Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 64, NWS Las Vegas, NV

September 1, 1997Mohave County, Arizona; Clark County, Nevada

NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 1, 1997, 3:20 PM MST for Mohave County, Arizona; Clark County, Nevada. It was in force for 80 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Sep 1, 1997, 3:20 PM MST (22:20 UTC)
Expired: Sep 1, 1997, 4:40 PM MST
In force: 80 min
Issued by: NWS Las Vegas, NV
Area: Whole counties

Counties Mohave County, AZ, Clark County, NV

The radar

The Las Vegas radar (KESX), 54 km from the middle of the area, began a volume at 22:23 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.

What was reported inside it

Time	Report	Where	Remark
Sep 1, 3:55 PM MST	Thunderstorm Wind	Cottonwood Lndg, NV	Thunderstorms rolling across The Lake Mead National Recreation Area knocked trees down at Cottonwood Cove and dumped heavy rain on Las Vegas Bay and Callville Bay.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 10.3 hours before the alert went out and 162 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: 157 J/kg
Mixed-layer CIN: -159 J/kg
Mixed-layer LCL: 2764 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 48 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 Sep 1, 2:46 PM MST, 34 minutes earlier.

Area forecast discussion, Sep 1, 2:46 PM MST, 34 minutes before

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
245 PM PDT MON SEP 1 1997

CONTINUING FLASH FLOOD WATCH FOR NVZ016-018>022...CAZ028-029 AND
AZZ031-001>003 TIL 9 PM.  WATCH MAY NEED TO BE EXTENDED INTO
LINCOLN COUNTY LTR IF CURRENT TRENDS CONT. 12Z UA CHARTS AND
SOUNDINGS POINTED TO AN ACTIVE TSTM DAY...AND THAT WELL UNDERWAY.
INCRG SLY FLOW BRINGING DEEP LAYER MONSOONAL MSTR INTO REGION. MSTR
COMBINED WITH DYNAMICS FRM APCHG MEX DISTURBANCE PRODUCING NUMEROUS
TSTMS.  SO FAR THEY ARE VRY HEAVY RAIN PRODUCERS WITH REFLECTIVITY
CORES BEING CARRIED LOW AND IR STLT TOPS WARM.  G55 KTS AT VCNTY
NXP LIKELY FRM WET MICROBURST AND HAVE HAD RPTS OF .25 INCH HAIL AT
HUALAPAI MTN IN MOHAVE CO.

DYNAMICS FRM VORT CROSSING WRN AZ WILL CONT TO KEEP TSTMS GOING
WELL INTO THE NIGHT WITH MAIN THREAT BEING FLASH FLOODING. MODELS
ALL KEEP DEEP LAYERED TROPICAL MSTR ACRS THE AREA INTO WED WITH
ETA48 AGAIN INDCG YET ANOTHER DISTURBANCE MOVG UP THRU WRN AZ TUE
AFT. NOT MATTER WHAT MODEL YOU PICK...LIKELY THAT ADDTIONAL
DISTURBANCES WILL RIDE UP ALONG THE PERIPHERY OF THE HIGH AND SPARK
TSTMS TUE/TUE NGT.  LEANING FCST THAT WAY FOR NOW WITH A DECREASE
IN POPS ON WED AS DYNAMICS FADE.  DRYING TREND CONTS INTO EXTENDED
FOR SRN NV (I HOPE) WITH SOME HINT AT RETURNING SWLY FLOW.  LAS
5332.

NEMETH

SRN NV...FLASH FLOOD WATCH 17Z-04Z NVZ016-018>22
ERN CA...FLASH FLOOD WATCH 17Z-04Z CAZ029-029
NW AZ ...FLASH FLOOD WATCH 17Z-04Z AZZ0031-001>003

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 1:17 PM MST	Flash Flood Warning	VEF	Mohave	2 hr
Sep 1, 2:30 PM MST	Flash Flood Warning	VEF	Mohave	2 hr
Sep 1, 3:20 PM MST	Flash Flood Warning	VEF	Mohave	80 min
Sep 1, 3:15 PM MST	Flash Flood Warning	VEF	Clark	2 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 1997 Severe Thunderstorm Warnings in Nevada, 1997 Every severe thunderstorm warning in 1997

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.