Mill Grove, Indiana Weather Forecast Discussion

669
FXUS63 KIWX 141832
AFDIWX
Area Forecast Discussion
National Weather Service Northern Indiana
232 PM EDT Sun Sep 14 2025
.KEY MESSAGES...
- Warm, dry and sunny through much of this week with highs in the
mid/upper 80s.
- Low afternoon humidities could introduce a fire weather concern as
fine fuels dry out but winds will remain light.
- The next chance of rain arrives late Friday into the weekend.
&&
.DISCUSSION...
Issued at 232 PM EDT Sun Sep 14 2025
Another long stretch of quiet weather is expected this week as a
pair of upper lows over the Southeast CONUS and Northern Plains keep
a strong ridge locked over the Great Lakes. Surface high pressure
over the Lower Great Lakes is maintaining a light but steady
easterly flow of dry/stable air preventing even any cu development
today. Flow becomes more muddled as the week goes on allowing for
some minor moisture advection at times. The only "impact" will be an
increase in diurnal cu though with no rain chances through at least
Thursday. The difference in this dry spell compared to earlier this
month is that this is being driven by a strong mid/upper ridge
directly over the area with no supply of cool, Canadian air. Dry
conditions each day will support deep mixing (to almost 700mb at
times) pushing afternoon highs into the mid/upper 80s which is
roughly 10-15 degrees above normal for this time of year. Afternoon
dewpoints will also crash into the low/mid 50s yielding RH values
likely around 30 percent. Thus, fire wx will be the main thing to
watch this week. Luckily, winds will be light and fuel moistures
(especially after yesterday`s rain) are still running high given
most vegetation and agriculture is still on the green side. Several
days of hot, sunny and dry conditions will take it`s toll though and
fine fuels will begin to dry out by Wed/Thu.
The ridge finally breaks down by next weekend, though models still
show very different solutions on the exact timing and evolution of
how this happens. Ensemble-based NBM shows precip chances beginning
by Thu night. Prefer to lean more on deterministic runs which all
indicate Friday at the earliest and likely not until Fri night or
Sat for our eastern zones. Still plenty of time for adjustments but
for now prefer to lean on the later side of guidance given degree of
dry/stable air in place and overall lackluster forcing from incoming
trough.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1250 PM EDT Sun Sep 14 2025
VFR conditions expected through this TAF period. Winds will be
on the decrease into the overnight period but should remain
elevated enough to help mix the lower levels and keep fog
formation at bay.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.
&&
$$
DISCUSSION...AGD
AVIATION...Andersen

NWS IWX Office Area Forecast Discussion