textproduct: Indianapolis

KEY MESSAGES

- Wind Advisory 5AM Through 8PM Friday

- Showers and storms return Sunday, low end chance for severe weather

- Much colder air early next week, lows in the teens Tuesday

SHORT TERM (Today through Friday)

Issued at 211 AM EDT Thu Mar 12 2026

Today Through Friday.

The primary focus in the short will be the potential high wind event late tonight into Friday. The cold front that brought convection Wednesday has now fully exited central Indiana with strong CAA ongoing. Upstream satellite and surface obs show a broad area of mid- level stratus beneath a strengthening subsidence inversion. Expect these clouds to linger through much of the night before high pressure building in from the west allows for some clearing toward dawn.

By late tonight, a highly dynamic northern stream shortwave will dive out of central Canada, deepening a sub-990mb surface low as it tracks across the northern Great Lakes. While the best moisture and forcing remain displaced to our north, the associated pressure gradient and low-level wind field are impressive. Forecast soundings for Friday morning show a 55-65kt LLJ at 850mb overspread by steepening low-level lapse rates as the diurnal cycle begins. Efficient mixing within the post-frontal environment even in a non- typical diurnal timeframe will likely tap into these higher momentum winds. Deterministic GFS and some of the higher resolution models remain in good agreement of surface gusts exceeding 40-45 mph across much of central Indiana, with potential for localized 50+ mph gusts across the northern tier of counties. These winds will be strongest during the pre-dawn to morning hours with the strongest gusts coming to an end by mid to late afternoon as the pressure gradients and associated LLJ begin to relax.

Based on coordination with neighbors, will be issuing a Wind Advisory for much of central Indiana with the potential that some of the northern portion could get upgraded to a High Wind Warning. There will be at least a low-end chance for a few rain showers late tonight across the northern counties, but that threat is low with the main focus being on the wind threat.

LONG TERM (Friday Night through Wednesday)

Issued at 211 AM EDT Thu Mar 12 2026

Friday night Through Late Sunday.

Surface high pressure briefly drifts across the Ohio Valley Saturday, providing a transient period of tranquil weather. However, the pattern remains highly progressive as a vigorous longwave trough begins to organize over the Rockies. There may be a few showers Saturday night with weak isentropic lift, though the bulk of the initial saturation will be fighting a lingering dry layer.

Focus for the next round of precipitation centers on Sunday into early Monday. Global ensembles depict a deepening surface reflection moving into the Great Lakes by Sunday evening, dragging a strong cold front into the region. Guidance continues to suggest a narrow but high-quality moisture tongue with dewpoints surging back into the 50s or even low 60s ahead of the boundary. Given the strength of the kinematics with 0-6km bulk shear values likely exceeding 50kts we will need to monitor for the severe threat Sunday afternoon and evening, provided the warm sector can sufficiently destabilize. Surface temperatures are expected to rise well into the 60s and potentially into the 70s, but poor lapse rates currently look to limit instability values to around 500 J/kg. Heavy rain also remains a concern as PWATs climb toward 1.25 inches, which is well above the 90th percentile for mid-March.

Monday Through Wednesday.

Behind this system, a significant airmass change is on the horizon. A deep polar lobe is progged to settle over eastern Canada, opening the gates for a modified Arctic airmass to spill into the Midwest with a 30+ degree drop likely Sunday night. Light snow accumulations are possible on the backend of the system Sunday night, but models often overdo this backend snow as the lift usually exits ahead of the arrival of colder air.

850mb temperatures are forecast to plummet to -12C to -15C by Monday morning. This will result in high temperatures on Monday and Tuesday struggling to reach the freezing mark, a stark contrast to the preceding weekend. Scattered snow showers or flurries are possible into the day on Monday in the cold advection regime, though accumulation is not expected at this time due to the lack of deeper moisture.

AVIATION (06Z TAF Issuance)

Issued at 111 AM EDT Thu Mar 12 2026

Impacts:

- A few westerly gusts to 20kts this afternoon at IND and LAF - Wind shift to the southwest after 00Z, gusts up to 40kts after 08Z

Discussion:

VFR conditions expected through the TAF period with low VFR cigs clearing towards 10Z. Mostly clear skies with only passing cirrus is expected through much of the day before higher level clouds begin to fill back in after 00Z. Northwesterly winds will gradually become more westerly towards daybreak with a few gusts up to 20kts at IND and LAF through the afternoon hours. These gusts will briefly come to an end during the early overnight tonight with winds further shifting to more southerly to southwesterly. Gusts upwards of 40kts will be possible at times at IND, LAF, and HUF after 09Z into much of Friday.

IND WATCHES/WARNINGS/ADVISORIES

Wind Advisory from 5 AM to 8 PM EDT Friday for INZ021-028>031- 035>049-051>057-060>065.