Alert archive / Arizona / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 7, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at May 20, 1997, 12:12 PM MST for Pima County, Arizona. It was in force for 48 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
- May 20, 1997, 12:12 PM MST (19:12 UTC)
- Expired
- May 20, 1997, 1:00 PM MST
- In force
- 48 min
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties
County Pima County, AZ
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| May 20, 12:59 PM MST | Thunderstorm Wind 55 | Davis Monthan Afb, AZ | Winds gusted to 55kts. |
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 12:00Z, 7.2 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.
- Mixed-layer CAPE
- 24 J/kg
- Mixed-layer CIN
- -156 J/kg
- Mixed-layer LCL
- 1784 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -4 m²/s²
- 0-3 km storm-relative helicity
- -7 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
232 WUUS1 KTUS 201914 RRA SVRTUS AZC019-202000- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 1212 PM MST TUE MAY 20 1997 THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 100 PM MST FOR PEOPLE IN THE FOLLOWING LOCATION... IN SOUTHERN ARIZONA ...EAST CENTRAL PIMA COUNTY AT 1211 PM MST...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 21 MILES WEST OF NORTHWEST TUCSON OR 9 MILES EAST SOUTHEAST OF SILVER BELL MOVING NORTH NORTHEAST AT 10 MPH.
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 May 20, 9:03 AM MST, 3 hours 9 minutes earlier.
Area forecast discussion, May 20, 9:03 AM MST, 3 hours 9 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 900 AM MST TUE MAY 20 1997 A TROUGH REMAINS OVER THE EXTREME SOUTHWEST UNITED STATES FROM THE LOW- TO UPPER LEVELS. THE H5 TROUGH AXIS EXTENDS FROM SOUTHERN CALIFORNIA SOUTHWARD ALONG THE SPINE OF BAJA CALIFORNIA. AS A RESULT A SOUTHERLY FLOW OF MOIST AIR FROM THE SUBTROPICS CONTINUES TO STREAM ACROSS SOUTHEAST ARIZONA WITH ISOLATED SHOWERS AND THUNDERSTORMS OCCASIONALLY DEVELOPING ACROSS THE AREA. THE PATTERN IS ESSENTIALLY THE SAME AS YESTERDAY. THE 12Z SOUNDING SHOWS A MID-LEVEL UNSTABLE LAYER AND THIS COUPLED WITH THE PASSAGE OF A WEAK DISTURBANCE ALOFT GENERATED THE SHOWERS THIS MORNING. CONDITIONS WILL REMAIN MOIST AND UNSTABLE TODAY ESPECIALLY IN THE EASTERN ZONES WHERE DEEP MOISTURE WILL CONTINUE TO STREAM ACROSS THE AREA. THE MOST LIKELY AREA OF FOCUS WILL BE THE SOUTHWEST HALF OF COCHISE COUNTY AND SOUTHWEST GRAHAM COUNTY AS CONVECTIVE ACTIVITY FROM THIS MORNING LIKELY LEFT AN OUTFLOW BOUNDARY ACROSS THESE COUNTIES. WITH MOIST SOUTHERLY FLOW FROM MEXICO MOVING ACROSS COCHISE AND GRAHAM COUNTIES EXPECT TO SEE MORE SHOWERS ESPECIALLY ALONG THE LOW LEVEL OUTFLOW BOUNDAY AND JUST TO THE NORTH OF THE BOUNDRY OVER THE COLD DOME. NOT AS UNSTABLE AS YESTERDAY SO PROBABLY ONLY SEE SMALL HAIL BUT LOCALIZED FLASH FLOODING WILL BE POSSIBLE. TUS 334. MCCOLLUM TUS...NONE
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 12:19 PM MST | Severe Thunderstorm Warning | TWC | Pima | 46 min |
| May 20, 1:03 PM MST | Severe Thunderstorm Warning | TWC | Pima | 62 min |
| May 20, 2:49 PM MST | Severe Thunderstorm Warning | TWC | Pima | 61 min |
| May 20, 3:16 PM MST | Severe Thunderstorm Warning | TWC | Cochise | 64 min |
| May 20, 4:12 PM MST | Severe Thunderstorm Warning | TWC | Cochise | 48 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 1997Every severe thunderstorm 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.