Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 201724

Area Forecast Discussion
National Weather Service Northern Indiana
124 PM EDT Tue Mar 20 2018

Issued at 637 AM EDT Tue Mar 20 2018

Windy but mostly dry conditions will continue today. The
exception is areas south of US 24, where there are chances for a
rain and snow mixture, especially by late evening. Snow is likely
in this area overnight, with up to 2 to 4 inches of accumulation
possible by Wednesday morning. Dry weather is expected Wednesday,
with decreasing clouds. Highs today will be around 40. Lows
tonight will be around 25.


.SHORT TERM...(Today and Tonight)
Issued at 401 AM EDT Tue Mar 20 2018

The upper low was near Evansville and was drifting northeast over
southern Indiana. A very chilly northeast flow will continue as
this system moves closer to the forecast area. Another system
upstream will interact with this Indiana system downstream and
cause a fujiwhara effect where the upper low will curve more
north. This interaction will bring precipitation farther north,
reaching Portland and Lima. Thermal fields favor precipitation
becoming all snow tonight. Given favorable isentropic lift on the
northern fringe of this system, have raised snow amounts to 2 to 4


.LONG TERM...(Wednesday through Monday)
Issued at 401 AM EDT Tue Mar 20 2018

The upper trof over eastern North America will be slow to move
east as waves of energy of pacific origin reach the Midwest late
this week. The resulting unsettled pattern will bring a good
chance for rain or snow from Friday night through Saturday night
as thermal profiles remain close the rain/snow threshold.
Otherwise, temperatures each day through Sunday will be 5 to 10
degrees below normal with highs mainly from 40 to 45.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 124 PM EDT Tue Mar 20 2018

VFR conditions with gusty NE winds will continue through the
evening. Main concern is midlevel vort lobe passing to our SE
tonight and the associated deformation band that may clip KFWA.
Latest guidance has trended slightly further NW...though still
some disagreement on where exactly the edge will be. Increased
confidence in some MVFR conditions at KFWA. IFR/fuel alternate
may be possible but confidence is too low at this time range. VFR
returns by late Wednesday morning.


LM...Small Craft Advisory until 11 PM EDT Wednesday for LMZ043-046.



SHORT TERM...Skipper
LONG TERM...Skipper

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