Flash Flood, River Flood Threat Continues in the Plains

Jon Erdman
Published: May 14,2015




 

Cars are submerged by flood waters in Clear Lake, Texas on May 13, 2015.
(Jenelle Shriner - KPRC TV)

We've seen multiple major flash flood events since last Monday in the Plains from Nebraska to Texas. The latest was a 7-11 inch deluge overnight Tuesday night in parts of the Houston metro area, submerging cars and flooding some homes in Webster, Texas.
(RECAPS: Nebraska | North Texas | Okla. City | Manhattan, Kansas)

Flooding Recap

May Estimated Rainfall

Additional clusters of storms fired up Wednesday morning near and to the west of Corpus Christi, Texas.
Just one day earlier, Tuesday morning, numerous roads were flooded and some cars were abandoned due to flash flooding in the Corpus Christi, Texas, area. A total of 4.68 inches of rain fell from 1 a.m.-6 a.m. CDT Tuesday morning at Corpus Christi International Airport.
Last Sunday, numerous storms dumped heavy rain over northern Texas, creating flash flooding conditions and swift water rescues in Krum and Sanger, Texas. The National Guard rescued numerous people who were trapped in their homes, as well as a pair of people stuck when their truck washed away in flood waters. The National Weather Service says that radar estimated more than 12 inches of rain just southeast of Corsicana, Texas. A total of 10.02 inches of rain was measured in Corsicana during a 5-hour period on Sunday.
(MORE: National Guard Performs Swift Water Rescues as Flood Waters Rise in North Texas Sunday
Thursday, May 5, torrential rain pounded parts of north Texas, including areas hammered by heavy rain early in the week north of Dallas. A train derailed near Valley View, Texas thanks to flood-damaged tracks. Interstate 35 was shut down for a time near the town. Numerous water rescues were performed in Gainesville and Denison, Texas.
On Wednesday, May 6, severe thunderstorms produced not just tornadoes, but heavy rains as well throughout the Oklahoma City region. As much as 3 inches fell within one hour at Will Rogers Airport on Wednesday, and a calendar day total of 7.1 inches was recorded as well. So much rain fell so quickly that a flash flood emergency was issued for the metro area.
Last Monday, May 4, significant flash flooding was reported in Manhattan, Kansas, Lubbock, Texas, and Seagraves, Texas. Monday was the third wettest May day on record in Lubbock (3.42 inches), and Manhattan, Kansas, picked up over 4 inches of rain.
Here are some May monthly rain totals, so far, through May 12:

• Corsicana, Texas: 11.31 inches
• Oklahoma City, Oklahoma: 11.16 inches
• Wichita Falls, Texas: 6.47 inches

It's been the record wettest year-to-date through May 12 in Corpus Christi, Texas - 20.97 inches of precipitation - and Oklahoma City - 20.34 inches.

Late April/early May Drought Monitor analysis from 2011 through 2015. Brown box denotes area in southern Plains of most persistent drought since 2011.

Three-month change in the Drought Monitor analysis ending April 28, 2015. Green shading indicates areas where the drought has improved. Yellow and orange shadings indicate areas with worsening drought.
(USDA/NDMC/NOAA)

Good News: Optimal Spring Drought Relief

While California is getting much of the nation's attention on the drought front, another long-term drought continues in the nation's heartland.
Parts of the southern and central Plains have been struggling in drought since fall 2010.
According to the Texas Water Development Board, some reservoirs in northwest and west-central Texas, as well as the Texas panhandle, are still running at less than half of capacity.
O.C. Fisher Lake, a secondary drinking water source for San Angelo, Texas, is still at only 0.5 percent of capacity. Just over a half dozen other reservoirs in northwest and western Texas are also running at less than 10 percent capacity.
The news isn't all bad in the Lone Star State. Most reservoir levels generally along and east of I-35 from the Red River to Austin are running at least 80 percent of capacity.
Also, 2015 has been wetter in the southern Plains. Well above-average precipitation has fallen in Amarillo, Texas and Wichita Falls, Texas, among other locations.
Recent heavy rain has brought up the level of Lake Kickapoo, one of the reservoirs supplying the city of Wichita Falls, to above 60 percent of capacity for the first time in several years. The lake level had risen over 8.5 feet in a week ending May 13.
While it will likely take at least one, if not multiple wet years to fully recharge still-depleted southern Plains reservoirs, the wet pattern over the next several days is about as lucrative for a short-term drought dent as you can draw up in the middle of spring.
(FORECAST: Dallas | Okla. City | Amarillo | Wichita)
Drought relief is easier to come by in the spring compared to the summer, when the jet stream migrates well to the north, leaving the southern Plains often subject to hot, dry high-pressure aloft, evaporating water from reservoirs.
In the absence of a remnant tropical cyclone, it's difficult to get widespread, significant drought-denting summer rain in the southern Plains.
Interestingly, a dry winter has left parts of the northern Plains and Upper Midwest in moderate to locally severe drought, according to the May 5 Drought Monitor analysis.
The recent warmth and dry weather has allowed farmers an early start on spring planting. However, rain is needed in parts of the Dakotas, Minnesota and Wisconsin.
While not as high a flood threat, some locally heavy rain is also expected to spread into these areas into the upcoming weekend.

MORE: Severe Outbreak May 8-10, 2015