|Mesoscale Discussion 804|
< Previous MD Next MD >
Mesoscale Discussion 0804
NWS Storm Prediction Center Norman OK
0607 PM CDT Sat May 20 2017
Areas affected...North-central Indiana
Concerning...Severe potential...Watch unlikely
Valid 202307Z - 210130Z
Probability of Watch Issuance...20 percent
SUMMARY...An isolated severe threat will be possible early this
evening across parts of north-central Indiana. Strong wind gusts,
hail and perhaps a brief tornado will be possible. Due to the
isolated nature of the threat, weather watch issuance is not
DISCUSSION...The latest surface analysis shows a frontal boundary
extending from northern Illinois southeastward into central Indiana.
A moist and unstable airmass is located to the south of the boundary
where surface dewpoints are generally in the upper 60s to lower 70s
F. This is contributing to a pocket of moderate instability with
MLCAPE estimated to be between 500 and 1500 J/kg. In addition, the
Indianapolis WSR-88D VWP shows 0-6 km shear around 45 kt with some
gradual veering of the winds with height in the lowest 2 Km AGL.
This should be enough for storm rotation and hail with the stronger
cells. As thunderstorms move northeastward across the warm front, a
brief tornado will be possible. Strong wind gusts will also be
possible. The severe threat is expected to be short-lived due to the
relatively stable airmass located to the north of the front.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 39968492 39528574 39488690 39698741 40158770 40968767
41378688 41158577 40878483 39968492
Top/All Mesoscale Discussions/Forecast Products/Home