Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 212258

Area Forecast Discussion
National Weather Service Northern Indiana
659 PM EDT Wed Jun 21 2017

Issued at 659 PM EDT Wed Jun 21 2017

High clouds will increase during the evening and overnight as a warm
front washes through the area. Increasing moisture and heat on
Thursday will lead to a chance of thunderstorms Thursday night into
Friday morning.


.SHORT TERM...(This Evening through Thursday)
Issued at 211 PM EDT Wed Jun 21 2017

All of the high resolution short term models are suggesting
suppression of convection through much of the evening and
overnight. Weak subsidence and downslope flow persists over our
area until the warm intrusion starts into the region late
tonight/early Thursday morning. Additionally, models suggest that
the deformation axis between TS Cindy and the approaching
shortwave trof will continue to diminsh moisture advection and
further suppress convection in the near term.

Heat indices on Thursday expected to rise into the lower 90s. The
challenge with this is the amount of cloud cover. Expect that we
will see more high level clouds overspreading the region as TS
Cindy continues moving north.


.LONG TERM...(Thursday Night through Wednesday)
Issued at 211 PM EDT Wed Jun 21 2017

Warm frontal passage and destabilization during the day Thursday
sets the stage for more organized convection late Thursday into
Friday morning. Similar to last few events this will be late,
beyond the peak insolation period, so expect the coverage and
intensity to be somewhat limited. Will also have to monitor
closely the cloud cover, as that will have an impact on the BL
temperatures and instability. With sufficient moisture, there is a
good chance of locally heavy rainfall and as the cooler air
settles in the wake of deeper convection could see a prolonged
period of steady rainfall persisting through Friday.

Cooler air settles across the region for the weekend and through
the mid week. Temperatures will be 5 to 10 degrees below normal.
With broad scale westerly flow and trof over eastern NA,
reinforcing cool air and occasional short waves cannot be ruled
out. While PoP is low through the period, have low confidence
that the entire period will be rain-free.


.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 659 PM EDT Wed Jun 21 2017

VFR this period. Old frontal boundary from yesterday in the process
of returning north but washing out with time. Thus little of
noteworthy mention for a discernable forcing mechanism to fire
storms this period as low level thermal inversion only intensifies
not to mention exceedingly poor mid level based lapse rates nwd of
TS Cindy. Gusty sw winds expected Thu aftn in association with
deepening warm sector.





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