textproduct: Indianapolis

KEY MESSAGES

- Cold Weather Advisory in effect for much of Central Indiana through 9AM

- Bitterly cold temperatures and gusty W/SW winds will produce wind chills as low as -15 at times this morning.

- Mostly Sunny Today and not as cold.

- Subzero lows possible Thursday and Friday nights with continued cold temperatures through early next week

- Snow possible late Saturday into Sunday as a winter storm passes to the south

SHORT TERM (Today and tonight)

Issued at 233 AM EST Tue Jan 20 2026

Surface analysis shows strong high pressure in place over OK. A ridge axis was extending northeast from the high pressure system across Indiana and Ohio. Low pressure was found well to the northeast, resulting in NW flow across the Great Lakes and westerly flow over Indiana. The high was an arctic air mass with temperatures in the single digits at most points across Central Indiana. Aloft, water vapor showed broad cyclonic flow in place across the CONUS east of the Rockies, with NW flow prevailing across the upper midwest, spilling into central Indiana. This puts Central Indiana in a favorable location for subsidence. GOES19 shows a leaf of mid cloud within the NW flow aloft, quickly pushing SE, with more clear skies found upstream over IA and MN.

Today...

Cold and quiet weather is expected today. Models suggest the surface high pressure system will drift to the east, pushing toward the Tennessee river valley while maintaining control of central Indiana/s weather also. The upper pattern remains relatively unchanged, with the cold, northwest, Canadian flow in place. Again, little in the way of forcing dynamics will pass. Forecast soundings show a dry column through the day with an inversion aloft. Thus a mostly sunny day is expected.

Warm air advection is in place today mainly due to the core of cold air exiting the area. 850mb temp improve to near -10C by late afternoon, which should allow for highs to reach the lower and middle 20s.

Tonight...

Another quiet but not as cold night is expected tonight. The broad NW flow aloft will remain in place, however by late overnight, a short wave providing some forcing appear to approach Indiana after 09Z. This will provide limited upper level forcing. Meanwhile within the lower levels, southwest lower level flow remains in place due to the departing high to the east, but a trough is seen approaching Indiana over IL and MO late overnight. This appears to be associated with the upper wave. None the less, the lower levels remain very dry as the high pressure to the south continue to block true gulf moisture and dew points are suggested to be in the single digits or teens. Not enough moisture. Forecast soundings show a dry column through the evening with saturation arriving aloft late overnight. Thus an increasing cloudiness forecast will be used.

Warm air advection and the arrival of clouds are also expected overnight. Thus warmer lows in the lower 20s will be expected.

LONG TERM (Wednesday through Monday)

Issued at 233 AM EST Tue Jan 20 2026

Wednesday Through Thursday.

During the daytime hours on Wednesday a weak clipper system will interact with the strengthening southerly flow which could bring precipitation to portions of central Indiana but there still remains a fair amount of uncertainty as to where precipitation onset occurs with some models keeping rain/snow to the north and east of central Indiana while others initiate over the area. Thus will continue to keep low POPs across the area with highest values in the east. With temperatures near freezing, precipitation type also remains uncertain with the potential for both rain and snow. Another blast of colder air moves in Wednesday night into Thursday in the aftermath of the system but the magnitude of the colder air doesn't look quite as robust as what is expected for the early this week.

Friday Through Early Next Week.

A much stronger blast of cold air looks likely Friday into the weekend as arctic air slinks southeastward in the aftermath of the exiting system and a 1048mb high builds over the Upper Midwest. Confidence is high in much colder than normal temperatures for the weekend with the potential for overnight lows at or below normal, especially over portions of north central Indiana. There continues to be some model differences on the northern extent of the precipitation with at least some low chances for snow as far north as central Indiana but with the strength of the high to the northwest and the fact that models often overdo the precipitation on the northern periphery of the system, feel fairly confident that much if not all of central Indiana will remain dry.

The high will gradually begin to break down Sunday into early next week, but the pattern continues to favor below normal temperatures for much of next week with signs of another intrusion of cold air Monday into Tuesday.

AVIATION (06Z TAF Issuance)

Issued at 1111 PM EST Mon Jan 19 2026

Impacts:

- VFR conditions are expected

Discussion:

Strong high pressure centered over the southern plains with a ridge axis extended northeast to the Ohio Valley and southern Indiana. This feature will drift east across the Tennessee Valley during the TAF period, keeping dry air in place across the TAF sites. Forecast soundings through the period maintain dry lower levels over the next 24-30 hours, indicating VFR conditions.

A few mid clouds will pass from time to time. GOES19 shows a leaf of mid cloud over IL, poised to push across the TAF sites within the flow aloft within the early hours of the TAF period. Have used a tempo group to account for that. More mid and high clouds will be possible on Tuesday evening as warm air advection returns on southerly winds. Still, all of this will be VFR.

IND WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until 9 AM EST this morning for INZ021- 028>031-035>049-051>057.