Heavy Rainfall Leads to Increased Chance of Landslides

The local forecast calls for increased showers tonight, with rain continuing through the rest of the week. Between 1 to 2 inches of rain is expected to fall tonight, with temperatures in the mid-40s.

Here's the special message from the NWS:

SOUTHWEST INTERIOR-EAST PUGET SOUND LOWLANDS-EVERETT AND VICINITY- SEATTLE/BREMERTON AREA-TACOMA AREA-HOOD CANAL AREA- LOWER CHEHALIS VALLEY AREA-EASTERN STRAIT OF JUAN DE FUCA- WESTERN STRAIT OF JUAN DE FUCA-NORTH COAST-CENTRAL COAST- 435 PM PST MON DEC 3 2012 ...HEAVY RAINFALL OVER THE LAST SEVERAL DAYS AND ABOVE NORMAL RAINFALL OVER THE LAST TWO TO 3 WEEKS WILL LEAD TO INCREASE RISK OF LANDSLIDES IN WESTERN WASHINGTON...

RAINFALL OF 2 TO 5 INCHES IN THE LOWLANDS OVER THE PAST WEEK HAS INCREASED SOIL MOISTURE TO HIGH LEVELS ACROSS WESTERN WASHINGTON. HEAVY RAINFALL OF 1 TO 2 INCHES IS EXPECTED OVERNIGHT TONIGHT AND INTO TOMORROW.

THIS AMOUNT OF RAIN WILL PUT EXTRA PRESSURE ON SOIL INSTABILITY...LEADING TO AN INCREASED RISK OF LANDSLIDES. CUMULATIVE RAINFALL OVER THE LAST WEEK HAS SOAKED SOILS TO THE POINT WHERE THE WASHINGTON LANDSLIDE RISK LEVEL IS LOW TO MODERATE. THE PREDICTED RAINFALL WILL KEEP OR RAISE THE LEVEL TO MODERATE THROUGHOUT THE AFFECTED AREA. THE HIGHER THE RISK LEVEL...THE MORE NUMEROUS THE LANDSLIDES ARE LIKELY TO BE.

ISOLATED LANDSLIDES CAN BE EXPECTED DURING THIS NEXT STORM AND FOR THE FOLLOWING COUPLE OF DAYS. 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.