833
FXUS63 KIND 011405
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1005 AM EDT Fri May 1 2026

.KEY MESSAGES...

- Spotty showers early this morning. Becoming partly sunny this
  afternoon.

- Below normal temps to continue through the weekend with frost
  likely Saturday and possible Sunday

- Slow warm up with rain returning early next week, potential for
  heavy rain at times

&&

.FORECAST UPDATE...
Issued at 1004 AM EDT Fri May 1 2026

Weak low pressure continues to push through the area this morning,
with the bulk of shower activity ahead of it soon to exit central
Indiana.  Lingering stratocumulus and weak cold advection in the
wake of the low will keep diurnal warming to a minimum across most
of the area today, with highs unlikely to get out of the 50s except
perhaps in the far southwest.

Steep low level lapse rates and lingering moisture, along with a
very weak secondary upper wave may be able to produce some sprinkles
this afternoon, and will insert a mention of this, but this is the
only real change to the going forecast.

&&

.DISCUSSION (Today through Thursday)...
Issued at 238 AM EDT Fri May 1 2026

Surface analysis early this morning shows a poorly organized trough
over MI, into western Indiana and to southern IL. Wind directions in
the wake of the front were mainly west to northwest. Radar was
showing scattered rain showers along and ahead of the front, with
best coverage over northern Indiana. Aloft, water vapor was showing
a deep low over Ontario and Quebec. This was keeping cyclonic upper
flow over the Great Lakes, but a brief zonal flow was in place over
Indiana. A weak short wave was within this flow, and was mainly
responsible for producing the weak surface trough moving across
Indiana.

Today...

The weak short wave will quickly depart central Indiana this
morning. In the wake of the system winds will become northwesterly
allowing for some cold air advection. Overall, subsidence will be
the main player through the day, but forecast soundings suggest BKN
CU for much of the day. The progression of the system could allow
for some lingering showers across the eastern parts of the forecast
area this morning, but this should quickly depart leading to a dry
and cool day.

Tonight...

Cool high pressure over the plains is suggested to begin to build
across Indiana. This result in clearing skies across Indiana through
the night. Forecast soundings suggest a dry column amid cold air
advection.  With 850mb temps falling to near -4C...lows in the mid
30s will be possible. This combined with light winds may result in
frost formation and a Frost Advisory will be issued.

Saturday...Another trough rotating around the low pressure across
Canada is expected to push across Indiana on Saturday, providing
some upper forcing. Forecast soundings show steep inverted V
soundings favorable for shallow convection. Convective temperatures
are attainable. Although widespread precipitation will not be
expected, enough of signal remains to include some low chance pops
in the afternoon. Highs will only be in the 50s.

Saturday Night and Sunday...

After heating is lost and the upper wave departs by Saturday night,
the upper flow is suggested to become more northwesterly as high
pressure at the surface sets up over the gulf coast. This will allow
for a warmer, southerly flow to develop. Forecast soundings show dry
lower and mid levels. Thus will just expect a partly cloud sky and
warm conclusion to the weekend.

Monday through Thursday....

Daily chances for rain showers will be expected on Monday through
Thursday.

On Monday, a nearly zonal flow will be in place aloft, while a
surface cold front is approaching from the west. This will allow a
warmer southwesterly flow across central Indiana, and we will reside
within the warm sector. Weak forcing along with diurnal heating may
lead to afternoon convection. Stronger forcing will arrive on Monday
night into Tuesday as the surface cold front will arrive and pass
through the day on Tuesday. Given this, chances will be needed on
both Monday and Tuesday as these features pass.

On Wednesday and Thursday, the upper pattern is suggested to change
as deep low pressure over Ontario sags southward across the Great
Lakes and into the Ohio valley. This will keep cyclonic flow in
place over Central Indiana on both Wednesday and Thursday. Weak
short waves within that flow are expected to pass. On Thursday, an
associated surface trough is also expected to pass. These features
will have no access to to deep gulf moisture, thus any precip with
them should remain rather light, but chances for precipitation will
be needed nonetheless.

Temperatures should be warmest on Monday, as that will be the only
day within the warm sector. Cooler temperatures will arrive for
Tuesday through Thursday as cyclonic flow aloft and mainly NW
surface flow will allow for cool Canadian air to remain present.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 628 AM EDT Fri May 1 2026

Impacts:

- Light showers ending by 14Z-15Z
- MVFR ceilings possible through 15Z.
- Return to VFR after 15Z.

Discussion:

Radar shows rain showers with passing wave over much of Central
Indiana. The back edge has passed LAF and HUF, with very limited
coverage near BMG. HRRR suggests this precip should quickly exit to
the east by 14Z-15Z, leaving just some clouds in it/s wake. GOES
shows clear skies over IL, however SC/CU development is expected
this morning before more dry air and subsidence arrives by this
afternoon, leading to VFR at all TAF sites.

Any remaining clouds will be lost late in the day as heating and
mixing is lost. High pressure will build across the area tonight and
mostly clear skies and light winds are expected under the influence
of the high.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

Frost Advisory from midnight tonight to 9 AM EDT Saturday for
INZ021-028>031-035>049-054>057-065.

&&

$$

UPDATE...Nield
AVIATION...Puma
DISCUSSION...Puma