When it rains...!

Up to 5" of rain fell in many neighborhoods across southeast Texas on Friday.  It was the first widespread soaking shower that some of us have had in seven months!  And there's more rain coming.

The slow moving storm pushed into the Houston area between 4-5 PM and it rained pretty much non-stop for about six hours!  Because the ground was dry, the water from the torrential showers rain off and collected in the streets, flooding many intersections and low-lying spots.

The map below shows the rainfall amounts estimated by Doppler radar.

Here are some specific rainfall totals from our exclusive network of Eyewitness Storm Spotters:

• 4.24" Texas City  Dee Ann Haney
• 3.70" Sugar Land  Kenneth Ellington
• 3.28" Richmond  Jeff Foltz
• 3.55" Norchester Debbie Lane
• 2.80" Jersey Village  Gary Faulkenberg
• 2.50" Hempstead  Jason Duke
• 1.85" Kingwood  Vernon Reed
• 1.75" Columbus  Charlie Herchek
• 1.19" Pasadena  Terri Williams
• 1.10" Sealy  Everett Crayne
• 0.90" Woodlands  Lori Hooper
• 0.64" Conroe  Paul Basile
• 0.64" Tomball  Lee Suleki

Now that the ground is saturated, any additional heavy showers are likely to cause more flooding problems.  You can track the storms online with our Live MegaDoppler 13 and our Interactive Weather Map.  If you're out and about this weekend, check out our mobile website on your web-enabled cellphone:  www.abc13NOW.com.

Large deadly tornadoes are not common in the Houston area

So far this year, 16 people have died from tornadoes tearing across Mississippi, Arkansas, Kansas and Oklahoma.  And all of these storms have developed in the last four weeks.

The large, wedge shaped tornadoes captured on video by storm chasers are responsible for most of the deaths and damage. These storms were classified EF-3 and EF-4 on the Enhanced Fujita Scale which ranks tornado damage on a scale of 0 to 5. That means the winds were probably blowing 150-200 mph.

Fortunately, the tornadoes that develop around Houston and Galveston are usually not as big.  Most of our twisters are small, short-lived tornadoes that develop and touch down very quickly.  We tend to have more EF-0 and EF-1 tornadoes although occasionally a stronger storm will develop. 

On November 21, 1992 a tornado outbreak produced six tornadoes in Harris County.  One twister that hit Channelview was almost a mile wide and was ranked an EF-4.  To date, that’s been the biggest tornado on record in this area.

Photo from ABC News.

Warmer Temps make for Stronger Storms

Strong south winds should help boost the temperatures this weekend. But the warmer air will also help some thunderstorms develop on Sunday.

Our exclusive FutureTrack forecast modelshows scattered storms developing during the second half of the weekend.  Temperatures should reach the low 70s by Sunday and the extra warmth and moisture will make the atmosphere a little unstable.  There is a slight risk some of the storms could produce large hail and damaging winds.

Don't think we're done with winter. Temperatures will fall behind the storms.

Another round of rain on Tuesday could be mixed with a little sleet and/or snow depending on fast we cool down.

2009 brought extreme weather to southeast Texas

We began the year 2009 with a drought which actually started to develop in the fall of 2008.  Widespread, soaking showers didn't return until April, when two separate weather systems dumped heavy rain and caused flash flooding. The thirsty ground easily soaked up the water, bringing an end to the drought.

We turned up the heat during the summer. The high temperature was 100° or hotter seventeen times between June, July and August. We hit 104° on June 24 and 26, the hottest it has ever been in June and just five degrees shy of the all-time hottest temperature ever recorded in Houston. Overall, the summer of 2009 was the second hottest on record!

The heat wave finally broke in early September when the first of many cool fronts brought our temperatures down to more seasonable levels.  A series of fronts in October brought more heavy rain, easing the drought conditions which started to re-develop during the summer.

No tropical weather systems tracked toward southeast Texas during the year 2009. But we did have a few severe weather events. Severe thunderstorms on March 27 produced a small tornado in Cleveland and pummeled the ground with baseball size hail. A waterspout moved ashore in Galveston on August 30 and produced minor damage along the Seawall. A few weeks before that, a tornado touched down in Beaumont.

The biggest weather event for many happened late in the year. A blast of cold air brought some snow to southeast Texas on December 4. It was the perfect ending to a weatherful year.

Strong Front Brings Storms Tonight, Cold for Christmas

Evening Update:

A new tornado watch now includes all of southeast Texas and expires at 6AM or when the front pushes through.  The atmosphere is becoming increasingly unstable in advance of a strong upper level storm pushing our way from west Texas.  Winds in the upper atmosphere are topping 140 mph, and as these strong winds move overhead, the threat of severe storms will increase.  A squall line should develop along or just ahead of the front, and the severe threat will transition from isolated tornadoes to damaging straight line winds. 

You can track the storms on our website with our interactive street-level mapping and Live Mega Doppler 13 HD. 

Previous Discussion Follows:

While a blizzard rages in the plains, severe storms are set to move into Houston overnight.  It's all part of a strong cold front that will put a chill in the air for Christmas.

A tornado watch is in effect until 9PM starting just north of Houston and stretching all the way past Dallas/Fort Worth into Oklahoma.  So if you're traveling up I-45 or Highway 59 tonight, be careful!  Strong southerly winds are blowing in warm, unstable air, and strong upper level winds could cause storms to start rotating.  If a rotating storm is picked up on radar, tornado warnings will likely be issued.

