National Weather Service Raw Text Product

Displaying AFOS PIL: AFDIWX Received: 2017-10-13 05:40 UTC

FXUS63 KIWX 130540

Area Forecast Discussion
National Weather Service Northern Indiana
140 AM EDT Fri Oct 13 2017

Issued at 139 AM EDT Fri Oct 13 2017

Mostly cloudy skies and patchy fog will prevail tonight. Lows will 
be in the 50's. Expect cloud cover to diminish gradually through 
Friday, especially south of US 30 as high pressure briefly settles 
over the area. Another system will bring chances for rain to the 
northwest Friday night. Highs will be in the 60's. Saturday will be 
much warmer, with highs climbing into the mid-upper 70's. Rain will 
overspread the region as a front moves through Saturday night into 


.SHORT TERM...(This Evening through Friday)
Issued at 306 PM EDT Thu Oct 12 2017

Strong subsidence inversion under shortwave ridge has locked in 
moist near surface layer. Depth of this moist layer per latest AMDAR 
soundings 1-2 km deep suggesting extensive low stratus deck will 
remain in place into tonight. A weak sfc trough draped from sw OH
wnw to central IL will lift north through the area later tonight 
into Friday morning. Could see some patchy fog/drizzle in advance 
and along this feature as it moves through, though coverage should
be limited with most locations remaining dry. Warm advection and 
expected mix out of low clouds in wake of weak trough (from sw to 
ne) in the morning/early afternoon should afford a warmer Friday 
as low-mid level flow veers more southerly.


.LONG TERM...(Friday Night through Thursday)
Issued at 306 PM EDT Thu Oct 12 2017

A relatively potent shortwave trough is still on track to work west 
to east across the US this weekend in progressive pattern, with the 
associated deepening sfc cyclone taking a Central Plains to Northern 
Great Lakes track by Saturday night/Sunday morning per latest model 
consensus. Excellent moisture return/convergence within downstream 
LLJ core will likely allow shower/embedded thunder coverage to 
blossom from Iowa east-northeast into the lower-central Great Lakes 
by later Friday night-Saturday. This strengthening baroclinic zone 
will be the focus for higher PoPs during this time into our nw IN 
and sw Lower MI zones, while ne IN/nw OH remains dry and 
unseasonable mild within a well mixed warm sector. Rainfall 
totals in excess of a half inch will be possible in sw Lower MI, 
with higher amounts just north from the IL/WI border into central 
Lower MI. 

Trailing cold front will work through later Saturday night/Sunday 
morning with additional shower chances. Transient/brief shot of 
cooler/drier/seasonable air then follows into early next week as 
high pressure builds in wake of trough.


.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 139 AM EDT Fri Oct 13 2017

Main concern tonight would be the potential return of IFR 
conditions, especially at KFWA. Weak WAA kicks in tonight ahead of a 
weak trough that will lift through. With WAA, nearly calm surface 
winds, and mid-level subsidence trapping moisture close to the 
surface, think KFWA will have a shot at developing some IFR 
conditions between 9-13Z due to BR or perhaps even fog. Have 
introduced a tempo group to cover this for now, and went 
conservative on the visibilities given uncertainty. Winds will be 
stronger over KSBN, thus potential is lower for IFR conditions, 
so have kept things MVFR for now. There is a chance that there 
could be some drizzle again with the passage of this weak trough, 
but did not include in the TAF for now given low confidence. We 
return to VFR conditions late Friday morning/early afternoon.




SHORT TERM...Steinwedel
LONG TERM...Steinwedel

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