381
FXUS63 KIND 010349
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1149 PM EDT Sun Jun 30 2024

.KEY MESSAGES...

- Pleasant and Cool Tonight and Monday.
- Heat and humidity returns on Tuesday and continues through Friday.
- Rain and thunderstorm chances Wednesday through Friday.

&&

.FORECAST UPDATE...

No changes needed to the ongoing forecast with conditions evolving
as expected.  Wind gusts continue to gradually become less frequent
with the boundary layer beginning to stabilize.  Expect to see
temperatures steadily fall overnight with the clear skies and dry
airmass in place with some spots towards Lafayette falling into the
upper 40s.

&&

.SHORT TERM (This evening through Monday)...
Issued at 257 PM EDT Sun Jun 30 2024

Surface analysis early this afternoon shows strong high pressure in
place over MN. This high was extending its influence from Manitoba
and Saskatchewan, through the northern plains and building across
Indiana and Ohio. Northerly flow was in place across Central Indiana
and dew points had fallen to the upper 50s. A moderate pressure
gradient was in place across central Indiana as the high was
building across the area, allowing for these northerly winds to gust
to near 20 mph at times. Aloft, water vapor showed ridging building
across the Rockies with northwest flow spilling from the upper
Midwest to the Ohio Valley. Subsidence was show in place over
Indiana. GOES16 showed some diurnal CU through the Wabash valley,
blowing off Lake Michigan.

Tonight...

Models suggest the strong upper ridging in place over the Rockies
will make slow but steady progress eastward tonight and into Monday.
This will continue northwest flow aloft along with subsidence. The
associated surface high pressure system is expected to push
southeast also, with its center reaching Lake Michigan by Monday
morning. Forecast soundings remain dry through the night. Any
diurnal CU across the area will quickly dissipate with daytime
heating loss leading to mostly clear skies overnight. Cold air
advection on northeast winds will also continue overnight. This
along with falling dew points through tonight will allow lows to
fall to the lower and middle 50s at most spots.

Monday...

Another day of quiet, pleasant weather is expected. The upper
ridging will continue steady progress eastward on Monday along with
its associated surface high pressure system as it pushes to the
eastern Great Lakes. This will result in continued dry easterly flow
flowing into Central Indiana. Again, forecast soundings show a dry
column. Of note, warmer air to the southwest looks to remain at bay
due to our northeast flow. However, that will change by mid west as
southerly flow returns then. So summing Monday up, mostly sunny with
highs in the upper 70s will be expected.

&&

.LONG TERM (Monday night through Sunday)...
Issued at 257 PM EDT Sun Jun 30 2024

An anomalous but fairly low amplitude ridge is taking shape over the
southern Plains as of this writing. It should then translate
eastward with time, settling over the southeastern states by mid-
week. From there, the ridge weakens and a zonal jet pattern with
embedded shortwaves sets up over the Midwest and Ohio River Valley.

After a cool start to the week with lows in the upper 40s or low 50s
Monday morning, a quick rebound is likely by Tuesday with highs in
the upper 80s. The primary reason is the aforementioned ridging
building in, along with surface high pressure sliding east allowing
low-level flow to become southerly. Warm moist advection should then
continue for a couple days.

Simultaneously, a strong system over central Canada will drag a cold
front through the Midwestern US. The front likely reaches Indiana,
but stalls out and becomes less defined somewhere over the state.
This presents a bit of a forecast challenge as the stalled boundary
will act to increase shower/storm chances. These showers/storms and
associated cloud cover may complicate temperature forecasts.
Showers/storms will also be hard to pin point as forcing is rather
nebulous and convection may alter/overturn the lower atmosphere
which may affect later rounds of convection.

Daily shower and storm chances continue as long as this front is in
the area. Wednesday, Thursday, and Friday all contain precipitation
chances at or over 50 percent. A drying trend is possible over the
weekend, since guidance is more or less on board with the idea that
a low pressure system develops to our north on Friday. This system,
as modeled, appears strong enough to push a front through the area
allowing dry continental air to flow southward.

Public Awareness Statement:

Storm chances exist before, during, and after the 4th of July
holiday. There is a chance that inclement weather interrupts holiday
plans. With that said, stay tuned for forecast updates as confidence
increases and we refine key details (timing, intensity, etc).

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1149 PM EDT Sun Jun 30 2024

Impacts:

- None.

Discussion:

A slight veering to more easterly wind direction this morning is
expected. Wind speeds will be a bit less than yesterday. VFR
conditions will prevail.

&&

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

$$

UPDATE...White
SHORT TERM...Puma
LONG TERM...Eckhoff
AVIATION...BRB