246
FXUS63 KIWX 151730
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
1230 PM EST Sat Nov 15 2025

.KEY MESSAGES...

- A few sprinkles are possible later today with highs well into
  the 60s.

- Cooler air returns Sunday with highs back in the 40s and lows
  around 30 through early next week.

- Rain is expected Monday night into Tuesday. It could begin as
  a brief wintry mix for areas north of US-30 but impacts are
  anticipated to be minimal at this time.

- More rain and warmer temperatures arrive later next week.

&&

.UPDATE...
Issued at 1046 AM EST Sat Nov 15 2025

SW flow continues to allow for some WAA ahead of the approaching
cold front. Some lower clouds have been noted well ahead of the
front, associated with a bit of higher moisture that is shifting
east. The clouds have limited heating somewhat although most
areas are now in the 60s. Questions remain as to how many
locations may touch 70 degrees south of US-30 with guidance
backing off somewhat (confined more to US-24 south). Satellite
showers mainly mid/high clouds upstream which should allow for
some additional heating. Will leave forecasted highs alone for
now.

With regards to precip, KILX and KGRB 12Z soundings show quite a
bit of dry air moving in. Radar mosaics suggest a band of light
precip from NW IL to the central U.P. Sfc obs depicted the
impacts of the dry air nicely with virga being noted in some
spots. The only rain reaching the ground is in the central
portions of the U.P. Have left the 20 pops in, but if trends
persist (as I suspect they will), will be removing them over the
next hour or 2.

&&

.DISCUSSION...
Issued at 232 AM EST Sat Nov 15 2025

Northern Pacific jet streak now pushing into the Upper Midwest will
dig into the Great Lakes by later today and carve out a modest PV
anomaly just north of our area. Ahead of this system, strong WSW low
level flow will push 850mb temps into the mid teens. Mixing heights
are a little questionable with a Nov sun angle and mostly cloudy
skies but bulk of raw and statistical guidance shows highs in the
mid/upper 60s with some 70s not out of the question. Records for SBN
and FWA are 70 and 72, respectively. A few sprinkles remain possible
both in the warm sector and along the associated cold front arriving
late afternoon. However, better midlevel CVA and upper jet dynamics
miss us to the north with some midlevel dry air also impeding
precip. Most places will likely remain dry but will maintain a 20
PoP mention. Much more seasonable temps return by late tonight and
persist through early next week with highs back in the 40s and lows
around 30F. Sun and Mon will still be pleasant otherwise though.
Incoming airmass is not quite cold enough to produce lake effect
precip given limited fetch and extreme dry air entrainment limiting
instability. Expect just a few lake clouds in the north and
increasing high clouds late Mon but otherwise sunny/clear skies.

The next system to watch will be Mon night into Tue. Upper low
pinwheeling off the California coast will eventually get kicked NE
with a piece breaking off and shearing eastward Mon night. Highly
confluent flow over the Great Lakes/NE CONUS will dampen the wave
significantly but models still show a decent fgen response given 40+
kt LLJ setting up just to the south and advecting ample moisture
into the region. Still some disagreement on exact track though and
this will likely continue until all of the relevant features are
more adequately sampled by the upper air network. Still, precip
seems likely for our area based on a consensus of probabilistic
guidance. Precip types at the onset remain a little tricky given
some lingering cold air in our NE half early Tue morning. Forecast
soundings hover right around freezing over a deep layer so this is a
very sensitive forecast but the northward trend in latest guidance
is also a warmer trend, validating the idea that if it is moist
enough to precipitate it will be warm enough to be mainly rain.
Suspect a few hours of snow or sleet at the onset generally north of
US-30 before changing over to rain quickly after sunrise. Impacts
seem unlikely at this point with just a few tenths of snow in our
far NE counties but will continue to watch this period closely.

This system will be quickly followed by a larger, deeper upper low
taking a more southern track through the region later in the week.
This allows for very efficient moisture advection and good large-
scale ascent at some point later in the week (still a few details to
work out). Luckily, temps climb well into the 50s during this time
and this will be an entirely liquid event for us.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1229 PM EST Sat Nov 15 2025

As a low pressure system passes by to the north, gusty winds occur
with some mixing out ahead of a cold front and then, when winds go
more northwesterly, excited winds will still be possible behind it.
Given the amount of dry air in the mid levels, will still keep VFR
prevailing even with a few hours of MVFR CIGs to start. The
column is expected to dry out completely overnight.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory from 7 PM this evening to noon EST Monday
     for LMZ043-046.

&&

$$

UPDATE...Fisher
DISCUSSION...AGD
AVIATION...Roller