Texas Spring-2015

[WeatherGuesser]

Several rounds of drenching rain in Texas this month — following a wet winter and early spring — entirely eliminated "extreme" drought in the state for the first time in nearly five years.

Just 15% of the state is now in a "moderate" to "severe" drought, the lowest percentage since October 2010, according to data released Thursday by the U.S. Drought Monitor, a federal website that tracks conditions.

Reservoirs are filling up due to all the rain: As of Wednesday, water storage in Texas' reservoirs had climbed to 78.5% of capacity — the highest in more than four years — meteorologist Brad Rippey wrote in this week's drought report.

Several rivers, including the Red River near DeKalb, Texas, and the Poteau River near Panama, Okla., climbed to their highest levels since May 1990, Rippey said.

http://www.usatoday.com/story/weather/2 ... /27727237/

[TeamPlayersBlue]

Lol, the October 2011 map is crazy. We have come a long way.

On the other hand, this Memorial Day weekend will likely be miserable.

[TheProfessor]

and i'm supposed to be going to sea world.

[TexasSam]

The neighbors and I were going to have a Bar-B-Que Memorial Day, but have called it off because the weather is looking awful.
Now watch it will be a beautiful day.

[Ntxw]

Corpus Christi just had 4.56 inches of rain in an hour

[gboudx]

Update from jeff:

***Potentially serious flood situation developing for the Memorial Day weekend.***

Models continue to come into better agreement that a slow moving potent upper air storm system will move into TX from the SW US late in the weekend. Deep tropical moisture surges into the region Saturday evening and by Sunday afternoon the air mass is saturated…this will result in efficient rainfall production. Upper level winds become strongly divergent Sunday night into much of Monday and possibly into Tuesday resulting in sustained lifting of the very moist air mass. Potential is there for several rounds of excessive rainfall Sunday-Tuesday with flooding likely.

Rainfall rates will increase Sunday with 2.0 inches per hour common under the stronger storms with greater hourly rates nearing 4.0 inches possible given the moisture profile expected by late Sunday. Widespread rainfall amounts of 3-5 inches with isolated totals of 5-8 inches will be possible.

With grounds saturated and area rivers already near or above flood stage significant flooding will be generated with the potentially forecasted rainfall amounts. Rapid flash flooding is also possible with the high hourly rainfall rates.

Given the ground and river conditions and the forecasted rainfall amounts along with the extended period of strong divergence aloft…this event is the most worrying of all those we have faced the last several weeks.

Residents are urged to keep up to date on weather conditions over the weekend and be prepared to act should flooding develop.

[Texas Snowman]

From KXII TV met Steve LaNore concerning Lake Texoma topping its spillway:

"UPDATE: 8:45 p.m. Thu 21 May 2015
The Army Corps now has the flood gates and hydroelectric releases totaling 35,000 cfs; this is slowing the rate of increase for Lake Texoma. It will not top the spillway before Sunday at the earliest, and more likely Monday or Tuesday. This projection is based on additional rainfall of two to four inches in the watershed. Without additional rainfall, the lake will probably stop just short of the spillway. However, rain is likely over the weekend, and heavy at times, so the odds still favor it topping the 640.0' opening early next week. Stay safe - Steve"

[gboudx]

As of last night Lake Lewisville was 1.8' from topping its spillway. Update from jeff:

***Heavy rainfall and flooding likely this weekend***

***Major river flooding increasingly likely next week***

Today:
A weak cool front has stalled overnight near the coast with surface winds out of the NE this morning advecting in a refreshingly drier air mass. Large surface high will slide eastward today allowing this boundary to begin to return northward as a warm front. Air mass along and south of this boundary will become increasingly unstable and areas radars already show showers/thunderstorms ongoing around Matagorda Bay this morning. Expect showers and thunderstorms to develop once low 80 degree convective temperatures are reached by early afternoon. Yet again…main threat is excessive rainfall with 1-2 inch per hour rates under the stronger cells.

Saturday:
Warm front will clear the area Saturday morning with a moist and unstable air mass firmly in place. Surface heating will likely bubble up more showers and thunderstorms during the afternoon hours with the greatest concentration likely along and N of US 59. Heavy rainfall remains likely with PWS starting to surge to 1.8 inches. Additionally, CAPE values rise into the 2500-3500 range which would support a few strong to severe storms.

