Alert archive / Utah / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 7, NWS Salt Lake City, UT
NWS Salt Lake City, UT issued this severe thunderstorm warning at May 23, 1999, 4:46 PM MDT for Davis County, Morgan County, Weber County, Utah. It was in force for 29 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
- May 23, 1999, 4:46 PM MDT (22:46 UTC)
- Expired
- May 23, 1999, 5:15 PM MDT
- In force
- 29 min
- Issued by
- NWS Salt Lake City, UT
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Davis County, UT, Morgan County, UT, Weber County, UT
The nearest sounding before it
Salt Lake City I, UT (KSLC), launched 12:00Z, 10.8 hours before the alert went out and 38 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2809 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- -14 m²/s²
- 0-3 km storm-relative helicity
- -26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
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 May 23, 3:30 PM MDT, 1 hour 16 minutes earlier.
Area forecast discussion, May 23, 3:30 PM MDT, 1 hour 16 minutes before
UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UTAH 330 PM MDT SUN MAY 23 1999 THUNDERSTORMS HAVE DEVELOPED ALONG BOTH EDGES OF THE MOISTURE BAND THAT IS WRAPPING AROUND THE TOP OF THE CLOSED LOW OVER SOUTHERN CA. SOME OF THESE ARE STRONG WITH HALF INCH HAIL AT SLC AND STRONGER LOOKING STORMS TO THE SOUTHWEST. ANOTHER SURGE OF MOISTURE MOVING ACROS EXTREME SOUTHEAST UT AND WILL REINFORCE THE MOISTURE OVER NORTHERN UT FOR LATER TONIGHT AND MON. MAIN DYNAMICS OVER THE NORTH BEING PROVIDED BY DEFORMATION AND LATER BY DIVERGENCE ALOFT AS A JET LEVEL SPEED MAXIMUM ROUNDS THE TOP OF THE LOW. HOWEVER ALSO LIKELY TO BE WEAK VORTICITY IMPULSES ROTATING AROUND THE LOW. SO VERY UNSETTLED OVER NORTHERN/CENTRAL UT FOR THE NEXT COUPLE OF DAYS UNTIL THE LOW GETS EAST OF THE AREA. THE BAND OF MOISTURE WILL CONTINUE TO WORK NORTH THROUGH THE EXTREME NORTHERN PORTIONS OF THE CWA BY LATE TONIGHT. THE EXTREME SOUTEHRN PORTION OF THE CWA WILL SEE A LITTLE LESS ACTIVITY BECAUSE OF LIMITED MOISTURE BUT WITH THE LOW TRACKING ACROSS THE EXTREME SOUTHERN PART OF UT THERE SHOULD BE ENOUGH MOISTURE AND INSTABILITY FOR AT LEAST SCATTERED DIURNAL CONVECTION. HIGH TEMPERATURES SHOULD BE A LITTLE COOLER WITH THE COOL PART OF THE LOW MOVING OVER THE SOUTH AND INCREASED CLOUD COVER HOLDING THINGS DOWN A BIT IN THE NORTH. IN THE EXTENDED THE SHORTWAVE MOVING PAST NORTH OF THE AREA WED LOOKS LIKE LESS THREAT EACH NEW MODEL RUN. HOWEVER IT STILL LOOKS LIKE A LOW LEVEL FEATURE TRIES TO PUSH INTO NORTHERN UT SOMETIME WED. SINCE THE MOISTURE NOW MOVING INTO THE AREA WONT BE ENTIRELY GONE BY THEN SCATTERED SHOWERS IN THE NORTH WED LOOKS GOOD WITH LESS ACTIVITY IN THE SOUTH. THEN A DRYING TREND THU/FRI WITH TEMPERATURES WARMING IN THE SOUTH FLOW AHEAD OF THE NEXT TROF. SLC 5554 CDC 3444 SANDERS .SLC...NONE.
The office that day
Everything else NWS Salt Lake City, UT issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 23, 2:43 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 32 min |
| May 23, 3:15 PM MDT | Severe Thunderstorm Warning | SLC | Tooele | 30 min |
| May 23, 4:15 PM MDT | Severe Thunderstorm Warning | SLC | Davis | 30 min |
| May 23, 5:13 PM MDT | Severe Thunderstorm Warning | SLC | Davis, Morgan, Weber | 32 min |
| May 23, 5:49 PM MDT | Severe Thunderstorm Warning | SLC | Box Elder, Weber | 26 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.