National Weather Service California Nevada River Forecast Center Department of Commerce National Oceanic and Atmospheric Administration National Weather Service

Printer Version
CNRFC Hydrometeorological Discussion

Version:  Current  |  Back 1  |  Back 2  |  Back 3  |  Back 4  |  Back 5  |
Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
715 AM PDT Sat May 15 2021



Main focus for the weekend will be the upr low traversing the region 
from northwest to southeast...bringing scattered showers and 
thunderstorms to the area mainly from the Cascades/Sierra along with 
points eastward over NV. Best totals continue to look to be along 
the entire crest of the Cascades/Sierra and inland over the state of 
NV between the I-80 and US-50 corridor. General amounts will be in 
the range of 0.25- to 0.75-inch...but with a convective element to 
the precip there will definitely be some localized higher totals 
under stronger cells. 

Current satellite imagery puts the location of the primary 
circulation near Sacramento...while radar data shows one band of 
showers/thunderstorms rotating from northeast to southwest from the 
Pit and Upper Klamath River basins down toward the upper Sacramento 
River basin...including areas just below Shasta Dam. The other area 
of precip is on the downstream side of this feature across northeast a favorable area of diffluence aloft. 

The next 24 hours will see the upr low wobble toward the southeast 
and only make it to about the Fresno area. Precip will become more 
widespread in the afternoon/early evening hours with solar 
insolation increasing. This will also be the case on Sunday as the 
upr low makes its way to the Las Vegas area...before finally 
shifting east and seeing precip taper off as a positively tilted 
transitory s/wv ridge slides across the area on Tuesday.

Models area still hinting at a cool upr trof moving from the 
northeast Pacific to the west coast for the latter half of the week. 
Still looking at the potential for some scattered precip to develop 
across the particular the northern half of the region.