Urban and small stream flooding advisory for Columbia County this morning until 8:45 AM. Please pass along to others at your agency or to other colleagues.
--Columbia County Emergency Management
++++++++++++
FLOOD ADVISORY
NATIONAL WEATHER SERVICE PORTLAND OR
601 AM PST MON FEB 28 2011
THE NATIONAL WEATHER SERVICE IN PORTLAND HAS ISSUED AN
* URBAN AND SMALL STREAM FLOOD ADVISORY FOR...
EASTERN WASHINGTON COUNTY IN NORTHWEST OREGON...
NORTHWESTERN CLACKAMAS COUNTY IN NORTHWEST OREGON...
SOUTHEASTERN COLUMBIA COUNTY IN NORTHWEST OREGON...
WESTERN MULTNOMAH COUNTY IN NORTHWEST OREGON...
CLARK COUNTY IN SOUTHWEST WASHINGTON...
SOUTH CENTRAL COWLITZ COUNTY IN SOUTHWEST WASHINGTON...
* UNTIL 845 AM PST.
* AT 551 AM PST NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
HEAVY RAIN DEVELOPING ACROSS THE PORTLAND AND VANCOUVER METRO AREA
THIS MORNING.
* THIS AREA OF HEAVY RAIN WILL REMAIN NEARLY STATIONARY THROUGH THE
EARLY MORNING HOURS...BUT MAY CHANGE TO WET SNOW ESPECIALLY IN THE
HILLS AS THE MORNING PROGRESSES. RAINFALL RATES OF ONE QUARTER
TO ONE THIRD OF AN INCH PER HOUR WILL CONTINUE THROUGH THE EARLY
MORNING HOURS ACROSS THE METRO AREA.
* AREAS WITH POOR DRAINAGE MAY HAVE MINOR FLOODING ISSUES THIS
MORNING. ADDITIONALLY...SMALL STREAMS WILL LIKELY RISE FAIRLY
RAPIDLY THIS MORNING.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
ADDITIONAL RAINFALL AMOUNTS OF AROUND AN INCH IS POSSIBLE WITHIN THE
NEXT TWO TO FOUR HOURS IN THE WARNED AREA.
EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE PONDING OF WATER ON
HIGHWAYS...STREETS AND UNDERPASSES...IN URBAN AREAS WITH POOR OR
OVERWHELMED DRAINAGE...AND WILL ALSO CAUSE ELEVATED LEVELS ON SMALL
CREEKS AND STREAMS.
LANDSLIDES AND DEBRIS FLOWS ARE POSSIBLE DURING THIS FLOOD EVENT.
PEOPLE...STRUCTURES AND ROADS LOCATED BELOW STEEP SLOPES...IN CANYONS
AND NEAR THE MOUTHS OF CANYONS MAY BE AT SERIOUS RISK FROM RAPIDLY
MOVING LANDSLIDES.
