Carolyn Seitz has helpfully complied the following comprehensive information about anticipated rainfall over the weekend, as well as mudflow and road closure warnings:
The County of Los Angeles, Department of Public Works has issued the following information, including estimates of rainfall, stormwater issues, mud and debris flows and road closures.
The information provided in their bulletin this evening provides anticipated rainfall amounts for the period between 6 PM Sat., Dec. 17 through 6 AM on Sunday.
For La Canada/Flintridge and the Altadena burn areas:
Rainfall amount expected to be 4 to 8 inches in the foothill/mountain areas. Please note that that is 4 to 8 inches of rain expected in a 12 hour period between Saturday evening and Sunday morning.
Potential for flooding as well as mud and debris flows in the burn areas (and please note that the details below are provided for La Crescenta and La Canada/Flintridge areas as well as Big Tujunga. As usual, Altadena is missing from the information.) It is strongly recommended that caution be exercised in the areas that have previously experienced inundation during storm events or other damage to roads and guardrails because of debris flows. These areas include Canyon Crest, Millard Creek and Millard Canyon.
Possible minor to moderate mudflow deposition on streets below the burned hillsides: Paradise Valley area (Derwood Dr; Bristow Dr; Earnslow Dr); upper Rock Castle Drive;upper Escalante Drive; upper La Forest Drive; upper La Canada Blvd; Big Briar Wy (above Haskell St).
Possible minor to moderate mudflow deposition on streets below the burned hillsides: in the Briggs Terrace area including Canyonside Rd and Maurice Av; Pineglen Rd (between Ridgepine Dr and Pinelawn Dr); and Pennsylvania Av (between Markridge Rd and Harmony Pl).
Possible minor to moderate mudflow deposition on streetsin: upper Boston Av; Dunsmore Av (above Henrietta Av); Deukmejian Park; Pennsylvania Av (above Harmony Pl); and access road west of Pennsylvania Av.
Possible minor to moderate mudflow deposition on streets below the burned hillsides including: private portions of Grenoble St; Owens St; upper Alpine Wy; Big Tujunga Cyn Rd; Oro Vista Av andits crossing over Big Tujunga Wash; Ebey Cyn Rd; Big Tujunga Wash (down to Hansen Flood Control Basin).
Streambeds and watercourses will also be subject to muflows and depositions.
Road closures:
ANGELES FOREST HY FROM ANGELES CREST HY TO ALISO CYN RD - Beginning Sunday, December 19
MT WILSON RED BOX RD FROM VIDEO RD TO ANGELES CREST HY - Beginning at 2:00 am, Sunday, December 19
Other public roads in the Angeles National Forest may be subject to closure due to mudflow/debris deposition at numerous locations below the burned hillsides.
Streambeds and watercourses will also be subject to mudflows and deposition.
ADDITIONAL INFORMATION:
The National Weather Service is estimating that rainfall between Saturday and Wednesday could be as much as 12 inches.
Updated information will be provided when available.
Please let me know if you have any questions.
Stay safe!