Grissom Arb, Indiana Weather Forecast Discussion

043
FXUS63 KIWX 052311
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
711 PM EDT Fri Sep 5 2025
.KEY MESSAGES...
- Mainly dry over the next 7 days. Only a 20% chance of showers
  or sprinkles north of US-6 Saturday night.
- Cool temperatures this weekend trend warmer, into the 80s, by
  the middle of next week.
- Dangerous swimming conditions expected for Lake Michigan
  beaches through Sunday.
&&
.DISCUSSION...
Issued at 244 PM EDT Fri Sep 5 2025
A 992mb low is swirling over northern Ontario, its cold front now
east of our area. Breezy westerly wind today subsides not only with
a loss of daytime mixing but with the 45 knot 850-mb jet departing
to the east as well. Tonight, clouds associated with a weak low
moving through the mid-Mississippi will provide some insulation
overnight helping to keep temperatures from bottoming out, but
still nearly 10 degrees below normal.
Broad troughing in remains in place through the weekend with this
large upper-low lingering over the eastern Great Lakes. Can`t rule
out lake effect showers Saturday night or Sunday as an embedded
shortwave ripples east across Lake Michigan. Duration will be
brief with high pressure quickly coming in to disturb
equilibrium levels. High pressure remains in place through the
coming week promising dry conditions (and an increasing risk of
drought). Temperatures will gradually warm back into the 80s by
midweek as the western US ridge finally tracks east.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 711 PM EDT Fri Sep 5 2025
Cool/dry air advection will continue to support a deep and
well-mixed boundary layer through the period...ensuring VFR
conditions. Ceilings will remain at or above 5 kft. Westerly
winds will only gust up to 20-25 kts on Saturday afternoon given
a weaker gradient.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement until 4 AM CDT Saturday for INZ103.
OH...None.
MI...Beach Hazards Statement through Sunday afternoon for MIZ177-
     277.
MARINE...Small Craft Advisory until 5 PM EDT Sunday for LMZ043-046.
&&
$$
DISCUSSION...AGD
AVIATION...Steinwedel

NWS IWX Office Area Forecast Discussion