Hydrologic Outlook
HYDROLOGIC OUTLOOK
ORZ001>014-WAZ019>023-039-040-281930-
HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE PORTLAND OR
1130 AM PST MON DEC 27 2010
...HEAVY RAIN WILL RAISE RIVER LEVELS THROUGH MID WEEK...
A WET AND WARM STORM SYSTEM IS EXPECTED TO BRING PERIODS OF HEAVY
RAIN TO THE PACIFIC NORTHWEST BEGINNING EARLY THIS EVENING AND
CONTINUING THROUGH LATE TUESDAY. THE CURRENT FORECAST FOCUSES THE
HEAVIEST RAINFALL OVER THE COAST RANGE OF OREGON DURING THE
OVERNIGHT HOURS TONIGHT...WITH PRECIPITATION FALLING MAINLY AS
SNOW IN THE CASCADES. THE POSSIBILITY OF SHARP RISES AND SOME AREA
RIVERS REACHING BANKFULL LEVELS EXISTS.
THE CURRENT FORECAST INDICATES THE HEAVIEST PRECIPITATION WILL
FALL OVER THE COAST RANGE OF OREGON...WITH 2 TO 3 INCHES OF
RAINFALL EXPECTED THROUGH TUESDAY. THE SNOW LEVEL IS AROUND 2000
TO 2500 FEET TODAY...THEREFORE PRECIPITATION WILL BEGIN AS SNOW
IN THE CASCADES. THE SNOW LEVEL WILL RISE TO 4000 TO 5000 FEET
LATE TONIGHT...TURNING SNOW TO RAIN AT PASS LEVELS WITH 1 TO 2
INCHES OF RAINFALL EXPECTED AT THESE LEVELS DURING THE DAY
TUESDAY. UP TO AN INCH OF RAIN CAN BE EXPECTED AT LOWER ELEVATIONS
INLAND.
THESE AMOUNTS OF RAIN WOULD PUSH RIVER LEVELS UP SHARPLY LATER
TONIGHT AND TUESDAY...AND SOME COULD REACH BANKFULL AS EARLY AS
TUESDAY MORNING. RIVERS DRAINING THE COAST RANGE ARE THE MOST
LIKELY TO BE IMPACTED.
VISIT WEATHER.GOV/PORTLAND FOR THE LATEST WEATHER AND RIVER
FORECASTS.