Sunday-Tuesday:

Critical weather period is likely with excessive rainfall and high flash flood threat.

Numerous flash flood watches will be required during this period.

An unusually strong upper level storm system will slowly move into TX late in the weekend while a surge of extremely moist Caribbean Sea air moves into the region. PWS rise to near 2.1 inches by late Sunday. Jet stream dynamics become very favorable for spreading (venting) of the upper levels resulting in sustained lift across the region. Appears a large slow moving thunderstorm complex will develop over W/C TX late Saturday and progress into SE TX Sunday afternoon. High potential for repeat cell training with this complex and slow forward complex motion…yet cell motions along the leading band may be on the order of 20mph. Air mass will be nearly saturated and tropical by Sunday afternoon supporting “tremendous” rainfall rates. Could easily see rainfall rates of 2-4 inches per hour with the stronger storms. Severe threat will also be possible given the arrival of storm during the afternoon hours. Position of the core upper level divergence will keep high rain chances into Sunday night and all day Monday with either rounds of storms (best option) or a sustained period of cell training (worst option).

Hydrologic set up is very concerning with several rivers already near or above flood stage and grounds completely saturated. Flash Flood Guidance is running around 2.5 inches for 1-hr and 4.0 inches for 6-hr…this could easily be exceeded in 1-hr with the incoming setup. Given the rainfall setup and saturated grounds significant run-off will result from excessive rainfall and push already flooding rivers into moderate or major flood levels.

Rainfall amounts will average 2-4 inches across the region with isolated totals of 4-6 inches possible. This is certainly the setup where 10 inches or greater of rainfall can occur and we have been such totals at least 5 times over SE TX in the last 10 days.

Hydro:

Trinity River:
Major river flooding is in progress at Liberty with homes threatened and numerous subdivisions and residences cu –off. River crossed over into major flood level this morning and will hold at this level for the next several days. Releases will continue from Lake Livingston due to upstream flood flow moving downstream from N TX (river is still rising this morning at Dallas). Releases may have to be increased this weekend to manage the upcoming rainfall event and upstream flows. The river at Liberty, TX is currently 1.9ft below record flood level set in October 1994.

Brazos River:
River is above flood stage at Rosharon with minor flooding in progress. Flood wave from Monday’s rainfall on the Brazos River above Hempstead has passed Richmond yesterday and moving toward Rosharon today. River will begin a slow fall today as the flood wave passes, but forecasted rainfall this weekend will likely result in a new rise early next week.

Navasota River:
River is above flood stage below Lake Limestone and will crest this weekend. Heavy rainfall will likely impact the basin before the river is able to fall back within banks

San Bernard River:
The river has crested and is falling back within banks today. Heavy rainfall this weekend will almost certainly push this river above flood stage.

Guadalupe River:
Moderate flooding is in progress at both Victoria and Bloomington. River will crest late today into this weekend, but remain above flood stage into the weekend. Additional rainfall will only worsen ongoing flooding.

Nueces River:
Major flooding is in progress along much of the entire river basin from Asherton, TX downstream to near Corpus Christi, TX. River is potentially more than a mile wide along portions of the channel with several sections of the floodplain inundated and livestock along the river potentially cut-off and drown.

Neches River:
Flooding is in progress along the entire river basin.

Sabine River:
Flooding is in progress both above and below Sam Rayburn Reservoir. River will remain in flood for the next several days.

As one may guess….additional rainfall is only going to make the current river flood situation worse!

[TheProfessor]

hmm... there are now 2 disturbances in the EPAC, I wonder if one or both of them will keep this wet pattern up?

[Ntxw]

As if that wasn't enough another heavy rain event looks in the works Monday night-Weds night time frame with another shortwave. Continue to watch the EPAC off the Mexico as development of a tropical system there is becoming likely by late week next week. Even if it doesn't recurve to us, it will sling more moisture at us as the atmospheric weakness sits over Texas...still.

[gboudx]

from jeff:

All,

Be advised that the integrity of the dam on Lewis Creek Reservoir in Montgomery County is in question. SJRA is meeting with officials at the moment to access the situation. Current elevations of Lewis Creek Reservoir suggest that most of the water in the event of a failure can be absorbed into the Lake Conroe pool resulting in a rise on the lake of about 1 ft, but will require flood gate operations at the lake and downstream rises on the West Fork of the San Jacinto River.

