Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 291027

Area Forecast Discussion
National Weather Service Northern Indiana
627 AM EDT Sat Apr 29 2017

Issued at 401 AM EDT Sat Apr 29 2017

A warm front will move slowly north from the Ohio River this
morning to southern Michigan Sunday causing showers and scattered
thunderstorms in our area. Heavy rainfall is possible, especially
over northwest Indiana and southwest Michigan tonight through
Sunday night. Cool temperatures tonight will warm considerably
Sunday behind the warm front. A cold front will sweep across the
area Sunday night causing showers and possibly thunderstorms.
Windy and cooler conditions with a chance of showers will follow
the front Monday and Tuesday.


.SHORT TERM...(Today and Tonight)
Issued at 401 AM EDT Sat Apr 29 2017

Warm front extending ne from low over TX into to the OH River this
morning with widespread tstm activity in vcnty of this boundary.
This front is expected to lift slowly north across srn IN today
resulting in an increase in shower coverage from south to north
across our cwa. Elevated instability will also be overspreading
the area providing chance of tstms to reach as far north as the
Toll Road. With the front remaining to our south today temps will
not rise much with highs fcst to range from the m50s north to the
m60s south. As the srn plains low lifts ne, warm front expected to
lift north into central IN tonight. Heaviest rainfall expected to
be across our nw closer to nose of LLJ ahead of the ejecting low.
Given very moist airmass over-running the front and deep warm
cloud layer, locally heavy rainfall psbl across the rest of the
area, but stronger forcing across the nw supports not expanding
the FFA in place for that area attm. With warm front apchg,
little diurnal temp drop expected tonight with lows ranging from
the m40s north to the m50s south.


.LONG TERM...(Sunday through Friday)
Issued at 401 AM EDT Sat Apr 29 2017

Warm front expected to lift into srn MI Sunday, followed by a
strong occluding cdfnt sweeping from sw to ne across the cwa
Sunday night. Main focus for widespread and potentially heavy
rainfall remains across the nw portion of the cwa closer to the
slow moving warm frontal boundary, while se should get more
solidly into the warm sector Sunday. Moderate instability should
develop in this warm sector Sunday aftn, but wk capping and lack
of forcing in this area supports just chc tstm pops. Temps should
warm into the 70s over most of the cwa Sunday and in the l-m80s
far se.

Strong occluding cold front will sweep from sw to ne across the
cwa Sunday night. Diurnal instability will be waning as front
moves through but given very strong wind fields there could be
some pockets of damaging wind gusts with stronger convective
elements along the front. Strong CAA Monday will result in steady
or slowly falling temps, mainly in the 50s west and lower 60s
east. Cyclonic flow associated with slowly departing deep low
across the upr grtlks/se Canada may keep some showers in the area
into Tue.

Medium range models have trended farther nw with track of another
deep low expected middle-late next week. This necessitated
bumping up pops a bit mainly for sern portion of the cwa, though
just to chc as still questionable if this system will track far
enough to the nw to impact our area. Temps should remain blo
normal through the week as upr troffing becomes established over
the ern U.S..


.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 622 AM EDT Sat Apr 29 2017

LIFR conditions have settled into KFWA as large area of rain and
embedded storms continues to work slowly north towards the site.
Thunder thus far has remained just south of the site and current
trends would suggest this may continue. However, will err on side
of caution and have a few hours of VCTS. Rain will either shift
north or more likely dissipate this morning, possibly not reaching
KSBN. Optimistic at least slight improvement to low end MFR/IFR
conditions at KFWA as drier air works in briefly.

Rain chances persist through the remainder of the period with
little overall change to past TAFs. Have kept vcts for a period at
both sites when instability appears best.


IN...Flash Flood Watch from this evening through Monday morning for

MI...Flash Flood Watch from this evening through Monday morning for

LM...Small Craft Advisory until 4 PM EDT Sunday for LMZ043-046.




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