Area Forecast Discussion
Issued by NWS Northern Indiana

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676
FXUS63 KIWX 011416
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1016 AM EDT Sat Nov 1 2025

.KEY MESSAGES...

- Light lake effect rain showers are possible over Michigan this
  afternoon into early evening.

- Highs today will be in the low 50s with lows tonight into the
  low 30s.

- Quiet weather is expected through much of next week with
  seasonable temperatures and mainly dry conditions through
  Thursday.

&&

.UPDATE...
Issued at 1014 AM EDT Sat Nov 1 2025

Sfc obs, satellite and radar all nicely depict a nearly
stationary meso low centered west of KMKG over central Lk MI.
Lake effect rain showers have continued to expand in this area
with a localized concern for waterspouts given the weak flow,
but favorable dynamics. HRRR has a good handle on the setup with
a very slow transition south for the rain showers, leading to
concerns as to how much may make it into far NW areas not only
this morning, but possibly through much of the afternoon as the
sfc flow remains SW and 925 mb flow more westerly. Vis sat is
showing some agitated cu over the lake on the southern fringe of
the mesolow which could eventually turns into a few light
showers that may clip N Berrien county in the coming hours. The
most favorable window (albeit still a low probability (20-30% at
best) being between 23Z and 3Z when the trough axis and mesolow
re-orient more SW to NE with some showers possibly grazing far
NW areas. Have tightened the gradient into early afternoon and
kept only a slgt chc in N Berrien county to account for concerns
noted with a slow expansion south the remainder of the
afternoon and early evening.

As for the cloud cover, a pocket of clearing has entered western
IN and should allow for some sunshine across many areas as we
progress into the afternoon. This should allow highs to reach
into the lower 50s for most spots, with the exception being
closer to Lk MI with the cloud cover lingering from the mesolow.
LAMP guidance still showing at least a brief hour or 2 of 50
degrees for a high so no changes to temperatures across the
area.

&&

.DISCUSSION...
Issued at 305 AM EDT Sat Nov 1 2025

Weak isentropic ascent ahead of upper low currently digging into the
region is supporting some very light precip at press time. This
activity will continue to shift NE and wane through the early
morning though. Attention will then turn to the expected lake
response during the day as passing vort lobe allows lake-induced
equilibrium levels to climb to near 10 kft. The resident airmass is
not particularly cold (850mb temps near -3C and 700mb temps near -
11C) but available moisture/instability and lack of subsidence
inversion will nevertheless yield some decent lake-enhanced showers,
especially with weakly convergent flow. Latest 00Z guidance is in
reasonable agreement that these showers will remain just to our N/NW
perhaps just grazing our MI counties during the day and into the
early overnight. Have therefore trimmed the area of PoP`s but
maintained some low chances. Highs today remain stuck near 50F with
at least partly cloudy skies and some light CAA. Lows tonight will
drop into the low 30s given clearing skies and light/variable winds.

SW flow/WAA ramps back up late Sun into early Mon ahead of a trough
swinging through the northern Lakes. Not surprisingly, latest
guidance and associated NBM has trended much drier for the
associated weak cold frontal passage in our area on Mon given best
forcing is well north and moisture return is negligible. Will
maintain some very low chances in our far north but suspect we will
end up entirely dry. We will face a very similar situation late Wed
and here again it is highly doubtful our CWA actually sees rain.
Much better chances for rain likely to arrive on Fri as a more
robust trough takes a more southern route through our area.
Obviously the details are still a bit hazy at this time range
though. Temps through much of next week actually lean on the warm
side of climo with no appreciable cold air in sight until perhaps
next weekend or even later.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 602 AM EDT Sat Nov 1 2025

Light flow in the low levels with a fairly dry sub cloud layer
will limit surface flow and low level cloudiness. Some light
showers may reach the SBN area, but given the relatively dry low
levels, have kept showers out of the TAFs and have kept VFR
conditions. Winds should become light toward 00Z as a relatively
weak surface pressure gradient prevails over the area.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

UPDATE...Fisher
DISCUSSION...AGD
AVIATION...Skipper