614
FXUS63 KIND 070144
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
944 PM EDT Fri Jun 6 2025

.KEY MESSAGES...

- Scattered to numerous showers and storms this afternoon through
  the evening. Isolated severe storms possible south

- Active weather continues into Saturday with localized heavy
  rain likely Saturday night into Sunday

- Cooler than normal with periodic rain early next week

&&

.FORECAST UPDATE...
Issued at 944 PM EDT Fri Jun 6 2025

A shortwave over eastern Illinois will continue to progress steadily
eastward overnight, ending showers between 04-06Z in western areas
and 06-09Z in eastern areas of central Indiana. Despite the
presence of 500-1000 j/kg of mucape noted on recent mesoanalysis,
observed soundings support that this CAPE layer is fairly shallow
and situated completely below the -20C level which will negate any
thunderstorm potential. Therefore, chances of thunderstorms have
been removed from the forecast overnight.

Low clouds will remain over southern portions of central Indiana
which may limit the potential for fog development later tonight.
However elsewhere in central Indiana, clearing mid level clouds
combined with light winds will favor another night of patchy
locally dense fog developing towards sunrise.

&&

.SHORT TERM (This evening through Saturday)...
Issued at 256 PM EDT Fri Jun 6 2025

The low cloud cover that impacted this mornings weather has lifted
leaving some patchy cloud cover across the NE half of central
Indiana. This is quickly filling in from the south, with broken alto
cumulus and stratus arriving ahead of a weak surface wave. This
will be the main feature to watch for thunderstorm development later
this afternoon and through the evening.

These waves are forming within strong zonal flow aloft, providing
just enough upward lift to tap into an unstable layer about 1000-
2000ft above the surface. This will lead to increasing convection
across central Indiana within the net 2 to 4 hours, beginning over
western Indiana, and pushing eastward. Generally, showers and
thunderstorms should remain mostly scattered, but in far southern
central Indiana, greater deformation in the low level will likely
lead to an increase in coverage between 5-9PM this evening.

Severe weather is unlikely tonight without steep lapse rates and
strong low level winds. However, there is enough mid to upper level
shear for a very isolated strong to severe thunderstorm (1in
hail/60mph winds) south of I-70. The focus would be on any strongly
forced updraft that is able to continuously tap into this greater
energy aloft.

Forcing is expected to exit quickly following wave passage
overnight, decreasing pops quickly after 02Z. Winds will also
quickly diminish over southern central IN, near a stalled boundary.
This will be an area to watch for potential for development
overnight, but will likely depend on clearing and amount of latent
heat surface fluxes overnight.

Lows tonight will be from around 60 to the mid 60s.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 256 PM EDT Fri Jun 6 2025

Saturday Through Monday.

Through most of the day on Saturday, the front that has brought
active weather to the area over the last few days will remain
stalled south of the forecast area across Kentucky. This should help
to limit the rain chances across much of central Indiana with most
models keeping any QPF limited to just the southern portions of
central Indiana through the early afternoon hours.

Another upper level low is expected to move through central Indiana
Saturday night with additional thunderstorms likely ahead of the low
Saturday afternoon and evening. Ahead of the low, stronger southerly
flow will return as a surface low undergoes cyclogenesis with good
model agreement in a period of heavy rain during the 00Z to 06Z
timeframe just ahead of the low. Model QPF varies on the exact
details but a broad 0.5 to 1.5 inches is likely with a narrower
swath of 2-3 inches.

A stronger upper level low will sink southeastward in the aftermath
of the Saturday system which will bring cooler air and renewed
lighter rain Sunday into Monday. There is some model differences
towards Monday as to where the jet stream will set up which will
impact where the better chances of precipitation will be. Confidence
is highest across the southern counties with ensemble probabilities
maximized towards the Ohio River.

Tuesday Through Thursday.

The upper level low will spin across the Great Lakes region into the
middle of the week which will help to keep temperatures slightly
below normal with higher than normal cloud cover. Periodic rain will
impact central Indiana but with no connection to Gulf air, amounts
will be light. High pressure begins to build going into Thursday as
the upper level low finally pushes off to the east with weak surface
winds and gradually warming temperatures to finish the work week.
Looking towards the weekend and beyond, the pattern begins to shift
more active again with above normal precipitation likely.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 759 PM EDT Fri Jun 6 2025

Impacts:

- Light showers/VCSH at the TAF sites gradually ending later
tonight.

- IFR/LIFR visibility with areas of fog late tonight into tomorrow
morning

- Scattered TS expected to develop late Saturday afternoon/early
evening across the area.

Discussion:

A mid level disturbance over IL was helping to generate fairly
widespread light showers at all terminals except LAF, where activity
will remain VCSH. Isolated TS will remain well southeast of KBMG
this evening. As the mid level disturbance shifts eastward away from
Indiana overnight, mid level clouds will gradually diminish with
mostly clear skies developing for a brief time across northern TAF
sites. With light winds and recent rainfall, areas of LIFR
vis/ceiling in fog are expected to develop later tonight /after 09Z/
for KIND/KLAF and KHUF. For southern areas, low clouds are not
expected to clear sufficiently for fog development, but IFR ceilings
and visibility is expected to develop towards morning.

By mid morning, visibilities will improve to MVFR or greater and by
midday lower clouds will scatter out. Light winds will shift from
E-NE to S-SE by afternoon ahead of the next approaching storm
system. Timing of next system is fairly consistent in the forecast
models, so confidence is high enough to put SHRA by late
afternoon. Moderate amounts of instability should support
scattered TS. So VCTS has been added for all terminals except
KBMG by 23Z.


&&

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

$$

UPDATE...Crosbie
SHORT TERM...Updike
LONG TERM...White
AVIATION...Crosbie