textproduct: Indianapolis

KEY MESSAGES

- Dry with above normal temperatures through at least Friday, afternoon highs in the 70s

- Patchy fog may occur in low lying areas late night/early mornings

- Showers may return for the Halloween weekend and/or next week

DISCUSSION (Today through Sunday)

Issued at 329 AM EDT Mon Oct 26 2026

Rather complex yet quasi-stagnant synoptic pattern over North America throughout this weekend will feature broad cut-off H500 trough over Pacific Northwest/BC and more progressive but overall retracted polar waves from interior Canada to New England. Between these northern features upper ridging will attempt to establish over the majority of CONUS...yet will be dampened by at least a couple weaknesses lifting from southern High Plains to Great Lakes. These less intense waves will combine with broadening surface high pressure over the eastern US to advect fetch of Gulf moisture from southern Plains to near IA/IL.

This will translate to much of the same conditions recently seen across central Indiana...rain-free weather under generally stacked high pressure through Wednesday...as readings ranging from the 40s/ around 50F to afternoons peaking near 70-75F. Remnant surface high centered to our southeast will be replaced by stronger air mass crossing Ontario into Tuesday...that will ultimately set up in the same general proximity over the country's eastern third by Tuesday night, albeit now with a seasonably strong gradient. Therefore expect typical October breeze finally returning to central Indiana for Wednesday/Thursday afternoons...when south-southwesterly gusts to 10-20 mph will yield highs in the mid-/upper 70s, respectively. (Thursday's record high at Indianapolis is 81, 1922). Considerable cloudiness also expected late Tuesday-early Wednesday from first, smaller southern wave lifting to our west...with high confidence dry column will continue dry conditions.

Second, broader weakness lifting across region this weekend will bring moderate certainty in scattered/numerous rain showers... assuming northern stream wave dives far enough south near Cape Cod to provide downstream confluence and prolong advection of better Gulf moisture north of the Ohio Valley around the Saturday night to Sunday timeframe. Timing of onset of showers would likely be around Halloween evening...although more organized rain coverage would be favored towards Sunday. Indianapolis is progged for a streak of 13 consecutive days with highs in the 70s through November 1st. The normal max/min at Indianapolis through the forecast period falls from 61/42 today...to 58/40 on Sunday.

AVIATION (12Z TAF Issuance)

Issued at 635 AM EDT Mon Oct 26 2026

Impacts:

- MVFR/worse visibility possible amid ground fog 09-13Z this morning at outlying terminals - Light winds likely veering at KLAF to northerly this afternoon

Discussion:

Patchy ground fog will likely bring quasi-transient MVFR, and possibly brief IFR mainly after 09Z...and before 13Z this morning at KLAF/KHUF. VFR is expected to otherwise prevail near central Indiana terminals through at least 06Z Tuesday morning.

Stacked ridging over southeastern third of the CONUS will shift southward as stronger surface high slides across Canada border/ Great Lakes through the TAF period. This will bring increased coverage of high/mid cloud today through the early evening, especially at KLAF.

Weak gradient around fading surface high pressure centered near the southern Appalachians will maintain very light winds. Flow at most terminals is expected to veer within 180-250 degrees through 20Z today, sustained under 7KT. Subtle boundary ahead of northern air mass will likely pass KLAF, veering winds through midday to more northerly by 18Z...sustained up to 7KT.

IND WATCHES/WARNINGS/ADVISORIES

None.