Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 301530
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ZCZC RNOWRKHMD 301527
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HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
930 AM PDT MON MAR 30 2015

...A FEW WEAK TROUGHS WILL BRING LIGHT SHOWERS TO THE NORTH COAST
AND NORTHERN AND EASTERN NV THIS WEEK...

.24 HOUR PRECIPITATION TOTALS (ENDING MAR 30 AT 500 AM PDT)...

A FEW SHOWERS AND STORMS WERE OBSERVED ALONG AND NEAR THE CREST OF
THE SIERRA YESTERDAY AFTERNOON JUST SOUTH OF LAKE TAHOE THROUGH THE
SOUTHERN SIERRA. PRECIP WAS GENERALLY LIGHT WITH LOCALLY HEAVIER
AMOUNTS BENEATH INDIVIDUAL CELLS. MUCH OF THE RAIN MISSED THE GAGE
NETWORK IN THE SIERRA


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

SATELLITE SHOWING A GENERALLY ZONAL FLOW PATTERN ACROSS THE AREA
WITH A TROUGH OVER THE EASTERN PACIFIC NEAR 140W. THIS TROUGH WILL
APPROACH THE COAST EARLY TUESDAY AND BRING A CHANCE OF SHOWERS TO
THE SMITH AND KLAMATH BASINS... PERHAPS REACHING AS FAR SOUTH AS THE
EEL BASIN. MUCH OF THE DYNAMICS ASSOCIATED WITH THIS SYSTEM WILL
PASS WELL TO THE NORTH, SO QPF AMOUNTS ARE LIGHT ACROSS NORCAL.

THE TROUGH WILL MOVE OUT OF THE AREA ON EARLY WEDNESDAY WHEN ANOTHER
TROUGH MOVES SOUTH DOWN THE COASTLINE AND BRINGS ANOTHER CHANCE OF
LIGHT PRECIP TO BASINS ALONG THE COAST. A FEW LIGHT SHOWERS ARE ALSO
POSSIBLE ACROSS THE CENTRAL SIERRA AND NORTHERN AND EASTERN NV WITH
THIS SYSTEM. EXPECT SHOWERS TO LINGER ACROSS NORTHERN AND EASTERN NV
INTO THURSDAY.

BY FRIDAY MORNING... THE TROUGH MOVES OFF TO THE EAST WITH MOSTLY
ZONAL FLOW ACROSS THE AREA. MODEL SOLUTIONS BEGIN TO DIVERGE AT THIS
POINT. THE EC DROPS A LOW PRESSURE SYSTEM SOUTH OUT OF THE GULF OF
ALASKA, KEEPING THE CENTER OFFSHORE AS IT MOVES SOUTH TOWARDS CA.
THIS SCENARIO BRINGS LIGHT RAIN TO THE CA NORTH COAST BY EARLY
SUNDAY, WITH MORE WIDESPREAD RAIN ACROSS THE CENTRAL VALLEY AND
SIERRA INTO EARLY NEXT WEEK. THIS WOULD BE A WELCOME PATTERN CHANGE
IF THIS SCENARIO PLAYS OUT. MEANWHILE, THE GFS HAS THIS SYSTEM
MOVING ONSHORE WELL TO THE NORTH ACROSS THE US/CANADIAN BORDER
BEFORE DROPPING SOUTH ACROSS THE NORTHERN ROCKY MOUNTAINS. THIS
PATTERN LEAVES CA COMPLETELY DRY. HAVE GONE WITH THE MORE OPTIMISTIC
EC AT THIS TIME FOR THE POSSIBILITY OF RAIN LATE SATURDAY/EARLY
SUNDAY ACROSS THE NORTH COAST.


.HYDROLOGICAL CONDITIONS...

LITTLE CHANGE IN RIVER LEVELS ACROSS CALIFORNIA AND NEVADA ARE
EXPECTED THROUGH THE WEEK AS MOSTLY DRY WEATHER PREVAILS.  ALL
STAGES ARE EXPECTED TO REMAIN WELL BELOW MONITOR LEVELS THROUGH THE
WEEK.

MORE INFORMATION ON THE CNRFC WEBSITE AT HTTP://WWW.CNRFC.NOAA.GOV

MI/AM

$$



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