651
FXUS63 KIND 051019
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
619 AM EDT Sat Jul 5 2025

.KEY MESSAGES...

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

- Scattered showers and thunderstorms return to the forecast
  Sunday afternoon, then daily storm chances persist into next week

&&

.SHORT TERM (Today and Tonight)...
Issued at 300 AM EDT Sat Jul 5 2025

Quiet early morning in progress with mainly clear skies and pockets
of haze likely influenced heavily by fireworks Friday evening. 06Z
temperatures were in the low and mid 70s across much of the forecast
area.

Ridging aloft has strengthened over the Ohio Valley in tandem with
surface high pressure remaining over the region. This will keep dry
and hot conditions across central Indiana today with only a subtle
increase in clouds tonight as an upper level wave and cold front
approach slowly from the northwest.

Cannot rule out lingering haze or brief pockets of fog through
daybreak with stagnant air within the boundary layer. Otherwise...
expect another sunny start to the day with temperatures warming
quickly through midday. Diurnal cu will again form through the
afternoon as convective temperatures are approached but soundings
show hints of an even stronger capping inversion than that we had on
Friday. While a stray shower or two is possible late afternoon and
early evening...confidence remains too low for a mention of any rain
in the forecast and anticipate the cap will essentially remain too
strong.

Dry air will persist over the Ohio Valley tonight even as deeper
moisture and a frontal boundary slowly push east through the western
Great Lakes back into the Missouri Valley. There is a subtle
weakness within the upper flow as the ridge retreats that may enable
scattered convective development over the western Tennessee Valley
north possibly as far as southern Indiana overnight. Not certain
this would come far enough north to impact southern portions of the
forecast area but will be something to monitor tonight.

Temps...low level thermals are a touch warmer today than Friday and
that should support low 90s for the entire forecast area this
afternoon. Lows tonight will fall into the lower 70s.

&&

.LONG TERM (Sunday through Friday)...
Issued at 300 AM EDT Sat Jul 5 2025

A typical July weather pattern persists across Central Indiana late
this weekend and into next week with near normal temperatures, high
humidity, and daily chances for scattered storms.

Large-scale ridging begins to break down over the weekend with
guidance consistently showing a weak trough and front approaching
from the northwest on Sunday. The main shortwave trough and upper
jet remain north of the region along with better forcing for ascent
and shear. The low level trough and surface front slow down as they
progress southward into Indiana as they become sheared out and
disconnected from the upper flow. Guidance over the past several
days has been consistent in showing a slowing trend for this front
and pushing back the timing of any precipitation for much of Central
Indiana. At the moment, higher confidence for any convective
activity will be across portions of North Central and Northwest
Indiana Sunday afternoon and evening...areas closer to the front.
With little forcing and shear, much of the convection will be
diurnally driven, weakening in coverage and intensity overnight. Odds
are increasing that a good portion of Central and South Central
Indiana may remain dry as the front becomes almost quasi-stationary
just to the north. Higher confidence exists in drier and warmer day
Sunday for a good portion of the area with the best threat for
storms from Terre Haute to Lafayette to Kokomo.

A warm, unstable airmass ahead of the front will be supportive of
disorganized convection with heavy rain and lightning as the main
threats. Little shear and forcing likely will inhibit much storm
organization and should keep the severe threat rather low.

The frontal boundary remains in the region on Monday as it very
slowly sags to the south through the state. Convective redevelopment
along the frontal boundary is likely during peak heating of the day.
Lower confidence exists on how quick the front moves southward.
Convective initiation may occur as far north as the I-70 corridor
Monday afternoon with storms pushing slowly south and east through
the afternoon. Again, with little shear and forcing, severe weather
is not a concern at the moment, but any storm could quickly pulse up
to severe levels briefly producing a strong wind gust.

By mid-week next week, uncertainty begins to increase considerably.
This is mostly associated with the emergence of a Gulf Low pushing
westward. As this warm core reaches Texas, the upstream impacts
could result in greater ridging over the Plains (depending on
strength of the warm core) and therefor stronger NW flow over the
Ohio Valley. In this scenario, greater upper level dynamics could
allow for periods of convective organization later in the week. As
stated, there is still high uncertainty in any long range
thunderstorm potential, but we will continue to monitor thunderstorm
trends for later next week in the coming days. Regardless of larger
scale convection, ensemble synoptic scale guidance suggests
temperatures should remain at or above seasonal normals through the
7 day forecast period.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 619 AM EDT Sat Jul 5 2025

Impacts:

- Haze early this morning will diminish quickly

Discussion:

Pockets of haze had lingered for much of the night...especially at
KBMG and KIND...and likely due to residual smoke from fireworks
Friday evening that had become trapped beneath a shallow inversion.
The onset of southerly winds to around 5kts should allow for haze to
diminish quickly over the next couple hours.

Mainly clear skies are then expected through late morning with high
pressure remaining over the region. Diurnal cu will develop for the
afternoon before diminishing near sunset this evening. Mid level
clouds will approach central Indiana towards daybreak Sunday as
moisture approaches from the west in association with a frontal
boundary. Winds will increase to S/SW at 5-10kts this afternoon
before weakening to light southerly tonight.

&&

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

&&

$$

SHORT TERM...Ryan
LONG TERM...CM
AVIATION...Ryan