Alert archive / Arizona / Flash Flood Watches in 2013

Flash Flood Watch 11, NWS Las Vegas, NV

September 8, 2013Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood watch at Sep 8, 2013, 3:13 AM MST for Mohave County, Arizona. It took effect at Sep 8, 2013, 11:00 AM MST. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued: Sep 8, 2013, 3:13 AM MST (10:13 UTC)
In effect from: Sep 8, 2013, 11:00 AM MST
Expired: Sep 8, 2013, 3:27 PM MST
In force: 4 hr
Issued by: NWS Las Vegas, NV
Flood severity: None

County Mohave County, AZ

The radar

The Las Vegas radar (KESX), 102 km from the middle of the area, began a volume at 10:17 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

Las Vegas, NV (KVEF), launched 00:00Z, 10.2 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-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: 6 J/kg
Mixed-layer CIN: -197 J/kg
Mixed-layer LCL: 1974 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -13 m²/s²
0-3 km storm-relative helicity: 48 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 flash flood watch 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 flash flood watch went out at Sep 8, 2:40 AM MST, 33 minutes earlier.

Area forecast discussion, Sep 8, 2:40 AM MST, 33 minutes before

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Hazardous weather outlook, Sep 7, 4:25 AM MST, 22 hours 48 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LAS VEGAS NV
425 AM PDT SAT SEP 7 2013

AZZ001>003-036-CAZ519>527-NVZ014>022-080700-
NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN SIERRA SLOPES-
OWENS VALLEY-WHITE MOUNTAINS OF INYO COUNTY-
DEATH VALLEY NATIONAL PARK-WESTERN MOJAVE DESERT-
EASTERN MOJAVE DESERT-MORONGO BASIN-CADIZ BASIN-
SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY-
ESMERALDA AND CENTRAL NYE COUNTY-LINCOLN COUNTY-
NORTHEAST CLARK COUNTY-WESTERN CLARK AND SOUTHERN NYE COUNTY-
SHEEP RANGE-SPRING MOUNTAINS-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
425 AM PDT SAT SEP 7 2013 /425 AM MST SAT SEP 7 2013/

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

.DAY ONE...TODAY AND TONIGHT

SCATTERED THUNDERSTORMS ARE EXPECTED AGAIN TODAY...ESPECIALLY IN THE
AFTERNOON AND EVENING. ISOLATED FLASH FLOODING IS POSSIBLE.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

CHANCES FOR THUNDERSTORMS WILL INCREASE BEGINNING SUNDAY...PRIMARILY
SOUTHEAST OF INTERSTATE 15. FLASH FLOODING WILL BE THE MAIN THREAT.
THUNDERSTORM CHANCES ARE EXPECTED TO PERSIST THROUGH WEDNESDAY
BEFORE STARTING TO DECREASE ON THURSDAY.

.SPOTTER INFORMATION STATEMENT...

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

MORGAN

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 8, 1:42 PM MST	Areal Flood Advisory	VEF	Clark	2 hr
Sep 8, 4:31 PM MST	Severe Thunderstorm Warning	VEF	Lincoln, Nye	44 min
Sep 8, 4:48 PM MST	Severe Thunderstorm Warning	VEF	Lincoln, Nye	42 min
Sep 8, 1:07 PM MST	Areal Flood Advisory	VEF	San Bernardino	3 hr
Sep 8, 2:44 PM MST	Areal Flood Advisory	VEF	Inyo, San Bernardino	3 hr
Sep 8, 4:06 PM MST	Flash Flood Warning	VEF	Inyo	114 min

Nearby

Flash Flood Watches in Arizona, 2013 Every flash flood watch in 2013

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.