-- Discussion containing changed information from previous version are highlighted. --
892
FXUS63 KIND 301858
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
258 PM EDT Tue Apr 30 2024

.KEY MESSAGES...

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- Low rain chances late tonight.

- Low chance for showers or storms Thursday, additional
  thunderstorms expected late Thursday into the weekend.

- Above normal temperatures expected to continue into next week.
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&&

.SHORT TERM (This evening through Wednesday)...
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Issued at 257 PM EDT Tue Apr 30 2024

Tonight.

Quiet weather is expected for much of the overnight period with the
main focus being watching convection across Iowa as it pushes into
Illinois towards midnight and gradually begins to weaken. Model
soundings show little to no elevated instability as far west as
central Illinois with the only fuel for the convective system being
driven by the cold pool which even by then will be weakening.  Will
keep low POPs across the northwestern counties to account for this
low potential scenario from 08Z to 12Z.  There is much higher
confidence in mid level clouds associated with the system to linger
and push into the area around the same timeframe and will help to
limit the bottoming out of temperatures towards daybreak and keep
dewpoint depressions high enough to inhibit fog formation. Lows
tonight will range from the low 50s in the east with lower cloud
cover to the upper 50s in the west where the mid level clouds will
be around the longest.

Wednesday.

Similar conditions expected for tomorrow except for residual thin
high clouds persisting through much of the daytime hours as
convective debris from the Plains continues to advect across much of
the Ohio Valley. This cloud cover will be thin enough to limit
diurnal heating and combined with the wind direction gradually
becoming less northwesterly, expect that highs should reach into the
low 80s for all but the far northern counties.
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&&

.LONG TERM (Wednesday night through Tuesday)...
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Issued at 257 PM EDT Tue Apr 30 2024

Wednesday night through Thursday...

A warm front associated with an approaching surface low will move
northward early in the period. Increasing isentropic ascent and
moisture could support isolated showers and thunderstorms. However,
overall forcing looks relatively weak due to the upper trough axis
overhead and most guidance show little to no convective coverage.
Will stick with low chance POPs for now given the benign signal for
precipitation. Increasing heights aloft and increasing southerly
flow at the surface will warm temperatures well into the 80s
Thursday.

Thursday night onward...

Better rain chances are expected late Thursday into Friday as the
aforementioned surface low and parent trough move into the region.
Stronger forcing and a relatively narrow corridor of deeper moisture
ahead of an approaching cold front supports better chances for
precipitation. The one caveat is guidance shows the approaching
front becoming displaced from the parent trough. This will likely
limit overall forcing and rainfall amounts across central IN. For
this reason, heavy rainfall does not appear to be a threat at this
time.

There are additional chances for showers or storms over the weekend
into next week, but diverging model solutions limits confidence.
Some models show the aforementioned cold front pushing through
central IN late Friday into Saturday providing dry conditions while
others show the front stalling over the area. Will stick with a
blended forecast of low POPs for now given the uncertainty, but
there is a chance for dry weather on Saturday. Severe weather is
unlikely due to limited instability and deep-layer shear. However,
some severe weather risk may materialize early to middle of next
week as guidance shows increasing instability and deep-layer shear.
Predictability remains low this far out, but will continue to
monitor the potential. Warm conditions should continue through the
extended though highs may be slightly cooler.
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&&

.AVIATION (18Z TAF Issuance)...
Issued at 138 PM EDT Tue Apr 30 2024

Impacts:

- VFR flight rules through current TAF period
- Light winds turning southerly then a frontal boundary will shift
winds to the northwest late in TAF.

Discussion:

VFR conds have continue through this morning and into the afternoon.
Some diurnally driven clouds have developed, but coverage remains
minimal due to the dry air in the mid-lvls. High pressure will be
shifting east overnight and allow some high based cirrus to float in
from the west, then a frontal boundary will arrive midday Wed and
allow winds to turn southwesterly to northwesterly.


&&

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

$$

SHORT TERM...White
LONG TERM...Melo
AVIATION...Updike