Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7
272
AGUS76 KRSA 221849
HMDRSA

Hydrometeorological Discussion
National Weather Service / California Nevada RFC / Sacramento CA
1045 AM PST Sun Jan 22 2017

...HEAVY PRECIP TODAY SRN CA AND PORTIONS OF SIERRA...
...LIGHTER PRECIP MON-TUE AND MAINLY DRY WED-FRI...

.24 HOUR PRECIPITATION TOTALS (ENDING JAN 22 AT 400 AM PST)...

Precip amounts along the coast from the nrn Santa Lucia range to the
OR border were around 0.5-1.5" with 0.5" or less for the remainder
of the coast.  San Joaquin Valley stations picked up 0.3" or less
while the Sacramento Valley reported 0.4-0.9".  The area around
Shasta Lake reported 0.7-2.8" while the upper Klamath received 0.1-
0.5" in the lower elevations and up to 1.2" in the srn OR Cascades.
Little precip was noted in far NE CA.  0.5-2" fell on the west slope
of the Sierra north of I-80, while 0.5-1" fell further south.  East-
side locations reported generally 0.1-1", locally higher.  Outside
of the Reno area, the remainder of NV reported 0.2" or less.


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

Currently seeing a cold front pushing across cntrl CA and nrn NV,
with precip set up along the frontal band from the cntrl coast to
the cntrl Sierra and across to NE NV.  Across srn CA, precip is
increasing in accordance with a highly-anomalous moisture flux
directed into the region.  For the morning period, main changes were
to increase QPF for Santa Cruz and nrn Santa Lucia range areas into
the Russian basin and to lower amounts in the srn Sierra and
remainder of the cntrl coast into the transverse ranges of srn CA
where precip was slower to develop earlier this morning but has
since begun to increase.  With the very impressive moisture flux and
with the cold front expected to eventually work its way across the
region, expect heavy precip to work its across srn CA coastal areas
now through late this afternoon.  Sierra precip could see a bit of
an uptick this evening as a vort max approaches aloft and upper jet
continues to stream over the region.  Precip over the region is
expected to gradually taper off and linger for the Sierra and parts
of srn CA higher terrain thanks to continued onshore flow and good
upper dynamics, despite the declining available moisture behind the
cold front.  Expect Sierra freezing levels 4000-6500 ft through this
afternoon, falling to 3000-3500 ft by Mon morning.

A low dropping south near the coast is still expected to bring light
precip to the region Mon into Tue.  Light precip is still possible
in the north Wed-Thu.  Otherwise expect dry conditions beginning Wed
through the end of the forecast period (Fri night).


.HYDROLOGICAL CONDITIONS...

Precipitation overnight and forecast rainfall for today through
Monday morning is expected to produce renewed rises on many rivers
and streams in the CNRFC forecast area.  Many rivers and streams are
currently above...or are forecast to rise above monitor levels by
Monday.  Several rivers and streams are currently above...or are
expected to rise above flood stage by Monday morning.

Overflow continues at Moulton, Colusa, Tisdale, Fremont, and
Sacramento weirs.  Moulton weir is forecast to end overflow by
Thursday.  All other weirs on the Sacramento River are expected to
continue overflow for several more days.

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

KL/SS

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.