FXUS63 KIND 052002 AFDIND Area Forecast Discussion National Weather Service Indianapolis IN 302 PM EST Mon Jan 5 2026 .KEY MESSAGES... - Temperatures warming this week to well above normal, especially Thursday and Friday - Periods of rain showers Thursday-Friday night with isolated thunder possible amid unseasonably mild conditions - Seasonably chilly weather returns this weekend && .SHORT TERM (This evening through Tuesday)... Issued at 302 PM EST Mon Jan 5 2026 A weak clipper system is departing well to our northeast, which has allowed a warm front to lift northward last night. Southwesterly winds between 10-15kt combined with diffuse sunlight is warming central Indiana up nicely. Temperatures well into the 40s are widespread, with some low 50s observed from Indy southward. Upstream, a second system is taking shape over the northern Plains. Like the previous system, it should pass well to our north with another round of breezy southwesterly winds. One key difference is greater low-level moisture advection, which looks to bring widespread stratus tonight. Additionally, model soundings depict the stratus layer becoming thick enough for drizzle at times into Tuesday morning. A few isolated showers cannot be ruled out either, but overall forcing is weak. Some patchy fog is possible, but the signal is better for a stratus deck compared to widespread fog. As is typical for this time of the year, the duration of low-level stratus will be our primary forecast challenge in the short term. Guidance is mixed on how quickly stratus clears out Tuesday afternoon, with solutions showing clear skies as early as 21z. Guidance has been trending towards a stronger surface low with a period of weak cold air advection and west-northwesterly flow Tuesday afternoon. This, combined with the tendency for stratus to linger...especially within broad cyclonic flow...we will lean towards this scenario for now. Lingering stratus presents an additional problem in terms of forecast high temperatures. High-resolution guidance that retain overcast skies also keep temperatures down in the 40s. Should an optimistic scenario unfold, clearer skies would lead to temps in the mid 50s potentially. We'll split the difference and forecast highs in the upper 40s (north) / low 50s (south). Forecast uncertainty is greater than normal for this time period, however, and highs Tuesday are highly dependent on the stratus situation. && .LONG TERM (Tuesday night through Monday)... Issued at 302 PM EST Mon Jan 5 2026 Quasi-zonal flow aloft will create some uncertainty in the early parts of the long range, especially regarding high temperatures. Ensemble guidance is showing a fast-moving trough passing through the Great Lakes and Northeast following Tuesday's system. A brief return to west-northwesterly flow was mentioned in the short term discussion, and this could persist into Wednesday. Depending on the magnitude of cold air advection, should it occur, will have impacts on how far south an east-west baroclinic zone is pushed. North of this zone, persistent stratus may help keep temperatures below what guidance is currently suggesting. Like with Tuesday's highs, we'll nudge Wednesday's downward a bit as well...keeping values in the 40s/low 50s. With a progressive flow pattern aloft, ridging will be quick to return as troughing digs into the southern Rockies. Ensemble guidance is in good agreement now showing a system developing from the trough as it ejects into the southern Plains. This system should then lift northeastward roughly towards Chicago. Guidance has also trended towards a gradual trough ejection, with multiple rounds of cyclogenesis occurring later this week. The first system, mentioned above, should reach Chicago late Thursday evening/night. A round of rain is likely, with a thunderstorm possible as well. The system then races northeastward with a cold front dropping southward temporarily. The front should stall out over southern Indiana or even a bit south into Kentucky. Persistent shower activity is likely where this front sets up, so we'll keep chance to likely PoPs in our south through Friday. Ensembles then show a second system developing over the southern Plains later Friday as the bulk of the trough finally ejects eastward. Uncertainty within guidance increases, however. The primary source of uncertainty is the nature of the trough as it ejects, which looks to be in a weakening state and positively tilted. At the same time, a potent short wave trough dropping south out of Canada may interact with the southern Plains trough. In these scenarios, guidance generally shows a stronger system developing over the Great Lakes on Saturday (some show this but more slowly, occurring after passes by Indiana with little impacts). Details such as timing and precipitation amounts are uncertain at this range. Forecast confidence is highest regarding a cool down following the second system on Saturday. Temperatures returning to near normal or even a bit below normal are increasingly likely this weekend into next week. && .AVIATION (18Z TAF Issuance)... Issued at 1239 PM EST Mon Jan 5 2026 Impacts: - Marginal LLWS tonight. - MVFR conditions developing late tonight, possible IFR Tue morning. - Drizzle with minor visibility reductions Tue morning. - WSW wind gusts 20-25kt Tue. Discussion: High-level clouds are increasing ahead of an approaching system. Increasing southerly flow ahead of it will promote a 35-45kt low- level jet overnight. This may lead to a period of low-level wind shear around 40kt generally between 04z-10z. Additionally, low-level moisture advection is expected to increase leading to MVFR stratus tonight. Ceilings may drop throughout the night into Tuesday morning, potentially dipping into IFR at times. Drizzle with minor reductions in visibility is also possible, especially between 10z-14z. Drizzle should end later Tuesday morning as the system departs. Winds turn more westerly with increasing gustiness (up to 25kt). Guidance is hinting at IFR/MVFR stratus lingering through a good portion of the day Tuesday, which is more likely than not this time of the year. We will retain MVFR ceilings through the end of the TAF period for now. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...Eckhoff LONG TERM...Eckhoff AVIATION...Eckhoff