031
FXUS63 KIND 120140
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
940 PM EDT Mon May 11 2026

.KEY MESSAGES...

- Near normal temperatures expected throughout the week

- Showers and a few t-storms Tuesday night, gusty winds possible
  with these

- Warming trend this weekend and into next week, above normal
  temperatures likely

&&

.FORECAST UPDATE...
Issued at 940 PM EDT Mon May 11 2026

Only minor changes were made to the going forecast, with increasing
high clouds moving in from the W-NW, have bumped up cloud cover to
partly cloudy overnight.

Winds will become light and variable overnight. Almost a carbon copy
of last night, most areas will see low temps in the lower to mid
40s. The main exception being in the immediate Indy area where a
heat island effect will keep low temps in the upper 40s.

&&

.DISCUSSION (This evening through Monday)...
Issued at 257 PM EDT Mon May 11 2026

Surface high pressure over the Great Lakes has provided clear skies
and relatively light breeze. A lake breeze off of Lake Michigan has
been working its way southward today with winds becoming northerly
behind it. Northerly winds continue through tonight before quickly
turning southerly Tuesday morning ahead of an approaching clipper
system.

The aforementioned clipper is associated with a potent vort max
embedded within broad northwesterly flow aloft. Surface cyclogenesis
over southern central Canada will result in a ~1000mb low which will
dive southeastward into northern Michigan, where gradual
strengthening is modeled. Despite a relatively weak low, a decent
MSLP gradient is shown by most guidance over Indiana. Southwesterly
winds around 15kt gusting to 25-30kt is possible. Situations where a
clipper passes to our north with strong southwesterly flow tend to
bring temperatures warmer than guidance suggests. With clearing and
strong May sunshine, we`ve bumped high temperatures for tomorrow up
from the consensus and into the upper 70s to low 80s.

A cold front associated with the clipper is expected to arrive late
Tuesday evening with scattered showers. Guidance shows some weak
instability with a couple of hundred J/Kg CAPE at most. Therefore,
some thunder cannot be ruled out. Even though instability is meager
at best, model soundings show dry air below 700mb. Efficient
evaporational cooling could allow for some potent downdrafts within
any shower or storm. Additionally, a 30-40kt SW low-level jet will
precede the low, and some of this momentum may easily mix downward.
Therefore, a strong to severe wind gust cannot be ruled out even
though the odds of thunder are low.

Once the clipper departs, surface high pressure builds back in on
Wednesday and is expected to persist through Friday. Pleasant
conditions with near-normal temperatures are expected to round out
the week.

By late Friday, and especially the weekend, southwesterly flow
returns as low pressure takes shape over the northern Plains.
Troughing aloft is likewise replaced by ridging. Ensemble guidance
is in good agreement showing above-average temperatures returning
this weekend and persisting into next week. Additionally, showers
and thunderstorms may be possible at times as moisture returns
northward.
.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 736 PM EDT Mon May 11 2026

Impacts:

- WSW wind gusts 20-25kt on Tuesday
- -SHRA and LLWS for IND Tuesday night

Discussion:

In the wake of the weak frontal boundary/pseudo dryline, winds have
shifted to the N-NW with much drier air working its way into central
Indiana. Wind gusts have been dropping off quickly during the last
hour, so have them removed from the TAFs. Overnight, scattered
mid and high clouds will move across the TAF sites with a brief
period of broken sky cover towards 12Z at KLAF. Winds will
gradually diminish while becoming N-NE this evening, before
becoming light and variable overnight.

Tomorrow a modest storm system will move SE into the western Great
Lakes. Ahead of the associated surface low pressure/frontal
boundary, winds will increase while becoming S-SW late in the
morning/early afternoon. This change in direction and increase
speeds will occur during the 15-17Z time period as the surface
inversion fully mixes out. By 18Z, gusty S-SW winds from 20-25 kts
are forecast across all of the TAF sites.

Ahead of the cold front clouds will gradually thicken late Tuesday
afternoon with the most predominate cloud deck being in the mid
altitudes /100-150/. Numerous showers will move into KIND between 03-
06Z Tuesday night. There is some indication that an isolated TS may
also be possible during this time period, but confidence and
coverage is too low to warrant any Prob30 inclusion at this time. In
addition to the showers, winds aloft will increase at 020 out of the
SW up to 45 kts leading to some LLWS potential at KIND after 03Z.


&&

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

$$

UPDATE...Crosbie
AVIATION...Crosbie
DISCUSSION...Eckhoff