Alert archive / Utah / Flash Flood Warnings in 1998

Flash Flood Warning 34, NWS Salt Lake City, UT

July 29, 1998Sanpete County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 29, 1998, 7:00 PM MDT for Sanpete County, Utah. It was in force for 75 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, 7:00 PM MDT (01:00 UTC)
Expired
Jul 29, 1998, 8:15 PM MDT
In force
75 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Sanpete County, UT

The radar

The Salt Lake City radar (KMTX), 216 km from the middle of the area, began a volume at 01:01 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

Salt Lake City I, UT (KSLC), launched 00:00Z, 1.0 hours before the alert went out and 151 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, Salt Lake City I, UT at 00:00Z on 1998-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 621 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, Salt Lake City I, UT at 00:00Z on 1998-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.193958Sfc1 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
621 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
2346 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
-8 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 300100
FFWSLC
UTC039-300215-

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

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * FLASH FLOOD WARNING FOR...
     CENTRAL SANPETE COUNTY IN UTAH

   * UNTIL 815 PM MDT

   * AT 650 MDT WEATHER SERVICE DOPPLER RADAR INDICATED MODERATE TO  
     HEAVY RAIN OVER SAN PETE COUNTY.

MODERATE TO HEAVY RAIN WILL MOVE UP CANAL CANYON SOUTHEAST OF SPRING 
CITY.  THIS CANYON IS PRONE TO FLASH FLOODING FROM EVEN MODEST 
AMOUNTS OF RAIN DUE TO RECENT FLOODING AND NUMEROUS DEBRIS DAMS IN 
THE CANYON.  

PEOPLES IN SPRING CITY AND SOUTHEAST TOWARDS THE CANYON SHOULD 
PREPARE FOR THE POSSIBILITY OF FLASH FLOODING AFTER 715 PM. 

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 3938 11165 3935 11138 3960 11132 3956 11156

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 6:02 PM MDTSevere Thunderstorm WarningSLCBox Elder43 min
Jul 29, 7:33 PM MDTSevere Thunderstorm WarningSLCDavis, Salt Lake42 min
Jul 29, 8:06 PM MDTSevere Thunderstorm WarningSLCDavis, Morgan, Salt Lake39 min
Jul 30, 4:10 PM MDTSevere Thunderstorm WarningSLCDuchesne, Summit, Wasatch50 min
Jul 30, 4:22 PM MDTSevere Thunderstorm WarningSLCBeaver, Iron53 min
Jul 30, 4:32 PM MDTSevere Thunderstorm WarningSLCEmery43 min
Jul 30, 5:38 PM MDTSevere Thunderstorm WarningSLCDavis, Weber52 min
Jul 30, 5:59 PM MDTSevere Thunderstorm WarningSLCWeber31 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.