Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 221705

Area Forecast Discussion
National Weather Service Northern Indiana
105 PM EDT Sat Jul 22 2017

Issued at 1001 AM EDT Sat Jul 22 2017

This afternoon into tonight will feature partly to mostly cloudy
skies and mainly dry conditions. Highs this afternoon will reach
the 80s, with lows tonight falling to near 70 degrees. A weak
front will move through the region Sunday afternoon and evening
with low chances for thunderstorms again during this period.
Drier and cooler air will then prevail for the first part of the
upcoming week.


Issued at 102 PM EDT Sat Jul 22 2017

Just another update to our forecast, now that the main precipitation
has exited the area. SPC again downgraded us from marginal risk to
no severe weather risk for today. Weak/limited forcing in the form
of a cold front will continue to slide slowly southeastward,
stalling out until Sunday morning when it moves out of our CWA. As
it does, expect that the precipitation chances will dwindle down
even further. Kept isolated POPS in the southeast along the axis of
the front for this afternoon, but have low confidence given current


.SHORT TERM...(Today and Tonight)
Issued at 530 AM EDT Sat Jul 22 2017

Several mesoscale convective complexes moving through the region
this morning. First MCV rotating through eastern area and severe
threat this morning ending as this feature exits. Strong warm air
advection and low level jet to our west has fueled a second MCS over
eastern IA and northern IL and this making its way into NW Indiana
early this morning. Primary concern will be heavy rain threat rest
of this morning with PWATs still over 2 inches. Expect this complex
to begin weakening as it translates through the area this morning as
LLJ weakens and moisture convergence diminishes.

Focus then shifts to afternoon convection and severe chances. Fully
expect composite outflow from this morning convection to be well
south of the area today and stable bubble over most of CWA. Clouds
will linger this morning and possibly into this afternoon once again
limiting heating and keeping thermal gradient to our south. High dew
point air still in place and even with clouds could see CAPE of at
least 1500-2000 J/KG develop. However lack of focus and with
boundary south of area along with local CIN thinking best chances
for any development will be in our far south. Last several CAMs runs
tend to agree and latest HRRR develops storms along our southern
border. Will trend afternoon pops in this direction with highest in
our far south. Isolated severe will be possible where storms do
develop and again primarily focused in our far southern counties.
Evening storms should then push south of the area with approach of
first synoptic frontal boundary and drying overnight.


.LONG TERM...(Sunday through Friday)
Issued at 530 AM EDT Sat Jul 22 2017

Short wave and associated secondary cold front to swing south Sunday
into Sunday evening. Models continue to indicate possible convection
with these features as low level moisture lingers and CAPE values
increase to over 2000 j/KG. Deep layer shear also increases to over
30 knots so isolated severe not out of question and thus the day 2
slight risk. Once this wave passes should finally see drier and
cooler air work in for Monday and first half of upcoming week.

Another short wave in west northwest flow looks to arrive mid week
with another sagging surface front. This will bring chances for
showers and storms back to the area for latter half of the week.
Basically accepted blends for later periods with focus this morning
on short term weather.


.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 101 PM EDT Sat Jul 22 2017

Any lingering MVFR stratocu at KFWA should mix out to VFR at or
shortly after issuance leaving mainly VFR/dry conditions and light
wnw winds at the terminals this afternoon into this evening.
Moist low levels and light winds may allow low stratus/fog to
build into northern Indiana later tonight into early Sunday
morning, though confidence in coverage remains of lower confidence
at this forecast range.




SHORT TERM...Lashley
LONG TERM...Lashley

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