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000
FXUS63 KIND 280705
AFDIND

Area Forecast Discussion
National Weather Service Indianapolis IN
305 AM EDT Sun Apr 28 2024

.KEY MESSAGES...

- Partly Sunny and warm with chances for showers today.

- Showers and storms return to the Wabash Valley overnight.

- Warm and active weather expected Monday through Saturday with
above normal temperatures and multiple opportunities for showers and
thunderstorms.

- Organized severe storms appear unlikely, though multiple rounds of
  rainfall may allow redevelopment of minor flooding along some
  rivers.

&&

.SHORT TERM (Today and tonight)...
Issued at 303 AM EDT Sun Apr 28 2024

Synopsis:

Surface analysis early this morning shows strong southerly flow
across Indiana, allowing warm and humid flow to arrive across the
area from the Gulf of Mexico. A strong area of Low pressure was
found over Central KS, along with a warm front that stretched
northeast across IA to WI and Lake Michigan. Aloft water vapor
showed ridging in place over the east coast, and a trough in place
over the Rockies. This was resulting in southwest flow aloft over
the plains and the Ohio valley, streaming toward the Great Lakes.
National Radar shows a large area of showers and storms ahead of the
trough stretching from WI to TX. Across Central Indiana, a few light
showers were found within the southwest flow, near LAF and Delphi.
Dew points across central Indiana remained moist, near 60.

Today...

Little overall change is expected in the overall weather pattern
today. Models suggest the strong upper ridging to the east will
remain in place through the day. This will result in any upper
forcing being pushed mainly to the northwest of Central Indiana,
keeping our forecast area protected under the influence of the
ridging to the east. However, The combination of surface high
pressure to the east and a surface low pushing toward the upper
Midwest from the plains will result in continued warm and humid
southerly flow across Central Indiana. Similar to yesterday,
forecast soundings show minimal CAPE and high pwats, but limited
instability and hint at a weak mid level cap. Models fail to develop
much in the way of showers or storms today. Thus confidence is low
for precipitation and will just trend toward partly cloudy/partly
sunny type forecast.

Given the ongoing warm air advection, highs around 80 will be
expected today.

Tonight...

Models begin to show the strong ridging pushing a bit farther east
as a deep upper low over the plains begins to push toward Minnesota.
This will allow for more of the active convective area to push into
the Wabash valley overnight. Upper forcing within the southwest flow
is expected to push across Illinois overnight reaching western
Indiana toward after 09Z. The air mass across Central Indiana will
remain warm and humid, favorable for showers and storm development.
Forecast soundings trend toward saturation late tonight. However the
CAMS are hinting at showers and storms over IL diminishing on
approach to Central Indiana. Thus will aim for dry weather for much
of the night, but include pops mainly after 08Z-12Z, with highest
pops in the Wabash Valley.

With the warm air mass still in place across Central Indiana,
overnight lows in the middle 60s will be common.

&&

.LONG TERM (Monday through Saturday)...
Issued at 303 AM EDT Sun Apr 28 2024

A warm and active period continues to be the expectation for this
coming week, with multiple opportunities for showers and
thunderstorms.

Large scale troughing will dominate over much of the CONUS this
week, with mean ridging of various intensity over or just off the
eastern/southeastern CONUS. The strong surface cyclone that has been
bringing a regional severe weather outbreak to the central and
southern Plains will be on its way northeastward into the Great
Lakes at the start of the period and weaken. The associated surface
frontal zone will weaken as well, as it is stretched/washed out with
time. Thus, only expecting showers and thunderstorms with it for
central Indiana as well as an isolated threat for localized
flooding. The precipitation with it will move out of the area by
midday to mid afternoon on Tuesday.

Another weak system is expected to follow in quick succession mid-
week, before a third, stronger system develops late in the week,
with potential for additional, perhaps somewhat higher precipitation
chances late week into the weekend, though uncertainty increases
with time both due to a complex evolution of these systems and model
differences. Though precipitation chances will be frequent this
week, several dry periods are likely between systems.

Analogs and experimental machine learning guidance continue to
suggest the area will be on the fringes of a low threat for strong
to severe storms mid to late week, though the signal is better for
areas west and south of the area. Again, there is still not a clear
signal between models for the latter half of the week to have much
confidence yet.

Temperatures will continue to be above normal throughout the long
term with highs ranging from the 70s to 80s and the warmest temps
expected Wednesday and Thursday. Behind the late week system, temps
look to get closer to normal, although still slightly above.

&&

.AVIATION (06Z TAF Issuance)...
Issued at 120 AM EDT Sun Apr 28 2024

Impacts:

- Mainly VFR this TAF period.
- VCSH possible through the night, mainly at HUF and LAF
- Southerly wind gusts to 25 kts mainly during daylight hours.

Discussion:

Southerly surface flow will remain in place across Central Indiana
through this TAF period. Convection from storms over the plains is
expected to continue to drift north and west of much of Central
Indiana through the period as upper ridging continues to steer flow
that direction.

Some weak showers may be possible overnight at LAF and HUF as seen
on radar, but these showers will be VFR based, weak and short-lived
as they progress northeast. Thus have used a VCSH mention for now.

On Sunday, Indiana will remain within the warm sector, with limited
forcing available, similar to Saturday. thus have again trended to
VFR cigs, but confidence remains too low for any precip mention.
Moderate pressure gradient across the area will allow gusts to near
25 mph when heating and mixing resumes.


&&

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

$$

SHORT TERM...Puma
LONG TERM...KF/Nield
AVIATION...Puma