textproduct: Indianapolis

KEY MESSAGES

- Winter Storm Warning/Advisory for much of central Indiana

- Snow amounts of 4-6 inches in the Warning area, 1-4 in the Advisory

- Additional snow chances Monday night into Tuesday

- Wind chills in the teens at night through most of next week

FORECAST UPDATE

Issued at 1002 PM EST Fri Nov 28 2025

No changes were made to the forecast through daybreak Saturday as it remains on track. Current surface analysis and observations show mostly clear skies across central Indiana with high pressure still in control. Expect this surface high to continue shifting east overnight while a developing winter storm over the Plains begins to approach the region towards daybreak. Residual low-level dry air should help delay any snowfall from the approaching system until after daybreak. Specific details on expected impacts Saturday can be found in the short term discussion below.

Clear skies and light winds aided by surface high pressure has helped temperatures cool quickly during the evening. Current observations show most areas have already fallen into the low-mid 20s. Increasing clouds later tonight will limit further cooling, but look for lows to generally range from the upper teens to low 20s.

SHORT TERM (This evening through Saturday)

Issued at 155 PM EST Fri Nov 28 2025

Tonight.

High clouds will begin to move in as early as the evening hours tonight ahead of the arrival of the first significant winter storm of the season. With the dry near surface conditions, expect to see temperatures quickly drop this evening before beginning to level out as the clouds move in. Overnight lows will likely end up in the low 20s which will help to prime the surface for accumulating snow Saturday morning into afternoon.

There will be a weak band of snow moving northeast during the late overnight and early morning hours across the northwestern portions of central Indiana, but much of this may not reach the ground due to the very light nature, dry low levels, and the fact that the better isentropic lift doesn't arrive until later into the morning.

Saturday and Saturday Night.

The main focus for the short term period will be tracking the accumulating snow threat for Saturday. Synoptically, an upper level shortwave will push southeast out of the Northern Rockies with weak southeasterly surface flow ahead of the arrival of the low. As the low nears, both surface and LLJ winds will begin to ramp up with the strongest winds aloft expected during the evening hours. The low track continues to look well to the northwest of central Indiana with the main question being the strength of the WAA and its impacts to surface temperatures and any warm nose aloft.

Some of the higher resolution modeling is beginning to pick up on what we've been discussing over the last few days with stronger WAA in the area southeast of the low helping to bring snow ratios lower and an earlier transition to rain. The positive snow depth change among even the more aggressive models remains much more modest at 4- 6 inches which makes sense in a marginal thermodynamic situation as temperatures will hover around freezing.

Travel impacts look increasingly likely during the afternoon and evening hours Saturday. Overall confidence is fairly high in the Covington to Muncie and points to the northwest area as there is good model agreement in mostly snow. Reasonable expectations for that area at this time looks to be 4-7 inches. Further south along the I-70 corridor remains the area of greatest uncertainty with a wider range of outcomes. We're leaning towards the warmer solution with a faster changeover to rain and lower snow ratios which would put much of the area in a 1-3 or 2-4 range with the lower numbers on the southern side and higher to the north. Near Indy there will likely be a fairly stark difference between the northern and southern suburbs. Further south total snowfall of 0.5-2 inches looks reasonable, but again we are leaning towards the lower-end scenario. Much of the impacts will be over a 6-8 hour window beginning sometime in the early afternoon hours with impacts lessening towards midnight as temperatures warm.

During the overnight, rain will gradually become the more predominant precipitation type, especially along and south of I-70. This will also lead to some melting of the fallen snow and may make it difficult to get accurate storm totals as folks measure in the morning.

For headlines we've upgraded the Winter Storm Watch to a Warning across the northwest where we have the overall greatest confidence with the understanding that some of the areas may not reach the typical 5 inch snow criteria. With the holiday weekend travel and the potential for the higher end amounts. We've upgraded the southern extent of the Watch to an Advisory where we have lower confidence on totals with the potential that the far northern ends may get close to 5 inches, but the southern extent has a low threat. Then to the south of the original watch we have also included much of south central Indiana where we expect amounts of at least 2 inches.

LONG TERM (Saturday night through Friday)

Issued at 155 PM EST Fri Nov 28 2025

Sunday through Friday...

