A severe storm brought three days of extreme weather to a large swath of the South, Midwest, and Mid-Atlantic over the weekend. Tornadoes, hail, flooding, and extreme winds wreaked havoc from Texas to Pennsylvania. Nine people died as a result of the storm, with causes ranging from trees falling to drowning in floodwaters. The number of confirmed tornadoes continues to climb as investigations continue, but as of this writing, the number has risen to 41 across 9 states. High winds, with speeds recorded up to 136 mph, destroyed dozens of homes. Over 200,000 residents lost power across the states. As communities still reel from the damage, another nearly identical storm is starting to move across Texas. Read more
A small fire began Saturday afternoon in the Pine Barrens area of the Penn State Forest in Southern New Jersey. In less than two days, the Spring Hill Fire proceeded to burn over 11,000 acres. By 8am EDT Monday morning, crews reported they had the fire contained. Firefighters will remain on scene to monitor the fire since some areas are still burning. Full fire containment means the fire resources no longer believe the fire will grow or move out of the area it already scorched; however, a contained fire is not necessarily ‘out’. Additionally, nearby towns will likely still see, and possibly smell, smoke from the fire. While the cause of the blaze has not been confirmed, it is believed to have been human-caused. In addition to the fire occurring in an area known for illegal bonfires, the fire burned in an area that had no lightning strikes reported, has no power lines nearby, and was not conducting any prescribed or planned. Read more
New Regulations Forcing Compliance
California utility companies have been working to address their liability to the growing risk for massive wildfire events. The California Public Utilities Commission, CPUC, has stringent rules and guidelines for maintenance and mitigation, and has often held utility companies liable to the damages caused by their equipment starting fires. Senate Bill 901, named The Utility Wildfire Mitigation Plans Bill, outlines further requirements for utilities to provide the state with plans to prevent, combat, and respond to wildfires in their service territories. It allows for CPUC to review and modify these plans before the utility is allowed to adopt the plan. Read on to learn how these companies plan to combat this ever increasing threat. Read more
2018 Hurricane Season Quick Stats
Each spring, several predictive services release their forecasts for the upcoming Hurricane Season, which officially runs June 1 – Nov 30. While named storms can form outside of this range, they are significantly weaker and rarely reach hurricane strength levels.
The morning of November 30th, 2018, at 8:29 AM local time, a 7.0 magnitude earthquake shook the city of Anchorage, Alaska. The origin of the quake was 7 miles north of the city, resulting in the residents of Anchorage feeling the full intensity of this earthquake. Luckily, the epicenter was at a depth of 27 miles into the Earth’s crust. The depth of the origin allowed for the seismic energy of the earthquake to diminish slightly while making the 27-mile vertical journey before wreaking havoc on the surface.
Upon reaching the surface, the resulting damages included widespread power outages, severe damage to roadways and other transportation infrastructure, and internal damage to residential and commercial structures. Immediately after the quake hit, the USGS released figures that contained frightening numbers depicting the probability of economic losses. The figure below shows that, according to the USGS predicted losses, there is a 35 percent chance of damages ranging from $100 million – $1 billion. The data goes on to show that there is a 20 percent chance that the economic losses could very well total over one billion dollars!
Immediately after the quake and ongoing through this week, the area continues to be inundated with relentless aftershocks that still hold immense power. As of this morning, the area has been the recipient of over 2,700 aftershocks and tremors, ranging in magnitude from 1 up to 5. There is still potential for an aftershock to be nearly as powerful as the original incident itself, which would cause even more damage during the recovery process.
In 1964, Anchorage fell victim to a 9.2 magnitude quake that caused damage to such an extent that certain parts of the city were unrecognizable. This earthquake killed 15 people during the event and another 124 from the resultant tsunami. Only one earthquake in recorded history has been more powerful (9.5 magnitude in Chile 1960). In the wake of this devastating event, the changes to the building codes may have resulted in massive economic saves in relation to building loss during this most recent quake. One of the key ideas that resulted from the research in the aftermath of the 9.2 magnitude event was the concept of integrating ductility into modern architecture and design. Ductility is the ability to bend without breaking, which helps absorb some of the seismic motion during an earthquake. One way this could be achieved in the case of concrete structures would be ensuring the right amount of steel reinforcement is located in the correct areas of the structure. This is just one example of the engineering constructs resulting from the Earthquake Hazard Reduction Act of 1977, which was sparked by the enormous 1964 earthquake.
