Alert archive / Arizona / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 10, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at May 20, 1997, 2:49 PM MST for Pima County, Arizona. It was in force for 61 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 20, 1997, 2:49 PM MST (21:49 UTC)
- Expired
- May 20, 1997, 3:50 PM MST
- In force
- 61 min
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties
County Pima County, AZ
The nearest sounding before it
Tuscon, AZ (KTUS), launched 12:00Z, 9.8 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.
183 WUUS1 KTUS 202151 RRA SVRTUS AZC019-202250- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 249 PM MST TUE MAY 20 1997 THE NATIONAL WEATHER SERVICE IN TUCSON AZ HAS ISSUED A SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 350 PM MST FOR PEOPLE IN THE FOLLOWING LOCATION... IN SOUTHERN ARIZONA ...EASTERN PIMA COUNTY A LINE OF SEVERE THUNDERSTORMS WAS LOCATED 10 MILE SOUTH OF TUCSON NEAR SAHUARITA. MOVEMENT WAS TO THE NORTH AT 15 MPH. THESE STORMS MAY PRODUCE VERY HEAVY RAINFALL...WIND GUSTS TO 60 MPH...HAIL AND DANGEROUS LIGHTNING.
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, 2:11 PM MST, 38 minutes earlier.
Area forecast discussion, May 20, 2:11 PM MST, 38 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 200 PM 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 SCATTERED SHOWERS AND THUNDERSTORMS LOCATED ACROSS THE SOUTHEAST ARIZONA. THE 12Z ETA AND AVN ARE INDICATING A VERY SLOW CHANGE TO THIS CURRENT PATTERN. THE NGM IS DRYING THE AIR MASS OUT MUCH TOO QUICKLY FOR SUCH A WEAK FLOW PATTERN. THINK MOIST MID-LEVEL AIR WILL CONTINUE TO MOVE ACROSS SOUTHEAST ARIZONA THROUGH TOMORROW AND THIS COUPLED WITH THE PASSAGE OF WEAK DISTURBANCES ALOFT WILL GENERATE PERIODS OF SHOWERS. THE NEXT SHORT WAVE WILL PASS ACROSS SOUTHEAST ARIZONA BY LATE TONIGHT. THE WIDESPREAD CONVECTIVE ACTIVITY TODAY HAS PRODUCED A LOW-LEVEL BOUNDARY ACROSS SANTA CRUZ AND EASTERN PIMA AND SOUTHWEST COCHISE COUNTIES. MOIST SOUTHERLY FLOW...MOVING INTO AZ FROM MEXICO...FLOWING ABOVE THIS BOUNDARY OF COOL AIR WILL FIRE CONVECTION INTO THIS EVENING. SOMEWHAT DRYER AND WARMER AIR AS WELL AS WEAKENING FLOW ASSOCIATED WITH SHORTWAVE PASSAGE LATE TONIGHT WILL BRING CONVECTION TO AN END FROM SOUTHWEST TO NORTHEAST. WITH ALL THE CONVECTIVE ACTIVITY TEMPERATURES AND WINDS WILL BE A GUESSING GAME FOR THE NEXT TWO DAYS. TUS 44^42. 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, 12:12 PM MST | Severe Thunderstorm Warning | TWC | Pima | 48 min |
| 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, 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; the sounding from the Mesonet's radiosonde archive.