Alert archive / California / Red Flag Warnings in 2017
Red Flag Warning 8, NWS San Diego, CA
NWS San Diego, CA issued this red flag warning at Dec 20, 2017, 11:57 AM PST for 4 counties in California. It took effect at Dec 21, 2017, 9:00 AM PST. It was in force for 9 hr. 1 report 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 20, 2017, 11:57 AM PST (19:57 UTC)
- In effect from
- Dec 21, 2017, 9:00 AM PST
- Expired
- Dec 21, 2017, 6:00 PM PST
- In force
- 9 hr
- Issued by
- NWS San Diego, CA
Counties Orange County, CA, Riverside County, CA, San Bernardino County, CA, San Diego County, CA
The radar
The Santa Ana Mts radar (KSOX), 88 km from the middle of the area, began a volume at 19:58 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 21, 10:15 AM PST | NON-TSTM WND GST 58 | 2 Nw Running Springs, CA | MESONET STATION HHPC1, RUNNING SPRINGS (2 NW). |
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, 8.0 hours before the alert went out and 124 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2877 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 83 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
647 WWUS86 KSGX 201957 RFWSGX URGENT - FIRE WEATHER MESSAGE National Weather Service San Diego CA 1157 AM PST Wed Dec 20 2017 ...RED FLAG WARNING FROM 9 AM TO 6 PM THURSDAY FOR PORTIONS OF ORANGE...SAN BERNARDINO...AND RIVERSIDE COUNTIES... .Surface high pressure building over the northern Nevada will bring gusty offshore winds tonight and Thursday. The strongest winds will arrive tonight and continue through Thursday. The lowest humidities will arrive Thursday morning and continue through Thursday afternoon. Critical fire weather conditions are likely in the mountains, foothills and inland valleys of San Bernardino, Riverside and Orange Counties. This includes the Inland Empire below the Cajon and Banning Passes, and inland Orange County. CAZ248-255>257-265-552-554-210600- /O.UPG.KSGX.FW.A.0007.171221T1700Z-171222T0200Z/ /O.NEW.KSGX.FW.W.0008.171221T1700Z-171222T0200Z/ San Bernardino and Riverside County Valleys - The Inland Empire- San Bernardino County Mountains- Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest-Riverside County Mountains- Including The San Jacinto Ranger District Of The San Bernardino National Forest-Santa Ana Mountains- Including The Trabuco Ranger District of the Cleveland National Forest-San Gorgonio Pass Near Banning-Orange County Coastal Areas- Orange County Inland Areas- 1157 AM PST Wed Dec 20 2017 ...RED FLAG WARNING IN EFFECT FROM 9 AM TO 6 PM PST THURSDAY FOR STRONG GUSTY WINDS AND LOW HUMIDITY... The National Weather Service in San Diego has issued a Red Flag Warning...which is in effect from 9 AM to 6 PM PST Thursday. The Fire Weather Watch is no longer in effect. * WINDS...Areas of northeast winds 20 to 30 mph with gusts to 50 mph. Isolated gusts to 60 mph below the Cajon Pass and along and near the coastal slopes of the Santa Ana Mountains. * HUMIDITIES...10 to 15 percent. * TIMING...Strong winds will surface tonight through early Thursday afternoon. The lowest humidities will occur Thursday morning through Thursday afternoon. * OUTLOOK...Weaker offshore flow Friday through Monday. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ Moede/17
3 follow-up statements
