Hydrometeorological Discussion
Issued by NWS California-Nevada RFC

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AGUS76 KRSA 271649
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- KRNO 271420
WRKHMD

HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
930 AM PDT FRI MAR 27 2015

...DRY EXCEPT FOR A FEW PERIODS OF LIGHT PRECIP OVER THE FAR NORTH...

.24 HOUR PRECIPITATION TOTALS (ENDING MAR 27 AT 500 AM PDT)...

HIGH PRESSURE ALONG THE WEST COAST BROUGHT WARM AND DRY CONDITIONS
TO THE REGION. NO PRECIPITATION WAS OBSERVED OVER THE PAST 24-HOURS.


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

WATER VAPOR LOOP THIS MORNING SHOWS A STRONG RIDGE OVER THE WEST
COAST THIS MORNING...WITH A TROUGH DEVELOPING OFFSHORE WEST OF 130W.
THE TAIL END OF THIS IS EXPECTED TO QUICKLY BRUSH THROUGH THE
NORTHERN PORTION OF THE FORECAST AREA TONIGHT...WITH LIGHT PRECIP
MOVING INTO THE SMITH BASIN LATE THIS EVENING. EXPECT THE SYSTEM TO
PUSH INLAND OVERNIGHT THROUGH THE UPPER KLAMATH...NOT MAKING MUCH
SOUTHWARD PROGRESS FURTHER THAN THE CA/OR BORDER...AND EXIT TO THE
NORTHEAST BY SATURDAY MORNING. QPF AMOUNTS SHOULD GENERALLY REMAIN
BETWEEN 0.1-0.2" FOR THIS TIME FRAME.

ON SATURDAY AFTERNOON...RESIDUAL INSTABILITY FROM THE S/WV PASSING
TO THE NORTH MAY POP UP A FEW SHOWERS OVER THE NORTHERN SIERRA...
BUT ONLY THE GFS AND NAM-WRF ARE EXCITED ABOUT THIS POSSIBILITY.
SIMILAR SITUATION FOR SUNDAY AFTERNOON AS A WEAK AND MOISTURE
STARVED UPPER LOW PASSES THROUGH THE REGION. INDICATED THE
POSSIBILITY OF A FEW LIGHT SHOWERS OVER HIGHER TERRAIN...BUT
CONFIDENCE IS LOW...AS WOULD BE THE QPF TO RESULT.


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

EARLY NEXT WEEK WILL SEE A FEW WEAK S/WV TROFS MOVE TOWARD THE PACNW
AND CLIP THE CA/ORE BORDER AREA. THIS WILL RESULT IN LIGHT PRECIP
THROUGH THE PERIOD. EARLY MONDAY...THE FIRST S/WV TROF WILL BE
CROSSING 140W WITH THE BASE OF THE SYSTEM SOUTH OF 40N.
HOWEVER...LOOK FOR THE SYSTEM TO LIFT OFF TOWARD THE NE AND
PRIMARILY AFFECT COASTAL SECTIONS OF WA AND ORE. LIGHT PRECIP AT THE
SOUTHERN EXTENT OF THE SYSTEM WILL AFFECT THE CA COAST FROM CAPE
MENDOCINO NORTHWARD AND THE CREST OF THE SOUTHERN ORE CASCADES.
TIMING LOOKS TO BE MONDAY EVENING INTO TUESDAY MORNING.

THE NEXT S/WV TROF WILL TRACK FROM MAINLY FROM W-TO-E...AND BE
FARTHER NORTH THAN THE FIRST WAVE. AS A RESULT...THE POSSIBILITY OF
PRECIP LOOKS TO BE LOWER. A FEW HUNDREDTHS OF AN INCH ARE POSSIBLE
OVER THE CREST OF THE SOUTHERN ORE CASCADES.

AT THE END OF THE FORECAST PERIOD...ANOTHER S/WV TROF WILL DIVE FROM
NW-TO-SE AND CROSS THE COAST NEAR THE PACNW ON ITS WAY TOWARD THE
GREAT BASIN.


.HYDROLOGICAL CONDITIONS...

WARMER THAN NORMAL TEMPERATURES OVER THE NEXT 5 DAYS IS EXPECTED TO
INCREASE SNOWMELT RUNOFF IN MANY RIVER BASINS IN THE SIERRA NEVADA.
ONLY MINOR RISES IN STAGE ARE FORECAST FOR THESE BASINS WITH
SNOWMELT RUNOFF.

ALL RIVERS AND STREAMS IN THE CNRFC FORECAST AREA ARE CURRENTLY
BELOW ...AND ARE EXPECTED TO REMAIN BELOW MONITOR LEVELS THROUGH
NEXT TUESDAY.


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

DRK/JM/DRK/SS

$$



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