Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
FXUS63 KIWX 211749

Area Forecast Discussion
National Weather Service Northern Indiana
1249 PM EST Tue Feb 21 2017

Issued at 1223 PM EST Tue Feb 21 2017

Rain continues to slowly come to an end as a front dissipates
across the region. With the residual moisture and warmth and
winds becoming light tonight, patchy dense fog is possible after
midnight. As we get into Wednesday, dry air moves into the region
associated with weak high pressure and some sunshine is expected
during the day. Clouds begin to come back in Wednesday night as a
low pressure system begins its trek towards the region. With
increasing moisture, rain chances will increase towards evening
Thursday with some thunder possible at night and Friday. Severe
thunderstorms are possible Friday as a cold front swings through
the area. Temperatures will be above normal for this forecast
period with highs around 70 Wednesday and into the 60s Thursday
and Friday. Behind the cold front Friday night, temperatures will
return to near normal and some back end snow showers are possible
on the northwest flow.


.SHORT TERM...(Today and Tonight)
Issued at 323 AM EST Tue Feb 21 2017

Wkng shrtwv movg across the upr Grtlks today should result in band
of showers over IL/WI reaching our nw this morning, but wk
forcing/limited moisture suggests showers prbly won`t survive
into the se. CAA behind this system negligible with H85 temps
remaining near 10c today, but considerable cloudiness should
result in high temps a bit lower than yday. Tonight, drying in the
mid-upr levels combined with a wk low level gradient may result
in some fog/stratus development. Temps will remain very mild with
lows only in the 40s.


.LONG TERM...(Wednesday through Monday)
Issued at 323 AM EST Tue Feb 21 2017

Another shrtwv expected to move east across the upr Grtlks Wed.
Low level WAA and increasing swly gradient winds/mixing heights
should result in warmer temps with highs expected in the upr 60s
to lower 70s. Cdfnt associated with this shrtwv will move into our
area Wed night. Wk forcing and limited moisture should result in
little or no rain along the frontal boundary. This front will
stall over our area Wed ngt as flow aloft backs in response to
strong shrtwv digging into the central Rockies. As this system
moves into the central plains and strengthens Thu some showers may
develop along the strengthening stnry frontal boundary. Sfc low
still expected to lift ne Thu ngt transitioning stnry front to a
warm front which will lift north into MI. Showers and a psbly
tstms expected along this frontal boundary with greatest impact
across nrn portion of the cwa. As the strong low lifts ne across
the upr Grtlks Fri, a strong cdfnt will sweep east across our
area. Wk instability, but strong wind fields and deep layer shear
should result in a line of showers and psbly tstms along the
front, some of which could be accompanied by damaging winds. Temps
will again be very mild ahead of this front with highs expected
in the mid to upr 60s despite considerable cloudiness. Strong CAA
overspread our area Fri ngt will result in temps back to late Feb
normals on Sat. Wrap around moisture and upr trof movg through
will likely result in some snow showers Sat, especially across the
nw where some lake induced instability will be present as H85
temps fall below -10c. Generally dry wx with seasonable temps
expected Sun-Mon, though with contd nw flow still some potential
for snow showers, mainly nw into Sunday.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1223 PM EST Tue Feb 21 2017

Cold front continues to push through the area this afternoon. Noting
some dryness in the low levels allowing for less precipitation
and VFR conditions across the area. Also, noting some IFR CIGs and
MVFR VISBY in N IL, but feel the wind direction and slow movement
of the front will keep those west of the area. Winds will be able
to become more southerly at the TAF sites as the front washes out
into the early overnight. Attention then turns to fog
possibilities for Wed morning as winds die out, nocturnal cooling
takes place and residual low level moisture gets trapped in
subsidence. FWA/SBN could reach into IFR and even LIFR fog as a
result. Clouds will then start clearing on Wednesday as drier air
works in.





Visit us at

Follow us on Facebook...Twitter...and YouTube at: is the U.S. government's official web portal to all federal, state and local government web resources and services.