Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 63, NWS Phoenix, AZ

September 4, 2012Riverside County, San Bernardino County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 4, 2012, 1:55 PM PDT for Riverside County, San Bernardino County, California. It was in force for 95 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 4, 2012, 1:55 PM PDT (20:55 UTC)
Expired
Sep 4, 2012, 3:30 PM PDT
In force
95 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

Counties Riverside County, CA, San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 151 km from the middle of the area, began a volume at 20:56 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

San Diego, CA (KNKX), launched 12:00Z, 8.9 hours before the alert went out and 177 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 2012-09-04Temperature 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 2012-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.193958Sfc1 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
2730 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

886 
WGUS55 KPSR 042055
FFWPSR
CAC065-071-042230-
/O.NEW.KPSR.FF.W.0063.120904T2055Z-120904T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
155 PM PDT TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  SOUTH CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 330 PM PDT

* AT 150 PM PDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
  VERY HEAVY RAIN FROM SLOW MOVING THUNDERSTORMS THAT WILL CAUSE 
  FLASH FLOODING. FLASH FLOODING IS EXPECTED ALONG THE UTAH TRAIL ROAD 
  AND NORTHERN PARK ENTRANCE TO JOSHUA TREE NATIONAL PARK. 

* THE STORM PRODUCING VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING
  WILL GENERALLY REMAIN OVER THE NORTHERN PORTIONS OF JOSHUA TREE
  NATIONAL PARK WHILE MOVING TO THE NORTHEAST. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

CAMPERS...HIKERS...AND OFF ROAD VEHICLE RIDERS SEEK HIGHER GROUND
IMMEDIATELY. AVOID WASHES AND STREAMS. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATER OR WATER OF UNKNOWN DEPTH.

A FLASH FLOOD WARNING MEANS THAT PEOPLE ALONG THE BANKS OF WASHES AND
CREEKS SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. NORMALLY DRY WASHES
AND STREAMS WILL SUDDENLY HAVE RUNNING WATER AND MAKE UNBRIDGED
CROSSINGS IMPASSABLE. STREETS...UNDERPASSES...AND LOW SPOTS WILL
BECOME INUNDATED MAKING DRIVING HAZARDOUS IN THE WARNED AREA.

&&

LAT...LON 3411 11604 3409 11603 3408 11600 3404 11599
      3403 11590 3402 11590 3391 11601 3400 11612
      3412 11616

$$

NOLTE
3 follow-up statements
961 
WGUS75 KPSR 042116
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
216 PM PDT TUE SEP 4 2012

CAC065-071-042230-
/O.CON.KPSR.FF.W.0063.000000T0000Z-120904T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
216 PM PDT TUE SEP 4 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO AND NORTH CENTRAL RIVERSIDE COUNTIES...

AT 208 PM PDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
MONITOR AN AREA OF THUNDERSTORMS PRODUCING VERY HEAVY RAIN 
THAT WILL CAUSE FLASH FLOODING.

THIS THUNDERSTORM WITH EXCESSIVE RAIN WAS OVER THE NORTHERN MOST 
PORTIONS OF JOSHUA TREE NATIONAL PARK...NEAR THE UTAH TRAIL AND 
LOOP ROADS. RUNOFF FROM HEAVY RAINFALL WILL IMPACT PARK ROADWAYS 
AND TRAILS. RADAR ESTIMATES OVER 1.25 TO 1.50 INCHES OF RAIN HAS 
FALLEN IN THE LAST HOUR. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

CAMPERS...HIKERS...AND OFF ROAD VEHICLE RIDERS SEEK HIGHER GROUND
IMMEDIATELY. AVOID WASHES AND STREAMS. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATER OR WATER OF UNKNOWN DEPTH.

