NATIONAL WEATHER SERVICENATIONAL WEATHER SERVICEAn agency of the Federal Governmentwithin the Department of Commerce,National Oceanic and AtmosphericClick for More... SACRAMENTO
950 PM PSTPSTPacific Standard TimeClick for More... MON JAN 25 2010 .DISCUSSION...WATER VAPOR IMAGERY SHOWS TWO PROMINENT SYSTEM OVER OR NEARING CALIFORNIA THIS EVENING. THIS FIRST OF WHICH IS BRINGING PLENTY OF RAIN AND MOUNTAIN SNOW TO AREAS PRIMARILY NORTH OF STOCKTON AS WELL AS SOME LOCALLY GUSTY WINDS. RADARRADARAcronym for RAdio Detection AndRanging; a radio device or systemfor locating an object by means ofultrahigh-frequency radio wavesreflected from the object andreceived, observed, and analyzed bythe receiving part of the device insuch a way that characteristics (asdistance and direction) of theobject may be determined.Click for More... IMAGERY ALSO SHOWS A PRETTY WIDE SWATH OF LIGHT TO MODERATE PRECIPITATIONPRECIPITATIONThe process where water vaporcondenses in the atmosphere to formwater droplets that fall to theEarth as rain, sleet, snow, hail,etc.Click for More... IN THESE AREAS...WITH THE NORTHERN AND CENTRAL SACRAMENTO VALLEY SEEING ANYWHERE FROM A QUARTER INCH TO A HALF INCH IN THE PAST 6 HOURS. THEREFORE...AN URBAN AND SMALL STREAM FLOOD ADVISORYADVISORYHighlights special weatherconditions that are less seriousthan a warning. They are for eventsthat may cause significantinconvenience, and if caution isnot exercised, it could lead tosituations that may threaten lifeand/or property.Click for More... REMAINS IN EFFECT FOR THE SACRAMENTO VALLEY NORTH OF SACRAMENTO...THE NORTHEAST FOOTHILLS...AND THE NORTHERN PORTION OF THE MOTHERLODE. THE FURTHER SOUTH...LIGHTER AMOUNTS HAVE ACCUMULATED. ALTHOUGH SOME WARMER AIR DID MOVE IN WITH THIS SYSTEM...SNOW LEVELS THIS EVENING ARE RELATIVELY LOW...ESPECIALLY IN THE SHASTA COUNTY REGION...AS COLD AIR REMAINS TRAPPED IN SOME OF THE VALLEYS. THEREFORE...SNOW LEVELS APPEAR TO BE RANGING FROM AROUND 2000 FEET IN SHASTA COUNTY TO AROUND 4500 FEET IN THE NORTHERN SIERRA...AND MAY LOCALLY BE LOWER IN SPOTS. THEREFORE...THE WINTER STORM WARNINGWINTER STORM WARNINGThis product is issued by theNational Weather Service when awinter storm is producing or isforecast to produce heavy snow orsignificant ice accumulations. Thecriteria for this warning can varyfrom place to place.Click for More... LOOKS ON TRACKTRACKThe path that a storm or weathersystem follows.Click for More.... ACTUALLY...THE CURRENT FORECAST LOOKS ON TRACKTRACKThe path that a storm or weathersystem follows.Click for More......AND NO UPDATES ARE PLANNED THIS EVENING. THE NEXT SYSTEM TO TAKE AIM AT CALIFORNIA IS ALSO MOVING INSIDE OF 130 THIS EVENING. MODELS CONTINUE TO TRACKTRACKThe path that a storm or weathersystem follows.Click for More... THIS STORMSTORMAny disturbed state of theatmosphere, especially affectingthe Earth's surface, and stronglyimplying destructive and otherwiseunpleasant weather. Storms range inscale from tornadoes andthunderstorms to tropical cyclonesto synoptic-scale extratropicalcyclones.Click for More... TOWARDS SOUTHERN CALIFORNIA...BRINGING THE BRUNT OF MOISTUREMOISTURERefers to the water vapor contentin the atmosphere, or the totalwater, liquid, solid or vapor, in agiven volume of air.Click for More... TO AREAS SOUTH OF SAY FRESNO AND THE SOUTHLAND. HOWEVER...THERE ARE SOME INDICATIONS FROM THE SATELLITE IMAGERY THAT THIS STORMSTORMAny disturbed state of theatmosphere, especially affectingthe Earth's surface, and stronglyimplying destructive and otherwiseunpleasant weather. Storms range inscale from tornadoes andthunderstorms to tropical cyclonesto synoptic-scale extratropicalcyclones.Click for More... MAY BE SPLITTING...WITH THE LOW LEVEL CIRCULATIONCIRCULATIONThe flow, or movement, of a fluid(e.g., water or air) in or througha given area or volume.Click for More... CONTINUING ON THE