textproduct: Indianapolis

KEY MESSAGES

- Cloudy this evening

- Chances for flurries or freezing drizzle late tonight and Sunday morning. Minimal measurable precipitation expected.

- Additional rain chances are expected Tuesday night through Wednesday...with light snow possible Thursday

SHORT TERM (This evening through Sunday)

Issued at 258 PM EST Sat Dec 6 2025

Surface analysis early this afternoon shows a frontal boundary across NRN Illinois and NRN MO. The front was extending from low pressure found over South Dakota. Westerly flow was in place across Indiana amid broad cyclonic flow. Un-organized high pressure was in place across the deep south. GOES19 shows stratus across Indiana. Aloft, broad and cold cyclonic flow was in place across the much of the northern half of the country, due to deep and large low pressure over Hudson Bay. Water vapor showed Pacific moisture flowing over the Rockies and Plains states.

Tonight and Sunday morning...

A weak short wave within the flow aloft is expected to pass across Indiana and the Ohio valley tonight. Forcing appears quite limited with this feature. Meanwhile within the lower levels the weak frontal boundary to the north is expected to sag southward across Central Indiana as the surface low over the South Dakota approaches, taking a south southeast trajectory. Models suggest plenty of dry air continues to be available this evening, but as the front and low arrive in the area overnight, forecast soundings suggest top down saturation. However, the lower levels appear to fail to become completely saturated. Moisture is limited as only Pacific moisture is available due to the blocking high to the south. Thus due to the limited forcing and moisture along with incomplete lower level saturation, the ongoing forecast trend for some light freezing drizzle or flurries, minimally measurable, appears on track. Best window for this precipitation appears to be late tonight, after 08Z- 10Z through mid morning Sunday. It is during this window that the best forcing will pass as the surface low pushes across southern Illinois and KY.

Regarding temperatures clouds and minimal temperature advection will allow for minimal temperature drops. Lows should fall to the upper 20s to around 30.

Sunday afternoon...

In the wake of the passed surface low and weak upper short wave subsidence appears to begin as forecast soundings begin to trend toward a top-down drying. Lower level moisture looks to linger through much of the day. A strong area of high pressure over the upper midwest will then begin to settle across Indiana on Sunday afternoon, leading to ongoing cold air advection and cold north winds.

Thus we should expect cloudy skies on Sunday afternoon with temperatures mainly steady in the middle 30s. Colder lows will be expected on Sunday night.

LONG TERM (Sunday night through Saturday)

Issued at 258 PM EST Sat Dec 6 2025

Sunday night through Tuesday...

Broad zonal trough occupying North America...that has brought recent light to significant snowfalls, and a couple very cold mornings for the northern Midwest courtesy its lingering snow pack...will allow at least a brief respite through the early workweek. Quasi-split upper flow facilitated by embedded, yet offset short waves concurrently tracking over southeastern Canada and the Mid South...will allow surface high pressure to drift east across the Great Lakes and Midwest through Monday...this, when coupled with a pause in upstream energy, will promote overall dry conditions through Tuesday. Although can not rule out very light mixed precipitation, trending from rain to flurries, lingering Sunday night over far southern zones.

Monday will be the visually nicer day with mostly clear skies for most locations, albeit with temperatures climbing from the teens into the 20s...with light breezes dropping wind chills down to around zero north of I-70 early in the day. Deepening low pressure across the north-central CONUS will provide a southern Chinook starting late Monday night, with gusts to around 20 mph only allowing readings to fall about 10 degrees, yet producing wind chills down into the single digits for many northern counties.

South-southwesterly wind gusts to increase to 20-30 mph Tuesday as 990 mb surface low spins into the Upper Midwest...bringing a long- awaited return to low 40s readings for much of the local region under considerable cloudiness. If Indianapolis does not exceed 39 degrees through Tuesday...it will tie the second-longest November- early December period held below 40*F (13 days, last recorded in 1903).

Tuesday night through Saturday...

Mainly light precipitation associated with the northern system's cold frontal passage is expected Tuesday night through at least Wednesday with chances increasing from north to south as the supporting vort's tail plunges across the Midwest Wednesday. Rain precip type is expected for most of this lighter episode, with mixing or changeover to light snow/flurries possible as the system exits east. Attention should be paid to ground temperatures north of I-70 Tuesday night into Wednesday which may be subfreezing to start despite air temps approaching 40F.

A transition back to the colder pattern favoring snow/mixed precipitation types will occur around the Wednesday night timeframe, with heights dropping ahead of the next, more southern short wave, that should strengthen while crossing the central US Thursday. Some model disagreement on organization/intensity of corresponding surface low...but appears so far a good shot of light accumulating snowfall for much of the region Thursday into Thursday night...with rain possibly mixing over southern zones. Both snow/mix line and amount of precipitation may be mostly dependent on proximity of downstream H500 trough over Quebec, whose wobbling will influence track and tilt of the central US system.

Workweek to most likely end with a few flurries amid brisk WNW surface flow holding readings below freezing and wind chills between zero and 20 degrees. However, bigger story will be the potential bitter cold to follow through the weekend...with arctic air under 520 dm H500 low capable of producing widespread single digits at night, mainly teens maximums....and possibly criteria wind chill values.

AVIATION (18Z TAF Issuance)

Issued at 1217 PM EST Sat Dec 6 2025

Impacts:

- MVFR Cigs expected to become IFR during the TAF period.

- Ceilings improving this afternoon and evening near HUF/BMG.

Discussion:

GOES19 shows stratus deck with MVFR cigs across the TAF sites. Clearing was found over southern IL along with a pocket of clearing over northern Indiana. These features may impact LAF...HUF and BMG briefly late this afternoon.

A slow moving cold front will slowly push across Central Indiana late this afternoon and evening. Time heights suggest saturation within the lower levels overnight as the front lingers with weak and limited forcing. This may result in some FZDZ or flurries across the TAf sites, but the main impact will be continue MVFR to IFR cigs.

IFR cigs will continue on Sunday morning in the wake of the front as lower level moisture lingers across Indiana.

IND WATCHES/WARNINGS/ADVISORIES

None.