Valley Fire: #3 on the California Fire Catastrophe List

Wildfires eased in many parts of the western U.S. with increased moisture and lower temperatures during the past few weeks; for instance crews gained the upper hand throughout Washington State on the huge fires reported there in August, as well as in Oregon and Montana.

However, there was a glaring exception to this good news - on September 12 a fairly small fire of some 100 acres morphed within 24 hours into a 100-square mile animal of flame, engulfing whole neighborhoods, schools, and even an apartment complex in the Napa Valley north of San Francisco.

Flames consume more than a thousand structures around Middletown / KGO-TV7

The normally quiet community of Middletown, home to about 1300 people, found itself in the epicenter of what officials are calling the 3rd most damaging fire ever in California. Located about 45 miles north of the city of Napa, Middletown residents had mere minutes to escape a fire that literally exploded in size and might on September 12-13. The “Valley Fire” was smaller in scope than last month’s Washington State Okanagan blaze but it caused a great deal more property damage: some 1,300 homes and an apartment complex were destroyed along with a school, 66 commercial buildings and at least 500 other non-residential structures. Insured losses are estimated to be “hundreds of millions” according to Lake County, California officials, making it the perhaps biggest insured loss event in the U.S. this year. About 3,600 Lake County residents lost their homes. Another large blaze to the east of the Valley Fire is known as the Butte Fire, and it has claimed nearly 100 homes on its own. Together, these two hot-spots incinerated more than 134,000 acres (about 200 square miles) and destroyed over two thousand structures. At least six people died in these California wildfires in the past two weeks. Both are now mostly contained, but wildfire risk remains high statewide.

A Horrific Night for Middletown, CA /davemillsphoto / Instagram

Two Middletown homes ablaze / KGO-TV

Photo by therichlifeonabudget /Instagram

NASA satellite imagery, color-enhanced, showing the huge burn scars all around Lake County, California.

Southern Cal. Floods: A Sign of Things to Come?

Meanwhile, Southern California received a rare September soaker that may be a prelude of what this winter holds in store: flooding and mudslides. Torrential rainfall descended upon Los Angeles on the morning of September 15 with many locations getting two inches of rain in just a couple of hours: that’s a lot for SoCal. There were at least 10 people rescued from the high waters of the Los Angeles and other area rivers, and a few mudslides were reported. At least one home began to slide down the hill after the foundation was eroded by the deluge. This could be a frequent scenario if El Nino comes in as strong as nearly every model now projects; we’re talking flooding, mudslides, possibly whole homes sliding down the hill as in 1983. So it’s looking to be a tough time with lots of adjuster work in the west this fall and winter.

California’s September soaker makes for a moment of irony on September 15 / Jim Angius / Los Angeles Times

Utah Tragedy No lives were lost in the California floods, but tragically this same weather system brought torrential rain that killed 18 people in the Hildale, Utah area on September 14.

16 people perished in these two vans, mangled by surging floodwaters. George Frey/2015 Getty Images

Most of the victims were trapped in two vans by a “wall of water and debris” as they raced to escape the treacherous situation. Although the flood affected a seven-mile stretch of river, property damage was relatively low at a few million dollars, but state officials, as reported by New York Magazine, said it’s one of the deadliest weather events in Utah History.

Tropics: Plenty of Storms but Few Hurricanes, and some Good Luck

The 2015 Atlantic hurricane season has seen a near-normal number of named storms, but only two hurricanes, which is low. Through September 27 there were 9 named storms, the most recent one named “Ida”, for a season total YTD that’s very near the average. The hurricane total has been low due to strong wind shear over the Caribbean and western Atlantic; it disrupted several systems like Hurricane “Danny” and Tropical Storm “Erika” before they could strengthen. So far, June’s Tropical Storm “Bill” has been the sole storm to hit the U.S., causing widespread flood damage across Texas and Oklahoma.

Strong wind shear over the tropics is typical of El Nino. However, a risk for landfalling storms continues well into October, primarily from Virginia southward to Florida, and westward along the Gulf coast to Texas. A new tropical depression off of the Carolina coast may become the 10th storm of the season, “Joaquin”, and it could affect the U.S. east coast in early October if hurricane models are right. So the season is certainly not over yet. In fact, it’s typical to see one or two named storms each October, the unknown is where they form and track.

El Nino: Strongest in Two Decades

A strong El Nino is in progress; it’s one where sea temperatures of 1.5 degrees (C) or higher than the average are observed in four eastern Pacific Ocean zones over a period of several months. That may not sound like much, but this warming has a big impact on weather across the world.

While every El Nino is a bit different, a five year drought has left the landscape of California with little defense to heavy, eroding rainfall that’s the signature of a strong “Nino” in the southwest. Florida’s worst tornado outbreak on record happened during the ’97-’98 Nino. Texas received devastating floods in just a moderate 1991 El Nino. Severe weather and floods are more likely than average this late fall and winter over the southern and southwestern U.S. thanks to the Nino effect.

Predicting a major snowstorm is not possible this far out; as mentioned in my August post, a shorter-range pattern called the AO (Arctic Oscillation) has a lot to do with that, and it’s only predictable out a few weeks. On the other hand, big snows are sometimes enhanced along the U.S. east coast in an El Nino winter and that’s the last thing folks in Boston and New York want to hear. What’s worse, these storms would not be as “cold” as the 2014-2015 winter storms, meaning heavy wet snow that can really cause a lot of damage.

The above graphic shows how much warmer than average the SST (Sea Surface Temperatures) are over much of the eastern Pacific: a classic signature for a “strong” El Nino, which is now in progress. NOAA data.

Here are the latest seasonal outlooks for precipitation and temperatures, based largely on the evolving El Nino, from NOAA (scroll down):

Note the “wet” southern U.S. and dryness along the northern border, a classic El Nino signature / NOAA

For southern Canada, the Great Lakes and the northern Plains a fairly dry and mild winter is forecast.

So, stirring the weather stew offers these adjuster hot-spots for Oct-Nov:

>>> Pacific States: Fire threat continues for another month; heavy rain episodes become more likely in November-December for California.

>>> Arizona and Utah: Flash Floods

>>> All of the southern United States: severe weather, flood potential. Severe weather in the nation’s midsection / Nebraska east to Ohio (October)

==========================================

Take Care,

Steve LaNore, Certified Broadcast Meteorologist Author of “Twister Tales: Unraveling Tornado Myths” and “Weather Wits and Science Snickers” / both available on Amazon