Alert archive / California / Red Flag Warnings in 2017
Red Flag Warning 2, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this red flag warning at Jul 15, 2017, 2:00 PM PDT for 5 counties in California. It took effect at Jul 15, 2017, 5:00 PM PDT. It was in force for 28 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 15, 2017, 2:00 PM PDT (21:00 UTC)
- In effect from
- Jul 15, 2017, 5:00 PM PDT
- Expired
- Jul 16, 2017, 9:00 PM PDT
- In force
- 28 hr
- Issued by
- NWS San Francisco Bay Area, CA
Counties Monterey County, CA, San Benito County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA
The radar
The San Francisco radar (KMUX), 33 km from the middle of the area, began a volume at 21:05 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.
The nearest sounding before it
Oakland, CA (KOAK), launched 12:00Z, 9.0 hours before the alert went out and 102 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
- 2041 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 8 m²/s²
- 0-3 km storm-relative helicity
- 41 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
291 WWUS86 KMTR 152100 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 200 PM PDT Sat Jul 15 2017 ...HOT AND VERY DRY CONDITIONS THROUGH SUNDAY ALONG WITH LOCALLY GUSTY WINDS IN THE HILLS... .Strong high pressure over California will continue to produce hot and very dry conditions across inland areas through the remainder of the weekend. Daytime relative humidity values will drop as low as the single digits and very poor humidity recoveries are expected in the hills above 1000 feet on Saturday night. In addition, northerly winds are expected to increase in the hills late on Saturday and be locally gusty Saturday night and though the day on Sunday. These weather factors will result in the potential for rapid fire spread across the warned area. Gradual improvement is expected Sunday night into Monday as winds ease, and a somewhat cooler and more moist airmass begins to spread across the area. CAZ507-511-512-517-518-161300- /O.NEW.KMTR.FW.W.0002.170716T0000Z-170717T0400Z/ North Bay Mountains-East Bay Hills and the Diablo Range- Santa Cruz Mountains- Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 200 PM PDT Sat Jul 15 2017 ...RED FLAG WARNING IN EFFECT FROM 5 PM SATURDAY AFTERNOON TO 9 PM PDT SUNDAY FOR HOT AND DRY CONDITIONS ALONG WITH GUSTY NORTHERLY WINDS. THE RED FLAG WARNING IS FOR FIRE WEATHER ZONES 507, 511, 512, 517, AND 518... The National Weather Service San Francisco Bay Area has issued a Red Flag Warning, which is in effect from 5 PM this afternoon to 9 PM PDT Sunday. * AFFECTED AREA...Fire weather zones 507, 511, 512, 517, and 518. This includes elevations above 1000 feet in the North and East Bay Hills, the Santa Cruz Mountains, the Diablo Range, the Santa Lucia Range, and the interior mountains of Monterey and San Benito Counties. * WIND...Northerly winds 10 to 15 mph with gusts as high as 25 mph. * HUMIDITY...Minimum relative humidity values as low as the single digits during the day. Very poor humidity recoveries overnight on Saturday night. * HIGHEST THREAT...At elevations above 1000 feet where driest air and strongest winds are anticipated. * 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. && $$
2 follow-up statements
311 WWUS86 KMTR 161205 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 505 AM PDT Sun Jul 16 2017 ...HOT AND DRY CONDITIONS WILL CONTINUE THROUGH TODAY ALONG WITH LOCALLY GUSTY WINDS IN THE HILLS... .Strong high pressure over California will continue to produce hot and dry conditions across inland areas through today. Very poor humidity recoveries occurred in the hills above 1000 feet overnight and daytime relative humidity values will drop as low as the single digits today. In addition, locally gusty north to northwest winds will continue in the hills through today. These weather factors will result in the potential for rapid fire spread in the warned area. Gradual improvement is expected from tonight through Tuesday as a cooler and more moist airmass spreads inland and to higher elevations. CAZ507-511-512-517-518-170400- /O.CON.KMTR.FW.W.0002.000000T0000Z-170717T0400Z/ North Bay Mountains-East Bay Hills and the Diablo Range- Santa Cruz Mountains- Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 505 AM PDT Sun Jul 16 2017 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM PDT THIS EVENING FOR HOT AND DRY CONDITIONS ALONG WITH GUSTY NORTHERLY WINDS. THE RED FLAG WARNING IS FOR FIRE WEATHER ZONES 507, 511, 512, 517, AND 518... * AFFECTED AREA...Fire weather zones 507, 511, 512, 517, and 518.This includes elevations above 1000 feet in the North and East Bay Hills, the Santa Cruz Mountains, the Diablo Range, the Santa Lucia Range, and the interior mountains of Monterey and San Benito Counties. * WIND...North to northwest winds 10 to 15 mph with gusts as high as 25 mph. * HUMIDITY...Minimum relative humidity values as low as the single digits today. * HIGHEST THREAT...At elevations above 1000 feet where driest air and strongest winds are anticipated. * 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 gusty winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
600 WWUS86 KMTR 170407 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 907 PM PDT Sun Jul 16 2017 CAZ507-511-512-517-518-170515- /O.EXP.KMTR.FW.W.0002.000000T0000Z-170717T0400Z/ North Bay Mountains-East Bay Hills and the Diablo Range- Santa Cruz Mountains- Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 907 PM PDT Sun Jul 16 2017 ...RED FLAG WARNING HAS EXPIRED FOR HOT DRY AND BREEZY CONDITIONS FOR FIRE WEATHER ZONES 507, 511, 512, 517, AND 518... The peak heat of the day has passed and cooling will begin tonight. Though fire conditions still remain high, the trend over the next 24 hours will be for a gradual increase of relative humidity. As such, the fire weather warning has been allowed to expire. $$
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 15, 2:23 PM PDT | Small Craft Advisory | MTR | 5 days |
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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.