266
FXUS63 KIND 141849
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
249 PM EDT Fri Jun 14 2024

.KEY MESSAGES...

- Dry weather and near or slightly above normal temperatures Saturday

- Hot and humid trend starts Sunday...increasing confidence in
  potentially hazardous heat into next week

- Low chance for a few showers or storms Monday and Tuesday

&&

.SHORT TERM (This evening through Saturday)...
Issued at 248 PM EDT Fri Jun 14 2024

A weak midlevel shortwave passing through the southern Great Lakes
now has nudged a cold front south of our area to near the Ohio
River. Temperature advection is weak so temperatures should be near
daily maximums experienced yesterday. A drier continental air mass
is noted in observations advecting in, and drying is enhanced by
mixing process given particularly dry/subsident layer aloft evident
in water vapor. ACARS soundings show enough residual low level
moisture for some cumulus at the top of the mixed layer but this may
wane later in the diurnal cycle given the drying trend.

No major concerns with a model blend approach to temperatures
tonight, though radiative processes may be strong enough for a few
locations to fall slightly lower. Given that we`re peripheral to the
MSLP high center and light winds should prevail overnight we won`t
adjust downward.

High-level moisture may crest the ridge bringing some cirrus later
tonight and through the day tomorrow. Diurnal cumulus tomorrow
should be minimal as we`re still a couple days away from meaningful
low-level moisture return. The warmer windward side of mid-upper
ridge axis will be positioned to our west tomorrow which will hold
off the onset of anomalous warmth that is to come as the synoptic
pattern shifts beyond the short term period.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 248 PM EDT Fri Jun 14 2024

Saturday night through Next Week

**Increasing confidence in an extended period of very hot and humid
conditions Sunday through much of next week**

The main story in the extended period will be the very hot
temperatures building across much of the eastern CONUS Sunday and
persisting through next week. Upper ridging initially centered over
the Great Lakes region Saturday night is expected to amplify and
become centered over the Northeast by early next week. At the
surface, high pressure should gradually shift east before settling
near or just off the Northeast coast supporting southerly flow back
across the Ohio Valley. Increasing heights aloft combined with
return flow will result in temperatures quickly warming up into the
90s at the beginning of the long term period. In addition, look for
humidity to be on the rise which raises concern for dangerous heat
indices near or above 100F by Monday.

Most guidance shows upper ridging remaining the dominant influence
through much of the period though the ridge may begin to flatten
late next week as a few troughs traverse far northern portions of
the Great Lakes or Canada. Unfortunately, there appears to be little
relief from the heat during this period and overnight lows are only
expected to fall into the 70s. The extended stretch of heat this
early in the season is abnormal so make sure to stay hydrated and
take frequent breaks in air conditioning if you are outdoors.

Increasing moisture from southerly flow combined with daytime
heating supports at least low end chances for showers and storms
most days. The strongest subsidence from the upper ridge/surface
high should be focused further east of the area suggesting capping
should not be an issue. Some models show ridging breaking down late
next week allowing for a system to move in, but diverging model
solutions leads to low confidence for this scenario.

&&

.AVIATION (18Z TAF Issuance)...
Issued at 1049 AM EDT Fri Jun 14 2024

Impacts:

- Northerly winds could occasionally gust this afternoon to 15-20 kt

Discussion:

A drier air mass is moving in, but there may still be enough
residual moisture to result in few to scattered cumulus this
afternoon as mixing matures. Also, as mixing depth increases, some
momentum transfer could result in gusts to around 15-20 knots. These
are unlikely to be persistent and more sporadic. VFR conditions are
expected to prevail.


&&

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

$$

SHORT TERM...BRB
LONG TERM...Melo
AVIATION...BRB