Fishers, Indiana 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

530
FXUS63 KIND 250137
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
937 PM EDT Thu Jul 24 2025

.KEY MESSAGES...

- Heat Advisory for all of central Indiana ending this evening,
  then across portions of central and southern Indiana Friday

- Heat indices remaining dangerous through Tuesday with peak heat
  indices as hot as 100-110 on many days

- Isolated storms this afternoon through tonight, more widespread
  potential into the weekend; potential for heavy rain and
  localized flooding and isolated strong to severe wind gusts

&&

.FORECAST UPDATE...
Issued at 937 PM EDT Thu Jul 24 2025

Convection has refired over far northeast portions of the forecast
area since about 00Z at the nose of the axis of highest instability
and likely with support from subtle low level convergence and
slightly higher 850mb flow. Elsewhere it remained oppressively nasty
with temperatures at 01Z still in the mid and upper 80s and
dewpoints generally at or above 75 degrees in most locations.

The ongoing scattered storms from northern Madison Co east into
northern Randolph Co will drift east and has already shown signs of
weakening which is to be expected with virtually no shear present.
Could see an isolated shower or storm just about anywhere north of I-
70 over the next few hours with MLCAPEs still at or above 3000 J/kg
in much of the northern half of the forecast area.

An ongoing mature convective cluster over the northern half of
Missouri is another matter however and while this is expected to
weaken into the overnight as it moves east...confidence is growing
in remnants of the cluster approaching the northern Wabash Valley in
the predawn hours and perhaps spreading east across the northern
portions of the forecast area through 12Z Friday. A closer analysis
at model soundings shows a shallow nocturnal inversion present but
that will likely not be sufficient enough to mitigate the potential
for higher winds with stronger cells as instability levels remain
plentiful and DCAPE values in particular linger at 700-1000 j/kg. In
a nutshell...the potential for strong but subsevere convection
remains with an increase in BL shear as a weak frontal boundary
slides south. A nonzero risk for damaging winds exists towards
daybreak in northwest counties as well. Torrential rainfall will
continue as the primary concern especially as PWATs rise back above
2 inches late tonight.

Lows tonight will remain at sultry levels in the mid and upper 70s.
Zone and grid updates out.

&&

.SHORT TERM (This evening through Friday)...
Issued at 230 PM EDT Thu Jul 24 2025

Rest of Today and Tonight.

As of early afternoon heat indices have risen into the low to mid
100s across much of central Indiana with the highest values along
the Illinois border. Some stations such as KFKR, KMQJ, and KUMP have
shown unrepresentative dew points in the mid to upper 80s, but
otherwise most sites have been hovering in the mid 70s to near 80.
IND ACARs soundings show the surface is now mixing to around 850mb
with wind gusts to around 20 mph mixing down to the surface. Dew
points have likely nearly hit their peak if not already with the
mixing out of some of the moisture helping to counteract the
evapotranspiration and moisture advection.

Isolated to scattered showers and storms continue to occasionally
pop up across central Indiana, initially along a moisture plume of
higher instability but with convective temperatures now being
reached, showers are forcing in a bit more haphazard manner. There
is plenty of DCAPE in an inverted V sounding profile but with a lack
of shear, severe weather looks unlikely through the afternoon.

Focus then shifts to a conditional severe weather threat this
evening into tonight with the expectation of a loosely organized
thunderstorm complex forming across northern Illinois with the
potential for this complex to clip the far northwestern and northern
counties if the complex ends up on the higher end of potential
organization. The NAM give an example as to how this could play out,
but with the well-known bias in the NAM when it comes to
instability, this looks to be an unlikely solution with how far
south the convection reaches. Additional convection will be possible
through the night as the LLJ ramps with model soundings showing
plentiful elevated instability.

Friday.

The Heat Advisory has been extended into Friday for much of central
and south central Indiana with another hot and humid day expected.
Clouds from overnight convection should limit the higher end
temperatures across the northern half of the forecast area but will
have to see how things evolve tonight. If convection fails to reach
north central Indiana, a northern extension may be needed.
Confidence on convection coverage tomorrow is low with the
uncertainty as to the impacts of morning cloud cover, but across the
more unstable areas such as southern Indiana, isolated to scattered
thunderstorms are likely to form by the mid to late afternoon.

&&

.LONG TERM (Friday night through Thursday)...
Issued at 230 PM EDT Thu Jul 24 2025

Large-scale ridging over the Midwest will retrograde into the Great
Plains by early next week. Ensemble guidance is in fairly good
agreement regarding this evolution. At the surface, high pressure
remains overhead or at least nearby. No significant air mass change
is anticipated until at least Wednesday, when guidance shows a cold
front potentially arriving with a shot of cooler continental air. As
such, hot and humid conditions look to continue through the weekend
and into next week.

There is a chance of daily showers and thunderstorms due to a nearby
boundary, which is approaching Indiana today. This boundary will sag
southward into the state, reinforced by storm outflow, before
stalling somewhere over central portions of the area. The boundary
will become quite diffuse and drift back northward, unless it
dissipates entirely. Shower and storm activity in the preceding air
mass will likely be spotty and dependent on prior convective
activity given lack of large-scale forcing. Higher likelihoods will
exist near and along the boundary due to slightly more forcing.

Wind shear looks to be low (25kt or less) throughout the period.
Sustained organized convection is therefore unlikely, but enough
shear may be present for some loosely-organized clusters or lines
capable of gusty winds. Model soundings show a deep warm cloud layer
along with high PWATs (over 2 inches). Warm rain processes will lead
to efficient rainfall production and heavy rain rates. Localized
flooding is possible each day through the weekend, perhaps into next
week. Flooding will be most likely where storm motions are slow and
or favor storm training.

As mentioned above, guidance is hinting at a stronger cold front
arriving mid next week. A substantial air mass change may finally
bring about an end to the heat and humidity that will have been
present for almost a week by that point. Guidance still differs
regarding the strength and timing of this front, so confidence on
the fine details is low.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 636 PM EDT Thu Jul 24 2025

Impacts:

- Scattered convection possible at times focused north of I-70...
  especially predawn Friday and again Friday afternoon
- Brief restrictions possible in convection

Discussion:

Isolated convection from earlier had diminished with diurnal cu
already in the process of decreasing in coverage early this evening.
Skies should become mainly clear through the evening although
thicker cirrostratus associated with convection across northern
Illinois and Indiana will drift south into the early overnight. Any
storms should remain north of the terminals through 06Z but
scattered convection will develop in the predawn hours...first at
KLAF and eventually at KIND Friday morning. Brief restrictions are
possible and stronger wind gusts may impact the terminals for a
short time with more intense storms.

What happens for the rest of Friday will be highly dependent on the
morning convection. The atmosphere will be highly unstable yet again
for the afternoon with the potential for renewed development as a
diffuse frontal boundary drifts south to near the I-70 corridor. A
few storms may produce gusty winds. Model soundings support a
healthy cu field again for Friday afternoon as well with southwest
winds less than 10kts.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM EDT Friday for INZ043>047-051>057-
060>065-067>072.

&&

$$

UPDATE...Ryan
SHORT TERM...White
LONG TERM...Eckhoff
AVIATION...Ryan