251
FXUS63 KIWX 312155
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
555 PM EDT Fri May 31 2024

.KEY MESSAGES...

- Somewhat slower trends for arrival of showers and isolated
  thunderstorms Saturday afternoon and evening. Heavy rain will
  be the main concern.

- Additional chances for showers and thunderstorms Monday
  through Thursday.

- Large temperature gradients possible due to precipitation and
  clouds Saturday and later this week, but overall still near or
  above normal.

&&

.DISCUSSION...
Issued at 320 PM EDT Fri May 31 2024

Next 12 to 24 hours will likely be dry for many areas with
models continue to trend somewhat slower with onset of
increasing moisture and lift. Some concern that best influx of
moisture may not arrive till closer to 00Z Sun as the upper low
and associated sfc reflection draw closer. Have slowed onset
considerably through 18Z but maintained likely or categorical
pops during the afternoon and evening hours. Thunder chances
still looking rather bleak but still maintained a mention. As
mentioned by the overnight forecaster, highs tomorrow will be
highly dependent on how fast the rain and clouds arrives. Have
increased temps slightly westward but not getting to crazy at
this point.

Limited ridging will move in for Sunday and at least the first
half of Monday before additional waves move towards the region
with chances for showers and maybe a few storms once again.
Confidence is low on how these chances evolve with timing of
specific waves still varying in models. Greatest chances still
reside with the main upper level low in the Plains that will
deepen and move east towards the region mid week. No significant
changes have been made in the forecast at this time due to the
timing challenges noted.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 550 PM EDT Fri May 31 2024

VFR ceilings and light winds will prevail through the overnight
hours. Around 15-18Z tomorrow, clouds will arrive ahead of the
next rain/storm chance and winds will pick up. Expect gusts
15-20 kts in the afternoon and evening on Saturday. Ceilings
will drop to MVFR, with potential to drop to IFR in the evening.
Have left mention of IFR ceilings out of the TAFs for now as
confidence is low; higher confidence in MVFR ceilings as the NBM
has greater than 70% chances for MVFR ceilings at both KFWA and
KSBN tomorrow afternoon. Scattered showers (with potential
embedded thunderstorms) arrive in the late afternoon. Have added
a -TSRA group to both sites at 18Z, although adjustments will
need to be made in future TAF periods to account for changes in
arrival timing.

&&

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

&&

$$

DISCUSSION...Fisher
AVIATION...Johnson