Alert archive / California / Flash Flood Warnings in 2021
Flash Flood Warning 1, NWS Los Angeles, CA
NWS Los Angeles, CA issued this flash flood warning at Jan 28, 2021, 12:02 AM PST for San Luis Obispo County, California. It was in force for 4 hr. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jan 28, 2021, 12:02 AM PST (08:02 UTC)
- Expired
- Jan 28, 2021, 4:00 AM PST
- In force
- 4 hr
- Issued by
- NWS Los Angeles, CA
- Area
- Storm-based polygon
- Flood severity
- None
County San Luis Obispo County, CA
The radar
The Vandenberg AFB radar (KVBX), 113 km from the middle of the area, began a volume at 08:04 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 |
|---|---|---|---|
| Jan 28, 1:00 AM PST | FLOOD | Cambria, CA | FLOODING OF WATER AND MUD INTO MULTIPLE HOMES ON SHERWOOD DRIVE. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Vandenberg AFB, CA (KVBG), launched 00:00Z, 8.0 hours before the alert went out and 118 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
- 8 J/kg
- Mixed-layer CIN
- -67 J/kg
- Mixed-layer LCL
- 489 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 628 m²/s²
- 0-3 km storm-relative helicity
- 730 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
364
WGUS56 KLOX 280802
FFWLOX
CAC079-281200-
/O.NEW.KLOX.FF.W.0001.210128T0802Z-210128T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Los Angeles/Oxnard CA
1202 AM PST Thu Jan 28 2021
The National Weather Service in Los Angeles/Oxnard has issued a
* Flash Flood Warning for...
Northwestern San Luis Obispo County in southwestern California...
* Until 400 AM PST.
* At 1202 AM PST, Doppler radar and automated rain gauges indicated
very heavy rain falling in Cambria and Cayucos. Between 4 and 8
inches of rain have fallen. The expected rainfall rate is 0.75 to
1 inch in 1 hour. Additional rainfall amounts of 3 to 6 inches are
possible in the warned area. Flash flooding is ongoing or expected
to begin shortly.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Cambria, San Simeon, Hearst Castle and Cayucos.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3576 12133 3578 12133 3579 12135 3579 12103
3539 12069 3536 12096 3538 12096 3539 12103
3540 12106 3557 12122 3558 12124 3565 12131
3567 12129 3569 12129 3571 12132 3572 12131
3572 12132 3575 12132
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...0.75-1 INCH IN 1 HOUR
$$
Kaplan/Bruno2 follow-up statements
914
WGUS76 KLOX 281026
FFSLOX
Flash Flood Statement
National Weather Service Los Angeles/Oxnard CA
226 AM PST Thu Jan 28 2021
CAC079-281200-
/O.CON.KLOX.FF.W.0001.000000T0000Z-210128T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Luis Obispo CA-
226 AM PST Thu Jan 28 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 4 AM PST EARLY THIS
MORNING FOR NORTHWESTERN SAN LUIS OBISPO COUNTY...
At 226 AM PST, Doppler radar and automated rain gauges indicated
that moderate to heavy rain was falling from Cambria to Cayucos
including Harmony, San Simeon and surrounding areas. Between 5 and
10 inches of rain have fallen. Rainfall rates of one half to three
quarters of inch per hour are expected to continue. Additional
rainfall amounts of 2 to 4 inches are possible in the warned area.
Hourly rainfall rates this high will continue to bring Flash
flooding across the warned area.
HAZARD...Flash flooding caused by heavy rain.
SOURCE...Radar and automated gauges.
IMPACT...Flash flooding of small creeks and streams, urban areas,
highways, streets and underpasses as well as other poor
drainage and low-lying areas.
Some locations that will experience flash flooding include...
Cambria, San Simeon, Harmony, Hearst Castle and Cayucos.
California Highway Patrol reported multiple mud and debris flows
around Highway 46 near Highway 1.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3576 12133 3578 12133 3579 12135 3579 12103
3539 12069 3536 12096 3538 12096 3539 12103
3540 12106 3557 12122 3558 12124 3565 12131
3567 12129 3569 12129 3571 12132 3572 12131
3572 12132 3575 12132
FLASH FLOOD...RADAR AND GAUGE INDICATED
EXPECTED RAINFALL...0.5-0.75 INCHES IN 1 HOUR
$$
Kaplan/Bruno621
WGUS76 KLOX 281159
FFSLOX
Flash Flood Statement
National Weather Service Los Angeles/Oxnard CA
359 AM PST Thu Jan 28 2021
CAC079-281209-
/O.EXP.KLOX.FF.W.0001.000000T0000Z-210128T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Luis Obispo CA-
359 AM PST Thu Jan 28 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 4 AM PST EARLY THIS MORNING
FOR NORTHWESTERN SAN LUIS OBISPO COUNTY...
The heavy rain has decreased in intensity. Flooding is no longer
expected to pose an immediate threat. However, please continue to
heed remaining road closures.
A Flash Flood Watch remains in effect until 1000 PM PST Thursday for
the San Luis Obispo County Central Coast and adjacent foothills.
LAT...LON 3576 12133 3578 12133 3579 12135 3579 12103
3539 12069 3536 12096 3538 12096 3539 12103
3540 12106 3557 12122 3558 12124 3565 12131
3567 12129 3569 12129 3571 12132 3572 12131
3572 12132 3575 12132
$$
DBThe office that day
Everything else NWS Los Angeles, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 27, 11:48 PM PST | Areal Flood Advisory | LOX | San Luis Obispo | 10 hr |
| Jan 28, 1:34 AM PST | Flash Flood Warning | LOX | San Luis Obispo | 56 min |
| Jan 28, 3:01 AM PST | Flash Flood Warning | LOX | San Luis Obispo | 104 min |
| Jan 28, 5:49 AM PST | Areal Flood Advisory | LOX | Santa Barbara | 8 hr |
| Jan 28, 1:03 PM PST | Areal Flood Advisory | LOX | Santa Barbara | 6 hr |
| Jan 28, 2:16 PM PST | Small Craft Advisory | LOX | 7 hr |
Nearby
Flash Flood Warnings in California, 2021Every flash flood warning in 2021
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.