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AGUS76 KRSA 262035
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
1230 PM PST Tue Nov 26 2024

...LOW PRESSURE TO MOVE ACROSS NRN CA/NV TODAY/TONIGHT DROPPING
SHOWERS AND POSSIBLE THUNDERSTORMS...
...MOISTURE PLUME CONTINUES TO IMPACT CNTRL/SRN CA TODAY MOVING OUT
EARLY WEDS...
...DRY CONDITIONS EXPECTED LATE WEDS THROUGH THE WEEKEND AS MODELS
BACK OFF ON PRECIP CHANCES...

.METEOROLOGICAL CONDITIONS (SHORT TERM: TUE PM - FRI AM)...

Moisture continues to stream into central CA this afternoon
funneling precip from the central coast through to the southern
Sierra. Over the past 6 hours another 0.50-1.50" has fallen over the
southern Sierra with 0.10-0.50" over Santa Barbara and Ventura
counties as well as scattered across the rest of CA. The upper
trough continues to move inland across the PacNW and nrn CA with
high pressure to the south and west.

Scattered showers over nrn CA/NV the rest of the day as that trough
passes overhead with slight chances of a thunderstorm or two. The
moisture plume will keep showers going mainly along the coast from
Monterey County to LA county and inland into the southern Sierra
which will remain the focus of higher amounts. Things will quiet
down overnight as the moisture shifts to the south and pulls
offshore. It will then exit to the south the rest of the morning
leaving only some light lingering showers across srn CA. No big
changes from the morning forecast, models are struggling with some
of the precip now around coastal soCal underestimating amounts.
Needed to make some manual adjustments to the current 6 hr period to
account for recent observations. Otherwise the forecast was a blend
of WPC guidance, the previous forecast, and the latest NBM. All in
all expecting another 0.50-1.50" for the southern Sierra with
isolated areas closer to 1.50-2.50" before tomorrow morning, 0.10-
0.75" for the rest of the Sierra/SJ valley/coastal srn CA from LA
County to Point Conception, and scattered lighter amounts for the
rest of the state. Dry conditions to follow for the next couple of
days as high pressure builds in behind the exiting systems.

Freezing levels 5-10 kft across the Sierra from north to south
dipping a bit overnight in the north as the trough moves through.
Levels rise back up the rest of the period as high pressure builds
with the state back up to 8.5-11.5 kft by Thursday afternoon.


.METEOROLOGICAL CONDITIONS (LONG TERM: FRI AM - MON AM)...

No change to the afternoon forecast as guidance continues to favor a
drying trend through the long term window. Both the GFS and EC show
some shower activity over southern California overnight Friday
through Saturday as a weak upper low/trough progresses over the
region. The afternoon forecast continued to follow the NBM and WPC
predicting no precipitation through the entire forecast window. Any
shower activity that does form over the weekend will be light and
result in minimal accumulations.

Freezing levels will start the forecast window ranging from 9k to 12
k feet north to south before rising to 10k feet across the north on
Sunday and lowering to 9.5k feet across central and southern CA as
the weak upper low approaches.


QPF graphics are available at www.cnrfc.noaa.gov/qpf.php



AS/CH

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