Alert archive / Arizona / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 39, NWS Las Vegas, NV
NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 9, 1998, 2:34 PM MST for Mohave County, Arizona; Clark County, Nevada. It was in force for 61 min. 3 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 9, 1998, 2:34 PM MST (21:34 UTC)
- Expired
- Sep 9, 1998, 3:35 PM MST
- In force
- 61 min
- Issued by
- NWS Las Vegas, NV
- Area
- Whole counties
Counties Mohave County, AZ, Clark County, NV
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Sep 9, 3:00 PM MST | Thunderstorm Wind 52 | Mesquite, NV | Thunderstorm wind gusts of 60 mph were reported by a weather spotter in Mesquite. |
| Sep 9, 3:20 PM MST | Thunderstorm Wind | Colorado City, AZ | Damaging thunderstorm winds downed power lines as they blew through Colorado City. |
| Sep 9, 3:40 PM MST | Thunderstorm Wind 50 | Boulder City, NV |
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, 9.6 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.
- Mixed-layer CAPE
- 266 J/kg
- Mixed-layer CIN
- -132 J/kg
- Mixed-layer LCL
- 1582 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 139 m²/s²
- 0-3 km storm-relative helicity
- 189 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KLAS 092135 RRA SVRLAS AZC015-NVC003-092235- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE LAS VEGAS NV 234 PM PDT (234 PM MST) WED SEP 9 1998 * SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN CLARK COUNTY IN SOUTHERN NEVADA NORTHERN MOHAVE COUNTY IN NORTHWESTERN ARIZONA * UNTIL 335 PM PDT (335 PM MST) * SOME LOCATIONS AFFECTED MESQUITE NV BUNKERVILLE NV COLORADO CITY AZ PIPE SPRING MONUMENT AZ * AT 230 PDT/MST DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS EXTENDING FROM 6 MILES NORTHEAST OF ECHO BAY TO THE WEST EDGE OF THE GRAND CANYON. MOVEMENT WAS TO THE NORTH AT 25 MPH. STRONG DAMAGING WINDS EXCEEDING 60 MPH ARE LIKELY AS TzHESE STORMS MOVE THROUGH BUNKERVILLE AND MESQUITE BY 300 PM PDT. COLORADO CITY AND PIPE SPRING CAN EXPECT DAMAGING WINDS BY 330 PM MST.
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, 9:50 AM MST, 4 hours 44 minutes earlier.
Area forecast discussion, Sep 9, 9:50 AM MST, 4 hours 44 minutes before
MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 950 AM PDT WED SEP 9 1998 ...CORRECTION FOR FLASH FLOOD WATCH PORTION... SYNOPSIS...A STRONG TROUGH OF LOW PRESSURE APPROACHING THE WEST COAST WILL MOVE INTO CALIFORNIA TODAY THEN REMAIN OVER CALIFORNIA AND WESTERN NEVADA THURSDAY AND FRIDAY. THIS SYSTEM WILL KEEP A MOIST SOUTHERLY FLOW OF AIR ACROSS THE REGION FOR A CONTINUED THREAT OF SHOWERS AND THUNDERSTORMS. DISCUSSION...APOLOGIES FOR THE DELAY IN PRODUCTS THIS MORNING... WANTED TO COORDINATE THINKING WITH SPC (THANKS MIKE V.) AND AREA WSFOS AND WFOS. STRONG UPPER TROF CONTINUES TO APPROACH CA COAST THIS MORNING WITH MAIN VORT CENTER NEAR SFO BAY AREA. BAROCLINIC BAND PUSHING INTO NW NV AND NEARING NRN INYO COUNTY. 12Z DRA SOUNDING INDICATES LITTLE 24 HOUR CHANGE IN MOISTURE/TEMPERATURE PROFILES WITH MODIFIED SOUNDING RESULTING IN -4 TO -7 LIFTED INDEX AND CAPES RANGING FROM 1500 TO 2500 J/KG. BIG CHANGE IS THE INCREASE IN SPEED SHEAR WITH SOME VEERING NOTED IN LOWER LAYERS (BETTER STORM ENVIRONMENT). PREVIOUS STORMS AND RAIN COOLED AIR HAVE STABILIZED LOWER LAYERS A BIT BUT WITH NEARLY FULL SUN ACROSS REGION...ANY CIN WILL BE ERASED WITH THUNDERSTORMS DEVELOPING A FEW HOURS LATER THAN TUE. LOOKING AT MODELS AND UPPER AIR DATA...APPROACHING