HYDROMETEOROLOGICAL DISCUSSION 
   NORTHWEST RIVER FORECAST CENTER PORTLAND OR 
   10:28 AM PST TUE FEB 09 2010 

   ...HYDROMETEOROLOGICAL CONDITIONS...PAST 24 HOURS...4 AM - 4 AM... 

   ANOTHER BENIGN WEATHER PATTERN WAS OBSERVED ACROSS THE REGION WITH  
   ONLY WIDELY SCATTERED LIGHT PRECIPITATION MAINLY OVER HIGH TERRAIN. 
   THIS MORNING FREEZING LEVELS ACROSS THE WEST SIDE RANGED FROM  
   4100 FEET AT QUILLAYUTE TO 5100 FEET AT SALEM. FREEZING LEVELS  
   FROM 2400 FEET TO AROUND 4000 FEET WERE OBSERVED FOR THE MIDDLE  
   AND UPPER COLOMBIA BASINS TO 7260 FEET FOR WESTERN WYOMING. 

   ...OBSERVED HYDROLOGIC CONDITIONS... 

   FLAT TO RECEDING FLOWS WERE OBSERVED FOR MOST LOCATIONS IN OUR  
   FORECAST AREA. 

   ...HYDROMETEOROLOGICAL FORECAST...FEB 09 - FEB 13... 

   A WEAK LOW PRESSURE SYSTEM ALONG THE CENTRAL CALIFORNIA COAST MAY 
   BRING A FEW WRAP AROUND SHOWERS TO SOUTHERN OREGON EARLY TODAY. A 
   A BLOCKING UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE NORTHERN  
   ROCKIES WILL LINGER FOR ANOTHER DAY WHICH WILL HELP TO PROVIDE 
   MOST OF THE REGION WITH BENIGN WEATHER. BY LATE WEDNESDAY A SERIES  
   OF SYSTEMS APPROACH THE COAST BRINGING A CHANCE OF MODERATE RAINFALL  
   TO THE OLYMPIC MOUNTAINS WITH LIGHTER AMOUNTS ELSEWHERE ALONG THE  
   COAST. LATE IN THIS FORECAST PERIOD... A SPLIT UPPER LEVEL FLOW  
   PATTERN IS FORECAST. HOWEVER... SOMEWHAT MORE FAVORABLE UPPER  
   LEVEL DYNAMICS AND A MOIST AIR MASS SUGGEST A POTENTIAL FOR  
   MODERATE RAINFALL FOR WESTERN WASHINGTON WITH MORE SIGNIFICANT  
   RAINFALL DIRECTED TOWARD VANCOUVER ISLAND AND BRITISH COLUMBIA.  

   ...HYDROLOGIC CONDITIONS... 

   SKOKOMISH NEAR POTLATCH IS EXPECTED TO RISE ABOVE BANKFULL THURSDAY. 
   AND A FEW OTHER LOCATIONS IN THE OLYMPICS WILL LIKELY RISE ABOVE 
   BANKFULL LATER IN THE WEEK. ELSEWHERE...LOOK FOR SOME LOCAL MINOR  
   RISES LATE PERIOD FOR THE REMAINDER OF THE WESTSIDE. ELSEWHERE EXPECT  
   LITTLE CHANGE IN MOSTLY FLAT TO RECEDING FLOWS. 

   ...6-10 DAY OUTLOOK...FEB 14 - FEB 18... 

   LATEST LONGRANGE GUIDANCE SUGGESTS A SPLIT FLOW PATTERN WITH SOME  
   SYSTEMS DIRECTED TOWARD THE BRITISH COLOMBIAN COAST WITH TRAILING 
   DISTURBANCES BRINGING OCCASIONAL RAINFALL TO THE PACIFIC NORTHWEST.  
   PRECIPITATION CHANCES TEND TO AVERAGE SLIGHTLY BELOW TO  
   NEAR NORMAL FOR MOST OF THE REGION AS THE UPPER LEVEL JET STREAM 
   RESTRENGTHENS TO THE SOUTH OF OUR REGION. TEMPERATURES ARE  
   EXPECTED TO CONTINUE AVERAGING ABOVE NORMAL. 

   ...GREEN RIVER... 

   OCCASIONAL LIGHT PRECIPITATION IS NOT SUFFICIENT TO KEEP GREEN RIVER  
   FLOWS FROM SLIPPING INTO GRADUAL RECESSION. LOOK FOR OCCASIONAL MINOR  
   RISES TO PICK UP LATE PERIOD AS THE GREEN RIVER BASIN INTERCEPTS SOME  
   MODERATE RAIN AT TIMES. 

   AO/BG/CO 

   VISIT US ON THE WEB AT HTTP://WWW.NWRFC.NOAA.GOV FOR DETAILED 
   GRAPHICAL PRECIPITATION...FREEZING LEVEL...AND TEMPERATURE FORECASTS. 

   $$ 

   $$