The situation is “serious”, but at the moment a failure does not appear imminent.

[wxman57]

How long can this El Nino last? I thought it was supposed to be a minor one, but seems it's blown out of control. In the past, El Nino's tended to last a much shorter time and droughts lasting much longer.

El Nino is only just beginning. Wait until fall/winter if it becomes as strong as forecast. California may be begging for dry weather again.

[TeamPlayersBlue]

How long can this El Nino last? I thought it was supposed to be a minor one, but seems it's blown out of control. In the past, El Nino's tended to last a much shorter time and droughts lasting much longer.

El Nino is only just beginning. Wait until fall/winter if it becomes as strong as forecast. California may be begging for dry weather again.

This. I noticed that in 97-98, there was a bit of very warm water off the coast as they are expecting this winter as well. I dont think the high pressure will be very persistant this winter. Liking the idea of being a good ski season though!

[Ntxw]

WSI energy has a good blog on our biblical rains if you want to understand why. Though we all know why already. As wxman57 said come fall and winter it will be California's turn.

[aggiecutter]

How long can this El Nino last? I thought it was supposed to be a minor one, but seems it's blown out of control. In the past, El Nino's tended to last a much shorter time and droughts lasting much longer.

El Nino is only just beginning. Wait until fall/winter if it becomes as strong as forecast. California may be begging for dry weather again.

You still think it will snow in Austin on Memorial Day.

[EF-5bigj]

Well if California gets as drenched as Texas I can see mud slides being a major hazard there.

[Texas Snowman]

Rain and thunder, thunder and rain. The daily cycle continues in the Red River Valley.

Austin College WX Station reporting 10.54 inches for May so far, after more than eight plus inches in April.

Texoma is 637.86 feet, a little more than two feet from topping the spillway.

I could have sworn we were in a drought not too terribly long ago.

[vbhoutex]

from jeff:

All,

Be advised that the integrity of the dam on Lewis Creek Reservoir in Montgomery County is in question. SJRA is meeting with officials at the moment to access the situation. Current elevations of Lewis Creek Reservoir suggest that most of the water in the event of a failure can be absorbed into the Lake Conroe pool resulting in a rise on the lake of about 1 ft, but will require flood gate operations at the lake and downstream rises on the West Fork of the San Jacinto River.

The situation is “serious”, but at the moment a failure does not appear imminent.

Currently work continues to shore up the dam and keep it from sloughing. So far so good. Hope it holds. /thank goodness it will go into Lake Conroe if it fails. I haven't heard of any danger to homes etc. nearby.

edit to add Jeff L. update:

Inspection of the dam today has revealed 8 locations where portions of the dam face have eroded. At least 50 personnel are onsite actively working several of these “potential failure” locations. Some of the locations will require roads to be constructed to reach the areas damaged due to extremely soft ground. Sandbags and berms are being constructed and deployed around the potential failure locations along with tarps covering the erosion to help prevent additional damage to the dam. Additionally, Entergy, the reservoir owner, is releasing water to help relieve pressure against the dam. All measures are currently being taken to attempt to secure the integrity of the structure and to prevent a failure or breach.

Breach analysis preformed this morning indicated that a failure of the Lewis Creek Dam would result in 10-12 inch rise in the pool elevation of Lake Conroe. Significant downstream flooding along Lewis Creek to Lake Conroe would be possible.

With the current increased releases from Lewis Creek ongoing, the pool elevation of Lake Conroe already elevated, and the potential for excessive rainfall SJRA has started controlled releases at Lake Conroe this afternoon of 4230cfs to start lowering the lake level in anticipation of the upcoming rainfall event and the remote possibility of a failure at Lewis Creek.


Additional information and press releases can be found at the Montgomery County EOC website: http://www.mctxoem.org/go/site/1945/

[Texas Snowman]

Per KXII-TV, inflow into Lake Texoma is 135,000 CFS this evening. Discharge at Denison Dam is 35,324 CFS.

Lake level as of 7 p.m. was 638.05, now less than two feet from topping the spillway level of 640.00 feet.

[Ntxw]

Flash Flood watches have resumed for much of the state of Texas (and Oklahoma)



BTW this May is the wettest month (any month) ever for Wichita Falls. Historic for some parts of the state, rivaled only by 1957, 1982, 1991, and 1997. All of them were associated with major El Nino.