Heavy Rainfall April 12-15th, 2012

 

Heavy rainfall fell over the course of four days as a series of upper level disturbances across the Rockies affected the plains. On Saturday, the main upper level low pushed into Nebraska with a severe weather outbreak and localized heavy rainfall. By Sunday, the system slowly tracked across the state with moderate to heavy rainfall along the cold front. While some locations saw significant rainfall accumulations during this four day period, significant rainfall distributions existed across small regional areas. For example, on Saturday, portions of the city of North Platte received upwards of 2-3" of rainfall as heavy thunderstorms trained over the same areas. However, the airport, only two miles east of the city, only received 0.21" of rainfall at the official measuring rain gauge.

To overcome widely spaced rainfall gauge reports, various techniques have been developed to estimate rainfall. One technique is the "multi-sensor" approach. This approach employs RADAR estimated rainfall and satellite estimated rainfall and bias-corrects this data to actual rainfall gauge reports on the ground. This technique, while not perfect, helps fill in the gaps between rain gauges. This can also depict large regional distributions that can develop during heavy rain events. The image below is a 5 day total rainfall from the 12th to the 16th. The scale on the right is in inches. Note the relatively scant precipitation across the eastern Panhandle generally less than 0.5". Farther east, however, many areas saw over 1-2" with some locations seeing 3-4". A few localized estimates are in excess of 5". Also note this rainfall estimation accurately depicts the heavy rainfall over North Platte proper with much less rainfall just east of the city--this was reflected well in the real rainfall guage observations at North Platte Airport. While not perfect, these rainfall maps are usually pretty reliable although the values may be both over/underestimated depending on the situation. For instance, the presence of large hail can skew the values towards the high side.

  5 Day Total Precipitation Estimation

 

 

Page composition by
Jason Ahsenmacher
 

 

 


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