Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 2, NWS Los Angeles, CA

January 12, 2017Los Angeles County, California

NWS Los Angeles, CA issued this flash flood warning at Jan 12, 2017, 1:02 PM PST for Los Angeles County, California. It was in force for 3 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 12, 2017, 1:02 PM PST (21:02 UTC)
Expired: Jan 12, 2017, 3:45 PM PST
In force: 3 hr
Issued by: NWS Los Angeles, CA
Area: Storm-based polygon
Flood severity: None

County Los Angeles County, CA

The radar

The Santa Ana Mts radar (KSOX), 68 km from the middle of the area, began a volume at 21:06 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 12, 2:41 PM PST	FLASH FLOOD	Azusa, CA	FLASH FLOOD AND DEBRIS FLOWS ONTO ENCANTO PARKWAY IN AZUSA. DEBRIS FLOWS ORIGINATED IN THE FISH FIRE BURN AREA.

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, 9.0 hours before the alert went out and 188 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: 852 m above ground
0-6 km bulk shear: 83 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 34 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

208 
WGUS56 KLOX 122102
FFWLOX
CAC037-122345-
/O.NEW.KLOX.FF.W.0002.170112T2102Z-170112T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service OXNARD CA
102 PM PST THU JAN 12 2017

The National Weather Service in OXNARD has issued a

* Flash Flood Warning for...
  The Fish and Reservoir Burn Areas in Northeastern 
  Los Angeles County in southwestern California...

* Until 345 PM PST

* At 1 PM PST, Doppler radar indicated heavy rain across the warned
  area. Flash flooding with mud and debris flows is expected to
  begin shortly. Rainfall rates are exceeding 0.30 inches per half
  hour.

* Some locations that will experience flooding include...
  The Fish Burn area...the Reservoir Burn area...
  and the City of Duarte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Warning for a recent burn area means that flooding and
debris flows are imminent or occurring. Residents living in or
immediately downstream should take immediate precautions to protect
life and property. Quickly move away from the burn area only if it is
safe to do so, otherwise shelter in place and move to a second story
or the highest location in your home to stay out of the path of
fast-moving water and debris flows.

&&

LAT...LON 3402 11796 3410 11815 3482 11771 3482 11767
      3456 11767 3455 11766 3442 11766

$$

CS

2 follow-up statements

785 
WGUS76 KLOX 122122
FFSLOX

Flash Flood Statement
National Weather Service OXNARD CA
122 PM PST THU JAN 12 2017

CAC037-122345-
/O.CON.KLOX.FF.W.0002.000000T0000Z-170112T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Los Angeles CA-
122 PM PST THU JAN 12 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM PST FOR
EAST CENTRAL LOS ANGELES COUNTY...

At 118 PM PST, heavy rain was occuring with 0.20 inch in 15 minutes
near the Fish Fire burn area with more downpours expected for
another hour or so. Mud and debris flows are likely to occur below
the burn scar into the streets of Duarte. Other areas near the
Reservoir Fire could also experience mud and debris. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Residents living in or immediately downstream should take immediate
precautions to protect life and property. Quickly move away from the
burn area only if it is safe to do so, otherwise shelter in place
and move to a second story or the highest location in your home to
stay out of the path of fast-moving water and debris flows.


LAT...LON 3414 11794 3417 11798 3419 11797 3422 11794
      3422 11789 3420 11784

$$
Smith

646 
WGUS76 KLOX 122246
FFSLOX

Flash Flood Statement
National Weather Service OXNARD CA
246 PM PST THU JAN 12 2017

CAC037-122252-
/O.CAN.KLOX.FF.W.0002.000000T0000Z-170112T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Los Angeles CA-
246 PM PST THU JAN 12 2017

...THE FLASH FLOOD WARNING FOR EAST CENTRAL LOS ANGELES COUNTY IS
CANCELLED...

The heavy rain has ended across the Fish and Reservoir burn
areas, allowing the flash flood warning to expire. There is
still a chance of brief heavy showers or thunderstorms this
afternoon across Los Angeles County, so a Flash Flood Watch
remains in effect. 

LAT...LON 3414 11794 3417 11798 3419 11797 3422 11794
      3422 11789 3420 11784

$$

Gomberg/Boldt

The office that day

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

Issued	Product	Office	Counties	Lasted
Jan 12, 1:44 AM PST	Small Craft Advisory for Winds	LOX		18 hr
Jan 12, 3:39 AM PST	Flash Flood Watch	LOX	Los Angeles	17 hr
Jan 12, 4:23 AM PST	Areal Flood Advisory	LOX	San Luis Obispo	3 hr
Jan 12, 5:08 AM PST	Areal Flood Advisory	LOX	Los Angeles	3 hr
Jan 12, 6:18 AM PST	Areal Flood Advisory	LOX	Los Angeles	3 hr
Jan 12, 7:26 AM PST	Areal Flood Advisory	LOX	San Luis Obispo, Santa Barbara	3 hr
Jan 12, 8:37 AM PST	Areal Flood Advisory	LOX	Ventura	3 hr
Jan 12, 9:25 AM PST	Areal Flood Advisory	LOX	Los Angeles	5 hr
Jan 12, 12:37 PM PST	Areal Flood Advisory	LOX	Los Angeles	113 min
Jan 12, 2:16 PM PST	Areal Flood Advisory	LOX	Los Angeles	119 min

Nearby

Flash Flood Warnings in California, 2017 Every flash flood 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.