164 
FXUS63 KIND 070633
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
233 AM EDT Thu Oct 7 2021

.Short Term...(Today through Friday)
Issued at 232 AM EDT Thu Oct 7 2021

The short term will start off wet, especially this afternoon and 
evening as an upper low, seen on H20 vapor imagery over the Ozarks, 
spins northeast to near St. Louis early this afternoon. Then it will 
continue northeast to just west of Chicago Friday morning and become 
absorbed by the fast northwest flow over the upper Midwest. 
Meanwhile, remnant trough will be pivoting northeast across central 
Indiana on Friday. 

National radar loop was showing convection lined up from eastern 
ALabama to eastern parts of Tennessee, Kentucky and Indiana within 
isentropic lift on the 305K level and modest 850 millibar flow. This 
activity will arc northwest across central Indiana overnight and 
this morning. By this afternoon, drier air aloft will allow for the 
atmosphere to destabilize further with mixed layer CAPES approaching 
1000 J/KG. Combo of upper impulses around the upper low, moisture 
and instability will fuel widespread afternoon showers and scattered 
thunderstorms. The activity will continue over areas near and north 
of Interstate 74 this evening and overnight as it ends over 
southwestern sections due to the upper low moving away and drier air 
moving in. More scattered convection on Friday afternoon, with best 
chances northeast, as the trough moves through. Mixed layer CAPEs to 
500 J/KG or so once again support thunder. With precipitable water 
amounts greater than the 75th percentile, rain could be briefly 
heavy today and this evening. Would not rule out minor localized 
flooding. 

Could see some breaks in the clouds this afternoon as the mid levels 
dry and even a better chance for some sunshine on Friday. This and 
southeast winds today and southwest winds on Friday should allow 
temperatures to be slightly above normal with afternoon highs in the 
middle and upper 70s.

&&

.Long Term...(Friday night through Wednesday)
Issued at 232 AM EDT Thu Oct 7 2021

Friday night through Sunday.

By Friday night, the majority of the precipitation will have fallen 
from the exiting closed low pressure system.  The low will continue 
to slowly travel to the north during the overnight hours and will 
gradually weaken with scattered rain showers continuing. Surface 
flow will remain southerly but the moisture advection begins to wind 
down as the 850mb flow weakens which will further limit the 
intensity and coverage of precipitation. By Saturday, the low will 
be far enough north to no longer be impacting the sensible weather 
across central Indiana with a weak upper level ridge across the 
area. Dry weather is then expected Saturday and Sunday. 

Monday through Wednesday.

By Monday, a strong low pressure system is expected to develop and 
rapidly strengthen as it exits the lee of the Rockies and moves into 
the Central Plains.  Models have come closer in line over the last 
24 hours with the track of the low moving from Kansas into the Upper 
Midwest with little impacts to central Indiana other than 
strengthening the southerly flow across the area and leading to 
temperatures much above normal.  There may be a few showers across 
the western counties, but overall impacts look minimal.  A stronger 
system then looks to develop midweek across the same area, but 
confidence that this system impacts Indiana is very low at this time.

&&

.Aviation...(06Z TAF Issuance)
Issued at 1147 PM EDT Wed Oct 6 2021

IMPACTS:
- Scattered showers with isolated embedded thunderstorms will 
continue through the period.
- VFR ceilings will drop to MVFR around 8 to 11z.
  
DISCUSSION: Scattered showers will continue at the sites off and on 
through the TAF period. Isolated storms will be around, but not 
enough coverage or confidence to include and will have to add in as 
they become more clear. Ceilings will drop starting after around 8z 
and could remain MVFR through most of the day. Winds will be out of 
the ESE around 3 to 8 kts through the period.


&&

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

$$

Short Term...MK
Long Term...White
Aviation...CP