Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
FXUS63 KIWX 151057

Area Forecast Discussion
National Weather Service Northern Indiana
657 AM EDT Tue Aug 15 2017

Issued at 327 AM EDT Tue Aug 15 2017

A weak cold front will move through the area today possibly
causing a few showers and thunderstorms. Fair weather is expected
tonight as the front stalls over central Indiana. Isolated storms
may develop south of Route 30 Wednesday afternoon as the front
remains stationary. A low pressure system will move northeast from
the Plains across the upper Great Lakes Wednesday night and
Thursday, likely causing some showers and scattered thunderstorms
in our area. High pressure will move across the area Friday
providing fair weather. Another low pressure system will move
through on Saturday bringing a chance of thunderstorms, followed
by high pressure with fair weather Sunday and Monday.
Temperatures will be seasonably mild through the next seven days.


.SHORT TERM...(Today and Tonight)
Issued at 327 AM EDT Tue Aug 15 2017

Shrtwv over nrn WI/MI with attendant sfc low along the IL/WI border
movg ese this morning. 25kt LLJ to the se of the sfc low providing
sufficient low level convergence/theta-e advection for sct
showers/isolated thunderstorms to develop from ne IL-srn MI. This
activity should impact our srn MI zones this morning as low moves
ese to sern MI. Wk trailing cdfnt will drop se across nrn IN/nw
OH this aftn. NAMBufr soundings suggest a brief period of moderate
instability will accompany the front early this aftn before
ridging aloft caps instability by late aftn. Wk moisture
convergence along this boundary may be able to pop an isolated
shower or thunderstorm, though with main upr forcing bypassing
this area to the ne, chances of deep convection here are slim
today. Temps should cont slow warming trend today, except nw where
fropa will turn winds off the lake and hold temps down a bit this

Wk front will stall out over central IN tonight as low pressure
moves east across KS/Neb. With only wk instability and
low level convergence, expect an isolated shower at most over srn
portion of the cwa, and will leave fcst dry for now. Skies should
be mostly clear and combined with light winds, expect fairly
strong radiational cooling allowing for lows in the the upr 50s
and lower 60s with some patchy fog likely.


.LONG TERM...(Wednesday through Monday)
Issued at 327 AM EDT Tue Aug 15 2017

Generally dry conditions should cont Wed as wk stalled frontal boundary
remains over central IN. Front close enough to allow some moisture
pooling and subsequent destabilization south which could allow
isolated aftn storms to develop.

Central Plains low will lift ne Wed ngt with LLJ spreading ne
across IL/IN and stalled sfc front lifting ne across our area as a warm
front. With a sub-tropical airmass in place upstream, this should
allow at least sct tstm activity overnight. Cdfnt associated with
this system should move across the area Thu. Cloud cover could
limit destabilization but forcing should be sufficient for
numerous showers and psbly thunderstorms. Deep layer shear fcst around
30kt suggests some storm organization likely if sufficient
destabilization materializes, so isolated svr storms psbl. Highs
both Wed-Thu should be in the l-m80s with muggy upper 60s to lower
70s Wed ngt.

High pressure will move across the area Friday providing fair wx
and a little cooler temps with highs in the upper 70s-lower 80s and
lows around 60. Another shrtwv expected to move east across
the Midwest Saturday bringing a renewed chc of tstms to our area.
This should be followed by fair wx Sunday-Monday as ridging moves
through. With flow aloft quasi-zonal, temps expected to cont at
or a bit above normal over the weekend.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 653 AM EDT Tue Aug 15 2017

An upper level disturbance will bring a chance for a shower this
morning to the SBN terminal. The activity should remain
relatively isolated. Ground fog at the vicinity of FWA will mix
out quickly this morning; however, low level moisture spreading
into the area will bring a better chance for fog tonight.





Visit us at

Follow us on Facebook...Twitter...and YouTube at: is the U.S. government's official web portal to all federal, state and local government web resources and services.