071 
FXUS63 KIND 310233
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
1033 PM EDT Tue May 30 2023

.Forecast Update...
Issued at 1033 PM EDT Tue May 30 2023

Showers from this afternoon have now completely dispersed across 
central Indiana with only a few clouds remaining. Only changes 
needed to the forecast were to adjust hourly temperatures down 
slightly to reflect current conditions but overnight low still looks 
to be in the mid 60s. Quiet conditions with southeasterly flow are 
in store overnight.

&&

.Short Term...(This evening through Wednesday)
Issued at 250 PM EDT Tue May 30 2023

Rest of Today.

Latest ACARs soundings are showing the PBL has deepened to around 
3500ft with no cap above the mixing layer which is allowing for the 
cu field to become more agitated.  Will have to keep an eye on 
vertical growth of the field for any potential showers and storms 
into the later afternoon and evening hours. SB CAPE is now 
approaching 1000 J/kg, but the LFC is pretty shallow with poor 
lapse rates above 600mb. Current thoughts are that at least a few 
showers by 4-5PM. Any shower will quickly dissipate after sunset 
with the loss of diurnal heating.

Tonight.

Quiet conditions are expected during the overnight hours with the 
diurnally driven cu field rapidly dissipating leaving only any 
potential residual convective debris assuming showers and storms end 
up developing.  If conditions remain dry, skies will be clear.  The 
slightly stronger daytime winds will also weaken to near calm with 
the loss of mixing.  Dewpoints are running about 10 degrees higher 
than yesterday which will keep conditions more mild through the 
overnight hours with lows in the mid 60s expected.

Wednesday.

Wednesday will begin similar to today with a rapid warm up and a 
quickly developing cu field. Shower and thunderstorm coverage is 
expected to be slightly higher on Wednesday with weaker subsidence 
above the PBL and slightly more favorable lapse rates in the mid 
levels which will lead to better instability.  Any residual outflow 
boundaries from showers and storms today would also create localized 
areas of increased lift and would be the focus points for initial 
convection tomorrow.  Highs should again rise into the mid to upper 
80s with a few 90s likely in spots.  Storm coverage will then lessen 
towards sunset.

&&

.Long Term...(Wednesday night through Tuesday)
Issued at 250 PM EDT Tue May 30 2023

Wednesday Night Through Thursday...

Hot and mostly dry conditions are expected through much of the 
period as upper ridging remains across the central and eastern 
CONUS. Highs will generally be in the upper 80s to low 90s which is 
around 10-15F above normal. Large-scale subsidence will keep most of 
central Indiana dry, but remnant low-level moisture and daytime 
heating may produce isolated showers and storms Thursday afternoon. 
Forecast soundings show steep low-level lapse rates, modest 
instability, and some low level moisture which supports the slight 
chance for precipitation. Any convection that develops would be 
short-lived/disorganized due to very weak deep-layer shear. 

Thursday night Through Tuesday...

The upper ridge will begin to retrograde westward late in the week. 
This will help advect a drier airmass into the area. Lower dewpoints 
in the upper 40s to mid 50s should promote more efficient daytime 
heating and limit the potential for diurnal convection. Expect highs 
in the low 90s with a few spots potentially warming into the mid 
90s. Flow aloft remains weak and with the stagnant airmass in place, 
air quality concerns will continue into the weekend. Afternoon RH 
values are expected to fall below 30 percent, but the fire threat 
will be limited due to relatively weak winds. 

Ensemble guidance suggest the upper ridge will continue to 
retrograde, allowing a deepening trough across the northeast CONUS 
to push a cold front towards central Indiana at the end of the 
period. A lack of better moisture return ahead of the front will 
limit precipitation, but a relief in temperatures is possible.

&&

.Aviation...(00Z TAF Issuance)
Issued at 751 PM EDT Tue May 30 2023

Impacts:

* Isolated showers continuing in the first hour of period and 
  possible again tomorrow afternoon

Discussion:

A diurnally driven cu field will diminish over the first few hours 
of the period with isolated showers and potentially a stray 
thunderstorm near BMG in the first hour. Tomorrow will be 
essentially the same as today with afternoon showers and storms 
possible, but chances and coverage is a little higher than was seen 
today. Will likely need to introduce TSRA or VCTS in subsequent TAF 
issuances, but confidence was not high enough to mention more than 
afternoon VCSH for now. Winds will generally be southeasterly at 5-
10 kts with brief periods up to 15 kts tomorrow afternoon. 
Conditions will remain VFR outside of any convection.


&&

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

$$

Update...KH
Short Term...White
Long Term...Melo
Aviation...KH