A FLASH FLOOD WARNING MEANS THAT PEOPLE ALONG THE BANKS OF WASHES AND
CREEKS SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. NORMALLY DRY WASHES
AND STREAMS WILL SUDDENLY HAVE RUNNING WATER AND MAKE UNBRIDGED
CROSSINGS IMPASSABLE. STREETS...UNDERPASSES...AND LOW SPOTS WILL
BECOME INUNDATED MAKING DRIVING HAZARDOUS IN THE WARNED AREA.

&&

LAT...LON 3411 11604 3409 11603 3408 11600 3404 11599
      3403 11590 3402 11590 3391 11601 3400 11612
      3412 11616

$$

NOLTE
602 
WGUS75 KPSR 042206
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
306 PM PDT TUE SEP 4 2012

CAC065-071-042230-
/O.CON.KPSR.FF.W.0063.000000T0000Z-120904T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
306 PM PDT TUE SEP 4 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO AND NORTH CENTRAL RIVERSIDE COUNTIES...

AT 300 PM PDT...EARLIER THUNDERSTORMS PRODUCING VERY HEAVY RAIN ACROSS
PORTIONS OF JOSHUA TREE NATIONAL PARK HAS MOVED INTO MORE MOUNTAINOUS
PORTIONS OF THE PARK. HOWEVER...RUNOFF FROM EARLIER STORMS WILL 
CONTINUE TO IMPACT PARK ROADWAYS AND TRAILS. RADAR ESTIMATES THAT ONE
QUARTER TO ONE HALF INCH OF RAIN FELL UNDER THE HEAVIEST THUNDERSTORM
CORES. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

CAMPERS...HIKERS...AND OFF ROAD VEHICLE RIDERS SEEK HIGHER GROUND
IMMEDIATELY. AVOID WASHES AND STREAMS. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATER OR WATER OF UNKNOWN DEPTH.


&&

LAT...LON 3411 11604 3409 11603 3408 11600 3404 11599
      3403 11590 3402 11590 3391 11601 3400 11612
      3412 11616

$$

NOLTE
696 
WGUS75 KPSR 042225
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM PDT TUE SEP 4 2012

CAC065-071-042233-
/O.EXP.KPSR.FF.W.0063.000000T0000Z-120904T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
325 PM PDT TUE SEP 4 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 330 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO AND NORTH CENTRAL RIVERSIDE COUNTIES...

HEAVY RAINFALL HAS ENDED ACROSS THE NORTHERN PORTIONS OF JOSHUA 
TREE NATIONAL PARK AND THE FLASH FLOODING THREAT HAS GENERALLY 
DIMINISHED. RUNOFF FROM STRONG THUNDERSTORMS MAY CONTINUE TO IMPACT
PARK ROADWAYS AND TRAILS OVER THE NEXT FEW HOURS. MAKE THE SMART
CHOICE...TURN AROUND...DONT DROWN. AVOID DRIVING THROUGH WATER
COVERED ROADWAYS AND PATHS.

LAT...LON 3411 11604 3409 11603 3408 11600 3404 11599
      3403 11590 3402 11590 3391 11601 3400 11612
      3412 11616

$$

NOLTE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 6:41 PM PDTAreal Flood AdvisoryPSRRiverside3 hr
Sep 4, 1:45 PM PDTSpecial Weather StatementPSRRiverside45 min
Sep 4, 2:42 PM PDTAreal Flood AdvisoryPSRRiverside94 min
Sep 4, 2:54 PM PDTSpecial Weather StatementPSRRiverside66 min
Sep 4, 3:18 PM PDTAreal Flood AdvisoryPSRRiverside, San Bernardino80 min
Sep 4, 3:33 PM PDTSpecial Weather StatementPSRImperial57 min
Sep 4, 3:56 PM PDTBlowing Dust AdvisoryPSR2 hr
Sep 4, 3:57 PM PDTSpecial Weather StatementPSRRiverside78 min
Sep 4, 4:09 PM PDTFlash Flood WarningPSRImperial92 min
Sep 4, 4:57 PM PDTSpecial Weather StatementPSRRiverside48 min

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

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.