Quick update on Northern California Wildfires (plus weather forecast)

As of now (5:30 pm PDT), the death toll in the California Wildfires is up to 35 and is expected to go up further. 18 in  Sonoma County, 9 in Mendocino County, 4 in Yuba County and 4 in Napa County. 5700 structures have been destroyed and 221,000 acres have been burned. Treating the conglomeration of fires as a single event (as all the Northern CA ones initiated Sunday Night), this is by far the most destructive fire event in state history and one of the deadliest. Simply horrifying and very sad.

Firefighters have begun to have some containment success the past 48 hrs with slower winds and at least some periods of slightly improved humidity. However, tonight-Sunday morning will feature an intensification of extreme fire danger. This is because a strong surface high pressure system will advance toward the central Intermountain West this weekend, intensifying downsloping Diablo winds from the hilly and foothill mountainous terrain of Northern California. North-northeast winds may gust as high as 45-60 mph Saturday, inducing very low humidity values, drying out fuels and potentially promoting extreme fire behavior (high forward speed, rapid growth) in existing fires as well as any new fires. Red Flag Warnings have been issued by the National Weather Service to cover this forecast potential.

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Strong high pressure moving over OR, ID and NV Saturday will promote strong Diablo winds over Northern California. (NWS forecast surface map valid 11 am PDT Saturday).

There are no thunderstorms forecast, so any new fires would be likely started by human activity. So folks in these areas need to very much be careful with anything which can potentially start fire and really…just avoid starting any outdoor fire or using  anything which sparks.

Some good news…mid-range computer model forecasts suggest a pattern shift toward precipitation and cooler weather by the end of next week. Just have to get through the next week of fire activity before some meaningful hydrologic relief to aid the firefighting efforts.

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The Global Forecast System Model forecast accumulated total precipitation valid 8 pm PDT Friday. This is one forecast scenario, but all global models point toward a wetter pattern, beginning the second half of next week into next weekend.

–Meteorologist Nick Humphrey

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Fire Conditions expected rest of this week and weekend for California

The fire conditions Wed Night into this morning were not as severe as expected thanks to weaker winds. This allowed firefighters to make some ground against fires through the night, however high fire danger remains and will continue for days into the future, with no rain in sight.

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Strengthening pressure gradients along the mountainous terrain of interior California and the warm, very dry air mass will promote high far danger with windy conditions near the mountains and adjacent valleys Fri Night-Sunday. (See tightly packed isobars…lines of equal pressure…on the map in CA just west of Nevada as high pressure shifts SE-ward over the Intermountain West).
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Very low dew points during the day Sat could mean relative humidity values as low as 10-20% across interior California, along with gusty winds for high fire danger.

Air quality remains terrible in the Bay Area. Folks in that region should do what they can to avoid being outside if at all possible.

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Unhealthy air quality exists across the entire Bay Area. Expect harmful air quality to be problematic into the weekend.

I’ll add any additional updates related to fires on this post today. Stay safe in these areas!

–Meteorologist Nick Humphrey

GOES-16 Satellite Loop of California Wildfire Smoke

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The new geostationary weather satellite, GOES-16 captured this high spatio-temporal resolution loop of the smoke plume over the Bay Area of Northern California this evening before sunset. The deep smoke is embedded in the low-level north winds, while the white, high cirrus clouds are in southwesterly flow. You can right click to save or open in the new tab to see the larger version of it. It’s amazing but frightening to know what’s happening under all that smoke.

–Meteorologist Nick Humphrey

California Fire Crisis (Wed Updates)

Update at 11:15 pm PDT Wed:

The Wine Country Fires in Northern California have now destroyed over 3500 structures, making it the most destructive fire event in state history. And with 23 deaths now reported, it is quickly approaching the record for the deadliest. There are still areas burned where police have yet to search for potential victims because the primary operations are focused on evacuations and maintaining safety in the current fluid situation. Unfortunately, given that the missing persons are over 280, even with many being found safe, the death toll is still likely to go up as some are found.

Amazing the disturbing level of destruction of this fire event. I was only 7 yrs old in 1991, but I remember the Oakland Hills Firestorm, as it was plastered all over the news as much as this event. I didn’t think I could imagine such a disastrous fire worse than that.

