194
AGUS74 KWCO 141518
HMDNWC

National Hydrologic Discussion - EXPERIMENTAL
NWS National Water Center - Tuscaloosa AL
915 AM CST THU NOV 14 2024

.Synopsis...
Potential for flooding impacts to continue across Puerto Rico and the
USVI... Rainfall returns to the Southern and Central Plains late this
weekend into early next week... River flooding continues, additional
rainfall expected in the Pacific Northwest... Coastal flooding expected
along the Eastern Seaboard... Ongoing river flooding across portions of the
Southern US...

.Discussion...

.Puerto Rico and the USVI...
The potential for urban and small stream flooding, along with mudslides in
complex terrain, will persist through day 4 (Sun). Daily showers and
thunderstorms will be capable of producing excess runoff due to nearly
saturated soils (NASA SPoRT), and with streamflows above to much above
normal (USGS), runoff added to these streams could produce out-of-bank
rises. Intense rainfall rates will be the primary driver of urban flooding.

.Southern and Central Plains...
Rainfall will return to the region early next week (days 4 and 5, Sun and
Mon), bringing the threat of flash and urban flooding impacts, along with
rapid rises on small streams and rivers. Topsoils have recovered somewhat
from previous rainfall (35 - 50% RSM, 0 - 10 cm, NASA SPoRT), but some
streams and rivers are still running high (USGS), suggesting some remaining
vulnerability to flooding. The GFS- and NBM-forced National Water Model
(NWM) and HEFS are all suggesting responses next week from the potential
rainfall; however, the overall placement and magnitude of those responses
continues to vary significantly. Despite some uncertainty in the potential
for flooding impacts, rapid rises on small streams and rivers appear likely.

.Pacific Northwest...
The Skokomish River near Potlatch, WA remains in moderate flood stage this
morning, but it is forecast to fall below moderate flood later today and
out of flood completely early on day 2 (Fri). At this time, no additional
river flooding is anticipated over the next several days.

In the wake of recent rainfall in coastal areas of WA, OR, and northern CA,
soils throughout the column in these areas are now quite wet (70% RSM,
NASA SPoRT). With additional rainfall expected in these areas on days 3 and
4 (Sat and Sun), the potential for localized urban and small stream
flooding impacts cannot be ruled out.

.Eastern Seaboard...
Coastal flooding is occurring with this mornings high tide, and additional
coastal flooding is expected at high tide each morning on days 2 and 3 (Fri
and Sat). This will include rises to moderate and major flood stage at some
tidal gages, primarily in and around Chesapeake Bay and along the Carolina,
DE, and NJ coasts.

.Ongoing River Flooding...
In coastal GA and SC, isolated minor and moderate river flooding is ongoing
and is expected to continue through the weekend. In southern LA, minor to
isolated moderate river flooding is ongoing or forecast; some locations
will drop below flood stage today, but a few others will remain in flood
through the weekend.

//Watson

$$