245
FXUS63 KIND 101833
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
233 PM EDT Mon Jun 10 2024

.KEY MESSAGES...

- Clearing and chilly tonight
- Warming trend beginning Wednesday, highs near 90 for Thursday
- Low chance of showers/storms Thursday Night into early Friday

&&

.SHORT TERM (This evening through Tuesday)...
Issued at 233 PM EDT Mon Jun 10 2024

Unseasonably cool day in progress across the region as a thick
stratocu deck has mitigated much warming through early afternoon
with many spots across central Indiana in the upper 50s and lower
60s as of 18Z. A breezy northerly wind has only added to the late
September-early October feel to the air this afternoon.

A wave aloft passing through the back side of the unseasonably
strong upper trough across the northeast states has been the feature
largely responsible for the axis of stratocu draped over our
forecast area this afternoon. The wave will shift off to the east by
late afternoon with the parent trough focusing across New England by
late Tuesday. Ridging at the surface and aloft will take over across
the Great Lakes and Ohio Valley...and this will begin the upward
trend in temperatures that will culminate with the hottest air of
the season into the region possibly as early as late this week...and
certainly by late weekend into next week.

The back edge of the stratocu is already working into far northern
portions of the forecast area and will press S/SE through the
remainder of the afternoon with sunshine returning for most of the
area prior to the evening. With the late sunset after 01Z
now...temperatures will get a late bump which should enable highs
into the mid and upper 60s for most locations with lower 70s
anticipated over the lower Wabash Valley. This very likely will be
the last day with sub-70 degrees highs over parts of the forecast
area until sometime in September.

Peak gusts may briefly increase once the sun gets back out late day
as mixing levels increase but as has been the case the last few
days...winds will diminish quickly near or just after sunset. A
surface ridge will expand into the region tonight and early Tuesday
with model soundings and RH progs both highlighting an influx of
drier air and deep subsidence. Skies will go clear this evening
behind the stratocu and remain so overnight with light and variable
surface flow. As will be discussed in the temperature section
below...ideal radiational cooling conditions overnight will set the
stage for an unseasonably chilly start to the day Tuesday.

The center of the surface ridge will drift into the Ohio Valley on
Tuesday with ridging aloft building in as well...creating a picture
perfect day for central Indiana highlighted by near full sunshine...
light winds and comfortable temps with low humidity levels. The
temperatures will keep rising into the second half of the week and
that will be discussed in greater detail in the Long Term section
below.

Temps...as mentioned above...lows tonight will be chilly and a good
15 degrees below normal in many locations. Mid and upper 40s will be
common by Tuesday morning but a few of our normal cool spots could
slip as low as the lower 40s. Temperatures will recover nicely
Tuesday underneath the ridging building in with mid to upper 70s
anticipated.

&&

.LONG TERM (Tuesday night through Monday)...
Issued at 233 PM EDT Mon Jun 10 2024

Tuesday Night Through Friday.

Upper level flow will remain northwesterly Tuesday night through
much of the middle of the week as central Indiana remains locked
into the periphery of a strong upper level ridge across the Central
Plains. Conditions are expected to remain quiet through Wednesday
with gradually warming temperatures as the stronger northwesterly
flow comes to an end and the surface air becomes more stagnant ahead
of a return to southerly flow later into the week. The first shot of
precipitation is expected Thursday night into Friday as a cold front
approaches the area.  There is at least some signal within the
models for a storm complex late Thursday night ahead of the front,
but this remains very uncertain more than 72 hours out.

That being said, most models that do generate a storm complex have
it decaying as it arrives to central Indiana if not before. Models
tend to decay these systems faster than what ends up occurring, but
will need to reassess as we get closer. High temperatures on Friday
may easily bust if the cold front is sooner than expected which
leads to a wide range of temperature possibilities ranging from the
mid 70s to near 90.

Saturday Through Monday.

The aforementioned ridge of high pressure will gradually shift
eastward going into the weekend in the aftermath of the frontal
passage. Confidence on the temperatures is low and will be dependent
on the final strength of the cold front with models gradually
trending towards a cooler solution with highs in the low to mid 80s
vs the upper 80s to 90 that were previously forecast. As the ridge
continues to move eastward, surface flow will become southerly
Sunday night into Monday which should bring a return to the near 70
degree dewpoints with a high likelihood of 90+ degree weather for
Monday.  Looking further out, there is a potential for more active
tropical weather bringing additional moisture to the Ohio Valley
towards mid week, but the strength of the ridge overhead should keep
the heavy rain to the south.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1229 PM EDT Mon Jun 10 2024

Impacts:

- MVFR ceilings possible at times through mid afternoon
- Occasional gusts to around 20kts this afternoon

Discussion:

A wave aloft on the back side of the parent upper trough over the
northeast U S was tracking through the region early this afternoon.
A large area of stratocu with ceilings generally between 2500-3500ft
was progressing S/SE in tandem with the wave aloft and will remain
across the forecast area over the next few hours. Scattering of the
deck has already expanded into far northern Indiana as of 16Z and
will move across the terminals from north to south during the second
half of the afternoon. May see gusts briefly jump up as sunshine and
low level mixing increases later this afternoon.

Skies become clear this evening as a broad high pressure ridge and
deep subsidence overspreads central Indiana from the north. Winds
will become light and variable with the ridge across the Ohio Valley
through Tuesday.


&&

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

$$

SHORT TERM...Ryan
LONG TERM...White
AVIATION...Ryan