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Update at 5:30 pm PDT Wed: Update on the Meteorological Conditions in the Bay Area/Napa Valley Region.

Numerous fires continue to largely out of control over the Napa Valley/North Bay region. Heavy Smoke (with particulate matter >2.5 micrometers) is spreading southward over the Greater Bay Area reducing visibility and causing air quality to be considered very unhealthy for all individuals in the region with VERY UNHEALTHY conditions in the hilly terrain east of Santa Rosa and Oakland. If you can stay indoors, do so, especially for the young, elderly, and those with chronic breathing problems.

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Particulate smoke (<2.5 micrometers) being produced by the fires and spread southward from northerly winds. This is causing very poor air quality across the state of CA. (earth.nullschool.net)

A RED FLAG WARNING REMAINS IN EFFECT FOR MUCH OF N. AND C. CALIFORNIA FROM NOW UNTIL TOMORROW AFTERNOON. As high pressure builds across Oregon into NE. Nevada, easterly downsloping winds will intensify the foothills across the interior of Northern CA, increasing the threat for any fires which develop to spread quickly and existing fires to expand acreage quickly. These winds will help maintain very conditions longer into the night, slowing humidity recovery and allowing fires to potentially exhibit extreme behavior (heat, forward speed, self-maintenance). Winds may gust up to 45-50 mph in some areas.

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High-Resolution Rapid Refresh (HRRR) Model forecast for around 10 pm PDT showing the intensifying pressure gradient and pressure ridging over the hills and mountains of northern CA. This will lead to development and intensification of dry Diablo winds overnight.
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The HRRR forecast valid for 1 am PDT showing widespread dew point temperatures in the mid-20s. With temps in the mid/upper-50s, this means humidity values in the 25-35% range, keeping fuels relatively dry for spreading fire in the face of 40-50 mph wind gusts near the foothills.

These fires have largely been a result of 1) the 5 yr extreme drought weakening trees 2) the very wet winter producing abundant brush growth 3) extreme hot, dry summer drying out all fuels.

New evacuation orders have already come out for some areas, including the City of Calistoga (northeast of Santa Rosa) where the entire town of over 5,000 are being told to leave. See the Impact Statement at the bottom of this post…but folks need to be ready to evacuate if necessary at a moment’s notice.

–Meteorologist Nick Humphrey

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CalFire has updated news at 11:30 am PDT and now say 21 people have been confirmed killed and 172,000 acres have now burned across the entire state. The most destructive fires are in North-Central California north of the Bay Area, but the Canyon 2 Fire continues to menace Anaheim in Southern California.

A RED FLAG WARNING is in effect for much of the interior valleys and foothill terrain of California.


This is for extreme fire danger today – Thursday. As high pressure builds this evening and tonight over Nevada and east of the Sierra Nevada Mountains, a NE-SW pressure gradient will intensify, leading to strong downslope winds known as Diablo winds or Santa Ana Winds (the former in Northern CA, the latter in Southern CA). These winds will gust potentially 40-45 mph+. In addition, because they are downsloping, the air undergoes adiabatic warming…warming caused by the air compressing as it flows down toward higher vertical pressure at lower elevations. The air not only warms, but also dries out, turning winds blasting out of canyons into a hot blow dryer…drying out fuels and allowing a fire to turn into a firestorm.

IMPACT STATEMENT:

I CANNOT STRESS ENOUGH…if you live in areas under the red flag warning or if you know anyone who lives in these areas, especially near the urban-wildland interface…please have a plan of what to do if a mandatory evacuation is ordered for your area and have a way to get warnings. ESPECIALLY AT NIGHT. Stay in contact with friends/relatives, have someone stay up to watch tv or listen to radio, keep your phone on and charged, have a weather radio. Most importantly, make sure those smoke detectors are working as they may be a final warning of danger impacting your home at night. These fires may intensify or new ones may start Wed night-Thurs morning because of strengthening winds and the humidity…which normally increases at night…may not do so because of the very dry nature of the winds. This will allow for potentially explosive fire behavior. And please, be smart with anything related to flammable materials and clear any brush away from your home if possible, to give you more time if a fire does approach.