Think about sitting around a campfire. The fire emits a measurable level of heat, and the nearer you sit to it, the hotter the fire feels. If you are farther from the fire, the heat is less intense. This simple example can explain common earthquake measurements – magnitude and intensity – and what these earthquake scales mean.
Consider, once again, the campfire. This temperature is measurable and absolute. When an earthquake occurs, the Richter scale measures the magnitude of the earthquake at its epicenter. The Richter scale was developed in 1935 as a way to quantify the strength of earthquakes. It is a logarithmic scale based on the amplitude of the waves recorded by seismographs. A logarithmic scale means a magnitude increase of 1 relates to an energy increase by a factor of 10. An earthquake measuring a 4.0 on the Richter scale is 10 times as strong as a 3.0!
Modified Mercali Intensity Scale
Now, you know the closer to the campfire you sit, the hotter the flames feel on your skin. This generally holds true with earthquakes as well. Typically, the nearer the epicenter the stronger the ground shaking you would feel; however, there are other factors that affect the intensity of the earthquake you feel at your location. The type of earthquake, bedrock the shockwaves traveled through, and amplitude of the shockwaves from the earthquake are a few of these factors. The intensity you feel is measured on a scale called the Modified Mercali Intensity Scale (MMI). The MMI scale ranges from “Not Felt” and “Weak Shaking” up to “Violent” and “Extreme” with well-built structures suffering damage.
Other Scales Around the World
While the Richter scale is widely known and the MMI scale is used in the United States, there are other magnitude and intensity scales in use around the world. The Japanese Meteorological Agency uses a separate calculation for shallow earthquakes (depth < 60km) which has been shown to be reasonable when the magnitude is 4.5-7.5; however, this magnitude measurement has historically underestimated larger magnitude tremors. Additionally, Japan and Taiwan use the Shindo intensity scale which has significant correlation to the MMI scale. During the middle to late 20th century, the USSR, East Germany, and Czecholsovakia established and utilized the Medvedev-Sponheuer-Karnik scale (MSK) to evaluate shaking and effects from earthquakes. This scale was built upon in the 1990s by the European Seismological Commission as they shifted to implement the European Macroseismic Scale for European countries. The MSK scale continues to be employed in Russia, India, Israel, and the Commonwealth of Independent States.
You can read more about some of these other scales here:
JMA Shindo intensity scale: https://www.jma.go.jp/jma/en/Activities/inttable.html
- Timeline: Aug 30 – Sept 13, 2017
- Severely Impacted Areas: USVI, Puerto Rico, Georgia, Florida
- Maximum Sustained Winds: 180 mph
- Fatalities: 52 direct (wind-driven debris, storm surge), 82 indirect (heart attack, house fires, vehicle accidents)
- Damages: $64.76 Billion (5th costliest tropical cyclone on record)
Hurricane Irma’s Trek Across the Atlantic
This week marks the anniversary of Hurricane Irma forming and making landfall across the Southern United States. Tropical Storm Irma became a named storm on the 30th of August, 2017. It moved steadily across the Atlantic Ocean at 10-15 mph. A week later, now a Category 5 Hurricane, Irma passed by Puerto Rico narrowly missing it to the north. The storm continued skirting along the northern coasts of the Caribbean Islands including the Dominican Republic and then Cuba. Then, a glancing landfall moment happened along the North Cuban coastline, briefly weakening Irma to a Category 3 Hurricane as it turned north toward Florida.
