Indiana’s Weather For Tuesday

HEADLINES
– Rain and storms at times. Biggest severe threat today east of I-69.
– Showers Wednesday late afternoon and evening.
– Another (smaller) severe threat Thursday.
– Showers at times Friday into early Saturday morning.

TODAY’S MAP

NWS TECHNICAL DISCUSSION

Surface analysis this morning shows a potent cold front extending from
strong low pressure over the upper Midwest southwestward into the
mid Missouri valley and into southwest Texas. This front will
serve as the primary focus for showers and thunderstorms today,
including a threat for severe storms this afternoon.

Plentiful moisture transport continues in the open warm sector ahead
of the front early this morning, and regional radar imagery does
show some light shower activity which may move through the area
early in the day, though the impact of this activity looks to be
relatively minor with a potential lull in precip late morning
before additional convective development along the advancing front
moves through the area during the afternoon hours, with an
attendant severe threat owing to at least moderate instability and
deep layer shear and weak-moderate low level shear. Damaging
winds look to be the primary threat, though depending upon
convective evolution/eventual storm mode, at least an isolated
tornado and large hail threat will also be present. Given frontal
timing, early day activity, and latest CAM guidance, day one
convective outlook appears to outline the threat fairly well,
maximized in the southern/southeastern forecast area.

This activity will wane this evening as the front settles through the
forecast area and stalls somewhere near or just south of the Ohio
River. Much of tonight looks to be relatively quiet as a result.

Outside of thunderstorms, breezy conditions are expected today as momentum
transfer shows potential for frequent gusts of 25-35 MPH during the
daytime hours, weakening in typical diurnal fashion this evening.

Temperatures will push well into the 70s again today across the
area if not near or above the 80 degree mark again, depending upon
eventual coverage and evolution of precip. In the wake of the
front tonight, lows are likely to see a significant gradient from
north to south across the area, with northern portions of the area
down into the 40s, while southern portions drop only in the mid to
upper 50s.

&&

.LONG TERM (Wednesday through Monday)...
Issued at 322 AM EDT Tue Apr 29 2025

The cold front will stall across Kentucky Wednesday morning then
lifts back north late Wednesday into Thursday in response to low
pressure lifting out of the southern Plains . The low will
strengthen as it tracks into the Great Lakes by late Thursday and
finally force the cold front to the east of the region by early
Friday. A trailing upper level wave will move across the region on
Friday with additional scattered showers before high pressure
builds in. After a brief cooldown into the first part of the
weekend as an upper trough passes through...ridging aloft and at
the surface will bring a return to warm and dry weather through
the first part of next week.

Wednesday through Thursday Night

After a largely dry start on Wednesday courtesy of high pressure
passing by to the north over the Great Lakes, periodic chances for
showers and storms will resume as the front lifts back north
across the entire forecast area into early Thursday. Scattered
strong convection is possible in the vicinity of the northward
moving front Wednesday afternoon across the southern half of the
forecast area. The arrival of stronger 850mb flow Wednesday night
will increase convective coverage and enable deeper low level
moisture to return into central Indiana. Strengthening low
pressure will track from the Missouri Valley into the Great Lakes
Thursday with a noted increase in 850mb flow late day immediately
ahead of the approaching cold front. MLCAPEs between 1000-1500
j/kg along with an increase in storm relative helicity levels
within the near surface layer support the potential for better
organized convection ahead of the boundary despite modest cloud
cover anticipated for much of the day Thursday. Signs are there
for at least a low end threat for severe weather late afternoon
and evening with damaging winds as the primary concern. Rain will
diminish Thursday night as the cold front sweeps east of the
region.

Friday through Monday

A trailing upper wave swing across the area Friday afternoon with
hints of a surface trough in the areas as well. With model
soundings showing steepening lapse rates developing underneath the
mid level cold pool...there is potential for scattered showers
during peak heating in the afternoon and early evening. The
arrival of high pressure Friday night will set the stage for a dry
weekend with mainly clear skies. Highs will likely only be in the
60s for much of the area Friday and Saturday as an upper level
trough passes through. The center of the high will move into the
Mid Atlantic Saturday night then off the coast Sunday enabling
return southerly flow into the Ohio Valley set to last into the
first part of next week. Highs will be back near 70 Sunday then
rise to near 80 early next week and possibly warmer than that
beyond.

&&

.AVIATION (12Z TAF Issuance)...
Issued at 736 AM EDT Tue Apr 29 2025

Impacts:

- Wind gusts at times around 30KT today

- Showers and thunderstorms at times today, especially during the
  midday to afternoon hours

- Potential MVFR ceilings very late in the period at BMG

Discussion:

VFR conditions are expected throughout the period, with the exception of
transient periods of restrictions in any showers or thunderstorms
that happen to impact a terminal, and possibly at BMG late in the
period with proximity to the stalled boundary to our south. Cloud
cover continues to increase as a frontal system approaches the
area, and a few light showers and isolated storms are present to
our west at this time. The cold front is expected to pass through
the area this afternoon, with showers and thunderstorms along and
ahead of it. Uncertainty remains regarding exact timing and
placement of these storms and will be dealt with accordingly in
the individual TAFs, but the highest chances for convection
continue to be midday into the afternoon hours. The organized
thunderstorm threat also appears to be highest with southern
extent per the latest high resolution model guidance. This threat
will end with the passage of the front.

Onset of boundary layer mixing this morning will result inbreezy
conditions, with gusts at times approaching or even exceeding
30KT.

Surface winds will be southerly or southwesterly through much of the day
today, becoming westerly after frontal passage and then
continuing to veer more northwesterly and northerly late in the
TAF period.

&&

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

$$

SHORT TERM...Nield
LONG TERM...Nield
AVIATION...Nield

INDY SEVEN DAY FORECAST
Today: Showers and storms. Storms could be produce damaging wind gusts or large hail. High 79.

Tonight: Scattered showers and storms in the evening. Low 50.

Wednesday: Partly to mostly cloudy. Later afternoon shower possible. High 71.

Wednesday Night: Scattered showers. Low 62.

Thursday: Showers and storms. Some storms could produce large hail and damaging winds. High 75.

Thursday Night: Showers and storms. Low 56.

Friday: Mostly cloudy. Scattered showers. High 68.

Friday Night: Periods of showers. Low 46.

Saturday: Mostly cloudy, with morning shower chances. High 62.

Saturday Night: Mostly clear. Low 43.

Sunday: Mostly sunny. High 70.

Sunday Night: Clear. Low 48.

Monday: Sunny. High 76.

NWS CHARTS FOR TODAY/TONIGHT