722 
FXUS63 KIND 100423
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1223 AM EDT Sat Aug 10 2024

.KEY MESSAGES...

- Dry and cooler weekend
- Generally milder and lower humidity through Tuesday. 
- Rain chances returning late next week. 

&&

.FORECAST UPDATE...
Issued at 924 PM EDT Fri Aug 9 2024

A little taste of autumn currently on this Friday evening as high 
pressure settles across the region. Diurnal cu from earlier had 
largely diminished with an axis of stratocu associated with a weak 
wave aloft extending from lower Michigan into north central Indiana. 
Wind gusts had diminished as well. 01Z temperatures were already 
into the mid and upper 60s across much of the forecast area.

The current forecast is in excellent shape for the overnight as the 
expanding high pressure serves as the primary feature over the 
region. Nudged cloud cover up in northern counties for the next 
couple hours as the upper level wave passes by to the north. After 
midnight...predominantly clear skies are expected. Lows will drop 
into the lower and mid 50s giving a distinctly mid September feel to 
the air by daybreak Saturday.

Zone and grid updates out.

&&

.SHORT TERM (This evening through Saturday)...
Issued at 252 PM EDT Fri Aug 9 2024

H20 vapor imagery was indicating an upper low spinning over northern 
Ontario. Meanwhile, the surface analysis was showing broad high 
pressure over the Plains. Finally, GOES-16 visible loop was showing 
an expansive area of diurnal cu over all but the upper Wabash Valley.
The upper low will wobble southeast across northern Ontario through 
Saturday as suffuse high pressure moves into the Wabash Valley late 
Saturday. Northwest winds ahead of the high will become light 
tonight and bring in cooler temperatures and a drier airmass. Hi-Res 
soundings were clearly highlighting a dry column, so look for only 
some passing cirrus and perhaps scattered diurnal cu Saturday 
afternoon. Afternoon dew points were starting to fall into the 50s 
and with winds becoming light and mostly clear skies, temperatures 
should bottom out all the way into the 50s per DESI. This will seem 
even cooler compared to the earlier week sauna-like weather. 

With the northwest winds continuing around the high, conditions will 
be comfortable Saturday with highs only in the 70s, some 5 to 10 
degrees below normal and humidity levels will be low.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 252 PM EDT Fri Aug 9 2024

High pressure will push southward into the Ohio Valley this weekend 
thanks to an efficient CAA regime behind a close low over the easter 
Great Lakes. This area of high pressure will broaden throughout the 
weekend and should push most waves south of the region keeping 
conditions mostly dry through the long term. 

There are a few potential exceptions to the rule, the first starting 
on Monday. A mid level wave on the subgeostrophic side of an upper 
level jet will develop late Sunday over the Plains and will quickly 
progress eastward. As stated, this wave will likely pass south of 
central Indiana, posing minimal impacts. However, there is enough 
variance in the ensemble solutions for a non-zero threat for light 
rain Monday morning, with highest chances (still low), over southern 
central Indiana. 

Then, as we head into the later portions of next week (Thursday 
onward), chances for rain increase as confidence decreases 
significantly. There is likely to be a greater push of moisture 
northward and potential for convective regimes on the northern 
extend of a moisture tongue, but how far north is still in
question. For now, slight chances have been included in the 
forecast, but this could shift as confidence in the pattern 
increases. 

With the continental Polar air mass in place this weekend, 
temperatures are expected to remain below normal until the high 
shifts eastward towards the middle of next week. By Wednesday, highs 
will likely push back into the mid 80s, with a greater moisture 
return potentially by Wednesday night into Thursday.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 1223 AM EDT Sat Aug 10 2024

Impacts: 

- VFR conditions this TAF period

Discussion: 

Surface high pressure over KS/NB will build eastward into the Ohio 
Valley this TAF period. This will result in continued dry weather 
and good flying conditions. Forecast soundings suggest a dry column 
with subsidence through the forecast period. Thus VFR will continue 
through the period. Diurnal heating/mixing will allow winds to 
increase to 10-15kts this afternoon, but will subside this evening 
as the high arrives.

Overall, ongoing forecast remains in good shape and only minor 
changes made.

&&

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

$$

UPDATE...Ryan
SHORT TERM...MK
LONG TERM...Updike
AVIATION...Puma