Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 290021
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
821 PM EDT THU JUL 28 2016

.SYNOPSIS...
Issued at 800 PM EDT Thu Jul 28 2016

Scattered showers and isolated thunderstorms will diminish in
coverage during the late evening and overnight hours. An another
upper level disturbance will approach the area for Friday bringing
another chance of showers and thunderstorms. Lows tonight will
range from the low to mid 60s. High temperatures on Friday will
reach into the lower 80s.

&&

.UPDATE...
Issued at 800 PM EDT Thu Jul 28 2016

Combination of a weak upper vort tracking across southern lower
Michigan, moderate diurnal instability, and lake breeze
convergence enhancement allowed scattered showers and
thunderstorms to develop across northwest Indiana/southwest lower
Michigan earlier this afternoon. These storms consolidated and
have allowed outflow-modified lake breeze boundary to sag across
central portions of the forecast area early this evening. Loss of
peak heating and weaker instability to the east has resulted in
diminishing thunder over past hour or so, and expecting precip
coverage to be on a diminishing trend through 03Z. Weak CIN for
near surface/mixed layer parcel should develop by 03Z, and
prospects of additional rain for the overnight appear to be
minimal and not much change to previous forecast with maintenance
of just some isolated shower PoPs in the 03Z-08Z timeframe. Still
a few strong cores possible over the next few hours with lingering
instability and several boundary interactions possible, but nature
of previous forecast kept intact. Did add some patchy fog late
tonight with weak flow, and weak moisture convg across the south.

&&

.SHORT TERM...(This Evening through Friday)
Issued at 213 PM EDT Thu Jul 28 2016

Primary sw trough of note this aftn ovr wrn MN w/conv remnant
waves noted in vapor ovr ne MO and sw WI. Old synoptic fntl zone
conts stalled out fm srn IN nwwd into cntrl IL w/new isold convn
contg fm cntrl through srn WI. Otrws benign pattn remains intact
w/ltl appreciable focus for convn this aftn outside lk breeze
ovr nw IN/sw MI.

Slwr ewd ejection and shearing out of lead WI wave lends ltl
confidence in prior fcst overnight esp in light of tremendously
weak flw environment in place. Hwvr given proximity of old
synoptic fntl zone and apch of sewd advg sw trough out of MN cant
rule out addnl dvlpmnt esp invof of wk ll mass flux seen in most
highres solutions esp within the highway 30 corridor in IN this
evening.

Elongated upr trough axis will hold in place on Fri as MN sw digs
into ne IL by aftn. Old fntl zone shld buck a ltl further north into
nrn IN and w/sufficient diurnal destabilization... resulting in a
btr chc of shra/tsra in the aftn. Will reorient pops to fvr more
cntrl and north.

&&

.LONG TERM...(Friday Night through Thursday)
Issued at 213 PM EDT Thu Jul 28 2016

Lingering mid lvl trough axis through the srn lakes is apt to
fire again Sat aftn/eve and expanded prior pops a bit more esp
underneath consensus mid lvl trough axis position. Otrws
generally flat zonal flw aloft underneath east Canada troughing
will break sharply twd more upr ridging cntrd acrs the cntrl
plains erly nxt week. Thus xpc general subsidence aloft will stave
off organized precipitation until lt pd as increasingly hot/humid
and unstable airmass begins to convectively cycle within nrn
periphery of upr ridge. Where exactly this lays out and
positioning of active w-e fntl zone remains speculative per contd
disparate med range solutions. Given lack of consensus solution
see no reason to detract fm inherited 20 pops. Regardless rtn of
abv normal temps seen by mid pd and beyond.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 800 PM EDT Thu Jul 28 2016

A weak upper level short wave combined with lingering diurnal
instability and boundary interactions will provide some scattered
showers across northeast Indiana through around the 03Z
timeframe. Lake breeze has been shifted well southeast of KSBN
early this evening as scattered storms congealed to make this
boundary more progressive late this afternoon. Threat of precip
appears to have ended at KSBN and will carry tempo group for
showers at KFWA through 02z. Otherwise, did add some MVFR vsbys
with some patchy fog potential late tonight into early Friday
morning. Winds should be generally light through this period with
northeast directions as very weak sfc reflection remains southeast
of terminals. Next upstream short wave should reach western Great
Lakes during peak heating on Friday providing another chance of
scattered showers and thunderstorms late in the period.

&&

.IWX Watches/Warnings/Advisories...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...Marsili
SYNOPSIS...Marsili
SHORT TERM...T
LONG TERM...T
AVIATION...Marsili


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