650
FXUS63 KIWX 221149
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
649 AM EST Mon Dec 22 2025

.KEY MESSAGES...

- Scattered light to moderate rain arrives tonight, changing to
  drizzle overnight into early Tuesday.

- Light rain is likely on Christmas, especially before daybreak
  and then again in the evening. Much of the daytime hours
  should be dry. Warm with highs in the 50s.

- Even warmer on Friday with highs in the upper 50s to low 60s.
  Rain and a few thunderstorms will be possible in the early
  morning hours.

&&

.DISCUSSION...
Issued at 301 AM EST Mon Dec 22 2025

Today is the start of a warming trend that will last through at
least the upcoming weekend! Southerly winds out ahead of the next
weather system will boost highs into the low to mid 40s today. WAA
ramps up throughout the day with gusts up to 20 to 25 mph,
especially this afternoon and evening. A shortwave ejects out of the
Rockies today, providing lift, and two approaching fronts will
interact tonight, bringing chances for rain and drizzle through
Tuesday morning. A warm front lifts north today and as the warm
sector advances north, forecast soundings depict the air becoming
saturated tonight. Simultaneously, a stationary front will
slowly advance south across the Midwest. Scattered light to
moderate rain will be possible after sunset tonight,
transitioning to a period of drizzle overnight as inversion
heights crash and mid level dry air moves in. Soundings for
early Tuesday morning show moisture confined to the low levels
with a steep inversion. Heavy drizzle may be possible area-wide
for several hours before daybreak depending on where the
stationary front ends up. Drier air and CAA follows into the day
on Tuesday as winds shift to become west/northwest.

A expansive upper level ridge will bring above average warmth to
much of the CONUS this week. A warm front will attempt to surge
north through the mid Mississippi River valley during the middle of
the week, but movement will be slowed by a developing high pressure
system over the Great Lakes. Chances for rain exist late in the day
on Christmas Eve into the early morning hours on Christmas Day as we
are once again in the warm sector of an advancing frontal boundary.
Could be a similar setup to earlier in the week with rain and
drizzle. As for the warming trend, the NBM is a huge outlier for
temperatures (forecast highs above the 90th percentile!) for
Wednesday and Thursday, so adjustments were made to decrease
temperatures by about 5 degrees both days. It will still be above
normal both days with highs in mid 40s to mid 50s. As high pressure
exits to the east, the warm front does eventually make it into the
area Thursday night into Friday. Friday`s highs will be the warmest
of the week; temperatures will be 200 to 25 degrees above
normal for this time of year in the upper 50s to low 60s! With
this warm front does come additional chances for rain (and maybe
even a few isolated thunderstorms) late Thursday into early
Friday.

Additional chances for rain, and maybe even some snow, appear
possible by the upcoming weekend. Temperatures should be near normal
to round out the end of December.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 641 AM EST Mon Dec 22 2025

VFR conditions at both terminals today, then predominantly MVFR
overnight. There is potential for IFR conditions, especially
after 7z. Broad isentropic ascent will lead to lower ceilings
and precipitation chances tonight. Initially it should start as
rain with decent saturation through the entirety of the atm
profile, then dry air builds in aloft slowly overnight beneath
a strengthening inversion-lowering ceilings to MVFR/IFR and
leading to more of a drizzle situation (including lower
visibilities from BR). Winds start light out of the south-
southeast (slightly variable initially at KFWA this morning)
then shift to the south-southwest through the overnight at
around 5-10 knots.

&&

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

&&

$$

DISCUSSION...Johnson
AVIATION...MCD