Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 121740

Area Forecast Discussion
National Weather Service Northern Indiana
140 PM EDT Sat Aug 12 2017

Issued at 346 AM EDT Sat Aug 12 2017

Low pressure will move northeast away from the Great Lakes today.
Generally fair weather is expected in its wake, though isolated
showers are possible, mainly north of the Toll Road. High pressure
will build into the Great Lakes tonight and linger through early
next week providing fair weather. Temperatures will be cooler
than normal over the weekend, with a slow warming trend early
next week. The high will move to our east by the middle of next
week allowing moist southerly flow to return. A low pressure
system moving east from the plains will interact with this
moisture providing a good chance for showers and thunderstorms
around Wednesday night or Thursday.


.SHORT TERM...(Today and Tonight)
Issued at 346 AM EDT Sat Aug 12 2017

Upr level trof across nrn MI/WI will move se across the wrn
Grtlks today. Sufficient lingering low level moisture/instability
expected for a few showers as this system approaches/moves
through, especially downwind of Lake Michigan where wk lake
induced instability should enhance shower intensity/coverage.
Sufficient sunshine and N-NW gradient mixing should allow temps to
reach the m-u70s this aftn. Winds should have some lake breeze
enhancement as well allowing waves in the NSH/SRF zones build to
at or above 4ft resulting in SCA/dangerous swimming conditions on
Lake MI.

High pressure will build into the area tonight allowing skies
to clear and winds to diminish. Strong radiational cooling should
allow temps to fall into the l-m50s. Patchy fog psbl in rural low
lying areas late as boundary layer decouples but held off adding
to fcst attm.


.LONG TERM...(Sunday through Friday)
Issued at 346 AM EDT Sat Aug 12 2017

High pressure expected to linger over the Grtlks Sunday-Tuesday.
Upr low over ne MT expected to shear out and move east across the
Grtlks Mon-Tue but combination of wk forcing and dry airmass
should prevent any showers from developing in our area. Temps
will be on a slow warming trend as airmass slowly modifies. Upr
level ridging will move across the area Tue ngt-Wed ahead of
rather strong shrtwv movg east from the plains. This system will
draw gulf moisture north into our area ahead of it which should
result in widespread showers as it moves through. Models still
have some timing differences but appears main impact will be Wed
ngt and/or Thu. Medium range models in decent agreement that
another shrtwv will follow quickly behind Thursday`s as zonal flow
begins to amplify a bit. However, sgfnt spread in timing/strength
of this system, so for now just a low chc of showers fcst.


.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 129 PM EDT Sat Aug 12 2017

Moisture provided by a trough to the east as well as northwest
winds allows a few showers to be around the region this afternoon
ahead of an incoming high pressure system. Subsidence and dry air
should keep the bulk of the showers at a minimum during peak
heating. Overnight, light and variable winds and sfc moisture
especially near crops and area lakes may be able to create more
fog/BR. The most likely TAF site to see fog/BR would be FWA while
SBN appears too dry.


IN...Beach Hazards Statement until 10 PM CDT this evening for INZ003.

MI...Beach Hazards Statement until 11 PM EDT this evening for MIZ077.

LM...Small Craft Advisory until 11 PM EDT this evening for LMZ043-046.




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