SOUTHEASTWARD TRACKTRACKThe path that a storm or weathersystem follows.Click for More... TOWARDS SOUTHERN CALIFORNIA AND THE UPPER LEVELUPPER LEVELIn weather observing, the termapplies to the portion of theatmosphere that is above the lowertroposphere, generally 850 hPa andabove.Click for More... CIRCULATIONCIRCULATIONThe flow, or movement, of a fluid(e.g., water or air) in or througha given area or volume.Click for More... HEADED MORE TOWARDS CENTRAL CALIFORNIA. AS A RESULT...BELIEVE A CHANCE OF SHOWERS WILL CONTINUE INTO TOMORROW...AS MORE ENERGY AND MOISTUREMOISTURERefers to the water vapor contentin the atmosphere, or the totalwater, liquid, solid or vapor, in agiven volume of air.Click for More... MOVE INTO THE REGION. BEHIND THIS SYSTEM THOUGH...HIGH PRESSURE WILL BRIEFLY REBUILD...GIVING US SOME OPPORTUNITY TO DRY OUT AND MAYBE EVEN SEE THE SUN ON WEDNESDAY AND THURSDAY. HOWEVER...LATE NIGHT AND EARLY MORNING FOGFOG(abbrev. F) Fog is water dropletssuspended in the air at the Earth'ssurface. Fog is often hazardouswhen the visibility is reduced to ¼mile or less.Click for More... WILL LIKELY BE AN ISSUE. PALMER .EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)...A GULF OF ALASKA TROUGHTROUGHAn elongated area of relatively lowatmospheric pressure, usually notassociated with a closedcirculation, and thus used todistinguish from a closed low. Theopposite of ridge.Click for More... WILL APPROACH NORTHERN CALIFORNIA ON FRIDAY. MEDIUM RANGE MODELS DIFFER ON THE HANDLING OF THIS TROUGHTROUGHAn elongated area of relatively lowatmospheric pressure, usually notassociated with a closedcirculation, and thus used todistinguish from a closed low. Theopposite of ridge.Click for More.... THE GEM AND ECMWFECMWFEuropean Center for Medium-RangeWeather Forecasts. Operationalreferences in forecast discussionstypically refer to the ECMWF'smedium-range numerical forecastmodel, which runs out to 10 days.Click for More... BOTH AGREE ON SPLITTING THE TROUGHTROUGHAn elongated area of relatively lowatmospheric pressure, usually notassociated with a closedcirculation, and thus used todistinguish from a closed low. Theopposite of ridge.Click for More... AS IT APPROACHES THE COAST...THOUGH THE TIMING DIFFERS. THE GFSGFSGlobal Forecast System - One of theoperational forecast models run atNCEP. The GFS is run four timesdaily, with forecast output out to384 hours.Click for More... CONSOLIDATES THE TROUGH`S ENERGY BUT KEEPS IT CONSIDERABLY FURTHER NORTH THAN THE OTHER TWO. PREFER THE FORMER TWO MODELS...BUT WHATEVER THE CASE MAY BE GENERALLY LIGHT (IF ANY) PRECIPITATIONPRECIPITATIONThe process where water vaporcondenses in the atmosphere to formwater droplets that fall to theEarth as rain, sleet, snow, hail,etc.Click for More... IS EXPECTED WITH THIS SYSTEM. KEPT PROBABILITYPROBABILITYA chance, or likelihood, that acertain event might happen.Click for More... OF PRECIPITATIONPRECIPITATIONThe process where water vaporcondenses in the atmosphere to formwater droplets that fall to theEarth as rain, sleet, snow, hail,etc.Click for More... AT NEAR CLIMATOLOGICAL LEVELS FOR THIS STORMSTORMAny disturbed state of theatmosphere, especially affectingthe Earth's surface, and stronglyimplying destructive and otherwiseunpleasant weather. Storms range inscale from tornadoes andthunderstorms to tropical cyclonesto synoptic-scale extratropicalcyclones.Click for More.... HIGH PRESSURE LOOKS TO REBUILD OVER THE CALIFORNIA NEXT WEEKEND...PUSHING THE STORMSTORMAny disturbed state of theatmosphere, especially affectingthe Earth's surface, and stronglyimplying destructive and otherwiseunpleasant weather. Storms range inscale from tornadoes andthunderstorms to tropical cyclonesto synoptic-scale extratropicalcyclones.Click for More... TRACKTRACKThe path that a storm or weathersystem follows.Click for More... NORTHWARD AND SETTING UP A DRY PERIOD. DANG
