894
FXUS63 KIND 041835
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
235 PM EDT Thu Jun 4 2026

.KEY MESSAGES...

- Pleasant early summer weather continues through Friday

- Next chance for widespread rain will be late Saturday-Sat night

- Very warm and humid next week with occasional showers/t-storms

&&

.DISCUSSION (This evening through Thursday)...
Issued at 234 PM EDT Thu Jun 4 2026

Today and tomorrow...

Very pleasant weather for early June continues across Central
Indiana as high pressure remains the dominant weather influence.
Variable winds earlier today already switched to southerly,
advecting in a more moist, tropical-like airmass from the Gulf. Low
level mixing up to 2 km agl this afternoon, present on current IND
acars soundings, will slow the rise in humidity levels until
Saturday when dew points are forecast to approach 70 degrees! 500mb
vorticity and height maps today indicate upper ridging overhead with
embedded convection in SW Arkansas associated with an upper wave.
Guidance shows this wave weakening as it pushes northward into the
area, but still increasing upper level moisture by tomorrow. Any
storm threat is expected to hold off until at least Saturday locally.

With a warmer airmass on the way, expect a noticeable increase in
surface temperatures today and tomorrow as highs reach the mid to
potentially upper 80s. This patterns shift marks the beginning of an
extended stretch of typical summer time conditions with warm to hot
temperatures and frequent storm chances.


Saturday...

Transition into more typical mid-summer pattern is expected this
weekend as the blocking ridge breaks time and transitions to a more
progressive pattern aloft. Northern stream troughing pushes east
into the Great Lakes this weekend, flattening the top of the ridge
while a low level boundary becomes stretched W-E across the I-70
corridor. Lower confidence in timing and location of better-
organized precipitation and mesoscale systems this far out as small
discrepancies in details upstream can have significant affects on
the downstream evolution of mesoscale features. For Saturday, will
be watching how convection evolves Friday evening towards the Quad
Cities region; however dry air locally may significantly weaken
anything approaching Indiana during the early morning hours. Despite
this, significant moisture advection ahead of the boundary on
saturday should lead to an environment supportive of shower and
storm development by late morning and into the afternoon hours. With
the boundary likely within Central Indiana, convective initiation
may occur overhead sometime on saturday depending on how quick the
atmosphere can recover from potential early morning clouds and
rain. While confidence is lower on the overall evolution of
mesoscale features, the environment Saturday afternoon and evening
along and ahead of the front should be supportive of a marginal
severe threat due to increasing instability and humidity and 30-40
kts of deep layer shear. Any waves of energy along the front will be
enough to spark off convection in this type of pattern.

Sunday through Next Week...

The 500mb subtropical ridge will re-establish itself through early
next week over the Great Lakes and much of eastern Canada, with a
corresponding amplified surface ridge from Quebec to the Deep South
...directing a copious supply of Gulf moisture into the region by
the end of the weekend.  At times scattered showers and isolated,
embedded pulse storms capable of stronger winds and downpours will
certainly be on the table...with perhaps localized flooding the
greatest concern given the stalled nature of the boundary.

Upper ridge axis should slide a bit east of Indiana around the
Tuesday timeframe, but at least widely scattered diurnally-driven
showers should be the rule through the end of the forecast period.
Otherwise between any convective showers, very warm and humid, July-
like weather can be expected amid lighter, mainly southerly breezes
that will maintain dewpoints in the upper 60s to around 70 through
at least Wednesday.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 136 PM EDT Thu Jun 4 2026

Impacts:

-None

Discussion:

VFR conditions are expected through the TAF period.

Surface high pressure is sliding eastward allowing winds to become
predominately southwesterly. Winds take on a more southerly
component overnight as the boundary layer stabilizes, with period of
light and variable conditions possible. Winds increase out of the
southwest again Friday morning to between 10-15kt with occasional
gusts to 20kt.

SCT to BKN cirrus at 25k feet is expected through the TAF period.
Diurnal cumulus around 6k feet this afternoon should diminish at
sunset, developing again Friday afternoon around 5k feet.


&&

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

$$

AVIATION...Eckhoff
DISCUSSION...CM/AGM