Precipitable water characteristics during the 2013 Colorado flood using ground-based GPS measurements

Abstract

Abstract. During 9-16 September 2013, the Front Range region of Colorado experienced heavy rainfall that resulted in severe flooding. Precipitation totals for the event exceeded 450 mm, damages to public and private properties were estimated to be over USD 2 billion, and nine lives were lost. This study analyzes the characteristics of precipitable water (PW) surrounding the event using 10 years of high-resolution GPS PW data in Boulder, Colorado, which was located within the region of maximum rainfall. PW in Boulder is dominated by seasonal variability with an average summertime maximum of 36 mm. In 2013, the seasonal PW maximum extended into early September and the September monthly mean PW exceeded the 99th percentile of climatology with a value 25 % higher than the 40-year climatology. Prior to the flood, around 18:00 UTC on 8 September, PW rapidly increased from 22 to 32 mm and remained around 30 mm for the entire event as a result of the nearly saturated atmosphere. The frequency distribution of September PW for Boulder is typically normal, but in 2013 the distribution was bimodal due to a combination of above-average PW values from 1 to 15 September and much drier conditions from 16 to 30 September. The above-normal, near-saturation PW values during the flood were the result of large-scale moisture transport into Colorado from the Tropical Eastern Pacific and the Gulf of Mexico. This moisture transport was the product of a stagnating cutoff low over the southwestern United States working in conjunction with an anticyclone located over the southeastern United States. A blocking ridge located over the Canadian Rocky Mountains kept both of the synoptic features in place over the course of several days, which helped to provide continuous moisture to the storm, thus enhancing the accumulated precipitation totals.

Thunderstorm Classification Functions Based on Instability Indices and GNSS IWV for the Sofia Plain

“…Reported in [16] is a severe flood, caused by intense rainfall, in Colorado, USA, from 9 to 16 September 2013. Analysis of IWV for the 10-year period showed that in 2013: (1) the seasonal IWV maximum extended into early September, and (2) the September monthly mean IWV exceeded the 99th percentile of climatology with a value 25% higher than the 40-year climatology.…”

“…The IWV frequency distribution in September was typically normal, while in 2013, a bimodal distribution was found with above-average IWV from 1 to 15 September, and much drier conditions from 16 to 30 September. The positive IWV anomaly during the flood was found to be a result of large-scale moisture transport from the Tropical Eastern Pacific and the Gulf of Mexico [16]. The potential of high-frequency IWV (5 and 15 min) in combination with weather radar reflectivity was exploited by [17] for a derecho event in Poland on 11 August 2017.…”

An Investigation of Extreme Weather Impact on Precipitable Water Vapor and Vegetation Growth—A Case Study in Zhejiang China

“…In addition, the frequency distributions of PWV and temperature are also analyzed in August 2014 to verify the extreme climatic anomaly [12,33]. Figure 5 gives the statistical frequency distributions of PWV and temperature for Augusts from 2010 to 2017 using the data from the ECMWF ERA-Interim data.…”

“…The Global Navigation Satellite Systems (GNSS) technique was proved to be able to detect sudden changes in precipitable water vapor (PWV) [6][7][8][9] and has been widely used in the monitoring of atmospheric storms and depressions [10] as well as the forecasting of heavy precipitation [11]. The authors of [12] pointed out that the PWV characteristics are an important factor because they could affect future climate change trends. Additionally, PWV variations are highly correlated with precipitation, and precipitation begins normally after the PWV reaches its peak and PWV returns to its climatological value after the end of the precipitation [12][13][14][15].…”

“…The authors of [12] pointed out that the PWV characteristics are an important factor because they could affect future climate change trends. Additionally, PWV variations are highly correlated with precipitation, and precipitation begins normally after the PWV reaches its peak and PWV returns to its climatological value after the end of the precipitation [12][13][14][15]. The authors of [16] also found that the increase of atmospheric water vapor could possibly lead to the occurrence of the precipitation events.…”