Alert archive / Utah / Flash Flood Warnings in 1998

Flash Flood Warning 9, NWS Salt Lake City, UT

July 23, 1998San Juan County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Jul 23, 1998, 7:37 PM MDT for San Juan County, Utah. It was in force for 68 min. 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 23, 1998, 7:37 PM MDT (01:37 UTC)
Expired
Jul 23, 1998, 8:45 PM MDT
In force
68 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County San Juan County, UT

The radar

The Grand Junction radar (KGJX), 212 km from the middle of the area, began a volume at 01:39 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

Grand Junction, CO (KGJT), launched 00:00Z, 1.6 hours before the alert went out and 202 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, Grand Junction, CO at 00:00Z on 1998-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 00:00Z on 1998-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
4 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
2692 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
-25 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 240145
FFWSLC
UTC037-240245-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
737 PM MDT THU JUL 23 1998

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY HAS ISSUED A

   * FLASH FLOOD WARNING FOR...
     CENTRAL SAN JUAN COUNTY IN UTAH

   * UNTIL 845 PM MDT

   * AT 735 PM MDT RANGERS AT NATURAL BRIDGES NATIONAL MONUMENT 
     REPORTED A FLASH FLOOD OCCURING AT THE MONUMENT  

THE RAIN HAD ENDED AT THE MONUMENT AT 735 PM BUT EXCESSIVE RUNOFF 
FROM THE STORM WILL KEEP THE WASHES RUNNING FULL FOR ABOUT ANOTHER 
HOUR.  

HEAVY RAINS TO THE SOUTH OF THIS AREA MAY ALSO CAUSE ADDITIONAL 
FLASH FLOODING OVER THE NEXT HOUR OR SO. 

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY.
MOVE TO HIGHER GROUND.

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

LAT...LON 3745 11025 3726 10993 3759 10960 3777 11005

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.

In the hours before

Special weather statement, Jul 23, 3:00 PM MDT, 4 hours 37 minutes before
UTZ001>004-240830-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
300 PM MDT THU JUL 23 1998

         ...A WET 24TH LIKELY...

TROPICAL MOISTURE ENCOMPASSES THE BEEHIVE STATE THIS AFTERNOON AND
WILL REMAIN THROUGH THE 24TH.  THE MAJORITY OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL BE IN THE NORTH ON FRIDAY.

AN IMPULSE IN EASTERN NEVADA WILL ROTATE IN NORTHERN UTAH TONIGHT AND
FRIDAY THAT WILL TEND TO ENHANCE THE SHOWER ACTIVITY.

CLOUDY SKIES AND THE POSSIBILITY OF SHOWERS IS ON TAP FOR THE 24TH
PARADES IN BOTH SALT LAKE AND OGDEN.  TEMPERATURES WILL BE IN THE 70S
AT THE START OF THE PARADES AND BY NOON NEAR 80.

SHOWERS AND THUNDERSTORMS WILL PREVAIL INTO THE^ AFTERNOON AND
EVENING.  THIS COULD BE A CONCERN FOR THE SCHEDULED FIREWORKS
DISPLAYS.

THOSE OUTSIDE CELEBRATING THE 24TH SHOULD BE ALERT LIGHTNING.
LIGHTNING IS A PROVEN KILLER.

WJA...2100Z
Special weather statement, Jul 23, 3:00 PM MDT, 4 hours 37 minutes before
UTZ001>004-240830-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
300 PM MDT THU JUL 23 1998

         ...A WET 24TH LIKELY...

TROPICAL MOISTURE ENCOMPASSES THE BEEHIVE STATE THIS AFTERNOON AND
WILL REMAIN THROUGH THE 24TH.  THE MAJORITY OF THE SHOWER AND
THUNDERSTORM ACTIVITY WILL BE IN THE NORTH ON FRIDAY.

AN IMPULSE IN EASTERN NEVADA WILL ROTATE IN NORTHERN UTAH TONIGHT AND
FRIDAY THAT WILL TEND TO ENHANCE THE SHOWER ACTIVITY.

CLOUDY SKIES AND THE POSSIBILITY OF SHOWERS IS ON TAP FOR THE 24TH
PARADES IN BOTH SALT LAKE AND OGDEN.  TEMPERATURES WILL BE IN THE 70S
AT THE START OF THE PARADES AND BY NOON NEAR 80.

SHOWERS AND THUNDERSTORMS WILL PREVAIL INTO THE^ AFTERNOON AND
EVENING.  THIS COULD BE A CONCERN FOR THE SCHEDULED FIREWORKS
DISPLAYS.

THOSE OUTSIDE CELEBRATING THE 24TH SHOULD BE ALERT LIGHTNING.
LIGHTNING IS A PROVEN KILLER.

WJA...2100Z

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 4:56 PM MDTFlash Flood WarningSLCSanpete2 hr

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.