Texas Spring-2015

[TheProfessor]

I know it's still spring, but are there any signs that show summer looking like the summers of 2007 and 2004? If it does there are going to be some serious flooding issues. I remember the park across the street from where I live flood in 2007 and in 2004 the trinity river flooded.

[Ntxw]

I know it's still spring, but are there any signs that show summer looking like the summers of 2007 and 2004? If it does there are going to be some serious flooding issues. I remember the park across the street from where I live flood in 2007 and in 2004 the trinity river flooded.

+PDO Nino summer, probably cool snaps like the past 3, we'll more than likely see the least days with 100+ of the past 5 years and quite possibly less than 10. CFS shows subtropical jet continue to rage meaning cloud cover will be persistent as it has been. I'm not sure about 2004 or 2007 analogs but May patterns often hint at summer. 1957-1958, 1965-1966, 1982-1983, 1990-1991, 1997-1998 are get sets with similar strength STJ, all feature less than 10 days and many less than 5 days of 100+ for DFW. Vegetation is as lush and green as I have seen it in a long time it will be tough to get heat waves. The wet conditions extends beyond just Texas but all across the plains. Ridges won't be able to sit.

[Shoshana]

Just read that Texas has no Exceptional Drought!

At the same time, from May 5 to yesterday afternoon, we have had seven inches of rain at our house. And it's raining right now. I need it to stop raining long enough for us to mow before it looks like a jungle.

At least we don't have to worry about flooding.

[Ntxw]

If guidance is correct, an MCS will come together tonight into tomorrow morning from West Texas and cross the I-35 corridor. Possibly again Friday night into Saturday morning. And again Saturday night into Sunday morning, and another heavy round of MCS again Sunday night into Monday morning. During the daytime hours it's more spotty with on and off severe weather possibilities.

[weatherdude1108]

Just read that Texas has no Exceptional Drought!

At the same time, from May 5 to yesterday afternoon, we have had seven inches of rain at our house. And it's raining right now. I need it to stop raining long enough for us to mow before it looks like a jungle.

At least we don't have to worry about flooding.

Oh my gosh, my yard is turning into a meadow! It has been too wet to mow lately, even between rainstorms. Too much dew. I'm hoping to get that done soon. Our backyard gets ponding near the rear of the property, and sometimes gets under garage if heavy and long enough the way our driveway is sloped. But nothing bad.

I saw on the news that Lake Travis is at its highest level in more than two years (since April 2013).

http://kxan.com/2015/05/13/highland-lak ... t-drought/

[weatherdude1108]

If guidance is correct, an MCS will come together tonight into tomorrow morning from West Texas and cross the I-35 corridor. Possibly again Friday night into Saturday morning. And again Saturday night into Sunday morning, and another heavy round of MCS again Sunday night into Monday morning. During the daytime hours it's more spotty with on and off severe weather possibilities.

Overnight/early morning MCS's are my favorite kind of thunderstorms. They tend to not be too severe, but are scary enough to get your attention and wake you up at night. They used to happen regularly in the Spring/early Summer when I was a kid growing up in San Antonio. Good old storms with lightning, thunder, and heavy rain.

[Ntxw]

I saw on the news that Lake Travis is at its highest level in more than two years (since April 2013).

http://kxan.com/2015/05/13/highland-lak ... t-drought/

Interesting these lake chains. I think the way they work we'll have to see the upper basin lakes fill up first (lets watch Buchanan) Once it fills up then prognostics for Lake Travis will be better. It's when upstream lakes have to release that the lower end lakes benefit. I wonder why these higher elevation lakes takes so long to fill up compared to the more flat plain lakes like in east and North Texas. Is it because of their depth due to elevation? I notice it here as well as the western areas have seen dumpings of rain but the higher elevation lakes such as Possum Kingdom are much more slower to respond.

[TeamPlayersBlue]

Travis has been getting solid rain into the lake as well, but yes, upstream is very important.

[weatherdude1108]

I saw on the news that Lake Travis is at its highest level in more than two years (since April 2013).

http://kxan.com/2015/05/13/highland-lak ... t-drought/

Interesting these lake chains. I think the way they work we'll have to see the upper basin lakes fill up first (lets watch Buchanan) Once it fills up then prognostics for Lake Travis will be better. It's when upstream lakes have to release that the lower end lakes benefit. I wonder why these higher elevation lakes takes so long to fill up compared to the more flat plain lakes like in east and North Texas. Is it because of their depth due to elevation? I notice it here as well as the western areas have seen dumpings of rain but the higher elevation lakes such as Possum Kingdom are much more slower to respond.

