HYDROLOGIC OUTLOOK

 
 FGUS76 KSEW 180020
 ESFSEW
 WAC009-027-031-041-045-053-067-182130-
 
 HYDROLOGIC OUTLOOK
 NATIONAL WEATHER SERVICE SEATTLE WA
 420 PM PST TUE NOV 17 2009
 
 ...NEXT STORM COULD CAUSE FLOODING FOR RIVERS ON THE OLYMPIC
 PENINSULA AND SOUTHWEST INTERIOR FOR THURSDAY AND FRIDAY...
 
 A FRONTAL SYSTEM WILL AFFECT THE REGION WEDNESDAY NIGHT THROUGH
 EARLY FRIDAY. THE HEAVIEST RAIN IS EXPECTED TO BE OVER THE OLYMPIC
 PENINSULA AND THE SOUTHWEST INTERIOR...SOME OF THE SAME AREAS THAT
 HAD HEAVY RAIN THIS LAST STORM. 
 
 CURRENTLY THE SKOKOMISH AND SATSOP RIVERS ARE STILL ABOVE FLOOD
 STAGE AT THIS TIME AND FLOOD WARNINGS REMAIN FOR THOSE RIVERS. THE
 LOWER CHEHALIS RIVER HAS BEEN SLOWLY RISING WITH THE SERIES OF
 STORMS RECENTLY. THIS LAST STORM WILL BRING THE LOWER CHEHALIS TO
 CREST CLOSE TO FLOOD STAGE BY WEDNESDAY JUST BEFORE THE NEXT RAIN
 STORM BEGINS. THEREFORE THE FLOOD WATCH REMAINS FOR THIS AREA FOR
 THE CREST ON WEDNESDAYS AND THE HIGH WATER WILL INCREASE THE
 THREAT OF FLOODING FOR LATER IN THE WEEK.
 
 CURRENT 24 HOUR RAINFALL PREDICTIONS FOR THE NEXT STORM ENDING
 MIDDAY THURSDAY ARE 5 TO 10 INCHES OVER THE OLYMPICS...3 TO 6
 INCHES OVER THE SOUTHWEST...3 TO 6 INCHES OVER THE NORTH CASCADES
 AND 1 TO 3 INCHES OVER THE CENTRAL CASCADES. THE FREEZING LEVEL IS
 EXPECTED TO BE 4000 TO 5000 FEET OVER THE OLYMPICS AND 2000 TO
 3500 FEET OVER THE CASCADES. THIS AMOUNT OF RAIN WOULD BE ENOUGH
 TO CAUSE FLOODING PROBLEMS ON THE SKOKOMISH RIVER WHILE OTHER
 RIVERS FLOWING OFF THE SLOPES OF THE OLYMPICS...LIKE THE
 SATSOP...WOULD ALSO BE UNDER PRESSURE. WITH THE CHEHALIS RIVER
 RUNNING HIGH...THIS RAINFALL WOULD BE ENOUGH TO DRIVE THE CHEHALIS
 RIVER ABOVE FLOOD STAGE. OTHER RIVERS IN THE AREA WILL ALSO BE AT
 RISK OF FLOODING INCLUDING...BUT NOT LIMITED TO...THE NEWAUKUM AND
 PUYALLUP RIVERS. LOWER AMOUNTS OF RAIN AND LOWER FREEZING LEVELS
 EXPECTED OVER THE CASCADES MEANS THE FLOOD THREAT FOR MOST OTHER RIVERS
 OFF THE CASCADES IS LOW.
 
 AT THIS TIME FLOODING IS NOT EXPECTED ALONG THE GREEN RIVER.
 
 

 
 JBB