990
FXUS63 KIND 031624
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1224 PM EDT Thu Jul 3 2025

.KEY MESSAGES...

- Warming trend back to the low 90s by Friday

- Heat indices mid 90s to near 100 degrees this weekend.

- Scattered showers and thunderstorms return to the forecast
Sunday.

&&

.FORECAST UPDATE...
Issued at 948 AM EDT Thu Jul 3 2025

Forecast is in good shape this morning. Mostly clear skies were
allowing temperatures to rise quickly.

Cumulus will pop up this morning and continue through the afternoon,
making skies partly cloudy. There will be enough instability for the
potential for a few showers or storms to develop this afternoon,
especially north where some weak forcing may move in. Confidence
isn`t high in these though.

Adjusted hourly temperatures for the quick warmup, but forecast
high temperatures look reasonable.

&&

.SHORT TERM (Today and tonight)...
Issued at 259 AM EDT Thu Jul 3 2025

A typical midsummer weather pattern continues for much of the CONUS
with ridging and high pressure remaining the dominant weather
features locally. Little change made to the forecast for today as
each day this week will have very similar conditions to the previous
one. Main ridge axis is still to the west of Indiana today, keeping
the core of the heat and humidity over the Plains. Subsidence from
high pressure aloft keeps large scale systems and precipitation away
from the area for the most part. A weak upper system passing through
the Great Lakes region this morning may result in remnant boundaries
sagging southward into Central and North Central Indiana this
afternoon. Best forcing for ascent will be displaced well to the
north and east and with high pressure overhead, these remnant
boundaries likely won`t have much impacts. There is a slight chance
(less than 20% chance) of an isolated pop up shower or storm north
of the I-70 corridor during peak heating of the day as the overall
environment will be unstable this afternoon; however with little
forcing and no shear, not expecting anything organized to develop.
The majority of the region will stay hot and dry today, but it is
worth mentioning the possibility of a rogue shower or storm this
afternoon. Other than that, the environment supports highs in upper
80s once again today, likely a degree or two warmer than yesterday.

Overnight lows start warming back up again into the upper 60s to low
70s as flow turns southerly as ridging and high pressure slide
eastward.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 259 AM EDT Thu Jul 3 2025

Another stretch of summertime heat continues through the weekend for
all of Central Indiana. While conditions are not expected to be as
oppressive as they were last week, both humidity and temperatures
will continue to rise over the next several days. Storm chances
increase Sunday and into the next week.

Strong ridging across the Central and Northern Plains slides
eastward this weekend, resulting in a gradual warming and moistening
trend as the core of the heat and humidity push closer to the state.
Expect each day to be a few degrees warmer and more humid than the
previous day in this pattern with highs reaching the lower 90s for
the 4th of July and this weekend. Dew points may reach or exceed 70
degrees again, especially by Sunday, resulting in heat indices
approaching the 100 degree mark again during the afternoon hours.

Large-scale ridging begins to break down over the weekend with
guidance consistently to show a weak trough and cold front
approaching from the northwest on Sunday. Guidance today has
continued the trend of slowing down the eastward progression of a
trough and associated low pressure system moving into the Upper
Great Lakes this weekend, keeping conditions relatively hot and dry
through at least the first half of the day Sunday. In these large
scale blocking patterns, it is common for longer range guidance to
struggling with how ridging breaks down and typically tries to bring
in precipitation too soon. Would not be surprised to see future
model runs further slow down the incoming trough and frontal
boundary. Keeping a chance for storms in the forecast Sunday
afternoon into Monday and will fine tune PoPs and exact timing of
the greatest storm threat as confidence increases in the coming
days.

The pattern going into next week looks fairly typical for July with
highs in the 80s, humid conditions, and additional storm chances.
Keeping a chance of storms in for Monday as there is lower
confidence on the timing of the aforementioned frontal passage.
Tuesday could potentially be the driest day next week as longer
range guidance and ensembles indicate a more active pattern setting
up mid next week and beyond with more frequent precipitation
chances... yet still warm and humid.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1224 PM EDT Thu Jul 3 2025

Impacts:

- VFR Conditions expected much of the TAF period.
- Chances remain for isolated IFR diurnal FG at LAF on Friday
morning.

Discussion:

Diurnal CU has blossomed across central Indiana due to daytime
heating. This will result in SCT-BKN VFR cloud cover through much of
the afternoon.

Surface high pressure will remain across the forecast area through
the period and forecast soundings agree with mainly a dry column
expected. As we have seen the past few days, clouds will dissipate
this evening as heating is lost, leading to clear skies and light to
calm winds overnight. Given the little change in the airmass, have
included a persistence fog mention at LAF.

Otherwise, look for sct-bkn CU to once again develop on Friday. All
CU cloud bases will remain VFR.

&&

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

$$

UPDATE...50
SHORT TERM...CM
LONG TERM...CM
AVIATION...Puma