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...METEOROLOGICAL DISCUSSION...

ISSUED: 1143 AM CDT SAT APR 30 2016
VALID: APRIL 30 THROUGH MAY 5
Day 1 Surface Map Jump To Hydro Section Jump To Hydro Section
Day 2 Surface Map

Day 3 Surface Map

...AN ACTIVE WEATHER PATTERN WILL CONTINUE INTO EARLY NEXT WEEK BEFORE A DRYING TREND BEGINS BY THE MIDDLE OF THE WEEK...

A series of weather producers will continue to affect the WGRFC area into the first part of next week. This will result in periods of showers and thunderstorms, as well as some periods of snowfall in the higher elevations of New Mexico and Colorado.

The first system is located over northwest Kansas this morning. This low brought precipitation to much of New Mexico and Colorado the past 24 hours. Further east, a dryline became active across central Texas. Numerous showers and thunderstorms developed across west Texas Friday morning which increased Friday afternoon over central Texas, then moved across east Texas and western Louisiana Friday night into early this morning. The heaviest rain occurred over east Texas where Marshall received 8.00 to over 9.00 inches. Palestine TX received just under 8.00 inches and Paris TX got 7.50 inches. The upper level low will lift northeast into southern Nebraska by this evening and most of the showers and thunderstorms will move east of our region. Mostly dry conditions are expected this afternoon and evening.

Meanwhile, a new low pressure system will be digging over Arizona on Sunday morning. This low will spread additional precipitation over New Mexico and Colorado starting tonight, with showers and thunderstorms spreading into west Texas Sunday afternoon into Monday. Also, a cold front is forecast to move into southeast Texas and will stall. This may result in additional scattered showers and thunderstorms near the Gulf coast later Sunday, especially from roughly Houston and Lake Charles into southern and central Louisiana. The main system will begin to weaken and will shift quickly east by Monday, and as the final trough moves across Texas there will be some residual rainfall over the southeastern half of Texas and western Louisiana Monday into Tuesday morning.

Drier conditions will finally return to the region later Tuesday and Wednesday into Thursday morning as a ridge of high pressure develops over the Rocky Mountains.



...PRECIPITATION FORECAST...

Day 1: 24-Hour Rainfall Total Day 2: 24-Hour Rainfall Total

For Today into Sunday morning, Mean Areal Precipitation (MAP) amounts of 0.25 of an inch or more are forecast over southeast Texas into Louisiana, as well as southern Colorado into northwest and north central New Mexico. The heaviest rain, with MAP amounts of 2.00 inches, are forecast along the lower Sabine River into southwest Louisiana. MAP amounts of less than 0.25 of an inch are forecast over the southeast quarter of Texas, the northern two thirds of New Mexico and most of Colorado.

For Sunday into Monday morning, MAP amounts of 0.25 of an inch or more are forecast from southwest Texas across central and east Texas into Louisiana, as well as over much of southern Colorado and the northern third of New Mexico. The heaviest rain, with MAP amounts of 1.00 inch, are forecast for southeastern Texas into southern Louisiana. MAP amounts of less than 0.25 of an inch are forecast over most of Texas and Louisiana, the northeastern three quarters of New Mexico and Colorado.

Day 3: 24-Hour Rainfall Total Day 4-5: 48-Hour Rainfall Total

For Monday into Tuesday morning, MAP amounts of 0.25 of an inch or more are forecast over roughly the southeast half of Texas, Louisiana, as well as over a few spots over northern New Mexico into southwestern Colorado. The heaviest rain, with MAP amounts of 1.00 inch, are forecast for the upper Texas Gulf coastline into southern Louisiana. MAP amounts of less than 0.25 of an inch are forecast over a good part of Texas and Louisiana, the northwest half of New Mexico and western Colorado.

For Tuesday into Thursday morning, MAP amounts of 0.25 of an inch or more are forecast over a few spots over southern Colorado and northeastern New Mexico. MAP amounts of 0.25 to 1.00 inch are forecast over the Gulf of Mexico southeast of Brownsville TX. MAP amounts of less than 0.25 of an inch are forecast over southeast and deep south Texas into southern Louisiana, over a good part of New Mexico and Colorado, and western Texas.

5 Day Total Rainfall Forecast

Soil moisture has rebounded this week as an active weather pattern has produced abundant rain. Soils are now very moist across a good part of the state, especially the eastern portions. Texas is now categorized as being 13% abnormally dry, with 2% in the moderate drought category. These dry areas are confined to the Texas panhandle and the far western portions of the state, with the remainder of the state free of drought. Over New Mexico, almost the entire state remains in the abnormally dry category, and 44% is in moderate drought. The rainfall which is forecast over the next 5 days will produce additional runoff into the rivers over the southeastern third of Texas and western Louisiana. Significant runoff can be expected because those areas have saturated soils. Elsewhere, only minor amounts of runoff are expected.

