AGUS74 KWCO 222132
AHDNWC

Area Hydrological Discussion #312 - EXPERIMENTAL
NWS National Water Center - Tuscaloosa, AL
324 PM CST Fri Nov 22 2024

WHAT: Locally considerable flooding
WHERE: Central California
WHEN Into tonight

FORECAST RAINFALL AND ANTECEDENT CONDITIONS...
QPF: 1 - 3, locally higher (HRRR)
Rainfall Rates: 0.25 - 1/hr (WPC)
QPE: 1 - 3, locally higher (48 hr MRMS QPE)
Soils: Mostly dry (NASA SPoRT)

DISCUSSION...
Persistent moderate to locally heavy rainfall will continue over the
area of concern this afternoon, resulting in increased flooding
concerns over the area. Though soils within the region are pretty
dry, the imperviable and channelized nature of the region will
support rainfall to quickly convert to overland flood increasing the
potential for quick increases on urban streams and some rapid flows
on roadways. This will result in a few considerable flood impacts
within this small region. Additionally, rockslides and landslides
will become increasingly possible as soils become completely
saturated and thus unstable.


The National Water Model (NWM) Short Range Forecast (SRF) continues
to highlight the potential for rapid onset flooding (ROF) between San
Francisco to Sacramento. ROF probabilities are generally around 50%
in the region with scattered AEPs around 10% and locally as low as
2%, increasing confidence in the potential of urbanized flash and
channel flooding.

GRAPHICAL REPRESENTATION weather.gov/owp/operations-ahd

Additional National Water Center products are available at
weather.gov/owp/operations

//GKendrick

ATTN...WFO...MTR...STO
ATTN...RFC...RSA...WPC