All Weather News

Rain of Biblical Proportions

25 May 2013, 4:48 pm

This is how it looked earlier on this morning at the I-35 highway at Lexington Exit when the rains had started to taper down.  The highway resembles a river, with the water almost reaching the top of the overpass.

A deluge of rain came down this morning on the city of San Antonio, TX, so much so that the San Antonio River rose a tremendous amount within a matter of hours!  Lines of showers and storms went through what we call “training,” where the thunderstorms go over the same area, over and over again, much like boxcars on train tracks.  The rain started to come down around 3AM CT and by the time it tapered off around Noon CT, over 9″ of rain had fallen at the San Antonio International Airport!

This image was taken around 1pm CT of the current weather conditions.  The rain has stopped but the skies remain overcast and the showers are now looming in the distance.

This is what it looked like earlier in the day in the downtown area.  Here are several pictures that came into our studios this morning.  We thank everyone that was able to share with us, and our viewers, of how it looked outside their windows.  We always encourage photos and videos to be taken, but only from a safe distance and not in harm’s way.

Here are the weather observations at the San Antonio International Airport for the day today (May 25th).  The most amount of rain of 3.88″ fell around the 6-7 AM hour.  It was apart of a 5-hour time span where at least an inch of rain fell per hour.  I’ve highlighted both above.

It looks like a dart board was painted over the area, with the bulls-eye placed smack dabbed right over the city of San Antonio.  The rain fell so quickly that the sewer system couldn’t handle the tremendous run off and thus, the streets started to become flooded.  In most metros there usually is a higher chance for flooding from thunderstorms (or even tropical storms) due to the lack of absorption of the rain into the ground with all of the blacktop, concrete and other paved surfaces all over the place.

Not only did the rain break the previous record, it annihilated it! The old record was 1.66″ of rain from back in 1933.  The day saw that record broken as of about 6-7 AM CT.  And there is a chance more rain could come later on in the day on Saturday if that line of showers swings back west.

So far, May 25th 2013, will go down in San Antonio, TX history as the wettest day for the month of May, beating the previous record of 6.82″ that has lasted since May 31st, 1937.

And as for the rest of the days in the year, the all-time wettest day was on October 17th in 1998 where almost a foot of rain fell at 11.26″  Normally you’d associated a total that high is with a tropical system, but the only tropical system that was around that area, at that time, was Hurricane Mitch that fizzled over southern Mexico in early November.  There was likely another instance of thunderstorms training over the same area due to a stalled, weak, frontal boundary.

As for the rivers, the one that stood out the most was the San Antonio River.  As the rain fell before 6 AM, the river started to pick up the run off and between the time span of 6:30-7:00 AM, the river rose from 5.61 feet to 13.94 feet.  That is a rise of 8.33 feet in 30 mins!  The river continued to rise at an alarming rate and in nearly 4 hours, it had crested almost 30 feet higher than where it was before.  That is just astonishing!  The record crest of the river of 32.6′ was broken.  Almost as fast as the river rose, the waters have receded, and the river is almost out of MINOR flood stage.  There had to be emergency rescued conducted for folks that’s cars got stranded in the flooded roadways, much like what you saw in the pictures above.

Here is hydrograph of the river.

There is a Flash Flood Watch up for much of the area around San Antonio, TX that will stay up until Sunday morning.  There is a chance an additional 2-4″ of rain could fall tonight.  The city itself is under a flood warning.

Remember, when you see flooded roadways, do not try and wonder if you can cross.  Often times vehicles will try to go through and end up flooding their engines, the cars stop working, and they end up stranded themselves and have to be rescued.  Or worse, flood waters carry the car away.  It only takes 18″ of water, or less, to carry most vehicles away, which includes heavy trucks.  “Turn around, don’t drown,” is the motto we always try to get across to people when it comes to flooding.

Stay safe out there and enjoy the rest of your Memorial Day Weekend!  Don’t forget to thank a veteran or a currently serving military member for all that they do this weekend.
Meteorologist Addison Green (Twitter: @agreenWNTV)

 

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