National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KIWX 181857
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
257 PM EDT Thu Apr 18 2024

.KEY MESSAGES...

- Showers and thunderstorms return this evening, an isolated
  storm or two may become severe. Gusty winds is the main
  threat. Precipitation/storms ending before sunrise Friday.

- Dry and cool this weekend with morning frost likely Sunday morning.

&&

.DISCUSSION...
Issued at 212 AM EDT Thu Apr 18 2024

Southwesterly flow with a vigorous jet ahead of an upper level
trough currently over the upper midwest will allow for low
level moistening (surface dew points increasing to the upper
40s to low 50s) and breezy to gusty winds across the area this
evening. A surface low over central MO will also move eastward
into the region overnight tonight and will accompany a cool
front draping along the eastern periphery of the upper level
trough. Lift will be increased along these focal points.
However, surface based and mixed layer CAPE values will be
lacking with less than 100 J/kg but MUCAPE values up to 1500
J/kg lead to a more elevated convection event. Downdraft CAPE
around 800 J/kg is expected. Effective bulk shear values up to
35 knots look to be available so some organization in the linear
feature would be possible. The main threat will be gusty winds
however with a non-zero hail threat with mid level lapse rates
only around 5.5-6 deg/km available. SPC does have a slight risk
for severe thunderstorms for parts of the CWA mainly south of
SR-14 and a marginal threat mainly south of SR-24 to SR-14. Of
course, heavy downpours look to be possible with PWATS of around
1.2 inches with any convection, but should be short lived with
relatively fast storm motion.

As the front continues to move eastward overnight the storms and
precipitation will wane from west to east with cooler
temperatures in it`s wake. Highs tomorrow will only get into the
mid to upper 50s and cooler yet on Saturday with highs only in
the upper 40s to low 50s. Lows this weekend will return to the
30s with Sunday morning being the coolest morning with even a
touch of frost possible.

Low ampltitude ridging begins to move into the region on Sunday
and allows for dry weather and gradually warming temperatures
into the beginning of next week. Highs on Sunday in the mid to
upper 50s and into the low to mid 60s on Monday and Tuesday.
Another trough from southern Canada will drop into the Great
Lakes region on Tuesday bringing chances of showers with a few
thunderstorms and cooler weather through the end of the week
with highs Wednesday and Thursday in the 50s and lows cooling
into the mid 30s each morning.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 100 PM EDT Thu Apr 18 2024

Warm/moist advection into a frontal wave will allow a band of
rain/storms to track through northern IN this evening into the
early overnight (01-06z). The leading edge of convection could
briefly bring down some higher end wind gusts at KFWA if a more
organized convective segment materializes, though confidence is
too low to include in the TAF for now. Trending dry and MVFR
post-frontal overnight, with clearing and somewhat breezy nw
winds by Friday morning.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory from 5 AM to 2 PM EDT Friday for LMZ043-
     046.

&&

$$

DISCUSSION...Andersen
AVIATION...Steinwedel