The tornado watch does not include Houston, but we're not in the clear yet from stormy weather.  A strong cold front will push through tonight, and a squall line is likely to race overhead in the hours after midnight.  Our exclusive FutureTrack computer model shows the squall line rolling into Houston around 3AM.  Winds behind the front will blow strongly out of the northwest with some wind gusts on Christmas Eve approaching 40 mph!

This front opens the door to some chilly weather that will hang around for the rest of the year!  Given the pattern, there is a chance that between Christmas and the New Year we'll see wintry precipitation fall somewhere in Texas. 

We all know that snow is rare here in Houston.  Multiple snowfalls in the same winter are even rarer.  Interestingly enough, whenever we've had multiple snowfalls in the same winter, the second snowfall has occurred almost exactly a month after the first.  Take a look at the 5 winters on record with multiple snowfalls:

1. 12/28/1925 and 1/26/1926
2. 1/14/1963 and 2/12/1963
3. 1/11/1973 and 2/9/1973
4. 1/19/1981 and 2/11/1981
5. 1/2/1985 and 2/1/1985

If it snows deep into the heart of Texas next week, history says it would be right on schedule.

Severe weather often develops this time of year

Here in the south we have a second severe weather season in the fall. Some years we have more severe weather in October and November than we do during spring.

This time of year, there’s still plenty of warm, moist air sitting over the Gulf. All it takes is a good strong wind to blow the moisture inland where it often collides with strong cold fronts dropping in from Canada. The result is often widespread severe weather.

We saw an example of that last week. A strong storm dumped over three feet of snow in the Rockies. When the front edge of that cold air pushed into the middle of the country it produced heavy rain and severe weather from Texas to Minnesota, from the High Plains to the East Coast. 

It felt like summer with high heat and humidity before the front arrived. Afterward, the sky cleared out and temperatures fell twenty degrees. That change from one season to the next over just a few hours causes much of our severe weather.

The jet stream has shifted north, taking us out of the storm track for a few days. We have lots of sunshine and mild temperatures in our forecast...until the jet stream wiggles again and sends another storm our way.

TowerCam video of storms rolling into Houston

We captured video of the squall line as it moved into Houston early Monday morning. This was the beginning of the wet weather that lasted all day.

The Eyewitness Storm Spotter volunteers reported between 1-3" of rain from the storms on Monday. A few spots got a little more because of training showers moving over the same area.

If you don't see a rainfall report for your neighborhood, consider joinging our network of weather observers. All you need is an accurate rain gauge.  If you're interested, send me an email: tim.heller@abc.com

 

Friday morning rush hour could be messy

Set your alarm a little earlier so you have time to get to work Friday morning.

A cool front will push into southeast Texas about 4:00 AM with a line of strong thunderstorms. The rain will likely be heavy. That will leave us with wet streets and some high water in low-lying feeder roads. Some of the storms could also produce straight line thunderstorm winds. There is a slight risk that severe weather warnings could be issued with these storms.

You can track the storms in real-time with our streaming Live MegaDoppler 13.  Or get a close-up look on our county-by-county radar maps.

This front will stall across the area giving more rain for the weekend. We expect periods of heavy rain, especially on Sunday. More rain is also possible early next week. As I mentioned during Eyewitness News on Wednesday, we could see 3-5" of rain over the next five days.

Damage report from Galveston tornado

Meteorologists from the Houston-Galveston National Weather Serice office surveyed the damage caused by the tornado in Galveston Sunday evening. A waterspout moved ashore just before 10 PM and damaged several buildings on the front side of the island.

Here is the NWS report, edited for punctuation:

At around 9:48 pm on Sunday, August 30, a waterspout moved onshore on Galveston Island near the intersection of 29th Street and Seawall Blvd. The tornado then produced an intermittent damage path for about one third of a mile to the northwest, ending near the intersection of 31st street and Avenue R. Several structures were damaged including the Dolphin World souvenir shop where windows were shattered and most of the metal roof was peeled off. A Galveston police department patrol car had its windows blown out in the same area. Heading further inland, the tornado pushed over a home on stilts and removed most of the roof of a mobile home. Another home at the intersection of 31st Street and Avenue R had its roof completely removed. Beyond this location damage was limited to small tree limbs and some shingles removed from roofs.

The observed damage suggests wind speeds in the 80 to 90 mph range, with maximum winds leading to an EF-1 rating on the Enhanced Fujita Scale. Damage path length was around one third of a mile, with a width of around 100 feet. There were three injuries reported. Two police officers, who were in the patrol car when its windows shattered were treated and released. Another man who was thrown against a wall remains hospitalized at UTMB.

Click here to see video of the damage.

Storm chasers catch Nebraska tornado

Over 80 tornadoes have been reported across the country since Sunday. Some areas have been hit more than once.

Storm chasers captured this video of a twister outside of Aurora, Nebraska on Wednesday. The large wedge tornado was about a half-mile wide and stayed on the ground for about 18 minutes. Despite the damage, there were no injuries.

The Storm Prediction Center expects another outbreak of severe weather across the midwest and northeast on Friday and Saturday.

The storms are developing around the edge of the hot high pressure that's keeping our temperatures in the upper 90s.