Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 301728
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ZCZC RNOWRKHMD 301614
TTAA00 KRNO DDHHMM

HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
930 AM PST FRI JAN 30 2015

...CONTINUING PRECIP OVER SRN CA AND NV THROUGH TONIGHT...
...LIGHT PRECIP OVER FAR NORTH SUNDAY NIGHT INTO WEDNESDAY...

.24 HOUR PRECIPITATION TOTALS (ENDING JAN 30 AT 400 AM PST)...

RIDGING ALOFT OVER THE SRN PLAINS AND A TROUGH NEAR THE CA COAST
BROUGHT SLY FLOW ALOFT OVER SRN CA AND NV.  LIGHT PRECIPITATION FELL
ACROSS MANY PORTIONS OF SRN CA AND ERN PORTIONS OF NV, WITH
VIRTUALLY ALL LOCATIONS RECEIVING LESS THAN 0.1".


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

SATELLITE THIS MORNING SHOWS A RIDGE OVER THE EASTERN PACIFIC WITH
QUITE THE DRY SLOT ON WV IMAGERY...WITH A SYSTEM PULLING SUBTROPICAL
MOISTURE FROM MEXICO NORTH INTO SRN CA AND NEVADA. THIS SYSTEM IS
PUMPING THE MOST FAVORABLE MOISTURE INTO THE FOUR-CORNERS REGION...
THOUGH PLENTY IS STILL MAKING ITS WAY INTO THE SRN CA AND NV DESERTS
THIS MORNING. MOIST FLOW ON THE EAST SIDE OF THE LOW IS BRINGING
PRECIP INTO THE SRN CA COAST AND MTNS AS WELL THIS MORNING.

THIS MONSOON-LIKE PATTERN IS EXPECTED TO DOMINATE THE REGION FOR THE
NEXT 24-HRS. THE UPPER LOW DRIVING THE SOUTHERLY PUSH IS EXPECTED TO
REMAIN FAIRLY STATIONARY OVER SRN CA THROUGH THE EVENING HOURS
TODAY...WITH PRECIP TO CONTINUE OVER MUCH OF THE SAME AREAS UNTIL
TONIGHT. MAY SEE SOME WRAP AROUND MOISTURE BEGIN TO MOVE INTO THE
SRN SIERRA THIS AFTERNOON AND BRING SOME PRECIP TO THE EAST SIDE AND
ALONG THE CREST. OVERNIGHT AND INTO SATURDAY MORNING...THE UPPER
RIDGE OVER THE EASTERN PACIFIC WILL NUDGE EASTWARD...SLOWLY KICKING
THE UPPER LOW TO THE SE. THIS WILL CUT OFF MOISTURE OVER SRN CA/NV
AND SLOWLY BRING AN END TO THE PRECIP OVER THE REGION. EXPECT DRY
CONDITIONS AGAIN BY EARLY SAT AFTERNOON.

RIDGING WILL KEEP THE REGION DRY THROUGH MID DAY ON SUNDAY. A WARM
FRONTAL PATTERN IS EXPECTED TO DEVELOP OVER THE PACIFIC NW SUNDAY
AFTERNOON...AND THE SOUTHERN EDGE SHOULD BRUSH THE SMITH BASIN BY
EARLY SUNDAY EVENING. LIGHT SHOWERS ARE EXPECTED OVER THE SMITH
BASIN AND UPPER KLAMATH THROUGH THE EVENING AND OVERNIGHT HOURS ON
SUNDAY...WHILE A SLIGHTLY HEAVIER PUSH WILL HOLD OFF UNTIL MONDAY AM.


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

EXPECT THE LONG-RANGE PERIOD TO BE CHARACTERIZED BY A MOISTURE PLUME
AND WEAK DISTURBANCES RIDING OVER A WEAK RIDGE NEAR THE CA COAST,
BRINGING GENERALLY LIGHT PRECIPITATION TO THE NORTH COAST AS WELL AS
FAR NRN CA/NV AND SRN OREGON THROUGH THE PERIOD.  MODELS AGREE WELL
EARLY ON WITH THE LIGHT RAIN PICKING UP ON THE NORTH COAST MON
MORNING AS THE LEADING EDGE OF THE MOISTURE PLUME REACHES THE
COASTLINE WITH PW VALUES AROUND 1.1" ALONG WITH WEAK ONSHORE FLOW.
LIGHT PRECIP IS EXPECTED TO SPREAD ACROSS FAR NRN CA/NV AND SRN
OREGON THROUGH MON EVENING.

MODELS THEN BEGIN TO DIVERGE A BIT FOR TUE, WITH SOME MODELS KEEPING
THE MOISTURE PLUME AIMED INTO NW CA WHILE OTHERS LIFT THE PLUME A
BIT INTO OREGON.  WILL KEEP LIGHT PRECIP GOING THROUGH WED ACROSS
THE SAME NRN TIER WITH THE POSSIBILITY OF WEAK ONSHORE FLOW AND A
MOISTURE PLUME IN THE VICINITY.  BY WED NIGHT, MODELS LIFT THE PLUME
TO THE NORTH ALONG WITH A WARM FRONT AS A LOW DEEPENS IN THE NE PAC.
EXPECT FREEZING LEVELS TO HOVER AROUND 7500-8500 FT.  MODELS
CONTINUE TO SHOW THE POSSIBILITY OF A WET PATTERN SETTING UP TOWARD
THE END OF NEXT WEEK, AT LEAST FOR NRN CA AND SRN OREGON.


.HYDROLOGICAL CONDITIONS...

PRECIP FORECAST FOR THE COMING WEEKEND WILL HAVE MINIMAL IMPACTS ON
AREA RIVERS. SOME MINOR SNOWMELT IS OCCURING IN HIGH ELEVATION
BASINS WHICH IS CAUSING SOME VERY MINOR RISES.  MOST AREA RIVERS ARE
EITHER FLAT OR RECEDING.

ALL RIVER STAGES ARE EXPECTED TO REMAIN WELL BELOW MONITOR LEVELS
THROUGH THE NEXT FIVE DAYS.


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

KL/JM/KL/PF

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