It is drier on average at those watersheds in West Central Texas that feed Lake Buchanan. The lakes between Buchanan and Travis are kept at a constant level. Lake Austin below Lake Travis is also kept at a constant level. There are hydroelectric generation operations on all the lakes except Inks Lake which has just a spillway. They pass water through hydroelectric generation on those dams, unless the flow is too much, then they move to the flood gates. Buchanan and Travis fluctuate based on water released and floods. Lake Travis was originally built as a flood control reservoir based on a catastrophic flood on the Colorado River that flooded downtown Austin. It can hold a tremendous amount of flood waters. The LCRA releases water at certain levels when it gets above the flood pool of 681 depending on conditions upstream and downstream. The top of the spillway is 714 feet. Mansfield Dam (holding in Lake Travis) has 24 floodgates it can use if necessary to protect the integrity of the dam if upstream conditions warrant it. The lake also functions to store the floodwaters in times of drought, which is what it has been doing.

http://www.lcra.org/water/dams-and-lake ... d-dam.aspx
http://www.lcra.org/water/dams-and-lake ... n-dam.aspx

Lake Buchanan stores water for the communities surrounding it. It releases water downstream through the chain if that lake gets to its full elevation. Travis gets water from the lakes upstream along the Colorado, and the Pedernales River to the west, along with several smaller tributaries in the basin. Buchanan gets it from the Colorado River, San Saba River, and smaller tributaries in the basin.

I think from what I have read, Lake Buchanan has gotten shallower due to the silting in of sediment brought in by the tributaries and mainstem of the Colorado River, which means it may hold less water in general. I-35 seems to be the divide lately for heavy rainfall amounts (east) to not as much (west). Not sure about the higher elevation lakes up in north Texas. I'm guessing they are generally drier and have been hit the hardest by drought (even worse than the Highland chain).

They were saying on the news about a week ago that if these flooding rain events over the past couple of years had been 30 to 60 miles to our northwest and west, Lakes Buchanan and Travis would likely be near average or full. Adding a caveat to that, if LCRA had not released a normal amount of water downstream to the rice farmers to flood their fields back in 2011 (hottest year on record), the lakes would be in much better shape.

A lot of the flooding events over the past years have been downstream of Travis and Buchanan. So LCRA has had to release water from Lake Austin several times to keep it level, and all that water went to the Gulf of Mexico, not able to be captured. They are building a reservoir downstream to take advantage of those events downstream to help the rice farmers and keep more water upstream. They have also cut off the farmers (interruptible) for the past three years with permission from the TCEQ to keep water upstream since the inflow into the lakes has been at record lows. The downstream farmers have historically had the first rights to the water since the 1930s I think(?). There seems to be a bubble over the lake chain for some reason. But while it is saturated, every rain it gets now will run off at least.

Note that both dams had historic highs back in December 1991. Wasn't that an El Nino year?

[TheProfessor]

I was reading Steve McCauley's Facebook and a conversation lead him to say that global warming models predicted tornado intensity to increase and then said that the last 5 years that they have. Am I missing something? Other than the 2011 outbreak and El Reno it's seem like tornadoes haven't been nearly as intense as they were between 1990-2008. In that period you have 4 of some of the strongest tornadoes seen in Andover, Jarrell, Moore, and Greensburg. 1 of those is the strongest tornado ever recorded and another might be the most destructive tornado to ever occur ( there wasn't any debris left).


P.S if this post breaks a rule tell me and I'll delete it.

[TeamPlayersBlue]

I was reading Steve McCauley's Facebook and a conversation lead him to say that global warming models predicted tornado intensity to increase and then said that the last 5 years that they have. Am I missing something? Other than the 2011 outbreak and El Reno it's seem like tornadoes haven't been nearly as intense as they were between 1990-2008. In that period you have 4 of some of the strongest tornadoes seen in Andover, Jarrell, Moore, and Greensburg. 1 of those is the strongest tornado ever recorded and another might be the most destructive tornado to ever occur ( there wasn't any debris left).


P.S if this post breaks a rule tell me and I'll delete it.

I think its a very shallow argument for the models to make that the intensity of tornadoes increases with GW.

