Alert archive / Arizona / Flash Flood Warnings in 1998

Flash Flood Warning 48, NWS Las Vegas, NV

September 11, 1998Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Sep 11, 1998, 3:43 PM MST for Mohave County, Arizona. It was in force for 4 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: Sep 11, 1998, 3:43 PM MST (22:43 UTC)
Expired: Sep 11, 1998, 7:40 PM MST
In force: 4 hr
Issued by: NWS Las Vegas, NV
Area: Whole counties

County Mohave County, AZ

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.7 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-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: 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 112244
FFWLAS
AZC015-120240-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
343 PM PDT (343 PM MST) FRI SEP 11 1998


*  FLASH FLOOD WARNING FOR
   NORTHERN AND CENTRAL MOHAVE COUNTY IN NORTHWESTERN ARIZONA

*  UNTIL 740 PM MST (740 PM PDT)

*  SOME LOCATIONS AFFECTED
   COLORADO CITY
   MEADVIEW
   LITTLEFIELD
   DOLON SPRINGS
   KINGMAN

*  AT 340 PM...SATELLITE AND RADAR INDICATED A RAPIDLY
   DEVELOPING AREA OF SHOWERS AND THUNDERSTORMS OVER
   NORTHWEST MOHAVE COUNTY. THESE STORMS WILL BE MOVING
   OVER AN AREA WHICH HAS HAD VERY HEAVY RAIN THE PAST FEW
   DAYS. THUS ANY ADDITIONAL RAIN WILL CREATE MORE FLASH
   FLOODING. IN ADDITION...A SPOTTER AT MEADVIEW REPORTED
   A QUARTER INCH OF RAIN IN TEN MINUTES WITH WASHES FLOWING
   RAPIDLY.

AREA RESIDENTS SHOULD MONITOR FLOOD CONDITIONS... AND BE PREPARED
TO MOVE TO HIGHER GROUND... SHOULD FLOOD WATERS THREATEN. IF FLASH
FLOODING IS OBSFERVED... ACT QUICKLY. MOVE TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

KOSIER

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 Sep 11, 1:55 PM MST, 1 hour 48 minutes earlier.

Area forecast discussion, Sep 11, 1:55 PM MST, 1 hour 48 minutes before

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
155 PM PDT FRI SEP 11 1998

SYNOPSIS...AN AREA OF LOW PRESSURE OVER WESTERN NEVADA WILL SLOWLY
MOVE SOUTHWARD INTO SOUTH CENTRAL CALIFORNIA TONIGHT. 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 TONIGHT FOR A CONTINUED THREAT OF SHOWERS AND
THUNDERSTORMS THROUGH SATURDAY.

DISCUSSION...VERY ACTIVE THIS AFTERNOON WITH NUMEROUS SEVERE AND
FLASH FLOODING REPORTS IN LAS VEGAS AREA. WATER VAPOR IMAGERY
INDICATING UPPER LOW SOUTH OF RENO WITH VERY DISTINCT DRY AREA
ROTATING AROUND INTO SOUTHERN NEVADA AND NORTHWEST ARIZONA. WILL
CONTINUE WITH SEVERE THUNDERSTORM WATCH UNTIL 6 PM AND FLASH FLOOD
WATCH UNTIL 9 PM. IN ADDITION TO COUNTIES ALREADY WILL ADD CLARK
COUNTY. DIDNT HAVE MUCH CHANCE TO LOOK AT NEW MODEL DATA BUT BASED
ON SATELLITE TRENDS WILL CONTINUE WORDING OF PREVIOUS FORECAST.
LAS +000. KOSIER

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 5:50 AM MST	Severe Thunderstorm Warning	VEF	Mohave	60 min
Sep 11, 11:42 AM MST	Flash Flood Warning	VEF	Mohave	2 hr
Sep 11, 2:30 PM MST	Severe Thunderstorm Warning	VEF	Mohave	105 min
Sep 11, 4:28 PM MST	Severe Thunderstorm Warning	VEF	Mohave	92 min

Nearby

Flash Flood Warnings in Arizona, 1998 Every 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.