678
FXUS63 KIWX 111046
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
646 AM EDT Tue Mar 11 2025

.KEY MESSAGES...

- Sharp temperature gradient sets up through Wednesday night
  with highs ranging from the upper 40s to middle 60s.

- Much warmer air makes a return Thursday into Saturday, along
  with showers and a few thunderstorms Friday night into early
  Saturday. Risk for strong to severe storms remains uncertain.

- Gusty southwest winds of 40 to 45 mph may occur Saturday
  afternoon prior to the arrival a cold front, bringing with it
  much colder air.

&&

.DISCUSSION...
Issued at 428 AM EDT Tue Mar 11 2025

Temperature forecast challenges associated with a tight
baroclinic zone abound through Thursday in what would otherwise
be a pretty tame couple of days.

Surface cold front extended from NE Wisconsin to eastern IA with
models generally agreeing in arrival into our NW counties prior
to 15Z and then quickly dropping SE. Low level thermal profiles
behind the front are rather interesting with a more N to NNW
flow pushing the first shot of colder air mainly into western
portions of the area where steady/falling temps are likely.
While temps will fall somewhat post frontal further east, lesser
CAA may limit overall drop initially. The result is a nearly 20
degree difference in highs from NW to SE today. By 00Z Wed, the
push of CAA will slow and thermal profiles level out for a bit
with some modest WAA commencing after 12Z Wed in SW areas. In
the NE, a much more challenging temp evolution is possible with
several models suggesting a NE to E flow advecting a shallow
cold layer into NE parts of the CWA. While this has been
advertised to some extent, this stronger push and persistent
flow may slow the eventual northward surge of warmer air moreso
into Wed night and Thursday. Have made some changes in
temperatures, but tried to limit.

Models have finally washed out the last of the slgt chc pops
with the dampening wave passing well south of the region
Thursday. In its wake, a rapid uptick in the low level flow will
commence as the deepening upper level digs into the SW states
with cyclogenesis occuring Friday resulting in a stacked low
that tracks into western WI by 18Z Sat.Highs Friday will soar
into the 70s for many areas, leading to the warmest day of the
upcoming week. Breezy conditions will also be in store. A narrow
corridor of PWATs over an inch arrives ahead of a trough that
sweeps across the area Friday night. Although quality of the
moisture available to the system is in question, impressive
shear and dynamics exist with at least some MUCAPE and even some
stout midlevel lapse rates. The best parameters seems to focus
in western areas during the late evening/overnight hours, a
typically unfavorable time, but do warrant some monitoring even
as trends suggest a weakening trend with east extent. Have
maintained likely to cat pops Fri night into early Sat.

If there wasn`t enough challenges, a pronounced dry slot
arrives late Sat morning into Sat afternoon. Current pops may
well be overdone, but are not the primary concern. Signs point
to an increased potential for strong mixing of the 50 to 60 kt
LLJ in place ahead of the main synoptic front as the sfc low
continues to deepen and pressure gradient increase. The
subsidence will allow stronger wind gusts to reach the sfc for a
3 to 6 hour period with some indications of at least advisory
level winds and possibly a few reports of near warning level.
Previous shift increased gusts and held with that for now.

Colder air will quickly filter in Saturday night and linger into
Saturday night before temperatures start to moderate back to
above normal levels Sunday into Tuesday. Another sfc low will
take shape well SE of the area with some clouds and maybe an
outside chance of some rain clipping our SE counties Sat night
into Sun.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 646 AM EDT Tue Mar 11 2025

Dry cold front will swing through the area today. Atmosphere
remains very dry/stable and VFR conditions will persist. Winds
will steadily veer through the period with gusts up to 25 kts
possible during the day. Some stratus is possible tonight as
cool, easterly flow develops and supports an increasingly
saturated inversion. For now, ceiling heights look to remain
above 3 kft but may drop below at the very end of this forecast
window.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 2 AM EDT Wednesday for LMZ043-046.

&&

$$

DISCUSSION...Fisher
AVIATION...AGD