Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 71, NWS Phoenix, AZ

September 9, 2017Imperial County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 9, 2017, 9:37 AM PDT for Imperial 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
Sep 9, 2017, 9:37 AM PDT (16:37 UTC)
Expired
Sep 9, 2017, 12:30 PM PDT
In force
3 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Imperial County, CA

The radar

The Yuma radar (KYUX), 73 km from the middle of the area, began a volume at 16:37 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

TimeReportWhereRemark
Sep 9, 11:00 AM PDTFLASH FLOOD13 Ne Glamis, CAHIGHWAY 78 CLOSED WEST OF OGILBY RD DUE TO FLOODING.

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, 4.6 hours before the alert went out and 201 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-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2017-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2017-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
992 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

612 
WGUS55 KPSR 091637
FFWPSR
CAC025-091930-
/O.NEW.KPSR.FF.W.0071.170909T1637Z-170909T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
937 AM PDT SAT SEP 9 2017

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Central Imperial County in southeastern California...

* Until 1230 PM PDT

* At 936 AM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Over one inch of rain has 
  already fallen locally. Flash flooding is expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Glamis and Highway 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

&&

LAT...LON 3319 11477 3298 11473 3278 11533 3292 11541
      3327 11541

$$

18
3 follow-up statements
743 
WGUS75 KPSR 091729
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1029 AM PDT SAT SEP 9 2017

CAC025-091930-
/O.CON.KPSR.FF.W.0071.000000T0000Z-170909T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Imperial CA-
1029 AM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 PM PDT FOR
CENTRAL IMPERIAL COUNTY...

At 1028 AM PDT, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Up to two inches of rain have already 
fallen along parts of Highway 78 between Brawley and Galmis. Flash 
flooding is expected to begin shortly.

Some locations that will experience flooding include...
Glamis and Highway 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3319 11477 3298 11473 3278 11533 3292 11541
      3327 11541

$$

18
216 
WGUS75 KPSR 091821
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1121 AM PDT SAT SEP 9 2017

CAC025-091930-
/O.CON.KPSR.FF.W.0071.000000T0000Z-170909T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Imperial CA-
1121 AM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 PM PDT FOR
CENTRAL IMPERIAL COUNTY...

At 1120 AM PDT, local law enforcement reported Highway 78 at and 
west of Ogilby Road flooding and closed. Up to two inches of rain 
have already fallen. Flash flooding is already occurring.

Some locations that will experience flooding include...
Glamis and Highway 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3319 11477 3298 11473 3278 11533 3292 11541
      3327 11541

$$

18
191 
WGUS75 KPSR 091936
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1236 PM PDT SAT SEP 9 2017

CAC025-091944-
/O.EXP.KPSR.FF.W.0071.000000T0000Z-170909T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Imperial CA-
1236 PM PDT SAT SEP 9 2017

...THE FLASH FLOOD WARNING FOR CENTRAL IMPERIAL COUNTY HAS EXPIRED...

The heavy rain has ended and water was beginning to recede. However, 
roads may remain closed due to debris. Please continue to heed any 
remaining road closures.

LAT...LON 3319 11477 3298 11473 3278 11533 3292 11541
      3327 11541

$$

18

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 5:12 PM PDTSevere Thunderstorm WarningPSRImperial, Riverside48 min
Sep 8, 5:43 PM PDTSevere Thunderstorm WarningPSRRiverside47 min
Sep 9, 9:43 AM PDTAreal Flood AdvisoryPSRImperial, Riverside3 hr
Sep 9, 11:14 AM PDTFlash Flood WarningPSRRiverside3 hr
Sep 9, 12:19 PM PDTFlash Flood WarningPSRRiverside3 hr
Sep 9, 12:53 PM PDTFlash Flood WarningPSRRiverside, San Bernardino3 hr

Nearby

Flash Flood Warnings in California, 2017Every 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.