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527 AGUS74 KFWR 271711 HMDFWR HYDROMETEOROLOGICAL DISCUSSION NATIONAL WEATHER SERVICE...WEST GULF RFC...FORT WORTH TX 1211 PM CDT WED MAY 27 2015 VALID MAY 27 THROUGH JUNE 1 ...ADDITIONAL HEAVY RAINFALL IS EXPECTED ACROSS NORTH TEXAS THE NEXT 24 HOURS... ...METEOROLOGICAL DISCUSSION... An upper level disturbance moved over North Texas yesterday causing some additional heavy rainfall and severe weather to impact portions of North and Southeast Texas. Total rainfall amounts of 3-4 inches were reported across Southeast Texas during the early morning hours. As a result, this heavy rainfall caused some additional rises across the San Jacinto and Brazos River systems. Currently, the activity associated with the upper level disturbance is moving off towards the east. The heaviest precipitation has moved offshore and is not significantly impacting any of the coastal basins at this time. For the remainder of the day, scattered showers and thunderstorms are expected for a good portion of the WGRFC area, due to the very unstable environment in place. However the main area for any organized activity is expected across North and Central Texas during the late afternoon and evening hours. Rainfall amounts of 0.50 to 1.00 inch are expected for areas along and north of I-20, with some higher isolated amounts possible. By tomorrow morning a new upper level disturbance is forecast to approach our region from the west. Showers and thunderstorms are expected to initially develop over eastern New Mexico and far west Texas by tomorrow morning. This rain will then move further northeast and cover the northwest half of Texas during the day tomorrow into Friday. Some locally heavy rainfall is forecast over northwest Texas during this time frame. The first disturbance is forecast to move northeast of our region by Friday night. Thereafter, minor upper air disturbances are forecast to cross north Texas Saturday into Sunday. Additional rainfall is forecast, especially over the western parts of north Texas, and the WGRFC will continue to monitor this storm and update as needed. ...PRECIPITATION FORECAST... For Today into Thursday morning, Mean Areal Precipitation (MAP) amounts of up to 1.00 inch are forecast for portions of Northeast and East Texas. Lesser amounts are forecast for areas mainly along and west of I-35. For Thursday into Friday morning, MAP amounts of up to 1.00 inch are forecast for portions of Northwest and West Texas....mainly for areas along and west of I-35. For Friday into Saturday morning, MAP amounts of up to 1.00 inch are forecast for areas along and north of I-20. For Saturday into Monday morning, MAP amounts of 0.25 to 0.50 inch are forecast for most of the WGRFC area...excluding the Texas Panhandle. Drought conditions continue to improve across most of the WGRFC area. Recent precipitation events have brought drought relief to many parts of Texas. In Texas, only about 15% of the state is experiencing moderate or worse drought, and extreme to exceptional drought conditions are no longer being observed. In New Mexico, a little over a third of the state is experiencing moderate or worse drought (37%), and they also are free from extreme or exceptional drought conditions. Many of the lakes in Texas have levels which have risen due to recent rainfall, and some lakes are full and are releasing water. The rainfall expected over the next five days over especially the northern half of Texas will be heavy enough to produce significant runoff, and minor runoff is expected over the remainder of Texas. Elsewhere over the WGRFC area no significant runoff is anticipated. ...HYDROLOGIC DISCUSSION... ...Guadalupe Basin... ...Major Flooding... The recent Flood Wave generated by very heavy, localized rainfall around Luling area has moved downstream; now moving through Gonzales (GNLT2) within moderate flood. This Flood Wave is following the heels of the Wimberley Flood Wave that passed earlier this week, bringing another rise near major flood. Downstream at Cuero (CUET2), the high flows from Peach and Sandies Creeks join which will add to duration and possibly the crest height. Both these flood waves have caused major damage along its path of the Blanco and San Marcos River mainstem, and now moving along the Guadalupe mainstem. These combined waves are expected to cause major flooding as it moves downstream along the mainstem through Cuero (CUET2), Victoria (VICT2), and Bloomington (DUPT2) to the coastal outlet. This event comes in the wake of an earlier Flood Wave still moving further downstream; now cresting through Bloomington (DUPT2). ...Nueces Basin... ...Major Flooding... Inflows into Choke Canyon Reservoir are on the increase. The Frio River near Derby (DBYT2) has crested within moderate flood level. This will cause a rise downstream at Tilden (TIDT2) in to minor flood late in the week. Choke Canyon is well below the top of the conservation pool at this time and is increasing only slowly. On the Nueces River, upstream points at Asherton (ASRT2) and Cotulla (COTT2) have crested and will remain near steady to slowly falling. Water is now moving downstream to Tilden (TILT2), which will be rising into major flood over the next few