Alert archive / Utah / Flash Flood Warnings in 1998

Flash Flood Warning 33, NWS Salt Lake City, UT

July 29, 1998Box Elder County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 29, 1998, 3:08 PM MDT for Box Elder County, Utah. It was in force for 82 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jul 29, 1998, 3:08 PM MDT (21:08 UTC)
Expired
Jul 29, 1998, 4:30 PM MDT
In force
82 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Box Elder County, UT

The radar

The Salt Lake City radar (KMTX), 114 km from the middle of the area, began a volume at 21:10 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Elko, NV (KLKN), launched 12:00Z, 9.1 hours before the alert went out and 114 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, Elko, NV at 12:00Z on 1998-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Elko, NV at 12:00Z on 1998-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
2 J/kg
Mixed-layer CIN
-275 J/kg
Mixed-layer LCL
2521 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
16 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 KSLC 292109
FFWSLC
UTC003-292230-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
308 PM MDT WED JUL 29 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * FLASH FLOOD WARNING FOR...
     NORTHWESTERN BOX ELDER COUNTY IN UTAH
     INCLUDING PARK VALLEY

   * UNTIL 430 PM MDT

   * AT 304 PM MDT WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY
     RAIN FROM PARK VALLEY WEST TO NEVADA BORDER.  THE THUNDERSTORMS 
     PRODUCING THE HEAVY RAIN WERE STATIONARY OVER THE MOUNTAINS.

THUNDERSTORMS OVER THE RAFT RIVER AND GROUSE CREEK MOUNTAINS HAVE 
BEEN PRODUCING HEAVY RAIN OVER THE PAST HOUR.  RUNOFF FROM THESE 
STORMS WILL CAUSE FLASH FLOODING OF THE DRY WASHES AND SMALL STREAMS 
COMING OUT OF THE MOUNTAINS.  FLASH FLOODING COULD AFFECT PORTIONS 
OF STATE ROUTE 30 WEST OF PARK VALLEY.

REMEMBER...DO NOT CROSS THROUGH WATER FLOWING OVER ROADWAYS.  THE 
WATER MAY BE FLOWING FASTER AND DEEPER THAN YOU THINK.

TO REPORT FLASH FLOODING HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY.
STAY TUNED TO LOCAL TELEVISION...RADIO...CABLE TV...OR NOAA WEATHER
RADIO FOR UPDATES.

LAT...LON 4168 11401 4163 11311 4199 11295 4199 11403

The office that day

Everything else NWS Salt Lake City, UT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 1:56 PM MDTSevere Thunderstorm WarningSLCBox Elder34 min
Jul 29, 2:28 PM MDTSevere Thunderstorm WarningSLCBox Elder47 min
Jul 29, 3:29 PM MDTSevere Thunderstorm WarningSLCBox Elder46 min
Jul 29, 4:44 PM MDTSevere Thunderstorm WarningSLCBox Elder31 min
Jul 29, 5:20 PM MDTSevere Thunderstorm WarningSLCBox Elder40 min

Nearby

Flash Flood Warnings in Utah, 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; radar from the NEXRAD Level II archive.