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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
830 AM PDT Wed Apr 24 2024

...COOL WITH PERIODS OF SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE, 
ESPECIALLY OVER THE HIGHER TERRAIN THROUGH FRIDAY THEN WARMER AND 
GENERALLY DRY OVER THE WEEKEND INTO MONDAY...

.METEOROLOGICAL CONDITIONS (WED AM - TUE AM)...

Upper level low off the Srn CA coast this morning weakens as it 
approaches and moves onshore as a shortwave trough into Srn CA this 
afternoon into tonight. Isolated to scattered showers and isolated 
thunderstorms possible over the higher terrain of Nrn CA and over 
the Central Sierra and into Nrn and Central NV. Showers possible 
over Srn CA mtns this afternoon into Thursday morning. Low clouds 
over the CA coast with deeper marine layer for possible drizzle/ 
light rain this morning. Precip amounts generally 0.25 inches or 
less but local amounts to around 0.75 inches possible, especially 
over the Central Sierra into Central/NE NV. The shortwave trough 
moves to the east of the region Thursday morning as a shortwave 
trough and associated cold front move into the Pac NW and Nrn CA 
Thursday and trough deepens over the region Friday with additional 
waves of energy. This will bring precip mainly to the north, 
especially over the higher terrain on Thursday and spreading south 
on Friday. Precip amounts 0.5 inch to around an inch for the Smith 
Basin and west slope of Srn OR Cascades and Ruby mtns and generally 
a third of an inch or less elsewhere over the higher terrain in the 
north on Thursday. Precip amounts for Friday generally around a 
quarter of an inch or less except locally to around a half an inch 
in the Nrn Mtns including the Srn OR Cascades and Ruby Mtns and 
along the NW CA coast. Precipitation may stretch south along the 
Sierra and into Srn NV and possible a few showers over the 
transverse mtns and into San Diego Count Mtns Friday. The trough 
shifts to the east over the weekend with weak ridging over the 
region and a low pressure system approaching the B.C./ Pac NW coast. 
This will bring warmer and generally dry conditions to the region 
except some light precip possible over the far north, mainly over 
the NW CA coast and west slope of Srn OR Cascades over the weekend 
into Monday. 

Max temperatures near normal to 15 degrees below normal over most of 
CA and near normal to 10 degrees above normal for Srn OR and NV this 
afternoon cool to around near normal to 15 degrees below normal 
across the region by Thursday afternoon and similar Friday 
afternoon. Temperatures warm up to near normal for most of the 
region except around 10 degrees below normal along NW CA coast 
Sunday afternoon and warming to near normal to 10 degrees above 
normal over SE CA and most of NV on Monday. Overnight temperatures 
near normal to around 15 degrees above normal decrease to around 
normal Friday night then warming to near normal to 15 degrees above 
normal Sunday night. 

Freezing levels around 10000 ft and higher today then dropping to 
around 8000-10000 ft for CA on Wednesday and around 10000-11000 ft 
over NV then drop to around 5000-7000 ft over Nrn CA and 8000-10000 
ft for Central and Srn CA and NV Thursday morning and around 4000-
6000 ft over Nrn CA and 6000-8000 ft elsewhere Friday night and 
rising to around 6000-8000ft over Nrn CA and 8000 ft and higher 
elsewhere over the weekend and 4000-6000ft over NW CA coast and Srn 
OR and 7000 ft and higher for the rest of the region on Monday.