Alert archive / California / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 26, NWS Las Vegas, NV

July 24, 2009San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Jul 24, 2009, 4:44 PM PDT for San Bernardino County, California. It was in force for 46 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
Jul 24, 2009, 4:44 PM PDT (23:44 UTC)
Expired
Jul 24, 2009, 5:30 PM PDT
In force
46 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon

County San Bernardino County, CA

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 11.7 hours before the alert went out and 198 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, Mercury/Desert R, NV at 12:00Z on 2009-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 106 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Mercury/Desert R, NV at 12:00Z on 2009-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
106 J/kg
Mixed-layer CIN
-230 J/kg
Mixed-layer LCL
2265 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
27 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 Las Vegas, NV wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 24, 4:00 PM PDT, 44 minutes earlier.

Area forecast discussion, Jul 24, 4:00 PM PDT, 44 minutes before
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Hazardous weather outlook, Jul 24, 4:11 AM PDT, 12 hours 33 minutes before
HAZARDOUS WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE LAS VEGAS NV
411 AM PDT FRI JUL 24 2009

CORRECTION FOR SPELLING ERROR

AZZ001>003-036-CAZ524-526-527-NVZ015-016-020>022-250215-
NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN MOJAVE DESERT-
CADIZ BASIN-SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY-
LINCOLN COUNTY-NORTHEAST CLARK COUNTY-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
411 AM PDT FRI JUL 24 2009 /411 AM MST FRI JUL 24 2009/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST
ARIZONA...CALIFORNIA AND SOUTHERN NEVADA.

.DAY ONE...TODAY AND TONIGHT
VERY MOIST CONDITIONS HAVE MOVED OVER THE AREA AND THIS COMBINED
WITH A VERY UNSTABLE AIRMASS WILL CREATE THE POTENTIAL FOR
SCATTERED THUNDERSTORMS AND LOCALLY HEAVY RAINFALL THIS AFTERNOON
AND EVENING. THIS HAS PROMPTED THE ISSUANCE OF A FLASH FLOOD WATCH
FOR THIS AFTERNOON AND EVENING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
DRIER CONDITIONS ARE EXPECTED ON SATURDAY AND SUNDAY...BUT
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ARE STILL EXPECTED
OVER THE AREA. FURTHER DRYING IS THEN EXPECTED MONDAY THROUGH
THURSDAY. HOWEVER ISOLATED THUNDERSTORMS WILL CONTINUE TO FORM IN
THE AFTERNOON...MAINLY OVER THE MOUNTAINS.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING IF
HEAVY RAINFALL AND FLASH FLOODING DEVELOPS FROM THE EXPECTED
THUNDERSTORMS. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT
WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.

CAZ519>523-525-NVZ014-017>019-250215-
EASTERN SIERRA SLOPES-OWENS VALLEY-WHITE MOUNTAINS OF INYO COUNTY-
DEATH VALLEY NATIONAL PARK-WESTERN MOJAVE DESERT-MORONGO BASIN-
ESMERALDA AND CENTRAL NYE COUNTY-
WESTERN CLARK AND SOUTHERN NYE COUNTY-SHEEP RANGE-
SPRING MOUNTAINS-
411 AM PDT FRI JUL 24 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CALIFORNIA AND
SOUTHERN NEVADA.

.DAY ONE...TODAY AND TONIGHT
ISOLATED TO SCATTERED THUNDERSTORMS EXPECTED MAINLY THIS AFTERNOON
AND EVENING. BRIEF HEAVY RAINFALL AND GUSTY WINDS MAY BE SEEN FROM
THESE STORMS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY
MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL BE SEEN SATURDAY
AND SUNDAY...BUT OVERALL A DRYING TRENDS WILL BE TAKING PLACE. BY
MONDAY THUNDERSTORMS SHOULD BE CONFINED TO MAINLY THE SOUTHERN
SIERRA WITH STORMS POSSIBLY FORMING OVER THE SIERRA THROUGH THURSDAY
WHILE THE REMAINDER OF THE AREA SEE MOSTLY SUNNY DAYTIME SKIES.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED TODAY. SPOTTERS ARE ENCOURAGED TO
REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING
PROCEDURES.

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 24, 3:43 AM PDTFlash Flood WatchVEFClark, Lincoln17 hr
Jul 24, 1:38 PM PDTAreal Flood AdvisoryVEFClark, Nye3 hr
Jul 24, 2:33 PM PDTFlash Flood WarningVEFClark117 min
Jul 24, 1:13 PM PDTFlash Flood WarningVEFMohave3 hr
Jul 24, 4:26 PM PDTAreal Flood AdvisoryVEF109 min

Nearby

Severe Thunderstorm Warnings in California, 2009Every severe thunderstorm warning in 2009

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.