[Ntxw]

I was reading Steve McCauley's Facebook and a conversation lead him to say that global warming models predicted tornado intensity to increase and then said that the last 5 years that they have. Am I missing something? Other than the 2011 outbreak and El Reno it's seem like tornadoes haven't been nearly as intense as they were between 1990-2008. In that period you have 4 of some of the strongest tornadoes seen in Andover, Jarrell, Moore, and Greensburg. 1 of those is the strongest tornado ever recorded and another might be the most destructive tornado to ever occur ( there wasn't any debris left).


P.S if this post breaks a rule tell me and I'll delete it.

It is very hard to differentiate what is man-induced and what is natural variability. The ocean cycles also have a say in tornado activity as well. 2011 was on the heels of a very powerful La Nina of 2010-2011, just as 2008 was a big tornado year after the 2007-2008 La Nina. 1999 May outbreak (Bridge Creek/Moore tornado) was after the heels of the 1998-1999 super La Nina the correlation there is much stronger than global warming can prove. Before we even consider something like that we need to fundamentally understand the Oceans first and their role.

The PDO is a player as well. From early 1970s, tornado outbreaks (1970-1974) were intense with many strong ones during the cold PDO Ninas. Then 1976-1995 was relatively quiet in when the PDO flipped warm. Late 90s saw the PDO flip cold for a short period with more outbreaks then shut down again in 2002-2006 when the PDO warmed. 2007 Greensburg ended the drought with the first EF5 since 1999 when the PDO flipped again that stayed cold through 2013 with 2011 being the apex of back to back Ninas. Last year and this year it has flipped warm, there have been no EF5's since 2013 to date. PDO is often tied with La Nina's and El Ninos.

[Ntxw]

Note that both dams had historic highs back in December 1991. Wasn't that an El Nino year?

Yeah 1991 was a moderate to strong El Nino.

[EF-5bigj]

I don't believe in global warming/climate change but I do think weather patterns play a big role in tornado intensity. La Niña obviously has caused the biggest most violent tornado outbreaks but El Niño is no slouch with violent tornadoes either. But we still don't understand a lot about what causes tornadoes the small level things that aren't on obvious. Violent tornados maybe caused by subtle atmospheric changes.

[TeamPlayersBlue]

If anything, i would think El nino would be an indicator for more tornadoes, but one think JB points out is the temps in the 400 MB layer. Some interesting stuff he used to highlight a few years back.

[Ntxw]

I don't believe in global warming/climate change but I do think weather patterns play a big role in tornado intensity. La Niña obviously has caused the biggest most violent tornado outbreaks but El Niño is no slouch with violent tornadoes either. But we still don't understand a lot about what causes tornadoes the small level things that aren't on obvious. Violent tornados maybe caused by subtle atmospheric changes.

I agree, the overall idea is, La Nina brings the jet down in the west and that pattern favors tornado outbreaks. With the strong North Pacific jet overhead you get a lot of shear for turning. The more outbreaks you have the more likely you will see violent tornado's. El Nino's feature the weaker subtropical jet which often creates lots of rain and can damper some outbreaks as we have seen this year with early day cloud cover and convection. However there are individual events (such as Jarrell) where there isn't a big outbreak but locally can still put down an intense tornado even during El Nino. But the probabilities favor La Nina.

We have a severe thunderstorm watch in West Texas. Lets see what conglomerates that way and if it sends us an overnight MCS.

[EF-5bigj]

The Jarrel,TX F-5 was pretty unique it didn't form on a classic supercell but it chewed up everything in its way to a extreme degree. Was Greensburg during a El Niño??

[Ntxw]

The Jarrel,TX F-5 was pretty unique it didn't form on a classic supercell but it chewed up everything in its way to a extreme degree. Was Greensburg during a El Niño??

Oncoming super La Nina 2007-2008

[TheProfessor]

And that's exactly what I was thinking, the different tornado outbreaks occurred because of the different patterns we see in the oceans, the same goes for hurricane season as well, I believe 2005 was a La nina year, though 2004 was a strange season, but 2004 wasn't your typical el nino as well.

[Ntxw]

Speaking of the Oceans, remember talk of re-curving typhoons? Noul is buckling the jet stream inducing a -EPO episode over North America! Cold front coming, not the same meaning as in winter but should cool the country off. Split flow underneath means continued wet weather for Texas. May also be the chatter of the outbreak around the 20th with the change.