Alert archive / California / Severe Thunderstorm Warnings in 2005

Severe Thunderstorm Warning 22, NWS Los Angeles, CA

October 17, 2005Los Angeles County, California

NWS Los Angeles, CA issued this severe thunderstorm warning at Oct 17, 2005, 1:27 PM PDT for Los Angeles County, California. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Oct 17, 2005, 1:27 PM PDT (20:27 UTC)
Expired: Oct 17, 2005, 2:30 PM PDT
In force: 63 min
Issued by: NWS Los Angeles, CA
Area: Counties, with a storm outline in the text

County Los Angeles County, CA

The radar

The Santa Ana Mts radar (KSOX), 71 km from the middle of the area, began a volume at 20:29 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

Pt Mugu Naws, CA (KNTD), launched 12:00Z, 8.5 hours before the alert went out and 78 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: 36 J/kg
Mixed-layer CIN: -173 J/kg
Mixed-layer LCL: 1181 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 231 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Los Angeles, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at Oct 17, 9:00 AM PDT, 4 hours 27 minutes earlier.

Area forecast discussion, Oct 17, 9:00 AM PDT, 4 hours 27 minutes before

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Hazardous weather outlook, Oct 17, 10:55 AM PDT, 2 hours 32 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1055 AM PDT MON OCT 17 2005

CAZ034>041-044>047-051>054-059-087-088-181300-
SAN LUIS OBISPO COUNTY CENTRAL COAST-
SANTA BARBARA COUNTY CENTRAL COAST-SANTA YNEZ VALLEY-
SAN LUIS OBISPO COUNTY INTERIOR VALLEYS-CUYAMA VALLEY-
SANTA BARBARA COUNTY SOUTH COAST-VENTURA COUNTY COAST-
LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES-
VENTURA COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS-
SANTA MONICA MOUNTAINS RECREATIONAL AREA-
LOS ANGELES COUNTY VALLEYS-SAN LUIS OBISPO COUNTY MOUNTAINS-
SANTA BARBARA COUNTY MOUNTAINS-VENTURA COUNTY MOUNTAINS-
LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE-
ANTELOPE VALLEY-CATALINA ISLAND-SANTA CLARITA VALLEY-
1055 AM PDT MON OCT 17 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWESTERN CALIFORNIA.

.DAY ONE... TODAY

AN UPPER LEVEL LOW IS CENTERED 300 NM SOUTH TO SOUTHWEST OF LOS
ANGELES. THE COUNTER CLOCKWISE CIRCULATION AROUND THIS LOW HAS
BROUGHT STRONG WINDS TO THE MOUNTAINS ALONG WITH RAINSHOWERS AND
THUNDERSTORMS TO MOST OF THE REGION SOUTH OF POINT CONCEPTION. RAIN
AND THUNDERSTORMS THIS MORNING HAVE ALREADY PROMPTED THE ISSUANCE OF
FLOOD WARNINGS FOR THE RECENT HARVARD AND TOPANGA BURN AREAS. THIS
MORNING...AN EAST WEST BAND OF SHOWERS SET UP OVER THE BURN AREAS
AND...ALTHOUGH INDIVIDUAL SHOWERS ARE LIGHT ENOUGH NOT TO PRODUCE
IMMEDIATE FLASH FLOODING AND DEBRIS FLOWS...THE CONTINUOUS TRAINING
OF SHOWERS OVER THE SAME AREAS RAISES THE POTENTIAL FOR FLOODING TO
WHERE WARNINGS ARE REQUIRED. THESE MAY HAVE TO BE REISSUED OR
EXTENDED AS THE DAY PROGRESSES.

SHOWERS ARE EXPECTED TO DIMINISH LATER THIS MORNING...BUT REDEVELOP
LATER THIS AFTERNOON AND TONIGHT AS THE UPPER LEVEL LOW BEGINS TO
MOVE NORTH AND EAST TOWARDS SAN DIEGO COUNTY. THEREFORE...THE THREAT
FOR MORE HEAVY RAIN WILL CONTINUE LATER TODAY AND THROUGH EARLY
TUESDAY. THE THREAT OF MORE RAIN LATER TODAY AND TONIGHT HAS
PROMPTED THE ISSUANCE OF A FLASH FLOOD WATCH FOR BOTH VENTURA AND
LOS ANGELES COUNTIES FROM NOW THROUGH MID DAY TUESDAY.

STRONG WINDS ARE CONTINUING THIS MORNING OVER THE MOUNTAINS OF
VENTURA AND LOS ANGELES COUNTIES. THESE ARE EXPECTED TO DIMINISH
THIS AFTERNOON. A WIND ADVISORY HAS BEEN IN EFFECT SINCE SUNDAY FOR
THESE EAST WINDS DUE...AGAIN...TO THE CIRCULATION AROUND THE UPPER
LOW SYSTEM TO OUR SOUTH. WIDESPREAD WINDS 45 TO 55 MPH HAVE BEEN
OBSERVED...WITH SOME ISOLATED AREAS RECEIVING GUSTS OVER 70 MPH.
AT THIS TIME...NO DAMAGE FROM THESE WINDS HAS BEEN REPORTED.

* FLOOD WATCH................SEE WGUS66 KLOX - FFALOX FOR DETAILS *

* FLOOD ADVISORY.............SEE WGUS86 KLOX - FLSLOX FOR DETAILS *

* WIND ADVISORY..............SEE WWUS76 KLOX - NPWLOX FOR DETAILS *

* MARINE WEATHER STATEMENT...SEE FZUS76 KLOX - MWSLOX FOR DETAILS *

.DAYS TWO THROUGH SEVEN... TUESDAY THROUGH SUNDAY

THE UPPER LEVEL STORM SYSTEM MOVES ONSHORE OVER SAN DIEGO COUNTY AND
CONTINUES EASTWARD ON TUESDAY...TAKING THE THREAT FOR CONTINUED
HEAVY RAIN WITH IT. THEREFORE...THE FLASH FLOOD WATCH CONTINUES
UNTIL MID DAY TUESDAY...WITH THE FLOOD THREAT EXPECTED TO DIMINISH
TUESDAY AFTERNOON.

* FLOOD WATCH................SEE WGUS66 KLOX - FFALOX FOR DETAILS *

* MARINE WEATHER STATEMENT...SEE FZUS76 KLOX - MWSLOX FOR DETAILS *

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

WOFFORD

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 16, 10:06 PM PDT	Marine Weather Statement	LOX		6 hr
Oct 17, 2:14 AM PDT	Flash Flood Warning	LOX	Los Angeles	2 hr
Oct 17, 2:23 AM PDT	Flash Flood Warning	LOX	Los Angeles, Ventura	2 hr
Oct 17, 4:11 AM PDT	Flash Flood Warning	LOX	Los Angeles	3 hr
Oct 17, 9:07 AM PDT	Marine Weather Statement	LOX		32 hr
Oct 17, 2:05 PM PDT	Severe Thunderstorm Warning	LOX	Los Angeles	40 min
Oct 17, 2:24 PM PDT	Flash Flood Warning	LOX	Los Angeles	66 min
Oct 17, 3:15 PM PDT	Flash Flood Warning	LOX	Los Angeles	2 hr

Nearby

Severe Thunderstorm Warnings in California, 2005 Every severe thunderstorm warning in 2005

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.