Allen, Indiana Weather Forecast Discussion

401
FXUS63 KIWX 222334
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
734 PM EDT Mon Sep 22 2025
.KEY MESSAGES...
- A very active weather period will continue through Friday with
  numerous showers and isolated thunderstorms.
- Flooding is not anticipated.
- High temperatures the rest of the week will be in the 70s.
&&
.DISCUSSION...
Issued at 214 PM EDT Mon Sep 22 2025
A positively tilted trof will settle south across the Upper
Great Lakes region. This system will bring numerous showers to
the forecast area as well as an occasional chance for a
thunderstorm at times. WPC rainfall amounts of generally 1.00"
to 1.50" are forecast through Friday. Heavier rainfall amounts
so far today (as of 1 AM EDT) have been generally 0.25" to 0.50"
over northeast Indiana and northwest Ohio. A short break in the
heavier rain is expected before another upper level trof brings
more rain Tuesday. Moderate drought conditions (D1) covered
most of northern Indiana and northwest Ohio. Ft Wayne observed
rainfall amounts since August 1st has been less than 2 inches
(1.90) which is the 2nd driest in 130 years. So far, the rain
that has fallen has not been sufficient to improve drought
conditions.
While isolated to scattered showers are possible at time through
Tuesday morning, more organized rainfall should develop Tuesday
afternoon with the next impulse that moves across the area. The
new WPC forecast indicates around a half inch of additional rain
through 8pm Wednesday evening is forecast. Limited impacts are
expected with this precipitation. Very minor rises on some
rivers have been noted with this past round of rain. This next
round of rain into Wednesday night should do little to effect
river conditions.
Otherwise, dry weather if forecast from Friday night into early
next week. Temperatures are expected to be near normal.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 726 PM EDT Mon Sep 22 2025
As this trough pulls away, the left over moisture gets trapped under
a forming inversion. There is definitely some uncertainty around
whether the TAF sites will be affected by fog or stratus or both,
but these tafs will run with the idea that SBN is affected by fog
given they had clouds scatter out before sunset. FWA has the
potential to see both stratus and fog. There`s also uncertainty
around how low flight conditions go at both sites. Aviation guidance
seems to point toward brief low MVFR or IFR conditions at SBN given
their ability to scatter out before sunset, but lowered flight
conditions look to stay longer and go lower at FWA, perhaps into
LIFR. LAV guidance from both sites indicates weak sub-5 kts
sustained winds which would point to some possibility for fog than
if it was 5 kts or above at their lowest, which would point to
solely a stratus situation. Have pulled SBN out of fog at around 13z
with these tafs, but RAP time sections keep the low level saturation
into the afternoon so wouldn`t be surprised to see it last longer
than that. Will pass this along to the next shift to hone in on. FWA
looks ready to give up its buck in the mid to late morning as it
heads back into VFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...Skipper
AVIATION...Roller

NWS IWX Office Area Forecast Discussion