VORTICITY MAXIMUM AND 75 TO 90 KT JET MAX WILL FOCUS BEST DYNAMIC FORCING ACROSS NRN INYO...ESMERALDA AND NRN/CNTRL NYE COUNTIES THIS AFTERNOON FROM PVA AND JET DIVERGENCE. SHEAR/DIVERGENCE AND FORCING ALSO INCREASING FARTHER S AND E TOWARD LINCOLN/CLARK AND MOHAVE COUNTIES LATE THIS AFTERNOON AND EVENING WITH SIGNIFICANT CONVERGENCE/DIVERGENCE COUPLING FORECAST BY NGM FOR CLARK AND MOHAVE COUNTIES THIS EVENING. PER COORDINATION WITH SPC...STORM ENVIRONMENT A LITTLE BETTER TODAY FOR ISOLATED SEVERE ACROSS NV ZONES AND EVEN NW AZ. WILL BEEF UP PRECIPITATION CHANCES AND ISSUE FLASH FLOOD WATCH FOR NEVADA AND ARIZONA ZONES THIS AFT/EVE WHERE BEST MOISTURE/DYNAMICS AND INSTABILITY ARE EXPECTED. INYO/SAN BERNARDINO COUNTIES MORE OF A QUESTION BUT WILL NUDGE FORECAST IN DIRECTION OF HIGHER PRECIPITATION CHANCES AND SEVERE. ALSO MODIFIED TONIGHT PORTION DUE TO DYNAMIC FORCING MOVING S AND E ACROSS CA/NV/AZ AND TO BLEND BETTER WITH ABOVE MENTIONED ADJUSTMENTS. TROUGH CONTINUES TO SLOW ON MODELS AND SEE NO REASON THAT THU WILL NOT BE ANOTHER ACTIVE DAY FOR AREAS FARTHER S AND E. LAS 664. NEMETH A FLASH FLOOD WATCH HAS BEEN ISSUED. PLEASE REFER TO THE LATEST FLASH FLOOD WATCH BULLETIN FOR DETAILS.
In the hours before
Special weather statement, Sep 9, 10:10 AM MST, 4 hours 24 minutes before
AZZ001>003-036-NVZ013>022-100500- BULLETIN...IMMEDIATE BROADCAST REQUESTED FLASH FLOOD WATCH...RESENT FOR CARSON NHP... NATIONAL WEATHER SERVICE LAS VEGAS NV 1008 AM PDT (1002 AM MST) WED SEP 9 1998 ...FLASH FLOOD WATCH FROM NOON UNTIL 10 PM PDT/MST FOR CLARK... ESMERALDA...NYE AND LINCOLN COUNTIES IN NEVADA...AND MOHAVE COUNTY ARIZONA... SOME LOCATIONS IN THE FLASH FLOOD WATCH INCLUDE....LAS VEGAS... HENDERSON...PAHRUMP...GOLDFIELD...TONOPAH...CALIENTE...KINGMAN... LAUGHLIN-BULLHEAD CITY...LAKE HAVASU CITY...THE WESTERN END OF THE GRAND CANYON...AND THE LAKE MEAD NATIONAL RECREATION AREA. SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND ARE EXPECTED TO BECOME WIDESPREAD IN MANY AREAS BY EVENING. SOME OF THE THUNDERSTORMS COULD PRODUCE HEAVY RAIN OF BETWEEN ONE AND TWO INCHES IN LESS THAN ONE HOUR. RAINFALL OF THIS INTENSITY WOULD CAUSE FLASH FLOODING OF WASHES...CANYONS...AND OTHER LOW-LYING OR URBANIZED AREAS. AREAS THAT HAVE RECEIVED RAIN OVER THE PAST FEW DAYS WILL BE ESPECIALLY PRONE TO FLASH FLOODING AS THE SOIL MAY BE SATURATED. A FLASH FLOOD WATCH MEANS THERE IS THE POTENTIAL FOR FLASH FLOODING IN AND CLOSE TO THE WATCH AREA. BE READY TO TAKE QUICK ACTION IF FLASH FLOODING IS OBSERVED OR A WARNING IS ISSUED FOR YOUR AREA. DO NOT BECOME A VICTIM BY ATTEMPTING TO DRIVE OR WADE THROUGH RUNNING WATER YOU COULD BECOME STRANDED OR THE FORCE OF THE CURRENT COULD SWEEP YOU OR YOUR VEHICLE AWAY. LISTEN FOR ADDITIONAL UPDATES OR POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. NEMETH
The office that day
Everything else NWS Las Vegas, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 4:14 PM MST | Flash Flood Warning | VEF | Mohave | 56 min |
| Sep 9, 4:14 PM MST | Severe Thunderstorm Warning | VEF | Mohave | 56 min |
| Sep 9, 1:49 PM MST | Severe Thunderstorm Warning | VEF | Clark | 61 min |
| Sep 9, 2:53 PM MST | Flash Flood Warning | VEF | Clark | 112 min |
| Sep 9, 3:13 PM MST | Severe Thunderstorm Warning | VEF | Clark | 52 min |
| Sep 9, 3:59 PM MST | Severe Thunderstorm Warning | VEF | Clark | 6 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 1998Severe Thunderstorm Warnings in Nevada, 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.