Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 181732

Area Forecast Discussion
National Weather Service Northern Indiana
132 PM EDT Sun Apr 18 2021

Issued at 410 AM EDT Sun Apr 18 2021

Pleasant weather will prevail through Monday with partly cloudy
skies and temperatures rising into the low to mid 60s both today
and Monday before a return to winter Tuesday and Wednesday. A rain
and snow mix will develop Monday night over northwest Indiana
with rain changing to snow from northwest to southeast especially
during the day Tuesday. Heavy snow is likely Tuesday night. It
appears initially traffic issues will be limited Tuesday, but snow
covered and slippery roads are likely to develop Tuesday night.
To top it off, a hard freeze is likely over at least part of the
area Tuesday and Wednesday nights that may seriously damage fruit


.SHORT TERM...(Today and Tonight)
Issued at 410 AM EDT Sun Apr 18 2021

A weak ridge of high pressure will continue to bring pleasant
weather today with a light wind flow. The airmass will modify with
highs climbing a little normal in the low to mid 60s. Temperatures
will finally stay above freezing tonight with lows near 40.


.LONG TERM...(Monday through Saturday)
Issued at 410 AM EDT Sun Apr 18 2021

The stage is getting set for an out of season snowstorm starting
Tuesday and continuing into Wednesday. Anomalously strong signals
and signs abound as an upper ridge taps some very cold air ahead
of a short wave trof and associated surface low. This system will
reach the Ohio Valley and Midwest regions by late Tuesday,
although light precipitation is likely near lake Michigan by
Tuesday morning. SPC upper air climatology along with CIPS
analogs and NAEFS ensembles including 42 members all support and
anomalous event for the second half of April. After coordination
with surrounding offices and the Weather Prediction Center, have
increased snow amounts to come in line with the latest model
guidance in light of this out-of-season event. Have significantly
undercut model blend guidance given diabatic processes Tuesday
into Tuesday night. Temperatures should fall during the day
Tuesday with rain changing to snow, especially late in the day.
Current thinking is there will be a heavy snowfall axis of 5" to
7" over northwest Indiana with lesser amounts southeast where rain
will change to snow at a later time. Given snow covered grounds
developing Tuesday night, low temperatures may really drop down
into the 20s and may cause considerable damage to fruit crops
Tuesday night and Wednesday night. Temperatures will recover to
above normal readings by the end of the week.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 132 PM EDT Sun Apr 18 2021

VFR conditions and light winds will persist through tonight as
the area remains in between systems. Plenty of high clouds but low
levels remain very dry. Cold front approaches at the every end of
this forecast period and may bring some MVFR ceilings to KSBN but
best chances appear just outside this forecast window.




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

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