I really hope the situation does not worsen significantly. Fires are scary events and incredibly destructive. Please be safe and be ready if you are in these areas.

I’ll have updates on this page throughout today and tonight.

–Meteorologist Nick Humphrey

 

Update on Wildfire Situation in Northern California.

The Northern California wildfires continue to rage and risk both lives and property. At least fifteen fires are currently burning across Northern California with little to no containment. The most significant fires include the Atlas Fire, Tubbs Fire, the Cascade Fire, Nuns Fire, and the Redwood Complex Fire. As of 8 pm PDT, there have been 17 deaths reported (11 in Sonoma, 2 in Napa, 3 in Mendocino and 1 in Yuba Counties). 180 people have been reported missing in Sonoma County with 57 out of originally 240 reported missing found since yesterday. More than 2,000 structures have been destroyed. 115,000+ acres have been burned with many fires at 0% containment.

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A SUV burns in the driveway of an already burned down home threatening another home in neighborhood off Fountaingrove Parkway near the Hilltop in Santa Rosa on October 9, 2017 in Santa Rosa, California. (Photo: Brian Van Der Brug/LA Times Via Getty Images).

Today, the atmospheric conditions were initially better for fighting fires this morning with higher humidity values and low winds. Winds have remained lighter today compared to previous days, but humidity has once again dropped this afternoon below 30% or even 20% in many areas in the hilly elevated terrain down into Napa Valley, allowing fires to continue to steadily spread.

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Low humidity values north of the Bay Area allowing fires to more easily attack vegetation and structures. (earth.nullschool.net).
Particulates
Very high surface particulates causing very poor to hazardous air quality over much of Northern California (particulate matter on map <2.5 micrometers). (earth.nullschool.net).

I wish there was more good news to give to the folks in NorCal, but unfortunately, NO rain is forecast for the region for the next seven days. In addition, the National Weather Service issued a RED FLAG WARNING for Wed Night-Thurs Afternoon as high easterly winds blowing out of the hilly terrain will produce very low humidity, allowing for potentially explosive wildfire growth.

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Global Forecast System model forecast valid 1 am PDT Thursday morning showing high pressure building over the elevated terrain of Nevada and northeast California. Strong easterly downsloping winds will develop, intensifying wildfire potential.
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Global Forecast System model forecast valid 1 am PDT Thursday morning showing wind gusts of 25-45 mph across north-central California.
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Global Forecast System model forecast valid 1 am PDT Thursday morning showing humidity values falling below 25%, keeping fuels dry for fires to spread.

If you know anyone in or near the effected region (or in the RED FLAG WARNING areas), tell them to make sure they clear vegetation near their homes/businesses and have an emergency plan in case evacuations are issued for their area. Unfortunately, this wildfire disaster is ongoing and requires those who are in or near rural country to be ready to escape at a moment’s notice.

Live Updates by the San Francisco Chronicle: HERE

—Meteorologist Nick Humphrey

Firestorm devastating portions of Napa Valley, CA.

Sunday Night, major fires erupted in California’s Napa Valley under strong easterly winds and low relative humidity. This resulted in a conflagration engulfing communities and homes in flames and forcing thousands to make quick escapes in the early morning hours. One of the worse hit communities is Santa Rosa, where much of the city has been destroyed by fire. Over 1500 homes and businesses are believed to have been burned down in the Napa Valley region. The flames continue to grow at this time with over 75,000 acres burned.

Photos via the San Francisco Chronicle.

The fires are occurring in a region which is currently not in drought conditions hydrologically (as of last Thursday). However, after an unusually wet winter, an unusually hot, dry season followed. This allowed fuels, which grew in abundance following the wet season to dry out, leading to the massive fires in CA in this summer going into the Fall. Much of Western North America has been suffering significant fires in 2017 (year-to-date acreage burned in the US, as of Friday, was 3rd to 2012 and 2015). Intensifying wildfire seasons (on regional/continental scales) and increasing frequency of large fluctuations in extremes between very wet and very dry periods are predicted signals of climate change from global warming as well.