days. Three Rivers (THET2) will be rising into moderate flood late in the week. Inflows into Lake Corpus Christi will once again be on the increase this week due to these rises. Releases are up slightly to 4120 CFS, which will lead to near steady levels at Bluntzer (CBVT2) and Calallen (CAAT2). Depending on how much inflow comes into the reservoir, renewed increases in release are possible at some point later in the week. ...San Jacinto Basin... ...Major Flooding... The San Jacinto River basin received additional heavy rainfall overnight. The West Fork of the San Jacinto river near Porter (PTET2) is currently in moderate flood category and is forecast to rise into major flood category. The West Fork near Humble is in moderate flood category. Peach creek near Splendora is forecast to rise into major flood category. ...Colorado Basin... ...Major Flooding... Heavy rain has fallen over the last 48 hours mainly over the middle and lower Colorado River Basin. River stages upstream of La Grange (LGRT2) have already crested and fallen below criteria. Downstream, the rivers continue to rise along the mainstem Colorado and its tributaries. Some of these locations are forecast to crest at major flood levels, in particular La Grange and Wharton (WHAT2). ...Trinity Basin... ...Major Flooding... Heavy rainfall across the entire Trinity River drainage has caused widespread bankfull, minor, and moderate flood flow conditions. The Trinity River at Trinidad (TDDT2) is forecast to hit major flood stage later today. Downstream near Long Lake (LOLT2) the river is expected to rise to major flood levels in the next day or two. At Padera Lake, on the Mountain creek drainage, the dam is closely being monitored. Flood control reservoirs continue to store flood waters minimizing downstream flood conditions. ...Neches Basin... ...Moderate Flooding... The Neches River system remains in elevated flow levels with several locations currently in flood. The Neches River near Alto (ATOT2) is at moderate levels. Nearly every forecast point within the Neches River system is above flood stage or forecast to rise above flood stage. Moderate flooding is expected on the lower Neches River at Weiss Bluff (WBFT2) and Beaumont (BEAT2) as well as on Pine Island Bayou near Sour Lake (SOLT2). Inflows into B.A. Steinhagen Lake are on the increase. Therefore event higher flows than currently forecast are possible downstream at Town Bluff (TBFT2) and Evadale (EVDT2). ...Brazos Basin... ...Moderate Flooding... Heavy, localized rainfall (3 to 4 inches) occurred over the last 24 hours in (1) the Possum Kingdom Lake area and (2) further downstream around Hempstead and Richmond. More widespread lesser rainfall amounts also occurred between these two locations. Moderate flooding is occurring or is forecast to occur along parts of the mainstem Brazos, areas of the Navasota River, the lower Little River, and a small area on the Leon River. Minor flooding is also occurring at various locations along the mainstem Brazos and tributaries from the Possum Kingdom region dowstream to the Texas Gulf Coast. ...Sabine Basin... ...Moderate Flooding... Heavy overnight rainfall has caused sufficient runoff to generate minor and expected moderate flood levels within the headwaters, Cowleech Fork (GNVT2), South Fork (QLAT2) and Lake Fork (QTMT2), and along the mainstem Sabine from Greenville to Toldeo Bend. Toldeo Bend continues to pass inflows with current releases at 28kcfs; not expected to increase next 24hrs. Moderate flooding continues on the lower Sabine River Basin through Bon Wier (BWRT2) and Deweyville (DWYT2) as Toledo Bend Reservoir continues to pass large inflows. ...San Antonio Basin... ...Moderate Flooding... Near Falls City, Cibolo creek (FCTT2) and the San Antonio River (FACT2) are below flood stage and falling. The San Antonio River at Goliad (GLIT2) is on the rise and expected to crest in moderate flood levels later this week. ...San Bernard Basin... ...Moderate Flooding... Heavy rainfall two nights ago has caused elevated flows on the San Bernard River. At Boling (BOLT2) and Sweeny (SWYT2) moderate flooding is occurring or forecast. ...Lavaca-Navidad Basin... ...Minor Flooding... Heavy rain has fallen over the last 48 hours over the upper and middle Lavaca and Navidad rivers. Several locations are forecas to crest at minor flood levels. ...Rio Grande Basin... ...Higher Flow Non-Flood Forecasts... Releases out of Marte Gomez Reservoir in Mexico are driving a rise on the Rio Grande near San Benito and Ramirez (SBNT2). This rise will continue downstream to Brownsville and Matamoros. ...Remainder of WGRFC Basins... Currently, most rivers are have ongoing flooding conditions and remain very sensitive to further rainfall. Soil conditions remain very saturated and any further rainfall will only exacerbate the ongoing flooding. ...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: The Flood Potential Outlook can be viewed on our webpage at: The West Gulf River Forecast Center is now on Facebook: National Precipitation Analysis: The forecast rainfall amounts (QPF) can be viewed on our webpage at: The US Drought Assessment: The latest on Reservoir Information for Texas: MCCANTS $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.