993
FXUS63 KIND 181608
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1208 PM EDT Thu Jul 18 2024

.KEY MESSAGES...

- Dry and mild conditions will make for a pleasant end of the week

- Seasonable warmth and moderate humidity to return early next week,
  with mainly low chances of rain/t-storms starting Monday

&&

.FORECAST UPDATE...
Issued at 907 AM EDT Thu Jul 18 2024

- Sunny and pleasant this afternoon

Surface analysis late this morning shows strong high pressure in
place over MN/WI and much of the upper Midwest. This was resulting
in cool northeast flow across Central Indiana. Dew points across
Central Indiana have fallen to the middle 50s as this cooler,
Canadian, air mass begins to settle across Indiana.  Aloft strong
ridging remained in place over the western CONUS. This was resulting
in cooler NW flow across the upper Midwest and into the Ohio valley
along with subsidence. This subsidence was allowing our surface high
pressure system to build.  Water vapor imagery shows subsidence
across Indiana and Illinois.

Pleasant weather is expected for the rest of the day. This is
expected to continue the next several days. Forecast soundings today
show a dry column with a mid level inversion that will prevent CU
development. Convective temps are in the 90s, which will not be
reached. Even CI will be hard to come by. Thus a sunny sky is
expected. Cold air advection is in play this afternoon as 850mb
temps fall to around 9C this afternoon. This will lead to high
temperatures in the middle and upper 70s. Ongoing forecast handles
this well. Little to no changes overall.

&&

.SHORT TERM (Today and tonight)...
Issued at 300 AM EDT Thu Jul 18 2024

The short term will span what will be some of the mildest conditions
of the midsummer, as a positively-tilted, yet pronounced upper
trough crossing southeastern Canada...drags its trailing axis across
central Indiana today.  Upper 50s have already observed as of 235A
this morning at Crawfordsville and Muncie, under clear skies that
will continue to slowly advance southeastward south of Interstate 70
through the early morning hours.  Northerly winds, out of a rather
strong and very slow-approaching dome of Canadian high pressure,
will trend from a light breeze early today up to afternoon gusts
around 15 mph.  This cold-advective flow will maintain noticeably
lower dewpoints of 55-60F, while only allowing readings to rebound
into the mid to upper 70s despite abundant July sunshine...which
should yield to at least a FEW afternoon cumulus with forecast
maxima across the region a few degrees above 21Z convective
temperatures.

Tonight will be the coolest of the 7-day forecast period for most
locations with winds diminishing while veering to northeasterly
under mainly clear skies.  Expect temperatures to drop into the low
50s over much of the CWA`s northern half, with lows closer to 55F
south of I-70.  The biggest story, past it being the coolest morning
since the near-50F marks early on July 1st...will likely be patchy
fog, favored along the East Fork White valley where slightly higher
dewpoints may hang on, and the Upper Wabash Valley where cooler
temperatures slowly spilling out from the broad northern surface
high will drain.

&&

.LONG TERM (Friday through Wednesday)...
Issued at 300 AM EDT Thu Jul 18 2024

Dry and rather mild weather will continue through the first half of
the long term as the broad and strong upstream upper ridge slows the
synoptic pattern, maintaining surface high pressure over much of
eastern North America.  The ridge will be in no hurry to leave the
local region, with its center only beginning to cross the southern
Great Lakes Friday.  A gradual moderation back towards seasonal
levels is expected through the weekend, with partly to mostly clear
skies through at least Saturday guiding mornings about 5 degrees
below normal.

Sunday should be a transition back to a more humid column, promoted
by a small wave plunging around the amplified western ridge and into
the central CONUS...with mid-level southerly flow on its downstream
side increasing clouds into the Midwest.  Nonetheless, expect
boundary layer readings to stay near/below normal courtesy what
should be lingering, yet light northeasterly flow, as more
seasonable moderate humidity slowly returns.  More southerly low-
level winds during the Monday-Wednesday timeframe will return at
least low-chances of showers and t-storms...albeit amid reasonable
temperatures for July with H850 marks around 15 degrees Celsius, as
the main subtropical ridge stays suppressed well to our south/west.
best chances for rain will be towards the end of the long term as
the next approaching wave favors greater precipitable water and
moderate forcing into the Midwest.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1207 PM EDT Thu Jul 18 2024

Impacts: None; VFR Expected

Discussion:

VFR is expected through Friday. Strong high pressure over the upper
midwest will build across Indiana and the TAF sites through the
period. Forecast soundings suggest a dry column with subsidence.
A few diurnal cu will be possible. Expect any winds to trend toward
less than 5 knts this evening as diurnal heating is lost.

&&

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

$$

UPDATE...Puma
SHORT TERM...AGM
LONG TERM...AGM
AVIATION...Puma