Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 161738

Area Forecast Discussion
National Weather Service Northern Indiana
1238 PM EST Thu Nov 16 2017

Issued at 1230 PM EST Thu Nov 16 2017

Temperatures will change little for the remainder of the
afternoon, struggling to reach to near 40. Clouds will linger with
isolated light showers through early evening. After a relatively
quiet weather day Friday, another potent and moisture laden storm
system will move through the region Friday night and Saturday
with periods of rain, wind, and milder temperatures expected.


.SHORT TERM...(Today and Tonight)
Issued at 337 AM EST Thu Nov 16 2017

Sfc ridge centered over nw MO will build ewd into sw IN by evening.
Vigorous but brief cold advection wing wrapping ewd south of upper
trough spinning through cntrl MI failing to foster any sig lake
response other than filling with stratocu. Thus highly doubt any
measurable precip in the offing later this morning this far south
given sharp frontal inversion seen in upstream 00Z raob out of DVN
and have dropped prior mention entirely across the far n/nw.

Otherwise sfc ridge continues east into the ern OH valley by Fri
morning with broad return flow warm advection ramping late which
will keep low clouds in place and stave off an even colder overnight.


.LONG TERM...(Friday through Wednesday)
Issued at 337 AM EST Thu Nov 16 2017

Warm sector gradually deepens Fri ahead of developing sfc cyclone
ovr wrn KS. Slower concensus ejection of this system into the lakes
Saturday warrants some contraction in pops Fri aftn. Otherwise gist
of prior fcst remains on track as system rapidly deepens overnight

Primary uncertainty is nwd progression and eventual stall of low
level baroclinic zone which will serve as the pathway for sfc
cyclone track with as yet enough spread to limit additional qpf
detail. Nonetheless sig warm sector moisture flux with some modified
gomex influence into baroclinic zone points to some locally heavy
rainfall possible through parts of the area. In addition H85 based
theta-e ridging favors bona-fide thunder risk as well which if
realized will augment heavy rain risk higher. However rapid
northeast progression of upper trough looks to preclude a sig flood

Brief but robust cold advection wing follows for a time late Sat
night/Sun morning. Per H85 based thermal trough aoa -10C would
expect some lake response esp through sw MI and will bump
appreciably higher over subdued blend. However boundary layer temps
appear too warm for snow.

Thereafter brief warm advection in wake of weekend system for Mon
followed by a general cooldown through Thu as a series of low
amplitude nrn stream disturbances amplify ewd through srn Canada and
reinforce sfc ridging across the lakes/OH valley.


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1230 PM EST Thu Nov 16 2017

Cyclonic flow and strong fetch across Lake Michigan will keep
stratus and lingering showers through the first 6 to 8 hours of
the terminals with MVFR cigs prevailing. As the gradient relaxes
and ridging builds into the region expect to see gradual lifting
of the cloud deck and inproved visibility. IFR conditions to
prevail after 8Z across the entire region.


LM...Small Craft Advisory until 7 PM EST this evening for LMZ043-046.




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