Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 190551

Area Forecast Discussion
National Weather Service Northern Indiana
151 AM EDT Sat May 19 2018

Issued at 119 AM EDT Fri May 18 2018

Showers will persist the rest of the night and through today. A
few thunderstorms also possible. Lows the next several nights will
be in the mid 50s to lower 60s with highs generally in the 70s.


.SHORT TERM...(This Evening through Saturday)
Issued at 330 PM EDT Fri May 18 2018

Northward drift of upper low was underway with first spoke of
energy around it bringing an expanding area of rain/rainshowers to
the area through 00Z. Pops have been increased to account for
coverage with a lingering thunder threat left in the south, albeit
very low. Challenges come after 00Z as models still varying on
coverage/location of additional rain chances as low level jet
ramps up once again. Best chances look to be prior to 6Z so have
maintained/expanded likely pops with a slow downward trend in the
west as best moisture and instability focus east.

Upper low will drift overhead on Saturday, allowing for better
instability in the area, especially east. Thunder chances look to
increase somewhat in the east with slug of maybe 500 J/KG MUCAPE.
Likely pops appear warranted in SE areas to high chc NW. Shear
will be lacking so should be safe in terms of severe risk with
more of a heavy rain threat given warm rain processes and gulf
moisture in place.


.LONG TERM...(Saturday Night through Friday)
Issued at 330 PM EDT Fri May 18 2018

Lull in precip is expected as upper low pulls away from the area
before the next one arrives from the west. Model differences
not helping the forecast GFS/SREF/EC keeping front and associated
instability well south of the area into central/southern Indiana
vs NAMNest/NAM further north Sun afternoon/night. Have kept shy of
likely for the time being given above concerns. Severe threat
across the south still looks reasonable with at least some
overrunning potential. Convective chances continue into Monday
evening as yet another ripple in the flow interacts with at least
some instability and plenty of moisture.

Western states upper low will struggle to come east and eventually
lose the battle from increasing heights in the SE allowing a nice
surge of even warmer air with highs at least 80 (possibly well
into the 80s). Could see some additional shower/storm chances but
may end up with best axis north of us. Time will tell.


.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 119 AM EDT Sat May 19 2018

A surface low pressure area will drift north today and continue to
spread showers over the area. Ceilings were extremely variable
early this morning with MVFR and areas of IFR over northern
Indiana. Tried to capture the essence of this system with a TEMPO
IFR group at SBN and a 6-hour IFR period at FWA. It is very
likely adjustments/amendments will be needed early in the TAF
period. Conditions should improve late in the day as the low moves
northeast out of the area.




LONG TERM...Fisher

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