Jan 17 - Practice Short Range Forecast

UPDATED: at 2:02 PM EST on 17 January 14, 2014 by Michael Kula and Matt Schall (mkula@purdue.edu and mschall@purdue.edu)

Cold temperatures and light snowfall will move into the state in the late morning hours as a low pressure system quickly passes through, blanketing the state with snow. Northwestern Indiana will be hit with some light snow shortly after midnight and continuing throughout the day. The low pressure system will move into the western portion of the state in the late morning hours before passing through the state by late evening.

The La Porte, Crawfordsville, Greenfield, and Seymour districts are most at risk of winter weather with total snow accumulations amounting to about 2" to 4" of snow. The Fort Wayne and Vincennes districts are looking at snowfall amounts of about an inch of total snowfall.

Short-Range Forecast

Cold arctic air is moving in today behind the front that passed over last night with the cold core moving over the southern portions of the state. An upper level vorticity maximum associated with a trough is creating some light snow showers across the state today as well. As the trough moves out this evening (creating some light snow in the eastern areas) warm air advection will follow it tomorrow as well as another vorticity maximum associated with another short wave trough. Relative humidities above the surface tomorrow will be heightened too. These conditions will create the possibility of 3-6” of snow starting around midday Saturday and lasting into early Sunday. On Sunday, during the day, another blast of cold air will move over the state. Most areas the state will remain clear, however the possibility of some light snow showers are possible for northern areas near Michigan.

Left image is KLAF GFS meteogram and right image is KLAF NAM meteogram. While we were looking through the models, both the NAM and GFS seemed to handle very well and were coinciding with what is to come this weekend.

GFS 500mb vorticity and heights (above image) and NAM 500mb vorticity and heights (below image) showing vort max pushing through Illinois and Indiana along with some warm air advection will create a large amount of lifting force around Saturday evening.

700mb relative humidity on 19 Jan 0000 showing a large amount of moisture in the upper atmosphere that will coincide with the passing warm air advection forcing and vort max.