908
FXUS63 KIND 300914
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
514 AM EDT Sat Aug 30 2025

.KEY MESSAGES...

- Dry and quiet weather for the weekend into early next week

- Below average temperatures expected to continue into next week

- Next chance for rain arrives Tuesday and continues into Thursday
  with shot of even cooler air behind a front

&&

.SHORT TERM (Today and tonight)...
Issued at 253 AM EDT Sat Aug 30 2025

Surface analysis early this morning shows strong high pressure in
place over the Great Lakes. This was resulting in cool and dry
northeasterly flow across Central Indiana. Water Vapor showed a deep
upper low in place over Quebec. This was resulting in a cool
northerly flow aloft over Indiana. A weak short wave within this
flow was providing some passing mid and high level clouds across our
state. Dew points were in the upper 40s and lower 50s.

Another pleasant day and night is in store for Central Indiana.
Models suggest the upper pattern will consist of ridging pushing
through the northern plains while the upper low slides eastward
across Quebec. This pattern will result in continued northerly flow
aloft today across Indiana along with continued subsidence. This
drying can be seen within the mid levels of the models, as well as
the water vapor imagery over Wisconsin.  Forecast soundings show the
departure of some of the mid and high clouds this morning before
drying out this afternoon. This will lead to partly cloudy skies
this morning giving way to a mostly afternoon. Highs in the middle
and upper 70s should be expected.

The strong surface high will remain over the Great Lakes tonight and
continue to maintain a stranglehold on Central Indiana/s weather.
Forecast soundings show a dry column through the night. This will
result in mostly clear skies, light east winds and cool temperatures
with lows in the upper 40s and low 50s.

&&

.LONG TERM (Sunday through Friday)...
Issued at 253 AM EDT Sat Aug 30 2025

Upper-level analysis shows large-scale troughing over the Midwest
and northeastern US. Ensemble guidance is in good agreement showing
this pattern holding steady through the forecast period. As such,
below-average temperatures are expected to continue through the
majority of the coming week.

The overall pattern looks dry, for the most part, as northerly
surface flow keeps deep moisture displaced to our south.
Additionally, atmospheric disturbances embedded within the jet
stream are being shunted south around the base of the trough. A lack
of moisture and a lack of forcing gives little reason to expect rain
any time soon.

The next decent chance of rain looks to be in the Tuesday/Wednesday
timeframe. Guidance is showing low pressure strengthening and
occluding to our north, with a cold front passing through the area
as well. Some surface moisture could creep north in response to the
deepening system. Rainfall amounts are uncertain, and will depend on
the position and strength of the system along with how quickly the
cold front passes through. As of right now, generally light amounts
are shown by most deterministic guidance.

Regardless of rainfall, an unseasonably cool air mass looks to drop
southward behind the front. ECMWF/GFS deterministic guidance shows
850mb temps between 2-6 degrees C, which could allow for low
temperatures potentially into the upper 30s assuming ideal
radiational cooling (clear skies and light winds). Blended guidance
has low to mid 40s, which seems reasonable for now given the
uncertainty in strength/position/timing of the occluding low. The
blend, however, shows highs in the mid to upper 60s Thursday and
Friday. This may be a bit pessimistic, since the sun angle is still
quite high and we have recently been running warmer than guidance
under optimal boundary layer mixing conditions.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 514 AM EDT Sat Aug 30 2025

Impacts:

- VFR this TAF period.

Discussion:

Little change from the previous forecast. GOES16 continues to show
some passing mid and high clouds across the TAF site, although cigs
are thin and high or unlimited. Overall, only minor changes made to
the ongoing TAFs.

Strong surface high pressure over the Great Lakes will continue to
provide a cool and dry easterly flow of air to Central Indiana during
this TAF period. Northwest flow aloft was allowing a few mid and
high clouds to pass across the TAF sites, although all of these
clouds will be at VFR levels.

This pattern is expected to persist through the TAF period, leading
to just continued passing high clouds and continued light
northeasterly surface flow. Forecast soundings are on board with
this idea showing dry lower levels and the mid and upper levels a
bit more saturated from time to time.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...Puma
LONG TERM...Eckhoff
AVIATION...Puma