...HYDROLOGIC DISCUSSION...

Current - Hydrology Of The Day
Current - Status Map

...Trinity Basin...
...Major Flooding...
Heavy rainfall occurred over the last 24 hours over the lower Trinity River Basin. Both Cedar creek Reservoir and Lake Livingston are currently passing inflow from upstream runoff. These releases are generating moderate flood levels on the mainstem Trinity River at Trinidad (TDDT2) and Long Lake (LOLT2). The Trinity River at Liberty (LBYT2) is forecast to rise into major flood levels by the middle of next week.

For the upper Trinity, water supply reservoirs are passing inflows to maintain their conservation pools. Flood control reservoirs are also evacuating their flood pools. This is keeping the mainstem of the Trinity and its tributaries well above normal.

...Neches Basin...
...Major Flooding...
Rainfall observed overnight in the upper half of the Neches basin has pushed numerous forecast points into minor and moderate flood stage. The most significant precipitation occurred near Palestine where 7+ inches was observed and is driving one forecast point to Major flood stage. Neches River near Alto is forecast to crest at Major flood stage mid-week due to routed flow from upper basin runoff. As of Saturday AM, the lower half of the basin was still receiving precipitation. Observed precipitation and QPF is driving several of the points on the lower end of the basin to minor flood stage.

...Sabine Basin...
...Major Flooding...
Widespread heavy rain fell across the upper Sabine over the past 24 hours, which has led to several major flood forecasts. Lake Fork creek at Quitman and Rabbit creek at Kilgore reached major flood stage this morning, and Sabine River at Gladewater is expected to reach major flood levels early next week due to the locally heavy rainfall and routed flows. Sabine River at Longview and Beckville are expected to climb into moderate flood from the routed flow, but points beyond that along the mainstem river should only reach minor flood or action stage, including sites downstream of Toledo Bend.

...Brazos Basin...
...Minor Flooding...
Higher than normal flows continue on the lower Brazos River due to last weeks heavy rainfall, and the additional rainfall that occurred over the past 24 hours. Navasota River at Easterly (EAST2) and near Normangee (NGET2) are the only sites in this basin that are forecast to go into minor flood from the recent rainfall. The other 6 sites on the lower end of the Brazos river basin will only reach action stage.

...San Jacinto Basin...
...Higher Flow Non-Flood Forecasts...
The three sites within the San Jacinto basin that were expected to climb into action stage yesterday have been dropped because the rainfall amounts did not materialize.

...San Bernard Basin...
...Higher Flow Non-Flood Forecasts...
Heavy rain that fell over the past 24 hours has slowed the recession within action stage for SWYT2, but other points along the San Bernard River basin appear to remain below criteria.

...Colorado Basin...
...Higher Flow Non-Flood Forecasts...
Colorado River at Wharton (WHAT2) remains in action stage but is slowly falling. The widespread rainfall that fell over the past 24 hours has had little effect on the Colorado River basin.

...Remainder of WGRFC Basins...
Unsettled weather is in the forecast for at least the next 4 days. Location and amounts of rainfall will be critical in determining river response, but the heaviest rainfall is expected on Monday.

12z-24 Hour Rainfall Accumulation Total
Excessive Rainfall Forecast

5 Day River Flood Outlook Potential
Drought Monitor


Drought Outlook


...SUPPLEMENTARY GRAPHICAL INFORMATION...

The following URLs (all lower case) provide additional graphical information on current and forecast hydrologic conditions, past and future precipitation, and drought and climate forecasts. This information is provided by a variety of National Weather Service, NOAA, and private sector entities.

For specific information on river conditions, refer to the AHPS pages from the local NWS offices at: http://water.weather.gov/ahps/

The Flood Potential Outlook can be viewed on our webpage at: http://www.srh.noaa.gov/wgrfc/?n=wgrfcfop

The West Gulf River Forecast Center is now on Facebook: http://www.facebook.com/US.NationalWeatherService.WGRFC.gov

National Precipitation Analysis: http://water.weather.gov/precip/

The forecast rainfall amounts (QPF) can be viewed on our webpage at: http://www.srh.noaa.gov/wgrfc/?n=wgrfcqpfpage

The US Drought Assessment: http://www.cpc.ncep.noaa.gov/products/Drought

The latest on Reservoir Information for Texas: http://www.waterdatafortexas.org/reservoirs/statewide

STORY

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