textproduct: Indianapolis

KEY MESSAGES

- Slick/icy spots early this morning as temperatures drop quickly to well below freezing.

- Snow showers at times into the early morning hours with accumulations up a half inch possible.

- Wind chills near zero degrees possible this morning.

- Moderating pattern Monday through Christmas Day with well above normal temperatures most likely for the late week

FORECAST UPDATE

Issued at 932 AM EST Fri Dec 19 2025

Snow shower coverage has gradually diminished this morning to scattered flurries with the back edge of the stratus already approaching the Indiana border. Winds continued to remain gusty with single digit and subzero wind chills. 14Z temps ranged from the teens north to mid 20s south.

Flurries will end prior to noon with a gradual decrease in stratus into the afternoon as a high pressure ridge builds in. Wind gusts will gradually drop back through the course of the day but brisk conditions will persist with gusts not likely to drop below 20mph until late day. Despite increasing sunshine this afternoon...highs will only range from the mid 20s north to mid 30s in the lower Wabash Valley.

Zone and grid updates out.

SHORT TERM (Today and tonight)

Issued at 319 AM EST Fri Dec 19 2025

An arctic front passed through central Indiana between 04-07z, with a quick drop in temperatures and changeover to snow. Snow has been fairly steady for the past hour or two with up to half an inch in some areas. Snow should become more showery as large-scale forcing lifts northeastward, leaving only shallow instability in its place. A few heavier snow showers are possible but these will be widely scattered. An additional few tenths to a half an inch could be possible especially under one of these heavier bands. All snow shower activity should come to an end around 12z, though stratus could linger through most of the day.

Temperatures in the low 20s are already being reported in northwestern portions of our area as of 07z, with teens upstream across Illinois. Continued strong cold air advection will bring most of central Indiana into the low 20s/teens by morning. Wind chills near zero degrees are expected. Additionally, the combination of rapidly cooling temperatures and snow should will lead to slick/icy spots on area roadways. A Special Weather Statement has been issued to address this possibility.

Winds are currently out of the west-northwest between 15-25kt gusting to 30-40kt. A gradual shift to more westerly direction is anticipated along with a slow decrease in speeds/gustiness. Winds decrease more quickly after about 21z as surface ridging advances eastward into Indiana. A period of light and variable winds is possible by sunset, which may allow for a quick drop in temperature early in the night. However, winds quickly reverse and become southeasterly as surface ridging passes east by around 06z. Southeasterly winds increase to between 10-15kt as the MSLP gradient tightens in advance of a trough over the northern Plains. Therefore, lows probably occur early in the night before warming through the 20s as morning approaches.

LONG TERM (Saturday through Thursday)

Issued at 319 AM EST Fri Dec 19 2025

The so-far early winter will continue its proactive trend...as the long term period oversees a passive regime change into an early January thaw. An overall upper zonal pattern will shift from late weekend troughiness to what should be a broad subtropical ridge building north over much of the CONUS, and bringing anomalously mild conditions to the local region by Christmas Day.

The short term's arctic surface high pressure will already be positioned along the eastern US by Saturday morning, as the next strong surface low begins to cross Ontario. Resultant robust southerly wind gusts will provide moderation, with most areas climbing 20-25 degrees, and low 50s expected along the Ohio Valley. Weaker cold frontal zone extending south of the Ontario system will pass Indiana late Saturday/Saturday night without precipitation... with the subsequent polar ridge maintaining seasonably cold overnights through the remaining weekend, and another chillier day Sunday where 30s will be the rule despite slackening northwest breezes and ample sunshine.

The workweek will see broad surface high pressure expand over much of the eastern half of North America, which will most often promote moderate southerly to southwesterly breezes over the Hoosier state. Steady moderation is expected to bring at least low 50s to most zones by Tuesday...perhaps 60 to the lower Wabash Valley by Wednesday...and a current forecast of widespread low to mid-60s across the CWA for Christmas Day. Occasional low chances of rain showers to accompany this trend, although location and timing to depend on weak warm/stationary frontal boundary near the Ohio Valley, which will in turn be influenced by progression of any northern-stream surface ridge riding the retracted upper flow along the Canadian border. Low chances in any appreciable precipitation for any single location from Monday night into the late week.

AVIATION (12Z TAF Issuance)

Issued at 636 AM EST Fri Dec 19 2025

Impacts:

- Snow showers through 14z, brief reductions in visibility possible.

- Gusts up to around 40kt at times this morn, gradually diminishing after 18z.

- MVFR ceilings persisting into the afternoon.

- Gusty SSW winds on Saturday between 25-30kt.

Discussion:

A strong arctic front passed through central Indiana last night, and all rain has transitioned to snow. Snow showers are expected to continue on and off through 14z, with brief reduction in visibility possible.

MVFR stratocumulus will likely persist into the afternoon hours as well, gradually retreating from south to north. Stratus should completely lift northward by 03z.

West-northwesterly winds between 15-25kt gusting to 40kt are expected this morning into the early afternoon. Winds gradually diminish this afternoon, becoming light and variable for a time after 00z. However, winds pick up again after about 03z from the southeast as surface high pressure quickly moves eastward. After sunrise Saturday, an approaching trough will allow gusty winds to return from a south-southwesterly direction.

IND WATCHES/WARNINGS/ADVISORIES

None.