Alert archive / Utah / Flash Flood Warnings in 1997

Flash Flood Warning 56, NWS Salt Lake City, UT

September 15, 1997Washington County, Utah

NWS Salt Lake City, UT issued this flash flood warning at Sep 15, 1997, 12:11 AM MDT for Washington County, Utah. It was in force for 119 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
Sep 15, 1997, 12:11 AM MDT (06:11 UTC)
Expired
Sep 15, 1997, 2:10 AM MDT
In force
119 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties

County Washington County, UT

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 00:00Z, 6.2 hours before the alert went out and 234 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, Mercury/Desert R, NV at 00:00Z on 1997-09-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 9 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, Mercury/Desert R, NV at 00:00Z on 1997-09-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939587897Sfc1 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
9 J/kg
Mixed-layer CIN
-41 J/kg
Mixed-layer LCL
2945 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
74 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 150614
FFWSLC
UTC053-150810-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
1211 AM MDT MON SEP 15 1997

THE NATIONAL WEATHER SERVICE IN SALT LAKE CITY UT HAS ISSUED A
FLASH FLOOD WARNING EFFECTIVE UNTIL 210 AM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...

IN SOUTHWESTERN UTAH

   ...NORTHEASTERN WASHINGTON COUNTY
 
AT MIDNIGHT...RADAR ESTIMATED FROM .75 TO 1.5 INCHES OF RAIN
HAS FALLEN IN AN HOURS TIME OVER THE UPPER REACHES OF THE VIRGIN
RIVER AND OVER THE WESTERN PORTIONS OF ZION NATIONAL PARK.

THIS MUCH RAINFALL ON ALREADY SATURATED GROUND IS LIKELY TO CAUSE
FLASH FLOODING IN PORTIONS OF THE PARK AND SIGNIFICANT RISES ON
THE VIRGIN RIVER WITHIN THE NEXT 1-2 HOURS.
 
IF FLASH FLOODING IS OBSERVED...ACT QUICKLY.  MOVE UP TO ESCAPE
FLOOD WATERS.  DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER
BEGINS RISING.

FOLLOW THE INSTRUCTIONS OF LOCAL AUTHORITIES.  MANY LIVES HAVE BEEN
LOST BECAUSE PEOPLE HAVE NOT HEEDED THE WARNINGS OF POLICE OFFICERS
AND PARK RANGERS.

MOTORISTS SHOULD BE ESPECIALLY CAREFUL AT NIGHT AND AVOID DRIVING
INTO MOVING WATER OF UNKNOWN DEPTH...LOW WATER CROSSINGS AND FLOOD
PRONE AREAS.

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, Sep 14, 7:00 PM MDT, 5 hours 11 minutes before
IDZ024-025-UTZ001>027-WYZ021-151200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
700 PM MDT SUN SEP 14 1997

...COLD FRONT AND TROPICAL MOISTURE TO BRING ACTIVE WEATHER TONIGHT
AND MONDAY...

A COLD FRONT CONTINUES ON TRACK TO MOVE INTO UTAH MONDAY.  IN
ADDITION...TROPICAL MOISTURE IS SPREADING INTO THE STATE FROM THE
SOUTH AHEAD OF THE FRONT.  THIS COMBINATION WILL PRODUCE WIDESPREAD
SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY HEAVY RAINFALL.

SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING IN THE TROPICAL
AIRMASS AND WILL CONTINUE TO DEVELOP TONIGHT.  THIS MOIST AIRMASS HAS
SPREAD OVER SOUTHERN AND EASTERN UTAH AS OF SUNDAY EVENING AND WILL
OVERSPREAD THE ENTIRE STATE BY SUNRISE MONDAY.

LOCALLY HEAVY RAINS HAVE OCCURRED OVER PORTIONS OF SOUTHWEST UTAH AND
WILL ACCOMPANY THE MOIST AIRMASS AS IT SPREADS NORTHWARD INTO THE
STATE.  THESE RAINS MAY PRODUCE LOCAL FLOODING OF ROADS AND WASHES.

THERE IS THE POTENTIAL THAT HEAVY RAINS MAY BECOME WIDESPREAD DURING
THE DAY MONDAY AS THIS MOIST AIRMASS BEGINS TO INTERACT WITH THE COLD
FRONT.

STAY TUNED TO LOCAL RADIO...TV...CABLE TV OR NOAA WEATHER RADIO FOR
UPDATES ON THIS STORM.

PJW...0103Z
Special weather statement, Sep 14, 7:04 PM MDT, 5 hours 7 minutes before
IDZ024-025-UTZ001>027-WYZ021-151200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
700 PM MDT SUN SEP 14 1997

...COLD FRONT AND TROPICAL MOISTURE TO BRING ACTIVE WEATHER TONIGHT
AND MONDAY...

A COLD FRONT CONTINUES ON TRACK TO MOVE INTO UTAH MONDAY.  IN
ADDITION...TROPICAL MOISTURE IS SPREADING INTO THE STATE FROM THE
SOUTH AHEAD OF THE FRONT.  THIS COMBINATION WILL PRODUCE WIDESPREAD
SHOWERS AND THUNDERSTORMS ALONG WITH LOCALLY HEAVY RAINFALL.

SHOWERS AND THUNDERSTORMS HAVE BEEN DEVELOPING IN THE TROPICAL
AIRMASS AND WILL CONTINUE TO DEVELOP TONIGHT.  THIS MOIST AIRMASS HAS
SPREAD OVER SOUTHERN AND EASTERN UTAH AS OF SUNDAY EVENING AND WILL
OVERSPREAD THE ENTIRE STATE BY SUNRISE MONDAY.

LOCALLY HEAVY RAINS HAVE OCCURRED OVER PORTIONS OF SOUTHWEST UTAH AND
WILL ACCOMPANY THE MOIST AIRMASS AS IT SPREADS NORTHWARD INTO THE
STATE.  THESE RAINS MAY PRODUCE LOCAL FLOODING OF ROADS AND WASHES.

THERE IS THE POTENTIAL THAT HEAVY RAINS MAY BECOME WIDESPREAD DURING
THE DAY MONDAY AS THIS MOIST AIRMASS BEGINS TO INTERACT WITH THE COLD
FRONT.

STAY TUNED TO LOCAL RADIO...TV...CABLE TV OR NOAA WEATHER RADIO FOR
UPDATES ON THIS STORM.

PJW...0103Z

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 6:42 PM MDTFlash Flood WarningSLCIron, Kane, Washington113 min

Nearby

Flash Flood Warnings in Utah, 1997Every flash flood warning in 1997

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.