15,459,540 Milwaukee, WI...Nashville, TN...Kansas City, MO...Cleveland, OH...Tulsa, OK...
   SPC AC 281630

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1030 AM CST Tue Feb 28 2017

   Valid 281630Z - 011200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF EASTERN MO...CENTRAL/SOUTHERN IL...CENTRAL/SOUTHERN
   INDIANA...WESTERN/NORTHERN KY...

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   MODERATE RISK AREA ACROSS PORTIONS OF THE MO OZARKS TO THE
   LOWER/MIDDLE OHIO VALLEY REGION...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   ENHANCED AREA FROM EASTERN OKLAHOMA AND ARKANSAS TOWARD THE LOWER
   GREAT LAKES REGION...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   SLIGHT ACROSS PARTS OF THE CENTRAL AND EASTERN STATES...

   ...SUMMARY...
   Severe thunderstorms are expected to develop from portions of the
   lower Mississippi Valley to the Ohio Valley through tonight.  Strong
   tornadoes will be possible, especially across portions of the lower
   and middle Ohio Valley. Otherwise, large hail and damaging winds are
   expected.

   ...Portions of the MO Ozarks through the middle MS Valley and the
   Ohio Valley region...

   A prominent warm sector will continue to build
   northward/northeastward across the region through tonight, as a
   midlevel speed maximum advances from the southern Rockies
   east-northeastward toward the Ohio Valley region. As lower/middle
   60s dewpoints also develop northward/northeastward, an expansive
   area of MLCAPE around 500-2000 J/kg -- aided by steep midlevel lapse
   rates surmounting returning moisture -- will support vigorous
   convective development. With warm-sector-coinciding effective shear
   around 40-70 kt, a widespread area of conditional significant-severe
   potential will exist -- especially from late afternoon into the
   overnight hours. Present indications are that clusters of storms
   will be evolving from eastern parts of the central/southern Great
   Plains northeastward to the vicinity of southern Lake Michigan by
   late afternoon/early evening in the vicinity of a baroclinic band --
   with this activity spreading eastward into tonight. Confidence has
   increased in more widespread severe-hail potential with this
   activity, including significant severe hail. Open-warm-sector
   convection will likely evolve along a low-level jet through parts of
   the Ohio Valley tonight as additional moistening occurs. Effective
   SRH of 300-400 m2/s2 will support tornado potential with evolving
   supercell clusters. This includes the potential for nocturnal
   significant tornadoes, and tornado probabilities have been
   increased.

   ...Portions of the Southeast...
   Destabilization along the southern/eastern flanks of convection over
   the TN Valley region may support some increase in convective
   intensity with storm clusters advancing toward the southern
   Appalachians. Locally damaging wind gusts may accompany this
   activity.

   ..Cohen.. 02/28/2017

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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