Weather observations at 6 PM placed a nearly stationary outflow boundary across Central Texas from Hondo to Austin to Mineola. Another outflow boundary is about to collide with the previously mentioned outflow boundary in South-Central Texas. Strong southeasterly low-level flow continues to pump in moisture values in the 99th percentile for mid-April. The atmosphere is primed for very heavy rains – just like what we saw many times in 2015. Short-term weather model forecasts have been consistent in showing an increase in precipitation coverage and intensity across Central Texas this evening. An additional 3 to 5 inches of rain may fall by late tonight where thunderstorms move over the same locations (training). We are also watching new storms forming in Southeast Texas between Galveston and Matagorda Bay. That activity, while still in the development phase, could become a problem this evening with heavy rain and flooding potential. The threat of flooding is very high tonight in Central Texas with a threat extending into southern sections of North Texas, the Brazos Valley, and Southeast Texas.
MESOSCALE PRECIPITATION DISCUSSION 0125 NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 746 PM EDT SUN APR 17 2016 AREAS AFFECTED...CNTRL TEXAS CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY VALID 172345Z - 180545Z SUMMARY...VERY HEAVY RAIN IS EXPECTED NORTH OF AN OUTFLOW BOUNDARY LOCATED ACROSS CNTRL TEXAS WITH HOURLY RATES OF 2+ IN/HR THROUGH 05Z. ALSO WATCHING POTENTIAL FOR THE DEVELOPMENT OF AN AXIS OF FLASH FLOODING RAIN ALONG THE CNTRL TEXAS COAST BY 03Z.