Archive‎ > ‎EAPS 434 - Fall 2014‎ > ‎schedule/calendar‎ > ‎Oct 29 2014‎ > ‎

long range event

I was looking at the rain event that is expected to come into our area next week on Tuesday. The time stamp that is being looked at is 900 UTC on Nov. 14, 2014. This would be early morning Tuesday, roughly 5 am. I began by looking at the upper air map at 500 mb to examine the winds and temperatures. It is clear that there is a strong jet streak at this level and rain can be expected in the left exit of the jet on the east side of the trough. Other terms will also determine the probability of this rain event as well.  
 Below is the 500 and 850 mb height, wind and temperature map.The 850 mb map shows less of the jet streak but there are still significant amount of strong winds to the north. 

I then looked at the temperature advection to see if there was any major advection that may cause concern for precipitation. There is a strong cold air advecton to the west and in the all throughout trough of the low pressure system. This could cause there to be rising on the warm air side which would make for precip to occur in front of the cold front. To the right of the temperature advection map is the vorticity. We can see there is a vort max at the same point of the strong cold air advection, on the southeast side of the trough. There is negative vorticity on the west side and positive forcing on the east of the vort max. This could be in association with the short wave ridge out east which could actually be showing us a vort min instead of a max.. 


The left image is of the frontogenesis, I think that there is also frontogenesis visible directly in the trough even though it is not highlighted on the map. There is clear temperature advection from the north west on the west side of the trough and there is a clear shift in the winds on the east side of the same trough. This is evidence that there is frontrogenesis. I think if there was a map at a different height that it might be more visible than that map below but it is distinguishable which is also highly likely to bring precipitation.

The precip that is expected from these forcing terms is below, the time stamp for the rain event is updated every 3 hours so the one showing is from 1200z but it is the actual rain amount from the 900z time. It is showing the line of precipitation lining up with what I have already mentioned. It also shows it extending all the way through the entire trough that ranges from the north all the way through Texas as well. There is strongest precip indicated in the texas pan handle. If we look at the vorcitiy map again we see there is positive forcing there and there is also a large amount of cold air advection. So the warm air in front of the front is rising and trying to stabalize to the cold air pushing through.