-- Discussion containing changed information from previous version are highlighted. --
190
FXUS63 KIND 231647
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1247 PM EDT Sun Jun 23 2024

.KEY MESSAGES...

- Showers this morning. Gusty winds possible.
- Tuesday likely to be warmest day of the week.
- More thunderstorms possible Tuesday into Wednesday, with one or
  more rounds of strong to severe storms possible, though uncertain.
- A brief respite from heat and humidity late in the week.

&&

.FORECAST UPDATE...
Issued at 844 AM EDT Sun Jun 23 2024

The band of rain remnant from previous diurnal convective cycle and
tied to lead midlevel shortwave perturbation is exiting the area
now. The cold front is lagging behind, currently analyzed from just
east of South Bend to near Danville, Illinois. Weak echoes on KIWX
radar and observations showing rain have been noted ahead of the
cold front. This appears to be a shallow convective process below
capping subsident layer in the mid-levels. Warm rain process is
probably resulting in small drops, and may seem like a heavy
drizzle. The spatial extent is in question. Ob trends and model data
suggest that greatest coverage through midday would be across east-
central Indiana, but could extend to around the Indianapolis area by
around 10:00am lasting for a couple of hours. There may be a
decreasing trend around noon if surface diabatic heating through the
stratus layer is enough to raise cloud bases sufficiently. The
chance for deeper convection is quite low given the strength of the
midlevel subsident layer evident in 7.3 micron water vapor and
upstream ACARS soundings.

Forecast changes with this update:
-removed thunder
-increased cloud cover through miday
-refined temperatures slightly
-refined precip probs, generally increased over east-central Indiana
through early afternoon

&&

.SHORT TERM (Today and tonight)...
Issued at 309 AM EDT Sun Jun 23 2024

Early This Morning...

A line of showers and thunderstorms extended from Lower Michigan
southwest into Missouri and was moving east/southeast. Scattered
cells were developing ahead of it. The convection was ahead of a
cold front and an upper wave.

Mesoanalysis shows that the convection was running ahead of the
better instability, and instability continues to weaken diurnally.
Satellite showed warming tops with the convection as well. Thus,
feel that odds of severe convection will continue to lower. With
some decent wind fields aloft still, there remains a threat of gusty
winds over 40 mph though.

With some upper support with the trough and the right entrance
region of an upper jet, feel that convection will survive
the usual diurnal weakening period and continue to push
south and east through the hours before 12Z. Will have likely or
higher PoPs northwest and PoPs up to likely southeast as the line
weakens diurnally.

Today...

The weakened line should be only across the far southeastern
portions of the area by 12Z. Will have high chance or low likely
PoPs there, with lower PoPs to the northwest. Will not go dry behind
the line initially, because the surface front will linger behind the
line and could spark some additional showers.

Will keep some PoPs behind the line early in the today period,
gradually diminishing from northwest to southeast into early
afternoon.

The remainder of the day should remain dry. Some CAMs are showing a
few showers developing in the afternoon, but just don`t see the
forcing for them. Will keep the forecast dry.

Temperatures will be cooler than recent days thanks to the morning
cloud cover and the passage of the cold front. Highs will peak in
the middle 80s to around 90.

Tonight...

Drier air will move in on northwest flow, and high pressure will
build in from the west. Skies will be mostly clear, and winds will
diminish as the high moves in. The result will be a cooler night
across central Indiana, with lows from near 60 northeast to the
middle 60s south.

&&

.LONG TERM (Monday through Saturday)...
Issued at 309 AM EDT Sun Jun 23 2024

Higher than normal warmth continues through the long term with a
couple of widespread 90s days possible between brief (relative)
relief in between. Tuesday will see the best chance of hitting low
to mid 90s across the region but could be possible again Saturday.
Late in the week will also see more comfortable dew points in the
40s and 50s behind the mid week system, but moisture and humidity
will return for the weekend with additional rain chances.

The retrograding ridge is expected to stay over the SW states for
much of the week, allowing a few systems to impact the local region.
The next system will arrive for Tuesday and Wednesday as a surface
low progresses across central Canada and its associated front will
move through the Great Lakes region. A couple rounds of storms with
this system may impact central Indiana: the first is more uncertain
but an MCS could arrive early Tuesday morning, reaching our NW to N
counties. The next, and more likely round, will move across central
Indiana along the frontal boundary, arriving late Tuesday and could
last through the day Wednesday. If severe storms are to occur in
central Indiana, it will be most likely be cold pool driven given
far weaker deep layer shear this far south, with damaging winds the
primary threat.

The latter portion of the work week will see quiet weather, slightly
lower temps, and significantly lower dewpoints as high pressure
returns over the SE states. This may be short-lived unfortunately
as guidance indicates potential for additional convective potential
along the periphery of the ridge as we get into next weekend. Model
differences are significant with respect to ridge amplitude and
location, and thus relatively low chances are forecast for the
moment.

&&

.AVIATION (18Z TAF Issuance)...
-- Changed Discussion --
Issued at 1247 PM EDT Sun Jun 23 2024

Impacts:

- Wind gusts to 20 knots this afternoon

Discussion:

Lingering MVFR ceilings primarily impacting KBMG early this
afternoon will give way to VFR conditions through the rest of the
TAF period. Wind gusts will be stronger during peak heating/mixing,
subsiding this evening.
-- End Changed Discussion --

&&

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

$$

UPDATE...BRB
SHORT TERM...50
LONG TERM...KF
AVIATION...BRB