Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 241649
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HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
850 AM PST MON NOV 24 2014

...SCATTERED LIGHT PRECIP FAR NORTH TODAY INTO EARLY TUESDAY...
...WIDESPREAD PRECIP RETURNS TO THE REGION LATER IN THE WEEK...

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

HIGH PRESSURE ALOFT OFF THE COAST AND NW FLOW BROUGHT DRY CONDITIONS
TO THE REGION OVER THE PAST 24 HOURS.


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

AN AMPLIFIED PATTERN HAS ONCE AGAIN SET UP ACROSS NOAM AND THE
EASTERN PACIFIC WITH AN UPR TROF CENTERED OVER THE WESTERN GREAT
LAKES AND PLAINS STATES...WHILE AN UPR RIDGE HAS PUMPED UP JUST OFF
THE WEST COAST ALONG 130W. NORTHERLY FLOW ALOFT IS THE RULE ACROSS
CA AND NEV THIS MORNING. OVER THE NEXT 3 DAYS...ONLY OPPORTUNITY FOR
PRECIP WILL BE WITH A WARM FRONT LIFTING NE TOWARD THE PACNW
CLIPPING THE CA/ORE BORDER AREA AND EXTREME NORTHERN NEV. THE NAM
AND SREF STILL SHOW A SLIGHT BIT MORE PRECIP THAN THE EC AND
GFS...BUT EVEN THEY ARE DOWN A TAD (FROM YESTERDAY) IN TERMS OF
AMOUNTS. LOOK FOR LIGHT PRECIP TO DEVELOP LATER THIS MORNING AND
THEN SHIFT INLAND OVERNIGHT INTO TUESDAY. AMOUNTS WILL BE NEAR OR
LESS THAN 0.10-INCH.

UPR RIDGE NUDGES TOWARD THE COAST LATER TUESDAY AND DRY CONDITIONS
WILL PERSIST THROUGH WEDNESDAY.


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

DESPITE WEAK RIDGING OVER THE WEST COAST, A MOISTURE PLUME IS
EXPECTED TO TAKE AIM AT THE FAR NORTH COAST BEGINNING THU.  PRECIP
SHOULD START OFF VERY LIGHT THU MORNING AND AFTERNOON.  HEADING INTO
THU NIGHT, AN UPPER LOW IS FORECAST TO MOVE WITHIN 140W OFF THE PAC
NW COAST, WITH A JET MAX MOVING INTO NW CA AND A SECONDARY COLD
FRONT/MOISTURE PLUME MERGING WITH THE FIRST.  THE GFS BRINGS THE
MOISTURE PLUME AND ASSOCIATED HEAVIER AMOUNTS INTO THE SMITH BASIN
EARLY THAN THE ECMWF SINCE THE ECMWF HOLDS THE BULK OF THE INITIAL
MOISTURE PLUME JUST OFF THE COAST UNLIKE THE GFS.  HOWEVER, BY FRI
MORNING, MODELS AGREE IN THE FORWARD PROGRESS OF THE SYSTEM THANKS
TO THE NEXT WAVE PUSHING IN FROM THE WEST.  MAINLY LIGHT PRECIP
SHOULD SPREAD ACROSS MUCH OF NRN CA AND SRN OREGON ON FRI AND
SPREADING INTO CNTRL CA BY SAT.  THERE IS POTENTIAL FOR SOMEWHAT
HEAVIER AMOUNTS NEAR THE COAST FROM AROUND THE SF BAY AREA UP TO
CAPE MENDOCINO AS A VORT MAX ALOFT BRINGS ENHANCEMENT FRI NIGHT/SAT
MORNING.  FOLLOWED A COMPROMISE SOLN BETWEEN THE 00 UTC RUNS OF THE
ECMWF/GFS WHICH HELPS SMOOTH THROUGH SOME TIMING DIFFERENCES BETWEEN
THE TWO.  FREEZING LEVELS START OFF ABOVE 10,000 FT THROUGH THU
EVENING, THEN GRADUALLY LOWER TO 6000-7000 FT ACROSS FAR NRN CA/SRN
OREGON, 7000-8000 FT IN THE SIERRA, AND 7500-8500 FT IN NRN NV BY
THIS WEEKEND.


.HYDROLOGICAL CONDITIONS...

RIVERS IN NORTHERN CALIFORNIA ARE RECEDING AFTER RAINFALL EARLIER
THIS PAST WEEKEND. DRY WEATHER OVER THE NEXT 4 DAYS WILL ALLOW
RIVERS TO RECEDE TO BASEFLOW CONDITIONS.

RIVERS ALONG THE FAR NORTH COAST OF CALIFORNIA ARE EXPECTED TO BEGIN
RISING AGAIN WITH RAINFALL FORECAST FOR FRIDAY.

ALL RIVER LEVELS ARE EXPECTED TO STAY WELL BELOW MONITOR STAGE FOR
THE NEXT FIVE DAYS.


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

KL/DRK/KL/PF

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