AGUS76 KRSA 151623
HMDRSA

HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
930 AM PDT TUE APR 15 2008

...COLD TROUGH MOVING EAST..

.24 HOUR PRECIPITATION TOTALS (ENDING APR 15 AT 500 AM PDT)...

HIGHEST ONE TO TWO TENTHS AMOUNTS WERE RECORDED OVER THE UPPER 
KLAMATH, MAD, AND EEL BASINS, AND PIT IN SHASTA CO. LESS THAN A 
TENTH OF AN INCH FELL ACROSS THE SMITH, LOWER EEL, UPPER RUSSIAN, 
SHASTA DRAINAGE, AND THE SIERRA AS FAR SOUTH AS I-80.

.METEOROLOGICAL CONDITIONS...

COLD FRONT PASSING THROUGH THE CNRFC THIS MORNING WILL PRODUCE A FEW 
LIGHT SNOW SNOWERS OVER FAR NORTHERN SITES. RETURNS THIS MORNING 
OVER THE SIERRA AS FAR SOUTH AS BLU. A VORTICITY MAX ROUNDS THE BASE 
INTO NV THIS AFTERNOON. MODIFIED HPC QPF BY ADDING LIGHT PRECIP TO 
ACCOMPANY THE TROUGH PASSAGE, BUT LESS THAN ONE OR TWO HUNDRETHS IN 
ANY GIVEN PERIOD. TIME-HEIGHT ANALYSIS SHOWS THE MOISTURE WILL BE 
SHALLOW, BUT ADDED A LITTLE OVER THE TRUCKEE BASIN, AND NORTHERN NV. 
VIRTUALLY DRY EVERYWHERE ELSE, WITH THE EXCEPTION OF FAR SOUTHERN 
OREGON. UNTIL THE FLOW BECOMES OFFSHORE 12Z WEDS, THERE WILL STILL 
BE COOL, MOIST CONDITIONS OVER THE CASCADES.


DAY 1 QPF (TUE 15/12Z TO WED 16/12Z): LESS THAN A TENTH OVER 
CASCADES, TRUCKEE BASIN AND NORTHERN NV.

DAY 2 QPF (WED 16/12Z TO THU 17/12Z): DRY

DAY 3 QPF (THU 17/12Z TO FRI 18/12Z): DRY


.HYDROLOGICAL CONDITIONS...

COOLER TEMPERATURES OBSERVED YESTERDAY AND FORECAST FOR TODAY ARE 
EXPECTED TO SLOW EARLY SNOWMELT AND CAUSE HYDROGRAPHS TO FALL BACK 
TOWARD BASEFLOW LEVELS.  WARMER TEMPERATURES THAT WERE OBSERVED OVER 
THE PAST WEEKEND HAD INDUCED SMALL RISES ON RIVERS IN THE SIERRA 
NEVADA AND NORTH COASTAL RANGES.  ALL FORECAST POINTS ARE EXPECTED 
TO REMAIN WELL BELOW MONITOR LEVELS.


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

EL/AH

$$