Alert archive / Utah / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 65, NWS Salt Lake City, UT

September 16, 1999Garfield County, Utah

NWS Salt Lake City, UT issued this severe thunderstorm warning at Sep 16, 1999, 2:05 PM MDT for Garfield County, Utah. It was in force for 40 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 16, 1999, 2:05 PM MDT (20:05 UTC)
Expired
Sep 16, 1999, 2:45 PM MDT
In force
40 min
Issued by
NWS Salt Lake City, UT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Garfield County, UT

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.1 hours before the alert went out and 294 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, Flgstf/Belemont, AZ at 12:00Z on 1999-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 563 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 1999-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.19395878Sfc1 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
563 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
1072 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
24 m²/s²
0-3 km storm-relative helicity
67 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 16, 9:00 AM MDT, 5 hours 5 minutes earlier.

Area forecast discussion, Sep 16, 9:00 AM MDT, 5 hours 5 minutes before
UTAH AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH
900 AM MDT THU SEP 16 1999

SYNOPSIS...A WEAK WEATHER DISTURBANCE WILL MOVE ACROSS UTAH TODAY
PRODUCING SCATTERED THUNDERSTORMS MAINLY N SOUTHERN UTAH.

DISCUSSION...SHORTWAVE TROUGH WILL MOVE ACROSS SOUTHERN UTAH TODAY.
12Z RUC HAS 300 CENTER NEAR ILC AT 15Z AND SATELLITE SHOWING AREAS
OF CONVECTION CONTINUING AHEAD OF WAVE.  RUC PROGS WAVE INTO SERN
CWFA BY LATE DAY.  ANOTHER WEAK WAVE IS NOW NEAR 4 CORNERS BUT
LEAVING CWFA.  LAPSE RATES UNSTABLE IN THE NORTH TODAY WHICH COUPLED
WITH EXISTING MOISTURE JUSTIFIES KEEPING POPS IN FIRST PERIOD.

SLC 211 CDC 621  BURCH

.SLC...NONE.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 1:47 PM MDTFlash Flood WarningSLCGarfield, Iron88 min
Sep 16, 2:45 PM MDTSevere Thunderstorm WarningSLCGarfield30 min
Sep 16, 3:15 PM MDTSevere Thunderstorm WarningSLCGarfield30 min
Sep 16, 3:20 PM MDTFlash Flood WarningSLCIron55 min
Sep 16, 3:51 PM MDTSevere Thunderstorm WarningSLCKane39 min
Sep 16, 4:29 PM MDTSevere Thunderstorm WarningSLCKane21 min
Sep 16, 4:49 PM MDTSevere Thunderstorm WarningSLCKane41 min

Nearby

Severe Thunderstorm Warnings in Utah, 1999Every severe thunderstorm warning in 1999

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.