485
FXUS63 KIND 221630
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1230 PM EDT Tue Apr 22 2025

.KEY MESSAGES...

- Patchy fog quickly dissipating after sunrise; Plentiful sunshine
  with highs in the 70s today

- Warm temperatures through the rest of the week

- Shower and thunderstorm chances late Thursday through Saturday

&&

.FORECAST UPDATE...
Issued at 909 AM EDT Tue Apr 22 2025

Surface analysis this morning shows strong high pressure in place
over SW OH. Weak southeasterly surface flow was found across Central
Indiana. Southerly surface flow was in place across the plains
ahead of weak low pressure in SW KS. GOES16 shows mainly high CI
streaming across Central Indiana and temperatures were quickly
climbing into the 50s. Aloft, water vapor showed mainly a zonal flow
in place. A weak upper wave was producing some rain over WI.

A pleasant and dry afternoon is expected across Central Indiana.
Weak warm air advection will be in play aloft, while our surface
high really still controls the weather across Central Indiana as it
departs to the east. Forecast soundings show a dry column through
the day, with unreachable convective temperatures in the 80s. Thus
will mainly expect a continuation of the high CI streaming across
the state within the flow aloft. The warm air advection and
southerly flow should allow for high temperatures in the middle 70s
to be reached. Also of note, the very dry column should result in
any of the precip over WI and northern IL to dissipate upon arrival
across Indiana.

&&

.SHORT TERM (Today and tonight)...
Issued at 248 AM EDT Tue Apr 22 2025

Quiet weather is expected through the period as surface high
pressure remains centered over the area. Current satellite imagery
shows mostly clear skies across central Indiana as surface ridging
continues to build in. This along with nearly calm winds should
allow for patchy fog to develop shortly.

Look for any fog that develops to quickly mix out after sunrise. A
beautiful spring day is then expected as plentiful sunshine and
light S/SW flow into the 70s. Dewpoints will also be very
comfortable in the 40s thanks to drier air advecting into the
region.

Light winds and mostly clear skies should allow for efficient
radiational cooling once again tonight. While quiet weather is
expected overnight, there is a low (10-20%) chance for light
showers across far N/NW counties due to a weak disturbance moving
through. Latest CAMs show a stalled frontal boundary and
associated nocturnal LLJ promoting the development of convection
across IL. This convection will then propagate eastward and likely
weaken as it moves into a drier airmass. Low POPs were added as
the weakening showers or storms could potentially reach the area.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 248 AM EDT Tue Apr 22 2025

Wednesday and Wednesday night...

Very warm temperatures are on tap for Wednesday with relaxed
southwest flow aloft and BUFKIT soundings showing a very dry column.
This should lead to mostly sunny skies and well above normal
temperatures with highs in the upper 70s, which is some 10 to 15
degrees above normal. The weak surface pressure gradient will result
in rare light southeast winds compared to recently. The column will
continue to be very dry Wednesday which should allow for good
radiational cooling but still well above normal lows in the 50s.

Thursday through Saturday...

A more active weather pattern will return late week into the early
weekend as an upper wave moves through in the southwest flow
Thursday night into Friday and the moisture deepens substantially
and a cold front moves in from the northwest Friday night. Models
suggest PWATs could briefly reach 1.5 inches, Friday afternoon and
evening, or the max moving average of ILX SPC sounding climatology
for late April. That said, PWATS may be slightly exaggerated with
the lack of a strong low level jet. Nonetheless, even PWATS
reasonably close to 1.5 inches along with some instability and the
front moving in would support widespread convection and a heavy rain
threat. Models suggest at least some weak instability, at the
least, should be around Friday evening.

Chances of convection drop off from northwest to southeast on
Saturday as the front moves southeast. Modest cold advection will
also bring temperatures closer to normal from the well above normal
temperatures in store for Thursday and Saturday.

Saturday night through Monday night...

High pressure over the Great Lakes and a dry column are expected to
lead to clearing skies Saturday and Saturday night. Winds will
switch to the southeast on Sunday and southwest Monday as the high
shifts to the Appalachians and a low pressure system takes shape
over the Plains. This will allow for gradually moderating
temperatures Sunday and Monday with more convection possible by
Monday.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1229 PM EDT Tue Apr 22 2025

Impacts:

- VFR expected this TAF period.

Discussion:

Surface high pressure east of Indiana and zonal flow aloft with
little forcing will allow for continued VFR conditions this TAF
period. Forecast soundings suggest a dry column across the area
through the TAF period. No forcing is expected aloft as weak
southerly flow continues due to the high departing east. Expect only
some CI streaming in the flow aloft.

&&

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

$$

UPDATE...Puma
SHORT TERM...Melo
LONG TERM...MK
AVIATION...Puma