textproduct: Indianapolis

KEY MESSAGES

- Dry through Saturday with most days at near to above normal temperatures under the influence of high pressure

- Fire weather conditions will require monitoring as several afternoons will likely feature minimum RH values well down into the 30s if not lower at times

- Rain chances return beginning early Sunday

DISCUSSION (This evening through Tuesday)

Issued at 248 PM EDT Tue Oct 6 2026

Surface high pressure has slid to our east allowing winds to become southeasterly. With an added southerly component to the wind field, warm air advection has commenced. A gradual warming trend will continue through tomorrow. High temperatures may climb into the 80s on Wednesday.

A broad trough skirts to our north late Wednesday into Thursday with an associated surface low over the Hudson Bay. Though displaced well to our north, this low will drag a surface cold front through the Ohio River Valley. Cold air advection takes hold on Thursday with a cool-down anticipated. Highs dip back into the low 70s both Thursday and Friday; lows once again into the 40s. Patchy fog is possible during the overnights with efficient radiational cooling.

The pattern repeats with surface high pressure arriving and then passing to our northeast on Friday. Winds regain a southeasterly component allowing gradual warming to begin again. Highs climbing into the upper 70s to near 80 are possible this weekend. Clear skies aside from occasional cirrus are expected through Saturday.

Dry conditions combined with daytime relative humidity values near 30 percent may allow for increased fire weather potential through Saturday. Surface wind speeds are likely to remain light, thus mitigating the threat.

SUNDAY ONWARD

Warming will continue into Sunday depending on whether a disturbance over the Gulf lifts north or northeastward. Guidance is beginning to hone in on the idea of tropical development over the southwestern Gulf and taking the resulting system northward in conjunction with a cut off upper-level low over Texas. This is a highly uncertain situation, since multiple factors are in play that have yet to develop.

First, the tropical cyclone may not develop at all and simply remain a tropical wave / moisture plume. Second, the upper-level low over Texas fails to materialize or is too fast/slow. Any combination of these may dramatically affect the outcome for Indiana. Recent model trends have been towards the idea of tropical development with an eventual merger between the upper low and tropical cyclone/remnants.

We can boil it down into two scenarios, however. One where it rains and one where it does not. Should moisture lift northward into Indiana, whether associated with a weak or strong low, then temperatures are likely to be suppressed and rainfall chances high. Should the system fail to develop or miss entirely, then above- average warmth continues into the new week. These systems are within a larger-scale ridge, so avoiding any precipitation will lead to a continued warming trend.

AVIATION (00Z TAF Issuance)

Issued at 556 PM EDT Tue Oct 6 2026

Impacts:

- Shallow ground fog possible again late tonight, otherwise VFR. - Periodic gusts near 20kts possible Wednesday afternoon

Discussion:

Strong high pressure over the Great Lakes and Ontario will continue to dominate weather across the region through tonight. The high will shift to the eastern Great Lakes on Wednesday with a weak frontal boundary dropping through the area. With deep subsidence lingering across the area...only a subtle increase in cirrus will signal the frontal passage along with a shift in winds to westerly. Periodic gusts to near 20kts is possible Wednesday afternoon.

Some patchy ground fog cannot be ruled out predawn Wednesday but little impact is expected from this should it occur.

IND WATCHES/WARNINGS/ADVISORIES

None.