Houston, Texas isn’t a place noted for having a lot of rainfall, but yesterday, according the the Weather Underground, the airport there got 6 inches of rain in 24 hours, with 1.17in falling in a seven minute period. Compared to the 8.3mm in the year to date, this is a serious amount of water; see the summary below the break:
Jan 2012 floods in Houston Texas
Angela Fritz of wunderground.com tweeted:
As of 2am CT, Houston has received over 6″ of rain. At one point, 1.21″ fell within 7 minutes, which is, well, meteorologically nuts.
— Angela Fritz (@WunderAngela) April 28, 2013
However, weather.com estimates 1.54in for the previous 24 hours. Not sure about the discrepancy. Could be timings or locations of gauges? Or a microclimate at the airport with aerosols from aircraft causing the cloudburst?
This isn’t an unprecedented event though, back in Jan 2012 160mm fell in a day, as this report tells us.
Tallbloke's Talkshop 
Rainfall is fickle. Sometimes comes down in buckets in one place and barely manages a drizzle just a few km away.
That’s just one reason why it should always be averaged over several dispersed sites throughout an area, over a given period.
Some regions have distinct “rainfall alleys” which seem to get the heaviest part of any rainfall. Such alleys can be just a few hundred metres wide and in other places perhaps 10km. I suspect that topography and surface hydrography has a lot to do with it.
Roger, it’s ‘Houston’.
Not to pick nits, but the Texicans spell the city “Houston”. No “e”. OK, so maybe I am picking nits.
Houston’s topography is flat and very low elevation, so water doesn’t readily drain off.
As a Houstonian who was hours late getting home because of all that H2O,
We get these sorts of monsoon-like storms as a matter of course.
I specifically recall April flood events from the 1970’s in April.
While we get street flooding, it is almost always cleared out in a few hours.
That picture you posted about yesterday’s flood is an open street today.
I know. I was stuck in one of those streets myself until about 10pm last night.
The rain in Houston was very fickle. The main +6 inches was in SW Houston like Sugarland; less than 0.1 inch in south Houston (League City); 0.5 to 1.5 in north Houston (Spring and Tomball). Typical thunderhead development and downpour.
I don’t know where the idea that the US is all desert comes from but Houston in fact gets about 50 inches of rainfall a year, i.e. about twice as much as Yorkshere – whoops, Yorkshire. Nothing in the least unusual about heavy rain there.
Does sound like typical convective deluges.
Seen some around the world, less severe nearer the poles.
Happens every so often here in England too where I could recount some surprising tales, of little interest outside of a locality. Looks as the Houston picture.
The density of rain-gauges reflects the random nature for some kinds of weather.
The UK is densely covered.
We live in old SW Houston, where the combination of old infrastructure and low lying land that is at or below the 1% flood risk elevation means we get some crazy fast street flooding.
The high water marks in surrounding areas was well up into front yards, meaning cars were stuck in > 1.5 foot deep areas. Last night was extremely lucrative for Houston car towing services, lol.
As a veteran of Houston high water, I did the prudent thing and stopped off at a good friend’s house for adult beverages and Mexican/Indian fusion home cooked food.
“Houston Forecast: Chance for severe weather overnight
Updated yesterday at 8:40 PM
HOUSTON – The National Weather Service has extended several weather warnings Saturday in regards to the severe thunderstorms moving through the Houston area.
The NWS has extended a flash flood warning for Brazoria, Fort Bend, Harris and Waller counties in effect until 9:45 p.m. A flood warning is in effect until 7:42 a.m. Sunday morning for Harris County.
A Severe Thunderstorm Watch is also in effect until 1 a.m. on Sunday for the following counties: Austin, Brazoria, Calhoun, Chambers, Colorado, Fort Bend, Galveston, Grimes, Harris, Jackson, Liberty, Matagorda, Montgomery, Polk, San Jacinto, Walker, Waller, Washington and Wharton.
The NWS said that thunderstorms capable of producing quarter-size hail and damaging winds up to 60 mph were moving southeast at 25 mph. Another line of storms will move through overnight increasing the chance of flashing flooding.
There is a 60 percent chance for rain on Sunday with temperatures in the mid-60s in the morning. The high should peak at about 80 degrees in the afternoon.”
— http://www.khou.com/weather
I’ve lived in Houston for the first 50 years of my life. It gets, on average, about 45 inches of rain per year, but in the spring, it can get a LOT of rainfall from heavy downpours. Flooding like this is an annual occurrence.
Looks like the records have changed.
http://www.wunderground.com/history/airport/KHOU/2013/4/27/DailyHistory.html
Bad record keeping always seems to make things look worse, no?
Sunday turned out completely beautiful/ My front yard has finally started to seriously green up after a dry cool winter and early spring.
Snowdog is spot on: Houston can flood and has flooded in any given month of they year.
Lived in Houston for a few years. Nothing unusual about this. I have seen what i took to be level ground in the space of a few minutes be buried under two inches of water and then watched as i discovered that there was a gradient to the land and that vast sheet of water was slowly flowing en mass “downhill”.
In Houston the expression — raining so hard you can’t see your hand in front of your face — has realty.
By the way, before Houston was a city — it was a large swamp.
Another thing about Houston rainfall — only place in the world you can stand in sunshine while across the street from you there is a “sheet of rain” falling. The demarcation line can be that abrupt.
“Houston, Texas isn’t a place noted for having a lot of rainfall” but, according to wiki, Houston gets about 50 inches of rain per year…..what constitutes heavy rain?
Listen to this: there was one 24 hour period in June, 2001, when parts of Houston got over 36″ (not millimeters) of rain.
“This set the stage for massive flooding in southeast Texas on on the 7th and 8th. The highest totals noted were 36.99 inches at the Port of Houston Texas, and 29.86 inches at Thibodaux Louisiana. Portions of Houston, Beaumont, Thibodaux, Lafayette, New Orleans, and Baton Rouge saw severe flooding from all this rain.”
I was there, then, and was on the opposite side of town from the port. We had a good 6 hours of the heaviest downpour I’ve ever seen. The kind where you walk outside and are immediately soaked to saturation, within a second or two.
http://www.hpc.ncep.noaa.gov/tropical/rain/allison2001.html
Wow. A yard of water in 24 hours!