891 
FXUS63 KIND 142326
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
726 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 (00Z TAF Issuance)...
Issued at 725 PM EDT Fri Jun 14 2024

Impacts:

- Winds mainly 7KT or less shifting from northerly this evening to
  east-southeasterly by 15Z Saturday

Discussion: 

VFR conditions will prevail through Saturday evening as seasonably 
strong surface high pressure centered to our north slowly crosses 
the Great Lakes.  Lighter winds through sundown may include isolated 
gusts to 13-18KT.  Winds will diminish to around 7KT at KIND and 5KT 
or less at other terminals while slowly veering to easterly by 12Z.
Only a modest increase in surface flow expected during the day 
Saturday under the southern portions of the passing ridge...with 
FEW/SCT cumulus returning for the afternoon.

&&

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

$$

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