Alert archive / California / Flash Flood Warnings in 2004

Flash Flood Warning 16, NWS Phoenix, AZ

December 28, 2004Imperial County, Riverside County, San Bernardino County, California

NWS Phoenix, AZ issued this flash flood warning at Dec 28, 2004, 3:08 PM PST for Imperial County, Riverside County, San Bernardino County, California. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Dec 28, 2004, 3:08 PM PST (23:08 UTC)
Expired
Dec 28, 2004, 5:15 PM PST
In force
2 hr
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

Counties Imperial County, CA, Riverside County, CA, San Bernardino County, CA

The radar

The San Diego radar (KNKX), 138 km from the middle of the area, began a volume at 23:10 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Yuma Intl Airpor, AZ (KYUM), launched 12:00Z, 11.1 hours before the alert went out and 153 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, Yuma Intl Airpor, AZ at 12:00Z on 2004-12-28Temperature 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 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Yuma Intl Airpor, AZ at 12:00Z on 2004-12-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.1939587897117Sfc1 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
1217 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
192 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.

000 
WGUS55 KPSR 282320
FFWPSR
CAC025-065-071-290115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
308 PM PST TUE DEC 28 2004

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN AND NORTH CENTRAL IMPERIAL COUNTY IN SOUTHEAST        
  CALIFORNIA. THIS INCLUDES THE CITY OF SALTON CITY. 
  CENTRAL RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA. THIS INCLUDES    
  THE CITIES OF...DESERT CENTER...CHIRIACO SUMMIT. 

* UNTIL 515 PM PST

* AT 304 PM PST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  HEAVY RAIN CONTINUING TO FALL OVER PORTIONS OF CENTRAL AND EASTERN 
  RIVERSIDE COUNTY AND OVER NORTH CENTRAL IMPERIAL COUNTY. THE HEAVIEST
  RAINFALL APPEARS TO BE OVER THE LITTLE CHUCKWALLA MOUNTAINS IN SOUTHEAST
  RIVERSIDE COUNTY AND OVER THE CHOCOLATE MOUNTAINS IN NORTHERN      
  IMPERIAL COUNTY. THE RADAR HAS ESTIMATED BETWEEN ONE HALF AND      
  THREE QUARTER INCHES OF RAIN PER HOUR IN THOSE AREAS...WITH        
  ISOLATED AMOUNTS UP TO 1 INCH. AUTOMATIC STATIONS AT JOSHUA TREE
  NATIONAL PARK HAVE RECORDED BETWEEN 1.6 AND 1.8 INCHES RAIN SO     
  FAR WITH THIS STORM. 

* MOTORISTS DRIVING IN THIS AREA SHOULD BE ON ALERT FOR              
  RUNNING WASHES AND FLOODED ROADWAYS...AND SHOULD NOT ATTEMPT
  TO DRIVE THROUGH FLOODED ROADWAYS.          

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

LAT...LON 3316 11628 3320 11502 3417 11496 3427 11646

$$

BERKOVITZ

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Dec 28, 2:02 PM PST, 1 hour 6 minutes earlier.

Area forecast discussion, Dec 28, 2:02 PM PST, 1 hour 6 minutes before
AZZ020>024-028-CAZ030>032-291200-

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE PHOENIX AZ
302 PM MST TUE DEC 28 2004

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH WEDNESDAY MORNING
FOR JOSHUA TREE NATIONAL PARK...EASTERN RIVERSIDE COUNTY AND THE
LOWER COLORADO RIVER VALLEY...

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE WEDNESDAY
AFTERNOON FOR LA PAZ COUNTY...

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE WEDNESDAY
AFTERNOON FOR NORTHWEST...CENTRAL AND NORTHEAST MARICOPA
COUNTY...INCLUDING THE PHOENIX METRO AREA...AS WELL AS NORTHWEST
PINAL COUNTY...AND SOUTHERN GILA COUNTY...

A STRONG PACIFIC WEATHER SYSTEM WILL CONTINUE TO DEVELOPMENT WITH
WIDESPREAD SHOWERS THIS THIS EVENING IN SOUTHEAST
CALIFORNIA...EXPANDING EASTWARD TO SOUTH-CENTRAL ARIZONA OVERNIGHT.
THE SHOWER ACTIVITY WILL BEGIN TO DECREASE FROM WEST TO EAST DURING
THE DAY WEDNESDAY. THERE WILL ALSO BE A SLIGHT CHANCE OF
THUNDERSTORMS ALONG WITH THE SHOWERS.

THIS SYSTEM HAS THE POTENTIAL TO PRODUCE HEAVY RAIN WHICH COULD LEAD
TO LOCALIZED FLASH FLOODING. STORM TOTAL AMOUNTS OF ONE INCH WILL BE
COMMON WITH SOME LOCATIONS RECEIVING UPWARDS OF TWO INCHES...
ESPECIALLY IN THE HIGHER TERRAIN AREAS.

