Alert archive / California / Red Flag Warnings in 2023

Red Flag Warning 5, NWS Los Angeles, CA

December 8, 2023Los Angeles County, Ventura County, California

NWS Los Angeles, CA issued this red flag warning at Dec 8, 2023, 3:10 PM PST for Los Angeles County, Ventura County, California. It took effect at Dec 9, 2023, 8:00 AM PST. It was in force for 31 hr. 16 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Dec 8, 2023, 3:10 PM PST (23:10 UTC)
In effect from: Dec 9, 2023, 8:00 AM PST
Expired: Dec 10, 2023, 3:00 PM PST
In force: 31 hr
Issued by: NWS Los Angeles, CA

Counties Los Angeles County, CA, Ventura County, CA

The radar

The Los Angeles radar (KVTX), 47 km from the middle of the area, began a volume at 23:13 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Dec 9, 9:50 AM PST	NON-TSTM WND GST 58	3 Ese Santa Paula, CA	MESONET STATION 040SE S MOUNTAIN LOOKOUT RD (SCE).
Dec 9, 10:10 AM PST	NON-TSTM WND GST 71	3 Nnw Chatsworth, CA	MESONET STATION 470SE PALO SOLA TRUCK RD (SCE).
Dec 9, 10:44 AM PST	NON-TSTM WND GST 64	6 Ne Pyramid Lake, CA	ASOS STATION KSDB SANDBERG.
Dec 9, 10:50 AM PST	NON-TSTM WND GST 62	3 N Moorpark, CA	MESONET STATION SE277 HAPPY CAMP RD (SCE).
Dec 9, 11:12 AM PST	NON-TSTM WND GST 61	4 W Camarillo, CA	ASOS STATION KCMA CAMARILLO AIRPORT.
Dec 9, 8:40 PM PST	NON-TSTM WND GST 71	5 W Chatsworth, CA	MESONET STATION SE519 E SIMI VLY COCHRAN (SCE).
Dec 9, 8:50 PM PST	NON-TSTM WND GST 77	1 Nnw Chatsworth, CA	MESONET STATION SE712 BROWNS CYN (SCE).
Dec 9, 11:40 PM PST	NON-TSTM WND GST 59	3 N Moorpark, CA	Mesonet station SE277 Happy Camp Rd (SCE).
Dec 10, 12:00 AM PST	NON-TSTM WND GST 67	3 Nnw Chatsworth, CA	Mesonet station 470SE Palo Sola Truck Rd (SCE).
Dec 10, 12:10 AM PST	NON-TSTM WND GST 76	1 Nnw Chatsworth, CA	Mesonet station SE712 Browns Cyn (SCE).
Dec 10, 12:20 AM PST	NON-TSTM WND GST 57	8 S Agua Dulce, CA	Mesonet station SE678 Magic Mtn Truck Trl (SCE).
Dec 10, 12:20 AM PST	NON-TSTM WND GST 61	5 W Chatsworth, CA	Mesonet station SE519 E Simi Vly Cochran (SCE).
Dec 10, 12:48 AM PST	NON-TSTM WND GST 62	2 Nne Chatsworth, CA	Mesonet station PHCC1 Porter Ranch RAWS.
Dec 10, 1:20 AM PST	NON-TSTM WND GST 56	3 Ese Santa Paula, CA	Mesonet station 040SE S Mountain Lookout Rd (SCE).
Dec 10, 2:49 AM PST	NON-TSTM WND GST 56	3 Sw Piru, CA	Mesonet station WLYC1 Wiley Ridge RAWS.
Dec 10, 9:12 AM PST	NON-TSTM WND DMG	3 Ssw San Fernando, CA	REPORT FROM MPING: 1-INCH TREE LIMBS BROKEN; SHINGLES BLOWN OFF.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 11.2 hours before the alert went out and 215 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 721 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 122 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this red flag warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Los Angeles, CA wrote its last area forecast discussion before this red flag warning went out at Dec 8, 2:08 PM PST, 1 hour 2 minutes earlier.

Area forecast discussion, Dec 8, 2:08 PM PST, 1 hour 2 minutes before

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The office that day

Everything else NWS Los Angeles, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 8, 1:47 AM PST	Small Craft Advisory	LOX		7 hr
Dec 8, 3:20 AM PST	High Wind Warning	LOX	Los Angeles, Ventura	57 hr
Dec 8, 3:20 AM PST	Wind Advisory	LOX	Los Angeles	57 hr
Dec 8, 9:16 AM PST	Gale Watch	LOX		5 hr
Dec 8, 9:16 AM PST	Gale Warning	LOX		11 hr
Dec 8, 9:29 AM PST	Red Flag Warning	LOX	Santa Barbara, Ventura	21 hr
Dec 8, 2:20 PM PST	Gale Warning	LOX		24 hr

Nearby

Red Flag Warnings in California, 2023 Every red flag warning in 2023

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.