133 
FXUS63 KIND 241915
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
315 PM EDT Tue Jun 24 2025

.KEY MESSAGES...

- *HEAT ADVISORY* continues through late day Friday

- Heat indices up to 100-109 degrees and low temperatures near or 
  above 75 degrees through Friday

- Scattered daily afternoon showers/t-storms, isolated strong to 
  severe wind gusts are possible

&&

.SHORT TERM (This evening through Wednesday)...
Issued at 300 PM EDT Tue Jun 24 2025

HEAT ADVISORY TO CONTINUE THROUGH WEDNESDAY FOR HEAT INDEX VALUES 
NOT FALLING BELOW MID-70S...TO AS HIGH AS 109 DEGREES.

High humidity will continue to guide temperatures through 
unseasonably warm/hot levels through the mid-week...albeit now with 
chances for diurnal showers and perhaps a few marginally strong/ 
severe thunderstorms.  Supporting broad, stacked subtropical ridge 
will continue its near-broken-record occupation of southeastern 
North America, while perhaps beginning to shrink slightly towards 
its cut-off center near the southern Appalachians.  Another muggy 
overnight tonight will again feature lows in the mid-70s...with 
highs Wednesday continuing the widespread low 90s and isolated mid-
90s pattern.

Given dewpoints persisting in the low to mid-70s... heat index 
values will continue their sultry range between the mid-70s and low 
to mid-100s.  Hoosiers are reminded to drink plenty of fluids, stay 
in air-conditioning when possible, limit time outside and stay out 
of the sun...and check up on relatives and neighbors.

The short term will include a couple opportunities for diurnal 
convective showers and even a few thunderstorms, courtesy of 
generous CAPE through PM hours and weak lift from a subtle quasi-
stationary boundary across the northern Midwest. Scattered pulse-
type showers late today, focused over the local region's 
northwestern half should peak in coverage early this evening when 
instability reaches its diurnal maximum. Lackluster midlevel lapse 
rates should limit vertical extent of cells and keep thunder mainly 
isolated.  A few brief downpours, small hail and perhaps isolated 
gusts to 40-50 mph are on table late today, although most showers 
will be less intense.  Expect the few showers that linger past 
sundown to dissipate through this evening.

A better shot at marginally strong to severe storms is on tap for 
Wednesday with the combination of slightly greater deep moisture 
with precipitable water values approaching 2.00 inches, slightly 
higher dewpoints nudge instability higher earlier in the day, with 
lift provided by both the synoptic boundary closer to the CWA's 
northern edge, and any subtle low-level convergence from boundaries 
out of this afternoon's stronger cells.  Most zones can expect 
scattered afternoon showers and isolated thunder, except for 
southwestern counties where coverage is expected to be less. Several 
t-storms may produce heavier downpours, small hail, and wind gusts 
near or above 45-55 mph.

&&

.LONG TERM (Wednesday night through Tuesday)...
Issued at 300 PM EDT Tue Jun 24 2025

HEAT ADVISORY TO CONTINUE THROUGH FRIDAY FOR HEAT INDEX VALUES NOT 
FALLING BELOW MID-70S...TO AS HIGH AS 109 DEGREES.

Wednesday night through Friday...

Hot and humid conditions to persist through the end of the workweek 
with temperatures expected to range from mainly the mid-70s to low 
90s...with subtle exceptions being a few locations peaking in the 
mid-90s Thursday...and a few northern zones likely falling to the 
low 70s on both overnights. Continued high humidity with dewpoints 
in the low to mid-70s will keep heat index values generally 10 
degrees above dry bulb readings, with daytime maximum heat indices 
as high as the mid-100s.  Hoosiers are reminded to drink plenty of 
fluids, stay in air-conditioning when possible, limit time outside 
and stay out of the sun...and check up on relatives and neighbors.

Chances for diurnally-driven convection will continue, although 
general lack of vertical wind shear should keep most of any 
strong/severe storm threat to the northwest of the local region.  A 
few stronger wind gusts cannot be ruled out during the late day to 
early evening hours...especially Friday when a very subtle weakness 
is progged to approach the CWA from the northwest.

Saturday through Tuesday...

The persistent pattern will continue this weekend into early next 
week, albeit at a small step down from the workweek's criteria-level 
heat and humidity.  Subtle changes in the stacked ridge's geometry 
will shift flow aloft from from WSW to more westerly, while H850 
temperatures will be generally 1-2 degrees lower than earlier in the 
long term. This will translate to more marginal heat that, when 
coupled with continued high humidity, should produce afternoon 
maximum heat index values in the upper 90s to around 100F.  Morning 
lows and corresponding minimum heat index values should nudge 
downward closer to the low 70s.  However, given the heat wave's 
duration reaching the 8-9 day mark this weekend...impacts may be as 
significant despite heat indices about 5 degrees lower.

Daily convection will continue, with even greater coverage, of 
perhaps numerous showers, expected through afternoon hours each day. 
Associated cloud cover should help mitigate daytime heat impacts, 
although rainfall will promote higher dewpoints and therefore higher 
subsequent overnight readings.  Embedded isolated to perhaps 
scattered t-storms may contain briefly stronger wind gusts, 
especially during late day hours when CAPE peaks over 3000 J/kg. 
Lack of any decent bulk shear should mitigate severe weather 
threats, with this potential refined with future updates.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 205 PM EDT Tue Jun 24 2025

Impacts:

- Isolated showers and storms possible through the evening, best chance 
  near LAF and HUF

Discussion:  

VFR conditions are expected through much of the TAF period although 
brief drop to MVFR visibility may occur within showers. SCT 
diurnally driven cu has developed and should into the evening. Best 
chance for convection will be near LAF and possibly HUF, but kept 
thunder mention to tempo groups as it will likely not be the 
predominant weather.  

Southwesterly winds around 7-10 kts this evening which will decrease 
to less than 5 kts overnight. Direction may become variable at times 
tonight. Winds are expected to increase again tomorrow to around 7-
10 kts. 

There is a chance for patchy fog late tonight, but this was not 
explicitly mentioned in the TAF due to low confidence.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Friday for INZ021-028>031-035>049-
051>057-060>065-067>072.

&&

$$

SHORT TERM...AGM
LONG TERM...AGM
AVIATION...KF