587
FXUS63 KIND 072302
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
702 PM EDT Fri Jun 7 2024

.KEY MESSAGES...

- Breezy today.

- Chance of showers Saturday.

- Near-average temps through midweek, then warming trend late next
  week.

&&

.SHORT TERM (This evening through Saturday)...
Issued at 143 PM EDT Fri Jun 7 2024

A nice cu field has developed once again early this afternoon in the
back side of the upper low moving east away from the Great Lakes.
Skies were mostly clear further to the southwest under increasing
influence from the upper ridge axis approaching. With winds
occasionally gusting to around 35mph this afternoon...temps had
risen into the 70s and low 80s.

Northwest flow aloft will expand into the Ohio Valley tonight and
Saturday wedged between a triple barrel upper low across Canada and
upper ridging along the Gulf Coast. This will set the stage for
multiple convective clusters tracking in tandem with waves aloft
traversing through the mean flow. Much of central Indiana will be on
the northern side of the track of the convective clusters...with an
expected increase in clouds into the first half of the weekend and
chances for rain Saturday morning with potentially isolated to
scattered convection by the afternoon and evening.

This Afternoon and Tonight

The rest of today will be superb with the stronger wind gusts
serving as the primary issue. As the upper ridge axis moves into the
region late today...anticipate a slow but steady decrease in cu
from the west along with a noticeable decline in wind gusts by this
evening. Clearing will be short lived with high clouds expanding
into the region from the west...then thickening and lowering towards
daybreak Saturday as the convective cluster that develops in the
Missouri Valley late tonight moves southeast towards the lower Ohio
Valley. Could see rain slip into the lower Wabash Valley near or
just after daybreak but most if not all of the rain should hold off
until later in the morning.

Saturday

The most intense part of the convective cluster late tonight will
remain displaced well to our southwest across Missouri and perhaps
far southern Illinois by morning as a strong low level jet feeds
moisture into an unstable environment. Further northeast across
central Indiana...residual dry air left from the high pressure over
the region today will cause moisture advection issues...particularly
within the boundary layer as model soundings show very clearly a
lack of deeper moisture below 700mb Saturday morning. The cluster
will be in the process of weakening as it moves away from the low
level jet and better instability with the most likely scenario
locally being a weakening area of diminishing showers pressing
across the southwest half of the forecast area through midday.

Behind this feature...greater uncertainty exists through Saturday
afternoon as flow turns southerly despite a warm front remaining to
the southwest of the region. Weak energy aloft tracking through the
mean flow will provide some forcing and model soundings do hint at
subtle amounts of elevated instability with some heating but low
level moisture remains somewhat problematic. Likely to see isolated
to scattered convection develop as a result during the afternoon and
evening.

Temps...lows tonight will largely hold into the upper 50s and lower
60s as clouds increase. With limited sunshine on Saturday...
expecting a cooler day with highs mainly in the low to mid 70s
supported by low level thermals.

&&

.LONG TERM (Saturday night through Friday)...
Issued at 143 PM EDT Fri Jun 7 2024

Saturday Night Through Sunday.

Late Saturday night a secondary low behind the main low pressure
system south of the Hudson Bay will push a cold front through the
state Saturday night into Sunday with scattered light rain showers
likely along with a complex of thunderstorms that looks more likely
to remain closer to the Ohio River.  There is good model agreement
in the track of the storm complex with the front passage helping to
ensure a more southerly component to the storms propagation. Little
change in temperature is expected in the aftermath of the frontal
passage for Sunday with a fairly warm airmass in the area behind the
front. Skies are expected to gradually clear through the day as
drier air erodes the residual moisture.

Monday Through Friday.

Robust northwesterly flow is expected then to dominate the weather
pattern through the early portions of the week with gradually lower
confidence in the forecast going towards the middle of the week as
models begin to differ on the evolution of the next low pressure
system.  Confidence is highest in the below normal temperatures
continuing to as far as Tuesday with dry weather, but towards
Wednesday and Thursday rain chances begin to slowly ramp up with
another potential closed low moving across the Great Lakes.  This
again remains very uncertain with numerous ensemble members keeping
the pressure fields more zonal with dry weather.

There is a potential to see the first widespread 90 degree day on
Friday but there remains significant model spread towards Friday
with the deterministic GFS and Euro models showing another cold
frontal passage and temperatures in the 70s while some of their
ensemble members are holding out on broad ridging and low 90s.
Leaning more towards the latter on the forecast with thoughts that
the models are breaking down the ridge too early and too far south
with the better shot for the cold air arrival being later into the
weekend and better chances for rain towards the Great Lakes.

&&

.AVIATION (00Z TAF Issuance)...
Issued at 702 PM EDT Fri Jun 7 2024

Impacts:

- MVFR ceilings at western sites Saturday afternoon
- Scattered showers Saturday...mainly at KHUF/KBMG

Discussion:

Gusty winds will diminish quickly by valid time. Mid and high clouds
will increase during the night, then lower level clouds will move in
during Saturday morning. Ceilings will likely reach MVFR levels at
KLAF/KHUF by early afternoon. Low VFR is expected at the other sites.

Scattered showers will move in after 12Z and will be around at times
during the day. Best chances will be at KBMG/KHUF, so used a VCSH
there.

&&

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

$$

SHORT TERM...Ryan
LONG TERM...White
AVIATION...50