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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
725 AM PDT Mon May 5 2025

...SCATTERED SHOWERS AND T-STORMS OVER SE CA/SRN NV TODAY AND 
TOMORROW AS ONE LOW EXITS AND ANOTHER MOVES INTO NV FROM THE NORTH...
...DRY CONDITIONS AND WARMING TEMPERATURES THROUGHOUT THE REST OF 
THE WEEK...

.METEOROLOGICAL CONDITIONS (MON AM - SUN AM)...

An upper low continues to exit the region into AZ this morning 
leaving behind about 0.75-1" PW of moisture over much of srn CA. 12z 
sounding out of San Diego recorded just over 1" PW at the airport 
well above the 90th percentile for the date. Lingering moisture 
along with some troughing has resulted in scattered showers over srn 
CA. Current radar shows a number of echos over the San Bernadino 
Mountains rotating in from the northeast across srn NV/se CA. 
Observations already show about 0.50-1" of precip over that area 
overnight. Increased the QPF there for the current period as showers 
persist. The rest of today, the low will continue to exit to the 
east though lingering moisture and troughing will generate 
additional showers over srn/se CA and srn NV with possible 
thunderstorms in the afternoon/evening. Much of NV and srn CA will 
also remain below normal for afternoon high temperatures thanks to 
the influence of the exiting low, anomalies about -5 to -15 deg F.

Behind the low, high pressure will build into the PacNW and nw CA 
raising afternoon highs for much of nrn/central CA to 5 to 10 deg F 
above normal while keeping conditions dry. Models then have another 
smaller low dropping into ne NV from ID into early Tuesday heading 
southwest through the state as it's caught up in the rotation of the 
previous low then over NM. This second smaller low may also drop 
some showers over NV and se CA Tuesday into Wednesday as it passes 
through along with isolated thunderstorms. Dry conditions and above 
normal temperatures for areas away from the low on Tuesday. 
Wednesday, the ridge will shift further into CA/NV as its shoved our 
way by a trough approaching the PacNW. High pressure will remain 
overhead the rest of the week allowing dry conditions to persist and 
temperatures to rise to above normal across the region. Expect 
anomalies of +5 to +15 deg F with Friday/Saturday being the warmest 
days. Some areas will approach +20 deg F above normal. Troughing 
will reach the coast Saturday morning gradually moving overhead this 
weekend. Not expecting any precip out of the trough thus far, but a 
couple showers over the Smith Basin will be possible into Sunday 
morning.

Most of the QPF for the period is expected today with precip 
diminishing tomorrow. Low confidence in amounts as the precip will 
largely be convective. Expect locally higher amounts than forecast 
in any thunderstorms. Freezing levels 9.5-12.5 kft across CA through 
Tuesday.


Please Note: This product may NOT be routinely updated this
summer. Please refer to the following product issued by the CNRFC
www.cnrfc.noaa.gov/Daily-Briefing for a graphical summary of
weather and hydrologic conditions.