AGUS76 KRSA 032012
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
1215 PM PST Tue Dec 3 2024

...SYSTEM MOVES OVER THE PACIFIC NORTHWEST AND DIVES TOWARD GREAT 
BASIN THIS WEEKEND...

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

No changes to a dry forecast with a blocking pattern in place...as a 
high pressure ridge dominates and aligns itself in the vicinity of 
the west coast stretching up well into western Canada. A s/wv trof 
will weaken and split as it approaches the west coast on Thursday 
with no precip expected from this feature.


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

Little to no change in the afternoon forecast for the long term. 
Still expecting mainly dry conditions as high pressure sits offshore 
of CA. Showers along the north coast and northern regional border 
Saturday as the southern end of a front brushes the area. Additional 
showers possible Sunday into Monday as a trough moves through the 
PacNW and digs into nrn CA/NV. GFS/ECMWF have come closer together 
in terms of timing/positioning of the trough with still some slight 
differences. Not expecting this system to produce much precip with 
no more than a few hundredths likely. Overall QPF has not changed 
more than a few hundredths to a tenth here and there from this 
morning. Predicting 0.10-0.25" along the north coast, 0.25-0.50" 
over the srn OR Cascades, and only a few hundredths or so elsewhere 
along the northern regional border. Possibility of light showers 
over nrn/eastern NV as the trough moves through Sunday into Monday, 
but so far not showing up in the NBM/WPC guidance.

Freezing levels start out at about 10-12 kft on Friday rising into 
Saturday due to high pressure up to 11-13.5 kft across the region. 
Cooler systems moving into the PacNW will lower freezing levels into 
Sunday over far nrn CA/NV to 4-8 kft with these levels spreading 
southward the rest of the weekend. By the end of the period 
expecting most areas away from srn CA and the central coast down to 
4-7.5 kft.


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



Kozlowski/AS

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