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Much above average to record precipitation in Northern California in January-March 2017.
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Much below average to record minimum precipitation (including NO measurable rain) in Northern California in August 2017. June-August 2017 saw much below average precipitation.
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Much above average and record warmth across the West Coast during August 2017. San Francisco Bay Area saw record highs over 100 degrees at the start of September.

So far the fires have killed 10 people (as of 10 pm PDT Monday Night), while more than 110 have been injured, some severely from burns, most from smoke inhalation. It’s being reported Monday Night that 100 missing persons reports have been called in to the Sonoma County, CA office.

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Region where fires are in progress in the San Rosa and Napa region far north of San Francisco and west of Sacramento.

Although relative humidity conditions will improve somewhat tomorrow, no rainfall is forecast for this region of Northern California for the next 7 days to dampen the fire situation. Winds Tuesday will likely gust over 20 mph and may be locally stronger near the fire, continuing the self-sustaining burn.

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11 pm PDT Monday Analysis by the High-Resolution Rapid Refresh (HRRR) showing the low dew point temperatures near and east of Santa Rosa. This area delineates a region of low relative humidity, allowing fires to burn and spread with little moisture on fuels to slow their extent.

 

For further updates see this updating page by the San Francisco Chronicle.

–Meteorologist Nick Humphrey

Start of October Drought and Climate Update

Nearly 14% of the Continental US is in at least moderate drought conditions right now. The most highly afflicted areas are over the northern tier states west of the Mississippi River…the Dakotas, Montana, Idaho, Washington and Oregon.

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There are scattered areas of drought and abnormally dry conditions across other parts of the country. However, an isolated area of severe to extreme drought has been hitting south-central Iowa for much of the summer and there are also areas of moderate drought developing over the the Desert Southwest and eastern Maine.

The level of dryness, particularly over Western North America has promoted a significant fire season, which continues at this time. British Columbia is having its worst fire season on record and the Western US is having an unexpectedly destructive fire season. This even after much of the region had a wet winter, showing that a significant period of dryness following well-grown fuels from a wet season can still lead to a major fire season. As of October 4, 2017, nearly record 8.5 million acres have been burned in the United States in 2017.* While below the 2015 record of 10.12 acres, it should be noted that anthropogenic climate change is increasing the risk of fire seasons in the US over 3 million acres and there has been a significant increase in fire seasons of 3 million acres or more since the turn of the century. 2017 may rank in the Top 3 for fire seasons (along with 2015 and 2012). Temperatures across the West were well-above normal or record levels over the summer. Various records for heat (as well as persistence of warmth and dryness) were broken in places such as Western WA/OR, central and southern CA as well as the portions of the Interior West.

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Drought Outlook for October 2017. Drought is expected to dissipate in Western WA from the incoming wet season, and improve somewhat in northeast MT. However, much of the drought in the US will persist and in fact additional areas may develop over the central Midwest and Mid-Atlantic states.
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The Probabilistic Precipitation Outlook valid Oct 10-16, 2017. This suggest by mid-month, the atmospheric pattern will be favorable for drier than normal conditions over the center of the nation with near normal or wetter than normal conditions over the coastal regions. The Climate Prediction Center also shows above normal temperatures likely over the Southwest US and Eastern third of the country. Dryness will maintain or promote further development of drought conditions in portions of the nation’s interior.

As of today, the NWS Climate Prediction Center indicates a 55-60% chance that a La Nina climate pattern will develop late in the Northern Hemisphere Fall and into the Northern Hemisphere winter. This is characterized by an intensified Walker Circulation (the east-west tropical Pacific wind circulation) and intensified cold water upwelling along and offshore the coast of South America.

Weather patterns common during La Nina events include abnormally wet, cool conditions in the western Pacific Northwest and TN/OH valleys, but abnormally dry and warm conditions across the southern tier of the United States. This is partially incorporated into the monthly and seasonal drought and temperature/precipitation outlooks.

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For those curious, the climate models are showing the US having a more than likely above normal winter throughout (including AK) with the La Nina-like distribution of precipitation (likely above normal Northwest, below normal Southeast). More on winter as we get closer.

*-I incorrectly stated that total acres burned in the US was around 3 million acres. (10/4/17)