849
AGUS74 KWCO 291541
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
1015 AM CDT TUE JUL 29 2025

.Synopsis...
Isolated flash and urban flooding may occur in portions of the Middle
Mississippi Valley, Northern Rockies into the Upper Midwest and Northern
and Central Plains and the Mid-Atlantic into the Northeast...Isolated flash
and arroyo flooding is possible this week for New Mexico...The threat of
flash flooding and landslides remains in American Samoa...

.Northern Rockies into the Upper Midwest and Northern and Central Plains...
Minor to isolated moderate riverine flooding will continue through the end
of the week. Most small order streams and rivers have already crested or
are in recession.

Isolated flash and urban flooding is possible in areas of SD, MN, NE and IA
through today with showers and thunderstorms producing 2 - 4" of rainfall
(WPC). Also, isolated flash flooding is possible in portions of MT and ID
today, especially near burn scar and flood prone areas. Streamflows in
these regions are running above normal (USGS) and top soils are variable
ranging from dry to wet (NASA SPoRT). Training rainfall and high rainfall
rates will be the primary driver for flooding impacts across the region.

.Middle Mississippi Valley...
The Middle Mississippi Valley, including MO, IL, and IA is at risk for
isolated flash and urban flooding on day 2 (Wed) due to the potential for
locally heavy rainfall. Forecast rainfall amounts of 2-3 inches, locally
higher, may lead to renewed river rises, with most already on the
Mississippi River at minor flood stage. Top soils are variable (40 - 75%, 0
- 10 cm RSM NASA SPoRT) along with streamflows above normal, which has made
conditions on the ground a bit more favorable for enhanced runoff. The
location of any flooding threat is highly dependent on rainfall rates and
training potential with the embedded storms.

.New Mexico...
Isolated flash and arroyo flooding is possible in portions of the state as
multiple rounds of monsoonal moisture continue through the week. Rainfall
will peak today and on day 2 (Tue/Wed). High rainfall rates and training
thunderstorms over recent burn scars, urban and poorly drained areas may
pose a significant risk of flooding impacts.

.Mid-Atlantic into the Northeast...
Heavy rainfall on day 3 (Thu) will bring the possibility of flooding
impacts to areas along the Mid-Atlantic and Northeast regions, primarily
from the Carolinas northeastward to MA. Antecedent conditions range from
dry to normal in most areas with WV being more wet (55-75%, 0-10 cm RSM
NASA SPoRT). Confidence in impacts and location will likely increase as the
event gets closer.

.American Samoa...
Flash and urban flooding will continue through today due to potentially
heavy rainfall lingering in the area. Landslides will also be possible in
areas of steep or complex terrain.

//TMK





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