746
FXUS63 KIND 232346
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
746 PM EDT Wed Apr 23 2025

.KEY MESSAGES...

- Warm temperatures through the rest of the week

- Shower and thunderstorm chances late Thursday through Friday night
  with the best chances Friday and Friday evening

- More active pattern setting up next week

&&

.SHORT TERM (This evening through Thursday)...
Issued at 245 PM EDT Wed Apr 23 2025

Surface high pressure centered over Ohio remains in control of our
weather. A light southeasterly wind prevails and modest warm air
advection continues. After temperatures topping out around 80 today,
overnight lows should dip into the 50s for the most part. Surface
winds should become light and variable or calm as the boundary layer
decouples after sunset. Southeasterly to southerly winds resume
Thursday morning as diurnal mixing begins.

As surface high pressure slides gradually eastward, winds gain a
more southerly component allowing richer moisture to slide
northward. Dew points likely rise into the 50s or low 60s tomorrow
compared to the mid 40s today. Combined with temps again near 80 it
will feel more muggy than today. That humidity might be enough to
allow for a few showers or thunderstorms during the afternoon hours.

Regarding the thunderstorm potential, there does not appear to be
much forcing involved and wind shear is very light. In fact, this
setup is more reminiscent of summertime air mass thunderstorms. As
such, severe potential appears very low. There may be enough dry air
present above the boundary layer for some sub-severe downbursts but
again the potential seems low. Coverage is more uncertain due to the
weak forcing, though it appears that any activity will be widely
scattered at best.

&&

.LONG TERM (Thursday night through Wednesday)...
Issued at 245 PM EDT Wed Apr 23 2025

Friday, another wave is expected to develop and push in from the
west, including a little more amplified kinematics. This increase in
bulk shear will still be on the lower end of severe thresholds, but
could be enough for isolated to scattered severe thunderstorms over
central Indiana. There are still many unknowns for Friday, and this
threat may not materialize if the second wave phases differently.
Model soundings are also showcase a much deeper buoyancy and
moisture profile, leading to some threat of localized heavy rain.

Ridging is expected to reestablish after Friday`s wave passage.
Ensemble members are starting to come to an agreement, with
strong surface high pressure developing over the Great Lakes,
pushing eastward Saturday through Monday. Current ensemble means
have the surface high around 1030mb, of which should keep
conditions dry through the weekend. There will be some moderate
CAA behind Friday`s wave passage, of which will likely drop
temperatures back into the 60s for highs Saturday and Sunday. With
the amount of dry air on Sunday, there`s a chance we could
overachieve on temps, pushing some probability of highs in the 70s
Sunday afternoon.

Next week, there is a growing concern for a highly active severe
thunderstorm pattern over the Great Plains and Mid-Mississippi
Valley. It is still unsure how this pattern will impact locations
downstream, including here in the Ohio Valley outside of much above
normal temperatures for early next week. This is mostly due to the
presence of a strong high over the W Atlantic, and the lack of a
strong low pushing through the CONUS. The current low is progged to
move over Canada, leaving a much more weakly forced boundary for the
Ohio Valley. Currently, the best chances for severe weather in
central Indiana look to be Tuesday evening/night.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 746 PM EDT Wed Apr 23 2025

Impacts:

- Low probability of a shower or thunderstorm Thursday afternoon.

Discussion:

VFR conditions expected through the forecast period. Expect winds to
be light and variable tonight under 5 kts at all sites.

A classic summer-time pattern sets up for Thursday with the chance
for isolated to scattered pop up showers and thunderstorms within a
weakly forced and low shear environment. Anything that develops will
be slow moving and brief with little to no organization. Best chance
for any convective activity will be at KBMG and points south and
east... however still added VCSH after 18z in the KHUF and KIND TAF
as they will be at the northern edge of the area of possible shower
development. Main threats are brief periods of MVFR or worse
conditions with heavy rain lightning, and gusty winds. In this
pattern, it is nearly impossible to pin point where specific cells
will form until the day of... so for now, VCSH will have to suffice.
Will add more details tomorrow based on afternoon mesoanalysis and
local boundaries.

Winds become SSE to S (150-180 deg) tomorrow in the 6-11 kt range as
daytime mixing increases during peak heating of the day.

&&

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

$$

SHORT TERM...Eckhoff
LONG TERM...Updike
AVIATION...CM