A FLASH FLOOD WATCH MEANS THAT FLOODING OF WASHES...CREEKS AND OTHER
DRAINAGE AREAS IS POSSIBLE WITHIN THE WATCH AREA. PEOPLE IN THE WATCH
AREA SHOULD KEEP AN EYE ON THE WEATHER AND BE PREPARED FOR IMMEDIATE
ACTION SHOULD HEAVY RAINS AND FLOODING OCCUR OR A FLASH FLOOD WARNING
BE ISSUED.

22/AJ
Hazardous weather outlook, Dec 28, 4:59 AM PST, 10 hours 9 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
559 AM MST TUE DEC 28 2004

AZZ020>024-028-CAZ030>032-282300-
GREATER PHOENIX AREA-JOSHUA TREE NATIONAL PARK-
LOWER COLORADO RIVER VALLEY AZ-LOWER COLORADO RIVER VALLEY CA-
NORTHWEST AND NORTH CENTRAL PINAL COUNTY-NORTHWEST MARICOPA COUNTY-
RIVERSIDE COUNTY/EASTERN DESERTS-SOUTHERN GILA/TONTO NF FOOTHILLS-
WEST CENTRAL DESERTS-
559 AM MST TUE DEC 28 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN RIVERSIDE COUNTY IN
CALIFORNIA...AS WELL AS LA PAZ...NORTHERN AND CENTRAL MARICOPA
...NORTHERN PINAL...AND SOUTHERN GILA COUNTIES IN ARIZONA.

.DAY ONE...TODAY

MODERATE TO HEAVY RAIN SHOWERS...AS WELL AS A FEW THUNDERSTORMS
...ARE EXPECTED TO DEVELOP THIS AFTERNOON AND TONIGHT OVER EASTERN
RIVERSIDE COUNTY INCLUDING JOSHUA TREE NATIONAL PARK IN CALIFORNIA
...AND LA PAZ COUNTY IN ARIZONA. LOCALLY HEAVY RAIN MAY RESULT IN
FLASH FLOODING...ESPECIALLY IN AND NEAR WASHES...SO A FLASH FLOOD
WATCH HAS BEEN ISSUED.

LOCALLY HEAVY RAIN IS POSSIBLE TONIGHT OVER NORTHERN AND CENTRAL
MARICOPA COUNTY INCLUDING THE GREATER PHOENIX AREA...SOUTHERN GILA
COUNTY...AND NORTHERN PINAL COUNTY IN ARIZONA. SOME FLOODING IS
POSSIBLE...SO A FLASH FLOOD WATCH HAS BEEN ISSUED.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

MODERATE TO HEAVY RAIN SHOWERS...AS WELL AS A FEW THUNDERSTORMS
...ARE EXPECTED OVER CENTRAL AND EASTERN LA PAZ COUNTY...NORTHERN AND
CENTRAL MARICOPA COUNTY INCLUDING THE GREATER PHOENIX AREA
...SOUTHERN GILA COUNTY...AND NORTHERN PINAL COUNTY ON WEDNESDAY.
SOME FLOODING IS POSSIBLE...SO A FLASH FLOOD WATCH HAS BEEN ISSUED
FOR THIS AREA.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED TODAY AND WEDNESDAY.

AZZ025>027-CAZ033-282300-
IMPERIAL COUNTY-SOUTHWEST DESERTS-SOUTHWEST MARICOPA COUNTY-
YUMA/MARTINEZ LAKE AND VICINITY-
559 AM MST TUE DEC 28 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR IMPERIAL COUNTY IN
CALIFORNIA...AND YUMA AND SOUTHWEST MARICOPA COUNTY IN ARIZONA.

.DAY ONE...TODAY

RAIN SHOWERS...AND A FEW THUNDERSTORMS...WILL BE POSSIBLE THIS
AFTERNOON AND TONIGHT. BRIEF HEAVY RAIN COULD RESULT IN MINOR
FLOODING OF POOR DRAINAGE AND LOW LYING AREAS...AS WELL AS CITY
STREETS. WASHES MAY BEGIN FLOWING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

RAIN SHOWERS...AND A FEW THUNDERSTORMS...WILL OCCUR WEDNESDAY.
BRIEF HEAVY RAIN COULD RESULT IN MINOR FLOODING OF POOR DRAINAGE AND
LOW LYING AREAS...AS WELL AS CITY STREETS. WASHES MAY BEGIN FLOWING.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY AND WEDNESDAY.

DG

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 28, 11:31 AM PSTFlash Flood WarningPSRImperial, Riverside, San Bernardino119 min
Dec 28, 1:18 PM PSTFlash Flood WarningPSRImperial, Riverside, San Bernardino117 min

Nearby

Flash Flood Warnings in California, 2004Every flash flood warning in 2004

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.