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 46 47 48 49 50
FXUS63 KIWX 230000

Area Forecast Discussion
National Weather Service Northern Indiana
800 PM EDT Tue May 22 2018

Issued at 226 PM EDT Tue May 22 2018

High pressure will build in tonight and remain in place across the
area through the end of the week. The result will be dry
conditions and moderating temperatures. Areas of fog and low
stratus will be possible tonight into Wednesday morning, mainly
across northwest Indiana and southwest Michigan. Warm and humid
conditions are expected for the holiday weekend with highs in the
80s. There is a low chance for a shower or storm each day, though
expectations are for most locations to remain dry.


.SHORT TERM...(Late This Afternoon through Wednesday)
Issued at 226 PM EDT Tue May 22 2018

Scattered showers/storms will remain possible near the Lima OH
area through 20/21z. A weak surface trough and 1000-15000 j/kg of
MLCAPE trailing a low/mid level circulation moving through MI is
providing the forcing. Storms should remain below severe limits.
Dry otherwise/elsewhere for the remainder of the afternoon, with
post-frontal marine layer/inversion resulting in much cooler
temps and low stratus across nw IN/sw MI.

Large scale subsidence/height rises in wake of this afternoon`s
system will allow high pressure to build in tonight into Wednesday.
This will provide dry conditions, light winds, and seasonable
temps. The main forecast challenge will be potential renewed
fog/stratus development overnight into Wednesday morning,
especially across nw IN/sw MI where winds will go calm overnight
and temps likely fall well below xover values. Bumped up sky cover
and fog probabilities given these trends.


.LONG TERM...(Wednesday Night through Tuesday)
Issued at 226 PM EDT Tue May 22 2018

An upper level ridge will fold over the Great Lakes region Thursday
into Friday promoting dry conditions and moderating temperatures.
Humidity/instability will be on the increase with the local area
situated between a developing Deep South/TN Valley upper low and
Upper Midwest/Northern Lakes frontal system as upper ridge breaks
down. This will bring non-zero (10-30%) chances for mainly diurnally
driven shower/storms back into the forecast near potential
outflow/lake/differential heating boundaries as instability builds.
Weak flow/forcing should preclude much of a severe risk with
storms more pulsy/isolated at best. Best chances for storms does
appear to be north of US 24 Saturday afternoon as forcing on the
southern fringe of a Central/Northern Great Lakes shortwave
possibly clips the Lower Great Lakes.


.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 753 PM EDT Tue May 22 2018

Stratus and fog will impact the coastal areas inland through
04Z. As the skies clear and winds decrease expect to see patchy
fog form throughout the forecast area, with aviation impacts south
and east of Lake MI. Extensive IFR cigs/vsbys at KSBN after 10Z
could result in fuel/alternate conditions for several hours.

Further east and away from Lake MI, conditions will be primarily
patchy fog with vsby dropping to 3 to 5 miles.

Conditions improve quickly after 12-14Z with VFR conditions for
the remainder of the TAF period.




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

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.