Indiana Weather: Case Study:(September 13-14, 2012)

           Between Thursday, September 13, 2012 and Friday, September 14, 2012, a weak storm system pushed through Indiana. This particular system did not produce and severe weather, however, it brought some needed showers for Indiana’s dry soils. The most recent drought monitor, retrieved from www.drought.gov, shows that the majority of Indiana is still under D1 Category, indicating moderate drought, and areas to the south are seeing severe drought (D2).

Figure 1: Drought Monitor (September 11, 2012)
www.drought.gov

                In Figure 2 (Surface Map Image), a dome of high pressure dominated over the east coast and into Indiana on September 12, 2012 during the evening (Approximately 8:15pm EDT). There was also a well-defined cold front pushing its way through Iowa, Illinois, Missouri, and Kansas bringing showers to those states.  Notice in the Infrared Satellite, the cloud cover associated with these lines for storms.  

Figure 2: Surface Map : September 12, 2012 (8:15pm EDT)

Figure 3: Infrared Satellite September 12, 2012 (8:01 pm EDT)

  

                By 8:15 pm EDT September 13, 2012, the cold front enters Indiana with showers closely behind in Illinois (Figure 4). On the 850 mb map (approx. 1 mile above the surface), you can see the defined frontal boundary, Gulf moisture feeding into the system, and the cold air influence from Canada. (Arrows on Figure 

5 show this).

Figure 4: Surface Map September 13, 2012 (8:15pm EDT)

850 mb Map: September 13, 2012 (8:00 pm EDT)

 The rain finally arrived overnight, and by 8 am September 14^th, the system became a bit more unorganized at the surface by the morning (Figure 6). The cold front had turned stationary, which left lingering showers in the area throughout the morning and early the afternoon hours.  By that evening, high pressure dominated the Indiana/Illinois region (Figure 7 ), once again, and the front pushed away toward the east coast.

Figure 6: Surface Map September 14, 2012 (8:15 am EDT)

Figure 7: Surface Map September 14, 2012 (8:15 pm EDT)

This low pressure system did not cause any severe weather and there were no severe weather reports, according to the Storm Prediction Center’s website (www.spc.noaa.gov). After analyzing the 300mb chart, the polar jet stream stayed to the north, which is one possibility on why this front did not produce any thunderstorms because of the lack of wind shear (Figure 8). 

Figure 8: 300 mb September 12, 2012 (8:00 am EDT)

Another reason that this system could’ve been weak was how the front became disorganized when it was residing over the state. Overall, this might have been a weak system to move through Indiana however, every little bit counts when the state is trying to recover from the exceptional drought that occurred last summer.

Surface Map Images and Upper Level Maps retrieved from: http://weather.unisys.com/archive/index.php