Kansas State University

What started out as a week with a spring-like feel in Kansas turned aggressive with a return to winter by mid-week. All of these changes were due to a strong storm system, one of which will be remembered for years to come. Various impacts extended across the central Plains Wednesday, Thursday, and into Friday, including a blizzard for the High Plains, heavy rains and flooding for Kansas/Nebraska, and very strong winds across the entire region. Satellite imagery displayed the extent of the massive impacts felt by this storm (Figure 1).

Impact: Heavy rain

Warmer temperatures helped turn the frozen ground surface into a muddy mess. Several rounds of heavy rain in advance of the storm on Monday through Wednesday didn’t ease the mud. In fact, with persisting frozen sub-surface coupled with no vegetation growth and saturated soils, most of the rain ran off. This created flooding issues along streams and rivers in the region. Heaviest rainfall in Kansas through the period focused on south central to east-central Kansas (Table 1). This event alone provided over half the March monthly normal precipitation for many locations (Figure 2).

Table 1. Locations of heaviest rain observed on the Kansas Mesonet and the NWS Coop network (Source: mesonet.ksu.edu, Weather Data Library).

Impact: High winds

Winds increased dramatically late morning across western Kansas as the storm system strengthened in eastern Colorado. As the low shifted eastward into Kansas, the wind field expanded across the state. Strong winds continued through the duration of Wednesday and even strengthened into Thursday morning. Damage was reported to buildings, trees down across the state, and trucks were flipped as a result. Table 2 provides Kansas Mesonet maximum wind gusts across the state.

Table 2. Maximum measured wind gusts on the Kansas Mesonet on March 13-14, 2019. (Source: http://mesonet.ksu.edu/weather/maxmin)

Atmospheric Pressure: why all the fuss?

Very low pressure at the storm’s center created a substantial pressure gradient across the region. With an increased pressure gradient, air movement towards the low becomes enhanced, converging and rising at the center. This rapid air movement develops the strong winds mentioned previously.

This system was so strong, it broke the state low pressure record in Colorado and came extremely close in Kansas as well. Standard air pressure in a benign atmosphere is around 1013 millibars (mb). At the peak intensity/lowest pressure of the storm, nearby weather stations in far southeast Colorado dropped to 970.2mb. This shattered the previous Colorado state record (976.3mb on February 9, 1960). The low weakened as it crossed the state line into Kansas, causing a slight rise in pressure (Figure 3). The Kansas state record low pressure is believed to be 971.2 mb set on March 13, 1973 at Goodland. Wednesday’s storm came within 0.6 mb of breaking the record with 971.87 mb measured at Stanton (Table 3). Mesonet data from this day has also been integrated into NOAA’s Weather Prediction Center lowest surface pressure archive to be used for future storms (Figure 4).

Table 3. Minimum recorded pressure at Kansas Mesonet stations. (Source: mesonet.ksu.edu)

Spring Arrives…Finally

Despite the brief return of winter on Thursday in the wake of the storm, warmer and drier weather is on the horizon for the weekend and into next week. This will help bring soil temperatures closer to normal and hopefully aid in drying out surface soil. Unfortunately, it appears the drier weather will not persist beyond next week as another stretch of cooler, wetter conditions are anticipated to close out the month.

Christopher “Chip” Redmond, Kansas Mesonet Manager
christopherredmond@ksu.edu

Mary Knapp, Assistant Climatologist
mknapp@ksu.edu