textproduct: Indianapolis

KEY MESSAGES

- Chances for rain and storms returns for much of the upcoming week with a risk for severe weather focused late Tuesday into Wednesday

- Warm temperatures expected all next week with multiple days in the lower to mid 80s. Record temperatures are possible.

MESOSCALE UPDATE

Issued at 737 PM EDT Sun Apr 12 2026

A potent convectively-augmented vort max is passing to our northwest. Satellite imagery reveals a comma-shaped cloud shield over southeastern Iowa, marking its current location as of 7pm. This feature is expected to continue northeastward into the Great Lakes tonight. The vort max will help intensify a nocturnal low-level jet this evening, which is modeled to strengthen to between 55-65 knots in the 925-850mb layer.

Warm air advection ahead of the vort max is strong, and temperatures have risen to near 80 across much of the area. Despite this, instability is absent as shown by recent ACARS soundings out of IND. One thing to note, however, is a deep inverted V signature below 800mb which signifies a deep mixed layer. Though instability is very low, guidance shows sufficient moisture and forcing for at least some shower activity overnight. Model soundings retain the inverted V signature through the night within the air mass preceding the vort max.

Since the deep mixed layer contains the strong low-level jet, there is a chance that rain showers tonight could efficiently mix some of this momentum downward. Although the probability is low, it cannot be ruled out that wind gusts nearing severe thunderstorm intensity occur (~60mph). Conditions and upstream observations will need to be monitored closely as we head into the night. Additionally, recent dry conditions may allow for patchy blowing dust which may reduce visibility at times. Blowing dust is more likely in rural areas where farm fields have been recently plowed.

DISCUSSION (This evening through Sunday)

Issued at 204 PM EDT Sun Apr 12 2026

Rest of This Afternoon through Monday Night...

Breezy and warm conditions will continue this afternoon under partly to mostly cloudy skies. Tonight, an upper wave and upper jet will move through, providing some lift. The best lift looks to be northwest of the area, closer to the wave itself. Overall moisture isn't great, but it will be enough for some scattered to perhaps numerous showers to move through tonight into perhaps Monday morning. Will go chance category to low end likely category PoPs.

For Monday afternoon and Monday night, central Indiana will remain in southwest flow aloft. Weak upper impulses may trigger an isolated shower or storm, so will have slight chance PoPs at times.

There will be enough instability for the potential of isolated thunderstorms, but nothing strong or severe is expected.

Lows tonight will be in the 60s with the clouds and showers around. Highs on Monday will be in the upper 70s to lower 80s, with readings depending somewhat on how fast clouds break up.

Tuesday through Friday...

The upper pattern will continue to be upper troughing across the western USA with upper ridging over the far southeastern USA. Central Indiana will be in southwest flow aloft. A surface front will initially be well west and north of the area, but it will get closer by Friday. Southwesterly flow will keep temperatures well above normal and keep decent moisture in the area.

An initial round of upper energy will move through around Tuesday, generating showers and thunderstorms especially near the front to the west and north of the area. Parameters indicate that strong to severe storms are possible, mainly west of central Indiana. However, some of these may get into the far northern and northwestern portions of the area. Locally heavy rain will be a threat.

A stronger upper wave will move through Wednesday/Wednesday night. This may produce more widespread rain to the area, but the severe threat looks to remain west, closer to the surface front. Locally heavy rain will be a threat again.

The upper wave may push the surface front closer to the area in its wake, which may keep the threat of rain around at times into Friday. However, lack of upper forcing will keep the chances lower.

Saturday and Sunday...

The upper trough will move into the area next weekend and push the surface front through. This will result in more showers and storms. Severe storms may occur depending on timing of the front, but confidence is low in details. Much cooler air will move in behind the front for Sunday.

AVIATION (00Z TAF Issuance)

Issued at 737 PM EDT Sun Apr 12 2026

Impacts:

- Wind gusts of 25 to 30kt this evening - Low level wind shear developing tonight - Scattered showers mainly late this evening into the overnight - Strong gusts between 30-40kt possible with rain showers - MVFR ceilings possible late tonight into Monday

Discussion:

A potent mid-level system passing to our northwest has allowed strong southerly flow to develop over Indiana. This has allowed for wind gusts between 25-30kt today, which should diminish as night falls. As surface winds diminish, a low-level jet is anticipated to strengthen after 02z. Guidance shows between 55-65kt as low as 2000ft agl, which should lead to low-level wind shear of nearly 50kt at times. Wind shear may not persist the entire night, and should decrease as the aforementioned mid-level system passes by.

Scattered showers and perhaps a thunderstorm may also accompany this system. Given the strong low-level flow just off the surface, these showers may be able to produce strong wind gusts despite being relatively weak. Wind gusts to 35kt have been added to the Prob30 group tonight.

Rain showers come to an end by 10z with lingering MVFR ceilings possible into the morning hours Monday. Low clouds may persist while oscillating between SCT and BKN throughout the day Monday. South- southwest wind gusts between 20-25kt return Monday afternoon.

CLIMATE

Issued at 204 PM EDT Sun Apr 12 2026

Within the setup described in the discussion above, near record temperatures are possible at times this week, mainly Tuesday, Wednesday, and Friday. Whether readings get close depends on sky cover and any rain staying away, which keeps confidence lower at this time.

Current deterministic model runs are cooler than the records, but the potential exists to get within a few degrees if everything lines up. On Tuesday April 14, Indy's record high is 85, set in 1883. Indy's record high for Wednesday is 84, set in 2002. On Friday April 17, Indy's record high is 87, set in 1896.

Record high minimum temperatures are also in play at times given the warm and relatively humid airmass. The first opportunity for this comes Monday, when the record high minimum at Indy is 63, set in 2014 and tied in 2018. At the moment, the forecast is for tying that number.

IND WATCHES/WARNINGS/ADVISORIES

None.