Dennis Practice Forecast


FORECAST UPDATED: 1:15 pm EST Thursday January 16, 2014 by Ryan Dennis (dennis3@purdue.edu)

Summary: With another clipper system moving through the Great Lakes and Midwest region, there is a possibility of statewide snow showers especially within the southern portion of Indiana. Through tomorrow afternoon, this system will bring colder, drier air from the north restarting the winter weather cycle for the next few days up through Saturday.

forecast summary (statewide)


Due to the passing of the northern midlatitude cyclone, there will be an area of positive vorticity advection that will most likely cause lift and heavier snow showers in the southern portion of Indiana. The probability of snow for the entire state is high as temperatures from the surface up to 700 mb are well below freezing through 1800 UTC tomorrow afternoon. Beginning around 1800 UTC on 16 Jan 2014, there is a section of warm air advection assisting lift along with PAA which will help the development of lower stratus deck clouds capable of precipitation. This Alberta clipper system that is coming through will advect a large amount of colder air at 850mb and near the surface from the north well into tomorrow afternoon and also into the evening. Be wary of the dropping temperatures as the probability for frost will increase tomorrow morning through to 1800 UTC. The chances of snow seem to be spread out around Indiana, however, current conditions and the models show a higher possibility of winter weather in the southern portion of the state.


Snowfall accumulation is expected not to reach above a couple inches even within the southern portion of Indiana.



optional district-specific discussions

La Porte district forecast/discussion


With the passing clipper system, there will be a temperature drop pushing through to tomorrow afternoon thanks to cold air advection from the north. The models show that there will be limited positive vorticity advection within this area along with no warm air advection. There is a limited possibility of snow showers in the La Porte district as there are very few lifting mechanisms capable of producing storm clouds regardless of the amount of moisture within 1000mb-500mb.



Fort Wayne district forecast/discussion

The Fort Wayne district will be experiencing the same type of snow probability as the La Porte district as there will be few lifting mechanisms capable of producing heavy storm clouds.




Crawfordsville district forecast/discussion

The northern portion of this district will be experiencing the same type of snow probability as the northern two districts. However, in the southern portion the chances of winter weather are increased due to more positive vorticity advection through tomorrow afternoon. Moisture within the 700mb height field will help to increase chances of heavier snowfall as temperatures will fall below freezing tomorrow morning.



Greenfield district forecast/discussion

Most of this district will experience a higher probability of snow because of the positive vorticity advection lifting mechanism. Along with Crawfordsville, the upper level moisture will help increase chances of heavier snowfall.



Vincennes district forecast/discussion

This district has a high chance of winter weather as lifting from positive vorticity advection will bring in more lower stratus deck storm clouds for heavy snowfall around the district’s area.



Seymour district forecast/discussion

This district has a high chance of winter weather as lifting from positive vorticity advection will bring in more lower stratus deck storm clouds for heavy snowfall around the district’s area.

   

Forecast map valid midnight-midnight: Friday, January 17, 2014.


 
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