293
AGUS76 KRSA 051535
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
830 AM PDT Sat Apr 5 2025

...DRY AND WARMER TODAY...
...PRECIP AROUND I-80 AND NORTH SUNDAY INTO MONDAY AND FAR NORTH
TUESDAY AND THURSDAY...

.METEOROLOGICAL CONDITIONS (SAT AM - FRI AM)...

Ridge of high pressure over the region today ahead of a weather
system approaching the west coast. Dry and warm conditions expected
today.  A shortwave trough and associated cold front approach the
Pac NW and Nrn CA coast during the day Sunday and the trailing end
of a weakening front and associated shortwave trough move through
later Sunday afternoon into night. This system taps into some
moisture with a PW plume about 1.3 inches aiming at the Nrn CA coast
Sunday and around the Bay area Sunday night with PW around 1.1
inches along the Nrn CA coast. Mainly light precip along the NW
Coast Sunday morning then increasing and spreading south and east
over Srn OR and Nrn CA in the afternoon/night with precip possible
down to around the I-80 corridor Sunday night into Monday morning.
Precip amounts for Sunday into Sunday night 1-2 inches over the
Smith Basin and the King Range and 0.25-0.75 inches for the Srn OR
Cascades and Eel Basin and Shasta Basin and around a third of an
inch or less for the Nrn Sierra and Russian Basins and generally
around a tenth of an inch or less for the Sac Valley. Another
disturbance moves into the Pac NW Monday brushing Nrn CA and another
one moves in farther north in the Pac NW/ B.C. on Tuesday. Lingering
showers possible over Srn OR and Nrn CA during the day Monday then
tapering off Monday night.  Precipitation amounts up to around a
half an inch for the Smith Basin and Srn OR Cascades and around a
quarter of an inch or less for the Shasta Basin and Nrn Sierra and
elsewhere generally a tenth of an inch to nothing over Nrn CA and
far Nrn NV.  Precip is mainly confined to the Smith Basin and Srn OR
Cascades on Tuesday with amount generally around a quarter of an
inch or less.

Ridging over the region on Wednesday for dry conditions in between
systems.  An upper/low level low approaches the Pac NW/B.C. on
Thursday for another chance of precipitation over the north.  Precip
amounts for Thursday into Thursday night generally less than a
quarter of an inch for the Smith Basin and less than a tenth for the
Srn OR Cascades. Although there is variable solutions with the
timing and track of this system for lower confidence in precip
amounts and coverage.

Maximum temperatures generally around near normal to around 10
degrees above normal for most of CA (except up to 10 degrees below
normal for SE CA) and near normal to up to 10 degrees below normal
over NV this afternoon then cool over NW CA to near normal to around
10 degrees below normal Sunday afternoon, otherwise generally near
normal to around 10 degrees above normal. High temperatures
generally below normal up to 15 degrees over Srn OR and Nrn CA on
and near normal to around 12 degrees above normal elsewhere on
Monday and Tuesday afternoons and warm to around 5 to 20 degrees
above normal (except near normal along the coast) on Wednesday into
Thursday. Low temperatures generally near normal to around 10
degrees above normal Sunday morning and above normal up to 15
degrees Monday morning. Low temperatures for Tuesday and Wednesday
mornings generally near normal to 10 degrees above for most of CA
and up to 15 degrees above for SE CA and NV.  For Thursday morning,
low temperatures generally 5 to 20 degrees above normal.

Freezing levels around 7500-11,000 ft over CA (SE-NW) and 7000-9,000
ft over NV (E-W) this morning and around 9000-11,500 ft over the
region this afternoon into Sunday morning.  Freezing levels drop to
around 4500-8000 ft over Nrn CA Monday morning behind the cold front
and fluctuate around 9000-12,500 over Central and Srn CA and over
NV.  Freezing levels around 4000-9000 ft over Nrn CA and 9000-12,000
ft over Central CA and 12,000-13,000 ft over Srn CA and around 7000-
12,500 ft over NV (N-S) Tuesday morning then rising to around 8000-
14,000ft over the region (N-S) Wednesday morning then fall to around
7000-10,000 ft over Nrn CA and fluctuate around 11,000-14,000 ft
over Central CA and Srn CA and around 10,000-13,000 ft over NV (N-S)
Thursday night.

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



Osborne

$$