680
FXUS63 KIND 081919 CCA
AFDIND

Area Forecast Discussion...CORRECTION
National Weather Service Indianapolis IN
319 PM EDT Sat Jun 8 2024

.KEY MESSAGES...

- Scattered showers possible this evening into tonight, a few storms
  possible over northwest portions of central IN

- Dry conditions expected Sunday through at least Wednesday

- Cooler Sunday night-Monday night...moderating to near-90F highs
for Thursday-Saturday

&&

.SHORT TERM (This evening through Sunday)...
Issued at 300 PM EDT Sat Jun 8 2024

Current satellite/radar observations show relatively quiet
weather conditions over central IN this afternoon. Rain chances will
begin to increase this evening as a cold front moves in. Low-level
theta-e advection ahead of the front and low-level convergence
should allow for scattered showers to develop with perhaps a few
thunderstorms.

Convective coverage will likely remain limited this
evening into tonight due to the surface wave or associated cold
front outpacing the parent trough. Rain chances remain capped at no
greater than 40% for this reason. The greatest rain chances are
across W/NW counties closer to the surface wave. Low rain chances
will persist early in the overnight hours as the front continues to
progress southeastward. Drier air then filters in late promoting
quiet conditions. Expect winds to become N/NW once the front passes
which should help keep temperatures near or slightly below normal.

Weak surface high pressure settles in for Sunday allowing for quiet
weather conditions to persist. While cool N/NW flow will be in
place, less cloud cover will warm temperatures well into the 70s. A
few locations could potentially reach the 80F mark. There is a low
chance for light rain across far southern counties as a disturbance
moves through Southern Indiana and Kentucky. Most guidance shows
precipitation remaining near or south of the Ohio River so this
appears unlikely.

&&

.LONG TERM (Sunday night through Saturday)...
Corrected at 319 PM EDT Sat Jun 8 2024

Sunday Night through Wednesday...

Mainly dry conditions will prevail through the first half of the
week while overseeing steady moderation from sub-seasonal readings
to near normal early June warmth by the Wednesday timeframe.  A
series of upper waves tracking generally along the US-Canada border,
will start with a larger trough over east-central North America
through Monday...followed by an amplified yet short wave ridge on
Tuesday...and then a couple of smaller, more northern-tracking short
waves during the remainder of the mid-week.  At the surface broad
Canadian high pressure will be building into Indiana at the start of
the long term, cross the region Monday night...and settle from the
Tennessee Valley to the Mid-Atlantic, along a more zonal pattern
south of the passing mid-week northern waves.

Despite adequate sunshine through the early week, light/moderate NNW
breezes will hold temperatures a solid 5-10 degrees below normal
through Monday night, with some typically cooler spots probably not
reaching 70F on Monday.  Widespread 50s Sunday night will set-up
colder conditions Monday night where clear and nearly calm
conditions will promote lows around 45-50F outside of the
Indianapolis Metro.  Distinct moderation to follow for Tuesday-
Wednesday with slightly above normal marks by Wednesday afternoon
from modest southwesterly flow...reaching the mid-80s for most
locations under scattered clouds.  Lack of stronger return flow
should at least help to hold off summer-like/moderate humidity until
at least Wednesday night of not Thursday.

Thursday through Saturday...

Above normal, mid-summer type warmth/heat with corresponding
moderate humidity will be the rule starting on Thursday under the
retracted upper flow...and a building ridge over the High Plains
directing several days in the upper 80s to around 90F.  Not the
greatest confidence in temperature forecast for any given day as the
pattern may support weak waves rippling down the east side of the
building, western ridge and into the Midwest.  Nonetheless moderate
certainty in several above normal days.  A small threat of potential
showers/storms will also exist given the increased theta-E, albeit
limited by an at-times capped profile and generally weak forcing.
The normal first 90F+ day at Indianapolis is June 19...and the
normal max/min at Indianapolis for the long term is 82/62.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1214 PM EDT Sat Jun 8 2024

Impacts:

- Isolated to scattered showers possible this evening and early
overnight
- MVFR ceilings possible late tonight and early Sunday
- Sporadic gusts to around 20kts possible this afternoon

Discussion:

Thick mid level cloud deck across the entire area early this
afternoon with pockets of light showers and sprinkles moving east.
Showers should largely diminish by or shortly after 18Z with clouds
lingering through the afternoon and evening. A large area of
clearing over central Illinois already is in the process of filling
in and expect only a brief period of filtered sun at best. Southwest
winds will become sporadically gusty through the afternoon then
diminish towards sunset.

Isolated to scattered showers are likely to redevelop later this
evening as a weak cold front slides southeast into the region. The
approach and passage of the boundary will have a greater impact on
ceilings however...as model soundings show moisture becoming trapped
beneath a boundary layer inversion. This will translate to a period
of MVFR stratus from late evening into the predawn hours before
ceilings lift Sunday morning.

The passage of another series of convective clusters through the
Ozarks and into the Tennessee and lower Ohio Valleys overnight and
again on Sunday will likely keep mid and high cloud coverage up a
bit across the southern half of central Indiana into Sunday. The
expansion though of a subtle surface ridge should promote decreasing
clouds into the afternoon with northwest flow.

&&

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

$$

SHORT TERM...Melo
LONG TERM...AGM
AVIATION...Ryan