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FORECAST UPDATED: 5:30 pm Tuesday, Mar 3, 2015 by Tyler Heckstall (email@example.com)
Summary: Heavy snow and wintry mix likely for southern Indiana Wednesday into Thursday. Unseasonably cold temperatures arrive for the latter half of work week. Dry weather and moderating temperatures expected for the weekend.
A cold front is projected to move through Indiana Tuesday evening and stall south of the Ohio River by Tuesday night. The location of this stalled frontal boundary is presenting significant challenges in the upcoming forecast. For Tuesday night, intermittent rain across the the northern half of Indiana is expected to come to an end before midnight as an arctic high pressure system builds into these areas. Locations in the 30% region might see sleet or snow flakes mix in before ending. After the rain, low level moisture may be sufficient enough to develop patchy dense fog or freezing drizzle in the 30% region. With surface temperatures gradually falling below freezing in these areas after midnight, there is somewhat of a concern for this moisture freezing to the surfaces before daybreak Wednesday. However as drier air mixes in from an incoming high pressure system, expect the freezing fog or freezing drizzle to come to an end before day break in the 30% areas.
For locations south of I-70 Tuesday night, an band of rain is projected to overspread the area and move southward through the overnight hours. The primary concern for significant amounts of snow, sleet, or ice accumulation lies within the 90% region as indicated on our map below. Locations in the 60% region should have rain change to a wintry mix of freezing rain and sleet around 2am EST Wednesday. By 4am, as colder temperatures continue to move south light snow may mix in before ending by daybreak. For the 60% region, ice accumulations are anticipated to amount to nothing more than a light glaze and snow & sleet accumulation less than 1". It won't be until predawn hours that rain begins to change to wintry mix of moderate intensity rain, freezing rain, and sleet for our 90% region. This may result in ice accumulations approaching values less than 0.1" by the late morning hours and sleet accumulations less than 1" as well. The wintry mixture should change to all snow between 10am-Noon EST as the colder air continues move south along with the area of high pressure. Being in close proximity to the stalled frontal boundary, indicates that the southward movement of the precipitation should stall and tend to linger in this area through the day Wednesday and possibly into Thursday. The will help continue the snow, and as the disturbance rides along the frontal boundary, the snow may become heavy at times Wednesday afternoon and night. Although less certain of this scenario, the disturbance may bring the snow back into the 30% & 60% areas briefly by Wednesday afternoon and end by the evening. The snow should begin to taper off late Thursday morning for the 90% locations. Snowfall accumulations in the 90% area may approach 6-12", 2-6" in the 60%, and less than 1" in the 30% area.
High pressure builds in for Thursday and brings drier and unseasonably cold weather into the state through the end of the week. Several disturbances passing well north of the state will allow temperatures to rise during the weekend and allow the unusually cold, arctic air to depart as well. A ridge of high pressure looks to build in early next week and this should bring in seasonal temperatures in the 40's and 50's and continue the streak of dry weather Indiana.
Forecast maps: (midnight - midnight Wednesday Mar 4)
Forecast map: (midnight - midnight Tuesday Mar 3)