Alert archive / Arizona / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 21, NWS Tucson, AZ

July 18, 1998Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 18, 1998, 1:44 AM MST for Pima County, Arizona. It was in force for 46 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 18, 1998, 1:44 AM MST (08:44 UTC)
Expired
Jul 18, 1998, 2:30 AM MST
In force
46 min
Issued by
NWS Tucson, AZ
Area
Whole counties

County Pima County, AZ

The radar

The Tucson radar (KEMX), 112 km from the middle of the area, began a volume at 08:47 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

Tuscon, AZ (KTUS), launched 00:00Z, 8.7 hours before the alert went out and 84 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, Tuscon, AZ at 00:00Z on 1998-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 979 joules per kilogram.LCLEL10008507005003002001001 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, Tuscon, AZ at 00:00Z on 1998-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
979 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
3214 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

122 
WUUS1 KTUS 180845 RRA
SVRTUS
AZC019-180930-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
144 AM MST SAT JUL 18 1998

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR WESTERN PIMA COUNTY IN SOUTHERN
ARIZONA UNTIL 230 AM MST

* AT 145 AM MST...DOPPLER RADAR INDICATED A SEVERE
THUNDERSTORM NEAR WHY AND ANOTHER SEVERE THUNDERSTORM OVER THE
ORGAN PIPE CACTUS NATIONAL MONUMENT MOVING SOUTHWEST AT 20 MPH.

VPH

The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 5:41 PM MSTSevere Thunderstorm WarningTWCPima49 min
Jul 17, 6:25 PM MSTSevere Thunderstorm WarningTWCPima60 min
Jul 17, 7:25 PM MSTSevere Thunderstorm WarningTWCPima45 min
Jul 17, 7:33 PM MSTSevere Thunderstorm WarningTWCGreenlee47 min
Jul 17, 8:09 PM MSTSevere Thunderstorm WarningTWCPima61 min
Jul 17, 8:17 PM MSTSevere Thunderstorm WarningTWCGraham48 min
Jul 17, 11:14 PM MSTSevere Thunderstorm WarningTWCPinal46 min
Jul 18, 12:15 AM MSTSevere Thunderstorm WarningTWCPima90 min
Jul 18, 1:37 PM MSTSevere Thunderstorm WarningTWCSanta Cruz48 min
Jul 18, 2:08 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz62 min
Jul 18, 2:44 PM MSTSevere Thunderstorm WarningTWCPima46 min
Jul 18, 3:25 PM MSTSevere Thunderstorm WarningTWCPima45 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1998Every severe thunderstorm 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.