Throughout Irma’s approach to the US Mainland, forecasts remained uncertain and models were not in agreement. Every update led to questions: would Miami or Orlando would be directly in the path, would the storm would move farther west and trail the Gulf Coast side of Florida, or would it shift a bit more west and come up the Gulf and end up hitting the Florida panhandle? One thing was certain – wherever landfall occurred, winds, rain, and storm surge were going to be affect a lot of people and infrastructure. Hurricane Irma ended up making landfall as a Category 3 Hurricane on September 10th, 2017, just south of Fort Myers along the SW part of Florida’s peninsula.
While power has been restored and roadways cleared, many areas still see the impacts of these storms. The Florida Keys and much of Florida’s peninsula experienced hurricane force winds, nearly a foot of rain, and around 10ft of storm surge. Cleaning up the wide-spread damage is a daunting undertaking; however, FEMA, charities from around the world, and community efforts came together to assist residents to get their areas back to habitable conditions. By October 1st, much of Key West’s historical district was back in operation and welcoming guests. Nearer the main land, the damage was more extensive. Some businesses and homeowners have chosen not to rebuild and now those that had less significant repairs have vacant lots as neighbors. Each family has to make the best decision for their circumstances and many chose to shift to a new location rather than go through the extensive rebuilding process.
When coming home after a storm, reentering the region, property, and structure safely is important. Ensuring flooding conditions haven’t led to moldy conditions, debris is properly removed, and the structure remains sound are just a few common checks. FEMA and the Insurance Institute for Business & Home Safety shared Safety Guidelines useful to making this process as smooth as possible.
National Hurricane Center, The Weather Channel, FEMA
Fall Means Santa Ana Winds
Annually, the onset of the fall and winter seasons brings the highest chance for Southern California’s famed Santa Ana winds. An unusually strong and persistent Santa Ana event was the largest factor in the spread of last year’s Thomas fire in Ventura (now second largest in size to Mendicino Complex). Much of Southern California experienced an on-and-off Santa Ana wind event for a little over two weeks, which contributed to the Thomas Fire burning a hot lap around Ojai and into Santa Barbara.
What Are Santa Ana Winds?
Typically Santa Ana air mass conditions are brought on by high pressure inland and lower pressure off the Pacific Coast which brings very hot and dry weather along with strong, down-slope winds. Santa Ana winds typically happen between September and May, in the winter months. We think this UCLA FAQ outlines Santa Anas the best. In the past, the critical fire weather conditions that accompany Santa Ana winds turn the typically dry chaparral of Southern California into explosive fuel. Some of the country’s costliest fires in history have taken place in these conditions.
The Outlook This Fall
Typically, a weather event occurs by mid-September that brings moisture to regions experiencing significant fire activity which allows for the western fire season to begin to decrease in activity. All signs point to a normal seasonal progression including a transition from ENSO Neutral conditions to El Niño, therefore such an event is expected. Most regions will exit the fire season at this point, but only a brief lull is expected across California before it enters its fall fire season by October and November. Given ongoing dryness in the fuels, the fall season may very well be robust across portions of the state. Fortunately for the drought situation, Meteorologists are expecting an El Niño cycle to begin affecting the area with rains by November. In the meantime, as the tropical air mass that has brought this summer’s rain gives way to autumn’s Pacific air mass, a few Santa Ana events should precede the El Nino’s wetting effect.
This year Hawaii has already experienced lava flows and earthquakes from the Kilauea eruption, now the state braces for high winds, flooding, mudslides, brushfires and even the possibility of tornadoes caused by the approaching Hurricane Lane. Hurricane Lane became a named storm on Wednesday August 15th off the southwestern coast of Mexico. The storm gradually strengthened, becoming a hurricane by that following Friday. As the hurricane churned its way slowly westward, early forecasts were already predicting the storms turn towards the Hawaiian Islands.
