Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 231725
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Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
930 AM PST Mon Jan 23 2017

...PRECIP WINDING DOWN TODAY WITH LIGHT AMOUNTS INTO TUE...
...LIGHT PRECIP IN THE NORTH WED-THU...

.24 HOUR PRECIPITATION TOTALS (ENDING JAN 23 AT 400 AM PST)...

Another system making its way across the region brought heavy precip
to areas mainly south of I-80. For the central/southern Sierra
amounts were generally from 1.50- to 3.00-inches with localized
totals reaching closer to 4.50-inches. Along the central CA coast
from the Santa Cruz mountains down through the Big Sur coast amounts
were generally from 1.00- to 3.00-inches with some localized totals
near 4.50-inches along the Monterey county coast. Down toward
southern CA...the amounts were also impressive with the higher
terrain from 1.50- to 3.00-inches with some amounts over the
transverse ranges reaching between 4.00- and 6.00-inches. For lower
elevations the totals varied from 0.50-inch near San Diego to as
much as 4.00-inches over portions of Los Angeles county. For
instance...the Long Beach Airport received 3.94-inches in the 24
hour period ending at 23/12Z. In the 6 hours ending at 23/00Z the
airport received 3.01-inches...which puts the 6-hour return interval
at a 1 in 50 year event! Also south of I-80...the San Joaquin Valley
was generally between 0.25- and 0.50-inch.

For areas north of I-80...amounts were not as impressive. Across the
higher terrain...amounts were from 0.50- to 1.50-inches with a few
localized totals closer to 2.00-inches near the crest of the Sierra
along I-80 and up in the Shasta Lake drainage. Lower elevations were
generally near 0.25-inch or so.

For the state of NV...amounts were greatest over the southern 2/3 of
the state with 0.25- to 0.50-inch (locally 1.00-inch over the higher
terrain and even more across the mountains to the west of Las
Vegas). Otherwise...totals were 0.25-inch or less for the far
northern portion of the state.


.METEOROLOGICAL CONDITIONS (SHORT TERM: MON AM - THU AM)...

In the wake of yesterday`s cold front, and upper jet and vort max
aloft are currently situated across srn CA and srn NV.  Numerous
showers continue across much of CA and portions of NV.  Expect
gradual diminishing of precip across the area this afternoon except
perhaps far SW CA as the upper jet drifts southward.  Still
expecting a sfc low and upper trough to drop south off the CA coast
later today through Tue, helping to keep the possibility of light
precip through Tue.  A weak system could bring light amounts to the
north starting Wed.


.METEOROLOGICAL CONDITIONS (LONG TERM: THU AM - SUN AM)...

An upr trof will drop through the interior from north to south on
Thu into Fri with light precip possible mainly near the CA/OR border
and then inland across northern NV. Once this system clears the area
to the south and east a slightly positively tilted upr ridge will
build across the west coast for dry conditions this upcoming
weekend into early next week. Finally! Some dry weather.


.HYDROLOGICAL CONDITIONS...

Many rivers and streams in the CNRFC forecast area are near...or
above monitor and flood levels as a result precipitation over the
past week.  Most rivers and streams are expected to recede over the
next several days. Some rivers and streams may fluctuate near
present levels for some time or recede slowly as a result of
upstream reservoir releases.

Overflow is expected to continue for the next several days at the
Colusa, Tisdale, Fremont, and Sacramento weirs.  Overflow is
forecast to end at Moulton weir on Wednesday.

More information on the CNRFC website at http://www.cnrfc.noaa.gov

DRK/KL/DRK/SS

$$



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