703
FXUS63 KIWX 171147
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
646 AM EST Mon Nov 17 2025

.KEY MESSAGES...

- Dry with increasing cloud cover this afternoon and evening.
  Highs will be in the 40s and low 50s, warmest further south.

-Rain is expected tonight into Tuesday, mixing with or changing
 over to all snow Tuesday morning for areas areas north of US
 30. Areas north of US 6, especially along and east of I 69,
 could see minor snow accumulations of around 1 inch or less.
 Travel with caution for the Tuesday morning commute as there
 could be slick slush or snow covered roads. Rain showers are
 likely in the afternoon as temps rise into the mid-upper 30s
 and low 40s.

-Wednesday will be dry with highs in the 40s. There is a 30-65
 percent chance of rain showers Thursday through Saturday.

&&

.DISCUSSION...
Issued at 437 AM EST Mon Nov 17 2025

Expect increasing cloud cover today into this evening ahead of the
next system to impact the area. Highs will be in the 40s and low 50s
(warmest south of US 30, west of I 69). Cloudy tonight with lows
largely in the 30s (mid-upper 30s far southwest). Locations further
northeast (Hillsdale/Branch County MI and Fulton County, OH) will
fall into the upper 20s as they are the last to see cloud cover and
precipitation move in. Warm air advection ensues overnight ahead of
the next system, with 850mb temps rising from around -5C to around 2-
6C (coldest in the northeast) by 15z Tuesday.

The upper level low over NE/IA/SD around 3-6z Tonight will drift
eastward with time, washing out into a trough by Tuesday evening
over NE OH and PA/NY. This will bring a decaying surface low through
MO/southern IL/IN and eventually KY/TN through that period. For our
area, isentropic ascent (290K) ramps up between 00z-6z and persists
through Tuesday though it weakens with time. The peak should be
around 12z. We have decent moisture transport at the nose of a LLJ
(45 knot) during this time, which is shunted eastward as we get
later into the day Tue (as the low moves east/weakens). With high
pressure initially in place over the E-NE, it will take some time
before we reach enough saturation to overcome the drier air-but
expect precipitation to increase from W-SW to E-NE starting around
6z. Models develop a decent Fgen band in the low-mid levels during
the 9-15z time frame, which could give us a period of moderate and
even heavy rain and/or snow. The better dynamics/heavier rates make
it more likely we completely transition to snow in areas with
temperatures in the upper 20s, low 30s (further north/east). Areas
north of US 30 have the best shot of seeing a mix (possibly some
sleet) or complete changeover during the morning hours. Areas north
of US 6, east of I 69 have the best potential for accumulation, with
up to around 1" or less possible near Branch/Hillsdale, MI and
Fulton, OH. As the temperatures warm somewhat during the day we`ll
transition back to rain or drizzle before precipitation tapers off
all together.

All in all, the Tue AM commute (especially where mix or the complete
changeover to snow occurs) could be hazardous as roads will likely
be slick and snow or slush covered. If travelling, allow for extra
time to reach your destination.

High pressure build back in overhead Tuesday night into early
Thursday before additional rain chances build in ahead of the next
system. We`ll see a trough swing through with some weak moisture
transport on Thursday afternoon/evening, then additional chances
Friday into Saturday with a similar set up to today albeit warmer.
Highs will be in the upper 40s and 50s, with overnight lows in the
30s and low 40s.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 550 AM EST Mon Nov 17 2025

Light wind this morning beneath high pressure increasing to
only about 10 knots this afternoon before diminishing.

Increasing clouds today ahead of a low pressure system moving
over the Central US. Warm air advection overnight will spout
showers across IL that will eventually spread east. High
confidence on dry conditions through at least 06z. There is a
strong model concensus for precipitation starting at 09/10z.

Forecast soundings favor rain at KFWA, while there is a solution
or two at KSBN that offer a 2-3 hour period of -RASN. Confidence
is higher in -SHRA, thus, opted for that p-type in the TAF.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until noon EST today for LMZ043-046.

&&

$$

DISCUSSION...MCD
AVIATION...Brown