Tornado Watch Issued as Severe Thunderstorms, Flash Flooding Take Aim on Southern Plains to Start the Week

Jon Erdman
Published: May 16,2016
Once again, a threat of flash flooding and severe thunderstorms will continue over the next several days in parts of Texas, Louisiana, and other parts of the Southern Plains and Gulf Coast, weary from what has been a 12-month siege of flood events.
Heavy thunderstorms have already caused some flooding in central and southeast Texas since this weekend. Scroll down to the flood reports section for details on the flooding that has occurred so far.
NOAA's Storm Prediction Center has issued the following severe weather watches:

• A tornado watch is in effect until 10 p.m. CDT for part of the Texas Panhandle.
• A severe thunderstorm watch is valid until 10 p.m. CDT for portions of the Oklahoma Panhandle and the Texas Panhandle. 

Late Monday afternoon, two separate tornadoes was spotted near Felt, Oklahoma but no damage or injuries have been reported. Monday evening, a tornado was also reported north of Dalhart, Texas, along with hail up to 2 inches in diameter. A wind gust of 70 mph was reported Monday evening near Spearman, Texas and in Goodwell, Oklahoma.

Latest Radar, Watches and Warnings

(MORE: View National Interactive Radar Map | Difference Between a Watch and a Warning)
Below is a look ahead at the severe weather and flood threats into the new week ahead.

Severe Storm Threat Forecast

Severe weather is also a possibility across the region. The atmosphere will be very unstable with plenty of moisture to work with, so the strongest thunderstorms could produce damaging winds (58+ mph), large hail (1 inch diameter or larger), and tornadoes.
A major outbreak of severe weather with dozens of tornadoes is not expected, however.
On Sunday, golf ball size hail was observed in Marathon, Texas and hail up to one inch in diameter was reported near Santa Fe, New Mexico Sunday afternoon.
Here's and overview of where severe storms could develop the next couple of days.
Monday Night:

• Scattered severe storms are expected from extreme southeast Colorado into parts of southern Kansas, Oklahoma and northwest Texas.
• Large hail and damaging winds are the biggest threats, though a tornado or two cannot be ruled out.

Monday Night's Thunderstorm Forecast

Tuesday: 

• The greatest chance of severe storms will be from central and eastern Texas to southwest Arkansas, extreme southeast Oklahoma and western Louisiana. This could include a development of a large thunderstorm complex that may sweep through parts of Texas.
• Once again, damaging wind gusts and large hail are the main concerns, though there is the possibility of a few tornadoes.

Tuesday's Thunderstorm Forecast

Flood Threat Forecast

The threat for locally heavy rainfall from thunderstorm clusters has already begun from parts of the Rio Grande Valley of central Texas into southeast Texas.
Then, as another cold front drops south and stalls out Tuesday, more rounds of thunderstorms with heavy rain are expected to occur each day and evening through Thursday or Friday from the Southern Plains into the Deep South and Gulf Coast.
(MAPS: 7-Day Rainfall Forecast)
Through late week, the greatest heavy rain threat appears to be in central, north and east Texas into parts of Louisiana, though some heavy rain may also fall as far north as the Ozarks and east into the Deep South.
(FORECAST: Houston | Austin | San Antonio | Dallas)

Forecast Rainfall Into Late Week

Flood Reports Through Monday

Early Monday morning, major flash flooding hit the Corpus Christi area with numerous water rescues reported throughout the city. Water was reportedly over the roofs of cars in the southeast part of town. Some residents of Ingleside had to be rescued from their homes. One location southeast of Corpus Christi picked up 11.51 inches of rain in the 24 hours ending Monday morning. For more details on this story, see the link below.
(LATEST NEWS: Major Flooding Hits Southeast Texas)
On Saturday, water rescues from vehicles were reported on the southwest side of Houston in Bellaire, Meyerland, and Westbury. Locally 4-5 inches of rain fell in the area during a short period of time. On Sunday, roads were flooded near Marathon, Texas and near Kingsville, Texas.
(MORE: Is Houston America's Flood Capital?)

Setup

A series of disturbances will track through the Southern Plains this week as the southern branch of the jet stream becomes more active.
By mid-late week, a more pronounced upper-level southward dip in the jet stream will swing out of the Desert Southwest into the Plains, triggering what should be the most significant round of thunderstorms in the Southern Plains, Lower Mississippi Valley, Deep South and Gulf Coast mid-late week.
A persistent south to southeast wind off the Gulf of Mexico will provide a plethora of moisture to fuel thunderstorm development. Therefore, any storms that form will have the potential to dump very heavy rainfall.

The setup for repeated rounds of thunderstorms with locally heavy rain in parts of the Southern Plains and Gulf Coast over the next several days.

Parts of Texas and Louisiana are already flood-fatigued after April's flood and several other floods over the past year, and they do not need anymore significant rain.

How Wet has it Been?

Houston has received over 74 inches of rain in the past 12 months, placing it as the wettest 12-month period ending on May 12 of any year.
This shatters the previous record for this period of 68.25 inches by about 6 inches. Houston currently sits at 24.8 inches of precipitation above average for this 12-month period, with Abilene, Dallas, and Austin also 20 to 25 inches above average over the past 12 months.
Some rivers in east Texas, Louisiana and Arkansas are still above flood stage, and soil moisture remains much higher than average in these areas, meaning even relatively brief heavy rainfall may quickly run off and trigger flash flooding.

MORE: Texas Flooding April 2016