Alert archive / Arizona / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 68, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Aug 13, 1998, 9:01 PM MST for Pinal County, Arizona. It was in force for 49 min. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Aug 13, 1998, 9:01 PM MST (04:01 UTC)
- Expired
- Aug 13, 1998, 9:50 PM MST
- In force
- 49 min
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties
County Pinal County, AZ
The radar
The Phoenix radar (KIWA), 52 km from the middle of the area, began a volume at 04:02 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 13, 9:51 PM MST | Thunderstorm Wind 52 | Maricopa, AZ | Near zero visibility with dense blowing dust. |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
The nearest sounding before it
Tuscon, AZ (KTUS), launched 00:00Z, 4.0 hours before the alert went out and 92 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
- 546 J/kg
- Mixed-layer CIN
- -22 J/kg
- Mixed-layer LCL
- 2417 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 127 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 3.1
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 Tucson, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 13, 2:30 PM MST, 6 hours 31 minutes earlier.
Area forecast discussion, Aug 13, 2:30 PM MST, 6 hours 31 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST THU AUG 13 1998 SYNOPSIS...HIGH PRESSURE ALOFT OVER THE WESTERN GREAT BASIN WILL DRIFT SLOWLY EAST DURING THE REMAINDER OF THIS WEEK. AN EAST TO NORTHEAST WIND FLOW AROUND THIS HIGH PRESSURE SYSTEM WILL ALLOW MONSOONAL MOISTURE AND THUNDERSTORMS TO PERSIST OVER SOUTHEAST ARIZONA INTO THE UPCOMING WEEKEND. DISCUSSION...THUNDERSTORM ACTIVITY BEGAN RATHER EARLY TODAY...BEFORE NOON. EXPECTED TO SEE MORE ACTIVITY OVER THE FAR EASTERN RIM AREA THAN SHOWING UP ON SATELLITE AT THIS TIME. WITH INVERTED V SOUNDING SEVERE WIND GUSTS POSSIBLE TONIGHT. SEE NO MECHANISM THROUGH 48 HOURS TO DECREASE MOISTURE ALREADY PRESENT. UPPER LEVEL HIGH PRESSURE REMAINS CENTERED NORTH OF TUCSON FOR EAST TO NORTHEAST STEERING FLOW. THIS IS FAVORABLE FOR STORMS MOVING OFF THE RIM COUNTRY AND INTO THE VALLEYS. TUS 534. .TWC...SEVERE THUNDERSTORM WATCH 3 PM TO 9 PM.
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 6:14 PM MST | Severe Thunderstorm Warning | TWC | Pima | 36 min |
| Aug 14, 12:15 AM MST | Flash Flood Warning | TWC | Pima | 2 hr |
| Aug 14, 4:00 PM MST | Severe Thunderstorm Warning | TWC | Pima, Pinal | 45 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.