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870
FXUS63 KIWX 192340
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
740 PM EDT Tue Sep 19 2017

.SYNOPSIS...
Issued at 730 PM EDT Tue Sep 19 2017

Skies will slowly clear overnight and areas of dense fog are
expected to develop, especially over northern Indiana and lower
Michigan. Visibilities could be near zero in some locations
toward daybreak. Low temperatures will be in the lower to middle
60s. The fog will dissipate through the morning with mostly sunny
skies in the afternoon. High temperatures will rise into the 80s.
Very warm and dry conditions will continue into the weekend with
highs in the middle to upper 80s and even some lower 90s possible.

&&

.SHORT TERM...(Tonight and Wednesday)
Issued at 253 PM EDT Tue Sep 19 2017

Pesky upper low over wrn Starke county has moved little through this
morning and will only slowly weaken newd into srn MI by this
evening. Trailing sfc trough and some weak sfc based instability
will yield greatest coverage of shra/thunder rumble this aftn
along/east of I69.

Otherwise upstream look across IL suggests partial clearing will
develop esp wrn half overnight and given widespread significant
rainfall early this morning and no appreciable advective change in
airmass expect dense fog will likely result late tonight. Will keep
close to prior gridded mention.

Subsidence behind departing trough and increasing swrly flow by late
morning will scour any remain fog/low clouds. Given insolation and
beginning of upper ridge amplification by aftn expect quite warm
temps... marking what looks to be a very warm long term period.

&&

.LONG TERM...(Thursday through Tuesday)
Issued at 253 PM EDT Tue Sep 19 2017

This period will be characterized by unseasonable warm and dryness
as blocking ridge expands across the Great Lakes upstream of wrn
Atlantic tag team of Hurricanes Jose and Maria. In fact upper ridge
exceeding 590 dm is seen in several model solutions this aftn
suggests some near record temps possible. Given strong/tight model
based concensus of both upper ridge intensity and placement will
thus drop any/all fallacious pop chances throughout the period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 728 PM EDT Tue Sep 19 2017

Satellite and surface observations show clearing skies working
into northwest Indiana. Clearing trend will be slow to work east
but expect clearing to gradually work into KFWA late this
evening. The combination of rainfall from earlier today coupled
with light to calm winds and clear skies should allow fog to form
quickly overnight with cross over temps well within reach.
Guidance in agreement hitting low visibilities and cigs rather
hard and given expected conditions see few reasons why dense fog
would not form across the area where skies clear. Gradual
improvement through Wednesday morning with conditions improving to
VFR.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...T
AVIATION...Lashley


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