Heavy Rainfall - risk of landslides...

posted Nov 19, 2012, 9:56 AM by smike@guemesfire.org
844 AM PST MON NOV 19 2012.

..HEAVY RAINFALL TODAY WILL LEAD TO INCREASED RISK OF LANDSLIDES IN WESTERN WASHINGTON...

RAINFALL UP TO 1.5 INCHES...WITH LOCALIZED AMOUNTS NEAR 3 INCHES...
DURING THE 24 HOURS ENDING AT 8 AM PST HAS INCREASED THE SOIL MOISTURE TO MODERATE LEVELS ACROSS WESTERN WASHINGTON. ADDITIONAL RAINFALL OF UP TO 2 INCHES IS EXPECTED BY LATE THIS EVENING. THIS AMOUNT OF RAIN WILL PUT EXTRA PRESSURE ON SOIL INSTABILITY...
LEADING TO A RISK OF SCATTERED LANDSLIDES.

CUMULATIVE RAINFALL OVER THE LAST WEEK HAS SOAKED SOILS TO THE POINT WHERE THE WASHINGTON LANDSLIDE RISK LEVEL WAS MODERATE.
THE PREDICTED RAINFALL COULD RAISE THE LEVEL TO HIGH. THE HIGHER THE RISK LEVEL...THE MORE NUMEROUS THE LANDSLIDES ARE LIKELY TO BE.

AREAS ABOVE 5000 FEET IN ELEVATION AND TO NEAR 3000 FEET IN THE CASCADES PASSES WILL SEE MOSTLY SNOW AND NOT BE AFFECTED.

WITH AN ELEVATED LANDSLIDE RISK...RAINFALL INDUCED LANDSLIDES ARE POSSIBLE DURING BURSTS OF INTENSE RAINFALL OR WHEN THERE IS HEAVY RAINFALL OVER A PERIOD OF A DAY OR TWO AS NOTED IN THE FORECAST ELEVATED RISK LEVEL. A GRADUALLY DIMINISHING RISK OF LANDSLIDES WILL CONTINUE FOR SEVERAL DAYS AFTER THE RAIN ENDS. AREAS MOST SUSCEPTIBLE TO LANDSLIDES UNDER THESE CONDITIONS ARE STEEP COASTAL BLUFFS AND OTHER STEEP HILLSIDES.

FOR MORE INFORMATION ABOUT CURRENT CONDITIONS...VISIT WWW.WEATHER.GOV/SEATTLE...SELECTHYDROLOGY...AND THEN SCROLL DOWN FOR THE LINKS TO THE LANDSLIDE INFORMATION PAGES.

TO REPORT LANDSLIDES TO THE STATE FOR TABULATION...GO TO THE WASHINGTON STATE LANDSLIDE RISK WEB PAGE AND THE LINK FOR REPORTING.
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