527
FXUS63 KIND 241633
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1233 PM EDT Mon Jun 24 2024

.KEY MESSAGES...

- Some thunderstorms possible late tonight north, potentially with
  gusty winds.
- 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...

Onset of surface heating has caused areas of shallow fog to
diminish. Surface ridge axis placement causing light winds and
slightly less moist air mass with seasonal temperatures will result
in a pleasant day. No forecast changes needed.

&&

.SHORT TERM (Today and tonight)...
Issued at 305 AM EDT Mon Jun 24 2024

Today...

A quiet day is in store today as surface high pressure moves across
central Indiana. This will keep some drier air across the area and
keep winds lighter.

A few cumulus will pop up, mainly northeast where cooler air aloft
will be. Some cirrus will pass by as well, but overall still expect
mostly sunny conditions.

Temperatures will be a little above normal and peak in the middle to
upper 80s.

Tonight...

An upper level wave will approach the area from the northwest
overnight tonight. 850mb winds will become west/southwest and
increase in speed. Isentropic lift and some frontogenetical forcing
will arrive overnight with these features.

The best forcing will be northwest/north of the area and should
generate some thunderstorms, some of which may slide into the
forecast area late tonight. Questions remain on coverage of
the storms as well as moisture availability this far south for the
storms to survive on.

CAMs are trending upward in storm coverage, giving support for at
least some convection around. Will increase PoPs across the northern
forecast area late tonight. Given the uncertainty, will keep them
low for now. If trends continue, may have to up them with later
forecasts.

With higher winds aloft, there is a low chance that some of the
storms may be strong enough for some gusty winds, perhaps near
severe levels. Confidence is low in this at the moment.

Temperatures will be warmer with the surface high off to the east
and some increase in cloud cover. Lows will be in the middle 60s to
around 70.

&&

.LONG TERM (Tuesday through Sunday)...
Issued at 305 AM EDT Mon Jun 24 2024

Warmth will continue through the long term period although more
bearable and closer to normal than has been seen in the past week or
two. Outside of Tuesday, which is expected to have widespread 90s,
highs should largely stick to the 80s. This period will also see
multiple thunderstorm chances, occurring Tuesday and Wednesday and
again sometime this weekend. The early period system also has a the
potential for isolated severe storms.

Tuesday will start off with a slight chance of storms from a
decaying complex but the better chance of storms will arrive Tuesday
night through Wednesday. Most likely will see another day of
widespread highs in the 90s on Tuesday but if storms stick around
long enough Tuesday morning, this may not be realized. More than
likely though, that heat and humidity will have a chance to dominate
before the cold front from a low pressure system arrives Tuesday
night. Storms forming along and ahead of the front should bring some
welcome rain amounts to the area. There is a marginal chance of
severe storms with this line of rain as ample CAPE will be present
and moderate shear. It will likely be that micro to mesoscale
features should drive any severe activity, and damaging winds will
be the main threat.

The front should make it all the way across the forecast area by
late Wednesday, leaving behind cooler temperatures and a few days
relief from humidity. Unfortunately, the heat and humidity are
expected to return for the weekend but highs should only top out in
the upper 80s to near 90. Models still lack agreement on timing, but
they do show that another system should bring additional rain
chances to the area at some point this weekend.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1233 PM EDT Mon Jun 24 2024

Impacts:

- Conditional chance of thunderstorms KLAF/KIND early Tuesday

Discussion:

Shallow fog is not expected to redevelop tonight given stronger
winds and mechanical mixing. VFR conditions should prevail outside
of thunderstorms. Thunderstorm coverage and timing confidence is
low. There is a low-mid range chance of thunderstorms approaching
KLAF and KIND early Tuesday morning. These storms may stay northeast
of TAF sites and redevelopment may occur during the afternoon (end
or just after TAF period) near the TAF sites. Expect amendments
given the uncertainty that is typical with weakly forced convective
events in the summer. For now, handled low potential with PROB30.

&&

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

$$

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