924
AGUS74 KWCO 041517
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT FRI JUL 4 2025

.Synopsis...
Catastrophic river flooding is ongoing in Texas with additional flooding
possible today...Periods of heavy rain are expected across the Carolinas
through the weekend, causing isolated flash and urban flooding... Renewed
flood potential increasing for the Northern Plains...

.Texas...
Catastrophic flooding is ongoing over portions of the Texas Hill Country
into Central Texas. Heavy rainfall this morning, 3 - 7" locally up to 10"
(MRMS), has resulted in numerous instances of significant urban flooding
and gages on both the San Saba, and Guadalupe rivers to quickly increase to
major stage. The system that resulted in this has slowly decreased in
intensity this morning, however it has not moved and it is expected to
reintensify with daytime heating. This will result in additional very heavy
rainfall rates in the already vulnerable area of San Angelo to San Antonio
and north to San Saba. The SRF High Water Start Time feature shows a number
of head water streams not hitting the highwater threshold until
midafternoon, with widespread AEPs in those areas still from 2 - 10%. This
increases confidence that there will be new rises on area small streams
which will only exacerbate issues on streams flooded early this morning.
Precipitation should move east of the immediate area mid to late afternoon,
however many streams across the region are expected to remain elevated
through the weekend.

.Carolinas...
Periods of heavy rainfall this weekend will bring the potential for
flooding impacts for mainly coastal regions of the states. The area that is
most vulnerable to flooding would be near the SC/NC border onto the
east-central North Carolina coastal plains as soils are nearing saturation
(NASA SPoRT 0 - 10 cm).

.Northern Plains...
Rainfall is expected across portions of the region through tomorrow,
potentially introducing a new and renewed flood threat to eastern NE, IA,
and southern MN by this weekend. Rainfall amounts are generally pretty low
(1.5" totals) however much of the region has been wet recently, with
streamflows still above normal across the aforementioned regions and
multiple rivers still in flood across southern MN from last weeks
rainfall. The NBM and GFS-forced NWM are showing potential for river rises
across southern MN through eastern NE by the end of this week, however much
of the signal is coming from a system in the middle of next week.

//GKendrick

$$