942
AGUS74 KWCO 131524
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT SUN JUL 13 2025

.Synopsis...
Considerable flooding is ongoing in portions of central TX, and isolated
flash and urban flooding possible elsewhere in New Mexico and the Southern
Plains...Flash and areal flooding possible in Florida...Isolated flooding
potential in the Middle Mississippi Valley into the Ohio Valley, Northern
Plains into the Upper Midwest, and Mid-Atlantic into the Northeast...

.New Mexico and the Southern Plains...
Locally heavy rainfall continues this morning in central TX where
considerable flooding is expected to continue through this afternoon.
Widespread 3 - 5", isolated 9" (MRMS) has fallen over the past 12hrs with
an additional 2 - 4" (HRRR) possible this afternoon. Additionally, model
guidance is suggesting a resurgence of heavy rainfall late this evening
into tonight which will keep the threat of at least locally considerable
impacts elevated. Streams have yet to recover from the historic rainfall
experienced earlier this week and soils remain primed for enhanced runoff.
The National Water Model (NWM) Short Range Forecast continues to suggest
that rivers and streams in the Texas Hill Country are susceptible to rapid
onset flooding with probabilities generally near 26 - 50%. High Flow
Magnitude Forecast is signaling many of the streams and creeks are running
high with annual exceedance probabilities roughly 20 - 4% with some
tributaries at 2%. Many of these reaches are forecast to peak over the next
8 hours with some of the larger mainstems remaining peaking late this
evening. Furthermore, minor to isolated moderate river flooding is ongoing
or forecast to begin shortly and continue through the week. Dry conditions
begin to prevail by day 3 (Tue) which will allow streams to recede
unimpeded.

Elsewhere across the Southern Plains, scattered showers and thunderstorms
persist through day 3 (Tue), particularly in portions of the OK Ozarks.
Ongoing training rainfall has kept this area at risk for isolated flash
flooding impacts. Due to the very active summer season, soils in this area
remain wet with streams running above normal. Fortunately, dry conditions
are forecast which will bring a much needed reprieve from the heavy
rainfall and flooding threat.

In New Mexico, locally heavy rainfall rates of 2 - 3" are possible this
afternoon through this evening which may elicit some flooding impacts on
small streams, arroyos,and low water crossings. This area remains sensitive
as numerous rounds of monsoonal rainfall have fallen over the past several
days. Recently burned areas will also remain susceptible to flash flooding
and debris flows.

.Florida...
Multiple rounds of moderate to heavy rainfall are forecast over the next
week (7-day totals of 3 - 5", locally higher) across much of FL with the
heaviest rainfall concentrated over the Florida Peninsula through day 4
(Wed). The antecedent soil conditions and streamflows are variable across
many of the basins in the state. The southern Peninsula in particular is
currently experiencing D1 - D3 drought conditions (NIDIS) so initially some
of this rainfall may serve to be beneficial. However, as the ground
conditions begin to saturate, and canals and creeks begin to run high, the
threat for isolated urban and areal flooding increases. While confidence in
the exact placement and magnitude of any such responses are low due to the
timing, this area will still need to be monitored through the next week for
any changes to the forecast.

.Mid-Atlantic into the Northeast...
Summer showers and thunderstorms continue (1 - 3", 48hr QPF) across the
region which could elicit some isolated instances of flash and urban
flooding through day 2 (Mon). Streamflows are above normal to much above
normal (USGS) and soils remain variable across the area which would suggest
that while widespread flooding impacts are not anticipated, though the
possibility of impacts in the flashier basins should not be underestimated,
particularly in the basins with steep or complex terrain. While the highest
chances for impacts are over the next 48hrs, rainfall is forecast to
continue through the week which will keep conditions primed for potential
flooding. As the extended range draws closer this area may need to be
reevaluated in the coming days.

.Northern Plains into the Upper Midwest...
Locally heavy rainfall (1 - 2", locally 5") is possible on day 3 (Tue)
which may cause isolated flash, urban, and small stream flooding. The
primary threat for this system will be the flash flooding from training
rainfall or in areas with high rainfall rates. The NWM Medium Range
Forecast is signaling some reaches with AEPs of 50 - 20% which may add some
confidence to a lack of widespread flooding responses. Furthermore, peak
flows are generally over the next 3 - 5 days with mostly clear conditions
allowing for recessions to begin on these streams and creeks.

.Middle Mississippi Valley into the Ohio Valley...
Scattered showers and thunderstorms are forecast over the next 7 days (1 -
2", locally higher possible) which may cause some isolated flooding
impacts. Due to the highly uncertain nature of convection it will be
difficult to nail down exactly where impacts may materialize. The primary
concern in this region is basins that experience high rainfall rates or
training rainfall that can quickly overcome these ground conditions to
enhance flows.

//Capp

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