Severe Weather Forecast in Southern States: Thousands with no Power and Heavy Rain in LA

This week we explore severe weather.

A very good source of information is the Weather Underground Severe Weather website (see current map below). 

In the southern states, Patricia's remnants left today thousands in Louisiana with no power and heavy rain. The threat of a few severe storms capable of producing damaging wind gusts or isolated tornadoes will continue along the Gulf Coast into Monday. Patricia's mid- and upper-level energy helped spawn a non-tropical surface low pressure system in the Gulf of Mexico. That low will make the environment at least marginally favorable for rotating thunderstorms that could spawn brief tornadoes through Monday.

Heavy rain will continue to stream into Louisiana and neighboring southwestern Mississippi on Sunday, threatening to trigger major flooding.

In addition to the flooding rain, southern Louisiana will remain at risk for isolated tornadoes as occasional gale-force winds will create rough seas over the western Gulf of Mexico to end the weekend.

A tornado was confirmed by NWS Storm Survey Sunday afternoon in Destrehan, Louisiana, just outside of New Orleans. One woman was injured due to damage to her mobile home according to local emergency management.

Also, the risk of flash flooding will affect far more people over the next couple of days.

http://www.wunderground.com/severe.asp

http://www.weather.com/news/news/southern-plains-flood-threat-texas-6-things-to-know

http://www.accuweather.com/en/weather-news/live-blog-flooding-corsicana-houston-texas-oklahoma-louisiana-arkansas-patricia/53160429

LANDSLIDES & ENSO

Wildfires potentially increase the risk of landslides.

This is not new in the Western US. The USGS Landslide Hazards Program alerts of the danger of landslides after a rainstorm in areas of recent wildfires, explaining what to do before and during an event. This makes me think of a very probable strong El Niño event this year after all the wildfires the state has endured so far…

NOAA just prepared an updated prediction that can be seen here. Basically, they say as today El Niño conditions are present and that there is an approximately 95% chance that El Niño will continue through Northern Hemisphere winter 2015-16, gradually weakening through spring 2016.

El Niño and La Niña, together called the El Niño Southern Oscillation (ENSO), are periodic departures from expected sea surface temperatures (SSTs) in the equatorial Pacific Ocean. These warmer or cooler than normal ocean temperatures can affect weather patterns around the world by influencing high and low pressure systems, winds, and precipitation

Another good source of information is the California Geological Survey (CGS), which has produced numerous maps that show landslide features and delineate potential slope-stability problem areas.

FEMA always is also a good place to keep informed about these hazards and what to do before, during, and after.

Maps of risk areas can be downloaded and studied (regional and local examples here), which would help the managers and planners know which areas will be needing help first/more frequently.

10/17/15 UPDATE:
Flash floods sent water flowing into South CA roads.  All lanes of California's Interstate 5 reopened Friday evening after a massive mudslide pushed up to five feet of mud across the roadway Thursday, trapping cars and forcing crews to close the highway in both directions for nearly 40 miles. 

Meanwhile, State Route 58 is expected to remain closed for days after the same storm system caused flash flooding and dangerous mud flows, trapping about 200 cars there in mud as deep as 6 feet.

More information at links below:

http://www.conservation.ca.gov/cgs/information/publications/ms/documents/ms58.pdf

http://landslides.usgs.gov/hazards/

http://www.conservation.ca.gov/cgs/geologic_hazards/landslides/Pages/Index.aspx

http://www.ready.gov/landslides-debris-flow

http://www.cjpia.org/news/news-and-updates/news-and-updates/2015/10/05/strong-el-ni%C3%B1o-probable

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

http://cdfdata.fire.ca.gov/incidents/incidents_current
http://www.weather.com/news/news/california-flooding-mudslides-stranded-motorists

http://www.nytimes.com/2015/10/17/us/a-wall-of-mud-in-california-and-warnings-to-heed-el-nino.html?hp&action=click&pgtype=Homepage&module=second-column-region&region=top-news&WT.nav=top-news

Obama declares South Carolina state of emergency: Worst Flooding in 1,000 years

This week we all watched hurricane Joaquin (right) move north from the Bahamas and heard how bad the flooding potentially would be for the East Coast…people prepared for massive flooding…

And the 1-in-1,000-year rain event came….curfews have been ordered, dozens of people are in need of rescue, several interstates are closed and five people are dead in some of the worst flooding South Carolina has ever seen, officials just said. Emergency managers sent out a statewide alert telling people to remain indoors.

President Barack Obama declared a state of emergency in South Carolina and ordered federal aid to help state and local efforts.

Charleston has received more than 14 inches of rainfall since the historic event began Friday. One area northeast of Charleston has reported more than two feet of rain….Coastal flooding and erosion are a great concern in seven states...We’ll all be watching how this evolves in the upcoming days..

Update 10/7/15:  62 dams across the state are being monitored, and 13 had already failed. There are two people missing and 17 killed so far. 

More at:
http://abcnews.go.com/US/wireStory/round-downstream-south-carolina-towns-brace-flooding-34303693
http://www.weather.com/news/news/south-carolina-floods-news