National Weather Service Text Product Display

Severe Storm Outlook Narrative (AC)
Issued by NWS

Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50


000
ACUS11 KWNS 191739
SWOMCD
SPC MCD 191738
OHZ000-KYZ000-INZ000-191945-

Mesoscale Discussion 0779
NWS Storm Prediction Center Norman OK
1238 PM CDT Fri May 19 2017

Areas affected...Portions of southern IN...northern KY...and
southern OH

Concerning...Severe potential...Watch possible

Valid 191738Z - 191945Z

Probability of Watch Issuance...60 percent

SUMMARY...An increasing damaging wind threat with thunderstorms
intensifying across southern IN may warrant watch issuance in the
next several hours. Isolated large hail may also occur.

DISCUSSION...A nearly stationary front extends across central IN/OH
this afternoon. Diurnal heating along and south of the front has
encouraged surface temperatures to warm into the upper 70s to lower
80s, and MLCAPE has increased into the 1000-1500 J/kg range in the
warm sector. A moist low-level airmass was sampled by the 12Z ILN
sounding, although mid-level lapse rates were modest around 6.5 C/km
in the 700-500 mb layer. Semi-discrete convection has recently
strengthened across southern IN as outflow associated with prior
overnight convection across MO/IL has encountered the unstable
airmass south of the front. With 0-6 km shear vectors oriented
nearly perpendicular to the strengthening convection, upscale growth
into one or more bowing line segments seems likely over the next
several hours. The damaging wind threat associated with this
activity should likewise increase this afternoon with 30-40 kt of
effective bulk shear present to support thunderstorm organization,
and at least some damaging wind threat may continue into the early
evening hours across parts of southern OH and northern KY per 14Z
experimental HRRR. Isolated large hail may also occur for the next
several hours if storms remain semi-discrete. Watch issuance is
possible pending signs of greater convective organization.

..Gleason/Kerr.. 05/19/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...RLX...JKL...ILN...LMK...IND...

LAT...LON   37988298 37868597 37988647 38848695 39168697 39718658
            40138512 40128308 39988237 39548212 38948222 38458257
            37988298

National Weather Service National Headquarters