Overall pattern through the upcoming extended periods remains progressive with a series of systems that will bring precipitation to the Ohio Valley, along with reinforcing shots of cold air advection. This could result in additional periods where precipitation falls as snow, with some accumulations possible mainly for the Tuesday period.

Sunday...Rapid departure to the surface low, quickly exiting the region to the northeast. In its wake will be strong cold air advection from northwesterly winds, still producing a tight pressure gradient and translating into a blustery day and falling temperatures from the potent 850mb thermal trough driving south. Temps will struggle once the frontal boundary arrives at the surface with generally temps in the 20s by midday and wind chill values in the teens. The deeper moisture will peel off to the northeast, but enough moisture could linger coupled with some vertical ascent to allow some flurries or light snow to be scattered across Central Indiana Sun through midday. The surface ridge will continue to slide southeast Sun evening, which will help to reduce the isallobaric gradient allowing winds to diminish with skies likely becoming mostly clear. This wills the stage for a free-fall to temperatures, and with a fresh snowfall for many locations north of Indy, expect lows to easily radiate into the single digits to lower teens.

Monday into Tuesday... Monday is the benign weather day with surface ridging overhead providing a cold/dry day for Central Indiana and minimal gradient allowing winds to be light and variable. But as mentioned earlier the progressive flow to the upper level jet will quickly usher the surface ridge to the east by Mon ngt. A potent trough axis will be digging south through the plains, as surface flow starts to turn southerly across Indiana. Moistening parcels with steadily strengthening isentropic lift will present some precip type challenges early Tue morning through the day Tue. The wildcard is with how deep the trough axis slides south, which could easily shift the track of the next system further south/southeast before it congeals into a more robust synoptic system. But at the present time guidance still indicates a large precip footprint across Indiana and temps likely cool enough to have parcels present as snow/dendrites, but still possible some partial melting due to the increased isentropic ascent and easily some rain or possible freezing rain enters the setup potential. The key for how Tue unfolds and the precip type will hinge on the depth of the cold air and forcing aloft.

Wednesday through Friday... The continued progressive flow to the upper level pattern remains through the end of next week, with the surface trough quickly sliding east of the region on Wed. This will result in weak ridging skirting the Ohio Valley while the 500mb pattern remains flat/zonal. The one bright spot for the second half of the upcoming week is that guidance continues to lean towards a scenario that the ridging will expand across the region. This will lead to perhaps a second dry day, although temperatures continue to be sub-seasonal but with lighter winds it will likely be more tolerable. Friday ensembles continue to demonstrate ridging pushing east and a return flow, southerly, component to winds. This will likely allow warm air advection back into the region to close the week.

AVIATION (06Z TAF Issuance)

Issued at 1256 AM EST Sat Nov 29 2025

Impacts:

- MVFR VIS by 13Z-15Z at KLAF/KHUF...with MVFR/VFR VIS at KIND/KBMG through 22Z - IFR VIS from steadier snow...likely at KLAF after 19Z...likely at KHUF, possible at times at KIND after 22Z - Ceilings overall deteriorating from west to east...with MVFR likely for most sites by 22Z...and IFR following by 02Z - Winds veering from SE to S after 20Z, while gusting up to 20-29KT

Discussion:

VFR conditions and calm/light southeasterly winds to prevail overnight ahead of winter storm approaching from west. -SN/SN to overspread KLAF/KHUF by 15Z...with more VCSH/periods of -SN for KIND/KBMG during 15Z-22Z. Overall MVFR conditions expected in snow through midday, although chances of IFR visibility in snow increasing into the afternoon, especially at KLAF/KHUF. Ceilings to lead flight condition reductions after about 00Z...concurrent with snow mixing with and changing over to -RA from south to north,,,except at KLAF where snow to remain predominant precipitation type through at least 03Z. IFR ceilings to prevail over most terminals by 02Z.

Southeasterly breezes to increase during the day, with gusts to 22 to 26KT after 20Z. Winds to further increase tonight as parent storm deepens while crossing southern Michigan...with headings veering to southerly by 03Z while gusts up to 23-29KT.

IND WATCHES/WARNINGS/ADVISORIES

Winter Storm Warning from 7 AM this morning to 10 AM EST Sunday for INZ021-028>031-035>041-043>047.

Winter Weather Advisory from 7 AM this morning to 10 AM EST Sunday for INZ042-048-049-051>057-060>065-067.