Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 43, NWS Las Vegas, NV

September 9, 1998Mohave County, Arizona

NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 9, 1998, 5:24 PM MST for Mohave County, Arizona. It was in force for 36 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 9, 1998, 5:24 PM MST (00:24 UTC)
Expired
Sep 9, 1998, 6:00 PM MST
In force
36 min
Issued by
NWS Las Vegas, NV
Area
Whole counties

County Mohave County, AZ

What was reported inside it

TimeReportWhereRemark
Sep 9, 5:35 PM MSTThunderstorm WindTopock, 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 00:00Z, 0.4 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 00:00Z on 1998-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 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 00:00Z on 1998-09-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2035 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
18 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 100026 RRA
SVRLAS
AZC015-100100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
524 PM PDT (524 PM MST) WED SEP 9 1998


*  SEVERE THUNDERSTORM WARNING FOR
   EXTREME SOUTHWESTERN MOHAVE COUNTY IN NORTHWESTERN ARIZONA

*  UNTIL 600 PM MST (600 PM PDT)

*  SOME LOCATIONS AFFECTED
   LAKE HAVASU CITY

*  AT 525 PM MST RADAR INDICATED A CLUSTER OF SEVERE THUNDERSTORMS
10 MILES SOUTHWEST OF LAKE HAVASU CITY.
MOVEMENT WAS TO NORTHEAST
AT 25 MPH. STRONG DAMAGING WINDS ARE LIKELY TO REACH LAKE HAVASU
CITY AHEAD OF THESE THUNDERSTORMS BETWEEN 530 AND 600 PM MST.

NEMETH

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 9, 3:35 PM MST, 1 hour 49 minutes earlier.

Area forecast discussion, Sep 9, 3:35 PM MST, 1 hour 49 minutes before
MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
335 PM PDT WED SEP 9 1998

SYNOPSIS...A STRONG TROUGH OF LOW PRESSURE APPROACHING THE WEST
COAST IS FORECAST TO SLOW AND THEN STALL OVER CENTRAL CALIFORNIA
THURSDAY AND FRIDAY. THIS SYSTEM WILL KEEP AN UNSEASONABLY MOIST
AND UNSTABLE AIR MASS ACROSS THE REGION FOR A CONTINUED THREAT OF
SHOWERS AND THUNDERSTORMS THROUGH THE END OF THE WEEK.

DISCUSSION...ACTIVE WEATHER DAY WITH APPROACHING TROUGH ON SCHEDULE
AND WATCHES/WARNINGS BEING ISSUED. SURFACE PRESSURE FALLS OVER SOUTH
CENTRAL NV WITH DEW POINT AXIS SURGING NWD ALONG CO RVR...ACROSS
CLARK AND INTO LINCOLN COUNTIES.  THUNDERSTORMS ORGANIZING IN N-S
LINES (NEARLY UNIDIRECTIONAL SHEAR WITH VEERING IN LOWER LEVELS) FROM
CO RIVER VALLEY AND WRN AZ NORTH INTO CLARK AND LINCOLN COUNTIES IN
NV. STORMS STARTING TO REALLY GET GOING AS DIVERGENCE AND UVV
APPROACH. AFTER INITIAL WIND GUSTS...CONCERN FOR FLASH FLOODING
INCREASING AS STORMS LIKELY TO START TRAINING IN UNIDIRECTIONAL SHEAR
ENVIRONMENT. COORDINATED WITH SPC (THANKS RICH AND MIKE) ON SLIGHT
RISK AREA WHICH LOOKS GOOD.  SEVERE THREAT TO CONTINUE INTO EARLY
EVENING WITH INCREASING DIVERGENCE EXPECTED DUE TO ENTRANCE REGION OF
JET OVER NV. ALSO WATCHING DARKENING AREA ON WV SATELLITE SWINGING
THROUGH BASE OF TROUGH AND APPROACHING SRN CA/SRN NV.

SATELLITE AND MODEL OVERLAYS INDICATE THAT NGM DOING BEST AT 18Z AND
PREFER NGM/AVN COMBINATION. USING RUC AND LOCAL RAMS MODELS FOR
DETAILS TONIGHT. FORECAST PRETTY STRAIGHT FORWARD AS TROUGH IS CUT
OFF FROM WESTERLIES THU AND REMAINS OVER CENTRAL CA THROUGH FRI. THIS
SIMILAR TO PAST WEEKEND EXCEPT DEEP MOISTURE PULLED UP AHEAD OF
TROUGH IS ACTED ON BY DECENT DYNAMICS THU. MOISTURE REMAINS OVER CO
RIVER VALLEY AND SRN/ERN NV AND AZ FRI AND EXPECT DYNAMICS TO WEAKEN
FOR MORE SCATTERED/DIURNAL NATURE TO STORMS. EXTENDED CONTINUES
PESSIMISTIC AND NOT WILLING TO BUY INTO MRF IDEA OF DRYING THINGS OUT
BY MON.  MOISTURE CONTINUES TO LINGER AT LEAST INTO SUN AS CUT OFF
WEAKENS AND SHEARS OUT. THIS PATTERN VERY UNUSUAL AND HAS BEEN
PERSISTENT SO WILL WAIT UNTIL I SEE THE WHITES OF THEIR EYES BEFORE
DRYING FORECAST OUT PREMATURELY. LAS 6443. NEMETH

A FLASH FLOOD WATCH HAS BEEN ISSUED. PLEASE REFER TO THE LATEST FLASH
FLOOD WATCH BULLETIN FOR DETAILS.

A WIND ADVISORY HAS BEEN ISSUED. PLEASE REFER TO THE LATEST WIND
ADVISORY BULLETIN FOR DETAILS.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 5:31 PM MSTSevere Thunderstorm WarningVEFMohave44 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.