Red Flag Warnings in seven states, December 11, 2017

Red Flag Warnings have been issued for areas in Southern California, Colorado, Nebraska, Oklahoma, Missouri, Arkansas, Illinois, and Kansas.

The map was current as of 11:20 a.m. MST on Monday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts.

Red Flag Warnings continue in Southern California

Red Flag Warnings have been issued for areas in Southern California, Colorado, South Dakota, Nebraska, and Kansas.

In Los Angeles and Ventura Counties east winds of 20 to 30 mph with gusts up to 45 mph will continue at times today (Sunday) and again late tonight and Monday, however, winds are expected to be weaker on Monday. Meanwhile, minimum humidities of 3 to 10 percent will be common through at least the middle of next week, with widespread poor overnight recoveries mostly staying under 30 percent. As a result, critical Red Flag conditions will persist over most of Los Angeles and Ventura Counties through Sunday with a chance for locally critical conditions continuing into Monday especially in the mountains. The Santa Barbara County Mountains will also remain in critical fire weather conditions today due to plume development of the existing fire and very low humidity.

The map was current as of 10:39 a.m. MST on Sunday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts.

Red Flag Warnings in Southern California and Colorado

Red Flag Warnings have been issued for areas in Southern California and Colorado.

An extended period of Santa Ana offshore winds will continue through at least Sunday focused over much of Los Angeles and Ventura Counties. The winds today will be the weakest of the next three days with gusts generally in the 30 to 40 mph range, and more afternoon onshore flow nearer to the coast. The winds should increase Saturday and peak on Sunday with gusts in the 40 to 50 mph range (but still much weaker than Thursday). Meanwhile, minimum humidities of 5 to 10 percent will be common through at least the middle of next week, with widespread poor overnight recoveries mostly staying under 30 percent. As a result, critical Red Flag conditions will persist over most of Los Angeles and Ventura Counties through Sunday.

The map was current as of 11:45 a.m. MST on Friday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts.

Ludicrous Fire Weather predicted in Southern California through Saturday

Above: the Red Flag Warning forecast through Friday for Alpine, California, east of San Diego.

(Originally published at 5:36 p.m. PST December 6, 2017)

In wildland fire we sometimes talk about “extreme fire weather”… strong winds with low relative humidity. But, the conditions in the forecast for Southern California Wednesday night through Saturday require a new description — Super Extreme, or Very Extreme, or, borrowing a term from Tesla vehicles, “Ludicrous” Weather?

Red Flag Warnings are posted through Saturday, with some of the strongest winds predicted for San Diego County which Wednesday night and Thursday could experience northeast winds of 25 to 35 mph, with gusts to 60 and isolated gusts to 90 mph. Oh, and relative humidity even at night will be in the low teens or single digits.

Wednesday night Ventura and Los Angeles County residents should expect northeast winds of 30 to 50 mph with gusts of 65 to 80 mph. Thursday through Saturday the winds will decrease slightly, 20 to 35 with gusts of 45 to 60 mph.

This is a very serious situation developing in Southern California — years of drought and several days of dry Santa Ana winds followed by Ludicrous Weather with winds gusting throughout the area at 80 to 90 mph. This of course could have a major effect on the existing fires. All it takes is one very small ember to be blown into receptive fuels and … well, perish the thought.

And there’s no doubt that new fires will break out. Wildland firefighting resources are stretched thin covering the 80,000 acres already on fire. It will be difficult to find hundreds or thousands of additional firefighters and large numbers of hand crews and engines if the worst case scenario develops. And the stronger the winds are, the less effective aerial resources can be. Those conditions can make it unsafe to fly low and slow over rough terrain, as they have to do, and the wind can blow the retardant or water far off target.

Ludicrous Fire Weather begins tonight!

Very strong winds bring Red Flag Warnings to Southern California

wildfire red flag warning weather

(UPDATED at 1:43 p.m. PST December 5, 2017)

The National Weather Service has issued Red Flag Warnings for the coastal and mountain areas of southern California. Strong Santa Ana winds are expected through Thursday, with wind gusts between 60 and 80 mph. The winds will diminish in strength later this afternoon through Wednesday with gusts generally between 35 and 55 mph. However by Wednesday night and Thursday, the winds will increase yet again with gusts between 50 and 70 mph likely. As the Santa Ana winds continue, very dry conditions will persist with minimum relative humidity in the single digits and very poor overnight recoveries.

The Red Flag map was current as of 11 a.m. MST on Tuesday. Red Flag Warnings can change throughout the day as the National Weather Service offices around the country update and revise their forecasts.

Wind gusts speed southern california
Wind gusts during the hour ending at 1:41 p.m. PST December 5, 2017. Click to enlarge.

Strong winds and extreme wildfire danger predicted for Southern California this week

This Santa Ana wind event will likely be the strongest and longest duration one we have seen so far this fire season. Red Flag Warnings have been issued for Sunday night through Thursday.

Above: Red Flag Warnings issued for Southern California December 3, 2017.

(Originally published at 9:31 a.m. PST December 3, 2017)

The strongest Santa Ana wind event so far this fire season is in the forecast for the coastal and mountain areas of Southern California this week. The National Weather Service has issued Red Flag Warnings for Sunday night through Thursday for areas within the counties of Santa Barbara, San Bernardino, Riverside, and San Diego.

It is unusual for a Red Flag Warning to extend over parts of five days. And this one has the possibility of being extended for an additional one or two days into the weekend.

The exact timing and speeds will vary by location, but generally, powerful winds will begin Sunday night out of the north and on Monday will be from the northeast at 25 to 40 mph with gusts of 50 to 65, reaching 80 at some peaks and exposed areas.

The NWS forecast includes this statement:

If fire ignition occurs, there will be the potential for rapid spread of wildfire with extreme fire behavior that could lead to a threat to life and property.

The strong winds and low relative humidities (5 to 15 percent)  should continue at least through Thursday. Long range computer models are showing the possibility that the Santa Ana winds could persist into Friday or Saturday, which may require the extension of the Red Flag Warnings.

Wind Gusts Tuesday california santa winds wildfire