Rare for Hurricanes to Make landfall on the Islands
Hawaii is normally protected from approaching hurricanes because of cooler waters around the islands. An additional buffer is provided by a high pressure system that sits over the state during the majority of the hurricane season. Only two hurricanes have made landfall in Hawaii since the 50s. Hurricane Dot (1959) & Hurricane Iniki (1992). It has been a slow year in the Atlantic, but this year’s warmer than normal waters in the Pacific Ocean has fueled storms. Hurricane Lane, which briefly became a Category 5 hurricane on August 21st, is the 12th named Pacific Storm this year. The storm continued its track towards Hawaii with most forecasts predicting its path to skirt the islands before turning to the west. Lane weakened to a Category 3 on Thursday the 23rd but the outer bands of the hurricane began unleashing torrential rains over the islands. The Big Island recorded 8” of rain during these initial hours and landslides were already beginning to threaten homes and close roadways.
Hurricane Lane Current Conditions
Hurricane Lane continues to churn to the north, slowing its forward movement and dropping to a Category 2 today. The outer bands of the storm continue to bring downpours all over the islands with rainfall rates reaching 1 to 3 inches per hour. So far Hawaii’s Big Island has been the hardest hit, receiving 31 inches of rain as of this morning. Widespread flooding has inundated downtown Hilo and flash flood watches will remain in effect until at least Friday evening.
Evacuations have been issued for flood prone areas on the Big Island, Kauai, Molokai and Maui. There have also been reports of power outages and mudslides have closed several roads. Forecasters are confident the storm track will have the hurricane skirting the islands. Landfall, however, isn’t the biggest worry as the slow movement of the storm greatly increases the amount of rainfall that will impact the already water logged and slide prone slopes.
Ahead of the Rains High Winds Spread Brushfires
High winds associated with Hurricane Lane are also caused of a brushfire that ignited around 1am Friday morning near Lahaina, Maui. Fire fighters are currently battling the 300 plus acre fire which has prompted evacuations and already impacted numerous structures. Another fire near Kaanapali on Maui threatened homes and burned down a banana tree patch before being contained. Maui is expected to get over 8 inches of rain today which should help to extinguish the fires and allow fire fighters to gain containment, but the burn scars could exacerbate debris flows.
After its westward turn Lane is expected to lose strength, dropping to a tropical storm. The threat to Hawaii, however, will continue well into next week as the storm continue to drop heavy rainfall.
The Ferguson Fire began last Friday evening (13/July) in the Savage Trading Post area of Mariposa County, CA. It quickly grew past 4,000 acres by Sunday morning. Evacuations were issued for several areas in the vicinity and parts of Hwy 140 were closed due to firefighting activities. From the beginning, crews focused on securing fire line along Hwy 140 and structure protection where needed. In preparation for the hot and dry forecast, additional resources worked to extend containment lines to the east on both north and south flanks of the fire. Daily, an inversion has kept the smoke low over the fire which limits the usage of aircraft for water and retardant drops. Another compounding factor to this very active fire is the available fuels – this area has had no significant wildfire in nearly 100 years.
The forecast has been much the same each day for the Ferguson Fire area. Today’s weather was similar to yesterday with upper 90os and into the triple digits, relative humidity around 17-20%, and light & variable west winds at 5-10 mph with gusts to 20 mph. As thunderstorms built over the area after lunch, these winds increased to 15 mph with stronger gusts. These conditions will lead to ongoing active fire behavior. As safety allowed, crews conducted burning operations along the western and eastern sides of the fire. This means they purposely burned fuel to remove it in controlled portions. Removing this fuel allows resources to better control where the fire can grow and spread next. At only 7% containment, crews are pre-positioned in the communities around the fire in case the winds drive it quickly to the houses. So far, no homes have been destroyed from this fire, but the destructive California fires of this past fall and winter remain fresh in everyone’s minds.
- As of: July 19th, 2018
- Location: Mariposa, CA
- Size: 21,041 acres
- Containment: 7%
- Fire Behavior: Moderate fire spread through brush/chapparal and light pine timber
- Structures Threatened: 108
- Structures Destroyed: zero
- Evacuations: In place for Jerseydale and Mariposa Pines to the south, Yosemite West to the east, and along Hwy 140 to the north
- Incident Page: https://inciweb.nwcg.gov/incident/5927/