SUMMARY...Significant to locally catastrophic flash flooding to
linger for several more hours this morning in West Central Texas.
DISCUSSION...700mb convergent flow out ahead of the MCV that was
responsible for the catastrophic flooding in the TX Hill Country
has positioned itself over the Edwards Plateau and Concho Valley
this morning. Doppler radar shows back-building storms producing
as high as 2.5"/hr rainfall rates around the town of Sonora and
south of San Angelo. RAP mesonanalysis shows an 850mb low-level
jet over the Rio Grande Valley is supplying ample moisture into
the region, as well as generating >20 kts of sfc-1km shear within
the area of thunderstorm activity. MUCAPE just north of the Rio
Grande remains above 1,000 J/kg and low-level theta-e advection is
also ongoing. It is possible storms gradually build southward
towards the Rio Grande as the edge of the growing cold pool inches
southward over the next hour or two.
The 11Z HRRR continues to generate additional thunderstorms this
morning in already flash flood warned areas. A Flash Flood
Emergency was issued for the town of Sonora, and current radar and
GOES-19 satellite shows the area will contend with at least
another 1.5-3" of additional rainfall. Locally higher amounts are
possible, especially in areas of prolonged training thunderstorms.
This will exacerbate an already increasingly dangerous situation
around the region with additional flooded roadways and potential
for flood waters to inundate nearby homes and businesses. Rapid
rises in nearby creeks and streams may also place nearby
structures at risk for significant flooding impacts.