958 WWUS86 KSGX 210427 RFWSGX URGENT - FIRE WEATHER MESSAGE National Weather Service San Diego CA 827 PM PST Wed Dec 20 2017 CAZ248-255>257-265-552-554-211400- /O.CON.KSGX.FW.W.0008.171221T1700Z-171222T0200Z/ San Bernardino and Riverside County Valleys - The Inland Empire- San Bernardino County Mountains- Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest-Riverside County Mountains- Including The San Jacinto Ranger District Of The San Bernardino National Forest-Santa Ana Mountains- Including The Trabuco Ranger District of the Cleveland National Forest-San Gorgonio Pass Near Banning-Orange County Coastal Areas- Orange County Inland Areas- 827 PM PST Wed Dec 20 2017 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM TO 6 PM PST THURSDAY FOR STRONG GUSTY WINDS AND LOW HUMIDITY... * WINDS...Areas of northeast winds 20 to 30 mph with gusts to 50 mph. Isolated gusts to 60 mph below the Cajon Pass and along and near the coastal slopes of the Santa Ana Mountains. * HUMIDITIES...10 to 15 percent. * TIMING...Strong winds tonight through Thursday afternoon. The lowest humidities will occur Thursday morning through Thursday afternoon. * OUTLOOK...Weaker offshore flow Friday through Monday. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ jmb weather.gov/sandiego
938 WWUS86 KSGX 211032 RFWSGX URGENT - FIRE WEATHER MESSAGE National Weather Service San Diego CA 232 AM PST Thu Dec 21 2017 CAZ248-255>257-265-552-554-212300- /O.CON.KSGX.FW.W.0008.171221T1700Z-171222T0200Z/ San Bernardino and Riverside County Valleys - The Inland Empire- San Bernardino County Mountains- Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest-Riverside County Mountains- Including The San Jacinto Ranger District Of The San Bernardino National Forest-Santa Ana Mountains- Including The Trabuco Ranger District of the Cleveland National Forest-San Gorgonio Pass Near Banning-Orange County Coastal Areas- Orange County Inland Areas- 232 AM PST Thu Dec 21 2017 ...RED FLAG WARNING REMAINS IN EFFECT FROM 9 AM THIS MORNING TO 6 PM PST THIS EVENING FOR STRONG GUSTY WINDS AND LOW HUMIDITY... * WINDS...Areas of northeast winds 20 to 30 mph with gusts to 50 mph. Isolated gusts to 60 mph below the Cajon Pass and along and near the coastal slopes of the Santa Ana Mountains. * HUMIDITIES...10 to 15 percent. * TIMING...Strong winds through this evening. The lowest humidities will occur this afternoon. * OUTLOOK...Weaker offshore flow Friday through Monday. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ Gregoria
972 WWUS86 KSGX 212126 RFWSGX URGENT - FIRE WEATHER MESSAGE National Weather Service San Diego CA 126 PM PST Thu Dec 21 2017 CAZ248-255>257-265-552-554-220200- /O.CON.KSGX.FW.W.0008.000000T0000Z-171222T0200Z/ San Bernardino and Riverside County Valleys - The Inland Empire- San Bernardino County Mountains- Including The Mountain Top And Front Country Ranger Districts Of The San Bernardino National Forest-Riverside County Mountains- Including The San Jacinto Ranger District Of The San Bernardino National Forest-Santa Ana Mountains- Including The Trabuco Ranger District of the Cleveland National Forest-San Gorgonio Pass Near Banning-Orange County Coastal Areas- Orange County Inland Areas- 126 PM PST Thu Dec 21 2017 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 6 PM PST THIS EVENING FOR STRONG GUSTY WINDS AND LOW HUMIDITY... * WINDS...Areas of northeast winds 15 to 30 mph with gusts to 45 mph. Isolated gusts to 55 mph below the Cajon Pass and along the coastal slopes of the Santa Ana Mountains. * HUMIDITIES...10 to 15 percent. * OUTLOOK...Winds will weaken quickly this evening, but relative humidity will remain low through the weekend. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ Albright
The office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 19, 5:13 PM PST | Wind Advisory | SGX | Riverside, San Bernardino, San Diego | 31 hr |
| Dec 19, 8:45 PM PST | Small Craft Advisory | SGX | 41 hr | |
| Dec 20, 3:43 PM PST | Blowing Dust Advisory | SGX | Riverside, San Bernardino, San Diego | 8 hr |
Nearby
Red Flag Warnings in California, 2017Every red flag warning in 2017
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.