Evolution of the NASA SPoRT LIS 0 to 10cm Below Ground Relative Soil Moisture Product During an Extreme Rainfall Event

NASA SPoRT has developed a real-time application of the NASA Land Information System (LIS) that runs over much of the central and eastern United States.  The LIS produces several products, including a suite of soil moisture products that can be used to help assess drought and flooding potential.  WFO Raleigh is currently evaluating these soil moisture products.

A significant rain event occurred across central and eastern North Carolina on 08 and 09 September 2014 as surface low moved northeast along a stalled cold front that was located in the Coastal Plain of the Carolinas. Radar estimates which match fairly well with surface observations indicated a large area of 2 to 4 inches of rain fell across eastern NC with several locations receiving between 6 and 8 inches of rain (Fig. 1).

Fig. 1. The 48 hour precipitation estimate for North Carolina for the period ending at 12 UTC on 9 September 2014.

Fig. 1. The 48 hour precipitation estimate for North Carolina for the period ending at 12 UTC on 9 September 2014.

This heavy rain resulted in a significant increase in the 0 to 10cm below ground Relative Soil Moisture (RSM) as noted in the animation of RSM from 12 UTC on 7 September through 00 UTC on 09 September, 2014 shown below (Fig. 2). The 0 to 10cm RSM product provides the ratio of the water content per total soil volume between the wilting and saturation points for a given soil type, expressed as a percentage. The RSM product provides information about the soil saturation state. Since this RSM product highlights the moisture in a very shallow layer between the surface and about 4 inches below ground, the values change quickly as the heavy rain begins and diminishes.

Fig. 2. An animation of the LIS 0 to 10cm below ground Relative Soil Moisture product from 12 UTC on 7 September through 00 UTC on 09 September, 2014.

Fig. 2. An animation of the LIS 0 to 10cm below ground Relative Soil Moisture product from 12 UTC on 7 September through 00 UTC on 09 September, 2014.

5 thoughts on “Evolution of the NASA SPoRT LIS 0 to 10cm Below Ground Relative Soil Moisture Product During an Extreme Rainfall Event

  1. Great example, guys! Did the relatively dry soil moisture over Central and Eastern North Carolina on September 7 (at the beginning of the time period described and shown in the animation) provide additional value to your forecast process for areal flood forecasting for this widespread, heavy precipitation event?

  2. Were there many reports of areal flooding with this rainfall event? I’d be curious to see how many (or how few) flood reports there were, given the fact that the soils were quite dry prior to the rainfall event.

  3. This is an interesting case and thanks to Raleigh for posting! I did some digging and there was a flood warning issued for the Neuse River at Smithfield affecting Johnston County (SE of Raleigh) initially at 1252 am EDT early Tuesday morning. That river was initially forecast to go into minor flooding, but went into moderate flooding Tuesday evening. It looks that by 18Z Monday, 0-200cm RSOIM values exceeded 60% in northern parts of that county. Values exceeded 55-60% in much larger portions of the county by 00-03Z. This is a good event and we should follow up with Raleigh about this.

  4. I pulled up the hourly RFC precip analysis for this area. It looks as though a good amount of rain fell in the Johnston County area after 18Z, at which point 0-200cm RSOIM values were near or over 55-60% in parts of the County. However, values in some locations were still around 45-50%. So, this may be an issue with differing drainage basin characteristics than our area, but may also have to do with the heavy rain that fell (several inches in a few hours).

  5. Pingback: Relatively Wet Soils and Future North Carolina Rains… | The Wide World of SPoRT

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