965 
FXUS63 KIND 082253
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
653 PM EDT Sat Aug 8 2020

.UPDATE...
The AVIATION section has been updated below.

&&

.SYNOPSIS...
Issued at 233 PM EDT Sat Aug 8 2020

An upper air disturbance is expected to move through southern 
Indiana during the day Sunday. A cold front is expected to affect 
the area around Monday night into Tuesday. This front may linger 
over the area for much of next week.

&&

.NEAR TERM /This Afternoon and Tonight/...
Issued at 233 PM EDT Sat Aug 8 2020

A remnant MCV currently over Missouri is progged by short term model 
data to drift into southern Illinois tonight. Some of the finer 
scale models blow up quite a bit of convection off to the 
west/southwest of the local area with this feature later tonight, 
with the fringes possibly reaching the southwest zones towards 
sunrise Sunday. Convective parameters not very favorable locally for 
much to happen tonight, so the better convective threat may remain 
off to the southwest. Will bring in some small chance PoPs towards 
sunrise Sunday over the far southwest zones to cover this feature, 
but keep the majority of the forecast area dry.

Low level thicknesses suggest the GFS MOS guidance lows tonight look 
reasonable, so any adjustments will be minor.

&&

.SHORT TERM /Sunday through Tuesday/...
Issued at 233 PM EDT Sat Aug 8 2020

The remnant MCV is expected to drift through southern Indiana on 
Sunday. Questions remain as to the amount of convection that may be 
associated with this feature locally, as convective parameters 
continue to look rather weak. Will keep some chance PoPs over the 
southern/southwestern zones on Sunday, due to the presence of the 
mid level feature. 

Convective potential looks to increase Sunday night and on through 
the rest of the short term, as an area of enhanced flow at 850mb 
moves into the area Sunday night, and a cold front sags into the 
area by Monday night or Tuesday. At this point, operational and 
ensemble data suggest the best precipitation potential will be 
Monday night into Tuesday, but any preceding outflows may change 
that as time goes by.

Air mass may become highly unstable by Monday afternoon, with models 
suggesting potential for Lifted Index values below -10 and CAPE 
above 4000, which may result in strong organized convection. Deep 
layer shear looks rather weak, though.

Lower confidence in high temperature forecast on Sunday, due to 
questions revolving around amount of cloud cover tomorrow. Will go 
with the GFS MOS highs for now, but highs may be too warm if cloud 
cover is more widespread than currently expected. Progged low level 
thicknesses suggest the guidance highs look too cool on Monday. Will 
raise the highs a category in that period.

&&

.LONG TERM /Tuesday Night through Saturday/...
Issued at 244 PM EDT Sat Aug 8 2020

An active weather pattern will persist throughout the extended
with periodic threats for scattered convection as waves aloft 
drift through the quasi-zonal flow and interact with a frontal 
boundary oscillating back and forth across the Ohio Valley. While
no day is expected to be a washout...the presence of the boundary
nearby with a steady slate of waves and energy aloft will result 
in a daily threat for scattered storms into the weekend with a 
moist and unstable airmass over central Indiana. Drier air over
the Great Lakes later in the week will try to advect south into
the area but confidence is not high in that occurring to any great
degree. Have much greater confidence at this point in the more 
stagnant pattern discussed above lingering.

Expect warm and humid conditions through the weekend with near 
normal temperatures. Highs will be generally in the mid and upper
80s with lows from the mid 60s to the lower 70s.

&&

.AVIATION (Discussion for the 090000Z TAF Issuance)...
Issued at 653 PM EDT Sat Aug 8 2020

VFR conditions are expected through the period.

Mainly mid and high clouds will pass across the area through 
Sunday as an upper level disturbance moves across southwestern 
Indiana. This disturbance could also bring some convection late 
tonight into Sunday, but most convection should stay west and 
south of the TAF sites. Thus do not have a mention in the TAFs.

Winds will increase closer to 10kt during the day Sunday.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JAS
NEAR TERM...JAS
SHORT TERM...JAS
LONG TERM....Ryan
AVIATION...50