So here is what the National Weather Service is saying:
Winter Storm Watch
URGENT - WINTER WEATHER MESSAGE National Weather Service Indianapolis IN 302 PM EST Mon Jan 31 2022 INZ061>065-067>072-011100- /O.EXA.KIND.WS.A.0001.220203T0000Z-220204T0600Z/ Greene-Monroe-Brown-Bartholomew-Decatur-Knox-Daviess-Martin- Lawrence-Jackson-Jennings- Including the cities of Linton, Bloomfield, Jasonville, Worthington, Bloomington, Nashville, Columbus, Greensburg, Vincennes, Washington, Loogootee, Shoals, Bedford, Mitchell, Seymour, and North Vernon 302 PM EST Mon Jan 31 2022 ...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY EVENING THROUGH LATE THURSDAY NIGHT... * WHAT...Heavy mixed precipitation possible. Total sleet and snow accumulations up to 3 inches and ice accumulations of one tenth to one quarter of an inch possible. * WHERE...Portions of central, south central, southeast and southwest Indiana. * WHEN...From Wednesday evening through late Thursday night. * IMPACTS...Power outages and tree damage are likely due to the ice. Travel could be nearly impossible. The hazardous conditions could impact the morning or evening commute. * ADDITIONAL DETAILS...There remains some uncertainty on the path of the storm which could impact precipitation types and amounts. PRECAUTIONARY/PREPAREDNESS ACTIONS... Monitor the latest forecasts for updates on this situation.
Area Forecast Discussion National Weather Service Indianapolis IN 252 PM EST Mon Jan 31 2022 .Short Term...(This evening through Tuesday night) Issued at 252 PM EST Mon Jan 31 2022 Quiet weather will continue tonight into early Tuesday, ahead of an approaching cold front that will begin wave one of a substantial mid week winter storm. Broad southerly flow aloft and at the surface will produce a substantial warmup ahead of the front into Tuesday with 50 degree readings likely to make inroads well into central Indiana tomorrow afternoon. Precipitation onset could be as early as Tuesday afternoon in our northwest but will likely hold off until later in the day as it will take some time for the atmosphere to fully saturate. Will ramp pops up steadily late Tuesday afternoon to categorical in the northwest by evening, then everywhere by late Tuesday night. The vast majority of Tuesday evening and night`s precipitation will fall as rain, before the cold front makes enough progress into the area to allow for a rapid transition to snow in the far northwest by daybreak Wednesday. This transition zone will continue to make slow but steady progress southeast beyond the short term period and into the long term. && .Long Term...(Wednesday through Monday) Issued at 252 PM EST Mon Jan 31 2022 Key Points: -- Still significant uncertainty on placement and amounts of ice, and southern extend of more significant snowfall. -- Significant snow amounts with potential tree limb and roof impacts across the northern portion of the area. -- Greater concerns for freezing rain and icing further south. -- A swath of significant sleet accumulation possible. -- Significant impacts to travel and some power grid impacts possible. -- Event-total liquid 2-3 inches raises concern for river flooding. Meteorological Analysis and Uncertainties: There are some synoptic-scale shifts that are contributing to uncertainty, but the general pattern of waves of anafrontal precipitation has been consistent in deterministic and ensemble NWP. Specific details of where the baroclinic zone/front is, thermal profile, and inherent microphyics considerations for precipitation type are all not entirely clear at the moment. Of course, these have significant implications for precipitation type, and timing transitions within the context of QPF can make accumulation amounts of freezing rain, sleet, and snow very difficult. We expect to gain more clarity and overall forecast confidence in the next 24-36 hours. We are concerned about the consistent QPF signal amidst supportive thermal profiles for snow across our northern counties for significant impacts. One limiting factor appears to be microphysics related, and tied to the character of the thermal profile perhaps supporting relatively low (near or just below climo) snow-liquid ratio. It`s a broad warm nose with a deep isothermal layer just on the cold side of 0C even for northern portions of the area, and some riming may occur. This is the primary reason for questioning the more extreme amounts of explicit 10:1 and Kuchera. Nevertheless, snow impacts to travel and also including weight on roofs and trees need to be considered within this heavy snow swath. Since flow from the initial wave veers/weakens and mean flow parallels the front, thus resulting in more anafrontal precipitation with time, areas further south closer to the I-70 corridor may experience a slower precipitation type transition. Initial shallow cold surge will change rain to freezing rain, but for much of the area the frontal slope should intrude far enough that the cold air becomes deep enough for refreezing and sleet. A significant amount of sleet may accumulate somewhere across the area depending on timing of waves of ascent/precip and character of the warm nose. A more amplified frontal wave and stronger flow atop the frontal slope would support this. Sleet would be most likely south of the axis of heavy snow and north of where the frontal slope is sufficiently shallow for freezing rain. There are growing concerns for freezing rain impacts, particularly further south where shallow cold air mass seems likely to reach. Even across the northern portion of the area a transient period of freezing rain may be enough for a glaze of ice. We adjusted the forecast for earlier arrival of cold and the entire area should be sub-freezing by around sunrise Friday. Once we have higher confidence on precipitation amounts within the time frame the thermal profile is supportive of icing, and better assess accretion potential using FRAM concept we will be more specific about amounts. For now there is enough of a signal to include the southernmost portion of the area in the Winter Storm Watch. Storm total liquid equivalent precipitation of 2-3 inches raises concern for river flooding late in the week and this weekend. Forecast confidence decreases considerably once this system departs. Some medium range deterministic guidance and ensemble members bring a short wave trough into the area with enough moisture/ascent for light precipitation this weekend. This seems low probability at this time.
