Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 45, NWS Las Vegas, NV

September 11, 1998Mohave County, Arizona

NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 11, 1998, 5:50 AM MST for Mohave County, Arizona. It was in force for 60 min. 2 reports 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 11, 1998, 5:50 AM MST (12:50 UTC)
Expired
Sep 11, 1998, 6:50 AM MST
In force
60 min
Issued by
NWS Las Vegas, NV
Area
Whole counties

County Mohave County, AZ

What was reported inside it

TimeReportWhereRemark
Sep 11, 6:00 AM MSTHail 1Wikieup, AZ
Sep 11, 6:05 AM MSTHail 1.75Wikieup, AZ

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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 0.8 hours before the alert went out and 185 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, Flgstf/Belemont, AZ at 12:00Z on 1998-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 1998-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 square meters per square second.193958Sfc1 km3 km6 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
1435 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
158 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 
TTAA00 KLAS 111250 RRA
SVRLAS
AZC015-111350-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
550 AM PDT (550 AM MST) FRI SEP 11 1998


*  SEVERE THUNDERSTORM WARNING FOR
   SOUTHEASTERN MOHAVE COUNTY IN NORTHWESTERN ARIZONA

*  UNTIL 650 AM MST (650 AM PDT)

*  SOME LOCATIONS AFFECTED
   WIKIEUP
   HIGHWAY 95

AT 549 AM MST...RADAR INDICATED A SEVERE THUNDERSTORM 8 MILES
SOUTHWEST OF WIKIEUP.  MOVEMENT WAS TO THE NORTHEAST AT 25 TO 30
MPH.

STRONG DAMAGING WINDS ARE LIKELY WITH THIS STORM.

IF YOU ARE OUTDOORS...MOVE TO A PLACE OF SHELTER IMMEDIATELY IF A
STORM APPROACHES.  MOTORISTS SHOULD REMAIN ALERT FOR REDUCED
VISIBILITIES DURING DOWNPOURS OF RAIN.  STREETS MAY FLOOD QUICKLY.

PIERCE

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 11, 3:30 AM MST, 2 hours 20 minutes earlier.

Area forecast discussion, Sep 11, 3:30 AM MST, 2 hours 20 minutes before
MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
330 AM PDT FRI SEP 11 1998

SYNOPSIS...AN AREA OF LOW PRESSURE OVER WESTERN NEVADA WILL SLOWLY
MOVE SOUTHWARD INTO SOUTH CENTRAL CALIFORNIA TODAY. THE UPPER LOW
WILL WEAKEN AND LIFT NORTHEAST INTO NORTHERN UTAH SATURDAY. A MOIST
AND UNSTABLE AIRMASS WILL ENCOMPASS PARTS OF THE SOUTHERN GREAT BASIN
AND MOJAVE DESERT TODAY FOR A CONTINUED THREAT OF SHOWERS AND
THUNDERSTORMS THROUGH SATURDAY.

DISCUSSION...WATER VAPOR LOOP SHOWS UPPER LOW OVER WESTERN NEVADA
WITH JETSTREAM SLICING ACROSS EASTERN NEVADA. SHORTWAVES ROTATING
AROUND UPPER LOW SEEN OVER CENTRAL CALIFORNIA AND SOUTHWEST UTAH.
PLUME OF MOISTURE OFF TROPICAL DEPRESSION JAVIER STREAMING NORTH INTO
ARIZONA. PACKAGE BASED ON NGM/AVN WITH ETA DISCOUNTED. PRECIPITABLE
WATER SOUNDER DETECTS AREA GREATER THAN AN INCH ACROSS ARIZONA MOVING
UP COLORADO RIVER TO EXTREME SOUTHERN NEVADA. AT 10Z...RADAR AND
SATELLITE CONFIRM THE PRESENCE OF THUNDERSTORMS IN NYE AND LINCOLN
COUNTIES AND STORMS ERUPTING IN PLUME OF MOISTURE OVER ARIZONA. UPPER
LOW WILL SLOWLY SAG SOUTH INTO CENTRAL CALIFORNIA TODAY. JUST LIKE
UPPER LOW FROM LAST WEEKEND BEST FORCING WILL BE ASSOCIATED WITH
UPPER LEVEL DIFFLUENCE WHICH TODAY WILL BE ACROSS ARIZONA THEN WRAP
BACK EAST INTO CENTRAL NEVADA. CLOSER TO UPPER LOW COLD POOL ALOFT
SHOULD BE ENOUGH TO DESTABILIZE THE ATMOSPHERE. MOST STORMS WILL END
IN THE EVENING BUT WOULD NOT BE SURPRISED TO SEE A FEW CONTINUE ALL
NIGHT OVER NORTHWEST ARIZONA WHERE MOISTURE WILL BE MORE PLENTIFUL.
ON SATURDAY NGM/AVN SPREADING DRIER MORE STABLE (WARM AIR ALOFT)
FURTHER EAST WHILE NORTHWEST ARIZONA LIES UNDER WESTERN JEDGE OF
MONSOON MOISTURE BOUNDARY. HAVE TRIMMED BACK POPS OR REMOVED MENTION
ALL TOGETHER IN THE WESTERN ZONES. A DECREASING TREND CONTINUES
THROUGH THE EXTENDED PERIOD WITH TEMPERATURES HOVERING NEAR SEASONAL
NORMALS. LAS 330 PIERCE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 11:42 AM MSTFlash Flood WarningVEFMohave2 hr
Sep 11, 2:30 PM MSTSevere Thunderstorm WarningVEFMohave105 min
Sep 11, 3:43 PM MSTFlash Flood WarningVEFMohave4 hr
Sep 11, 4:28 PM MSTSevere Thunderstorm WarningVEFMohave92 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1998Every severe thunderstorm warning in 1998

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.