Alert archive / Arizona / Flash Flood Warnings in 1998
Flash Flood Warning 8, NWS Las Vegas, NV
NWS Las Vegas, NV issued this flash flood warning at Jul 20, 1998, 3:45 AM MST for Mohave County, Arizona; San Bernardino County, California. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jul 20, 1998, 3:45 AM MST (10:45 UTC)
- Expired
- Jul 20, 1998, 6:00 AM MST
- In force
- 2 hr
- Issued by
- NWS Las Vegas, NV
- Area
- Whole counties
Counties Mohave County, AZ, San Bernardino County, CA
The nearest sounding before it
Mercury/Desert R, NV (KDRA), launched 00:00Z, 10.8 hours before the alert went out and 176 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 4616 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 91 m²/s²
- 0-3 km storm-relative helicity
- 118 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 flash flood 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 flash flood warning went out at Jul 20, 2:07 AM MST, 1 hour 38 minutes earlier.
Area forecast discussion, Jul 20, 2:07 AM MST, 1 hour 38 minutes before
MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 900 AM PDT MON JUL 20 1998 SYNOPSIS...THE UPPER LEVEL HIGH PRESSURE SYSTEM OVER SOUTHEAST UTAH WILL MOVE VERY LITTLE THROUGH TUESDAY. THIS WILL ALLOW FOR MONSOONAL MOISTURE TO FLOW NORTHWESTWARD ACROSS THE MOJAVE DESERT AND SOUTHERN GREAT BASIN CONTINUING THE CHANCE OF LATE DAY THUNDERSTORMS. DISCUSSION...UPPER RIDGE THAT HAS BEEN DOMINATE ACROSS THE AREA THE LAST FEW DAYS HAD SHIFTED EAST TOWARD THE FOUR CORNERS AREA. THIS HAS ALLOWED THE MOIST MONSOONAL FLOW TO SURGE NORTH INTO THE CWA. LOW LEVEL MOISTURE HAD INCREASED...WITH LOW LEVEL DEWPOINTS INTO THE 50S ACROSS THE NORTH AND 60S ACROSS THE SOUTH. MCS FROM LATE LAST NIGHT AND EARLY THIS MORNING HAD DECREASED WITH A LEFT OVER CIRCULATION CENTER APPARENT ACROSS SOUTHERN NEVADA. LOOKS LIKE THE 12Z ETA DID A BETTER JOB OF INITIALIZING THIS FEATURE. VORT WILL LIFT NORTH- NORTHWESTWARD THROUGH THE DAY TODAY AND HELP TO INITIATE FURTHER CONVECTION. BEST INSTABILITY WAS PROGGED ACROSS SOUTHERN PORTIONS OF THE CWA...WHERE LIFTED INDICES DROP TO -2. WILL BE MAKING SOME FIRST PERIOD ADJUSTMENTS TO ZONES BASED ON CURRENT SATELLITE AND RA^DAR TRENDS. LAS 343. MATUSIEWICZ
The office that day
Everything else NWS Las Vegas, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 19, 5:00 PM MST | Flash Flood Warning | VEF | Mohave | 110 min |
| Jul 19, 10:36 PM MST | Severe Thunderstorm Warning | VEF | Mohave | 59 min |
| Jul 19, 11:39 PM MST | Severe Thunderstorm Warning | VEF | Mohave | 81 min |
| Jul 20, 12:53 AM MST | Severe Thunderstorm Warning | VEF | Mohave | 57 min |
| Jul 20, 12:53 AM MST | Severe Thunderstorm Warning | VEF | San Bernardino | 57 min |
| Jul 20, 2:09 AM MST | Flash Flood Warning | VEF | San Bernardino | 111 min |
Nearby
Flash Flood Warnings in Arizona, 1998Flash Flood Warnings in California, 1998Every flash flood 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; the sounding from the Mesonet's radiosonde archive.