Alert archive / Arizona / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 76, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Aug 27, 1999, 3:00 PM MST for Pima County, Pinal County, Arizona. It was in force for 45 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
- Aug 27, 1999, 3:00 PM MST (22:00 UTC)
- Expired
- Aug 27, 1999, 3:45 PM MST
- In force
- 45 min
- Issued by
- NWS Tucson, AZ
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Pima County, AZ, Pinal County, AZ
The nearest sounding before it
Tuscon, AZ (KTUS), launched 12:00Z, 10.0 hours before the alert went out and 73 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
- 672 J/kg
- Mixed-layer CIN
- -86 J/kg
- Mixed-layer LCL
- 1305 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- 30 m²/s²
- 0-3 km storm-relative helicity
- 38 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 Tucson, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 27, 2:15 PM MST, 45 minutes earlier.
Area forecast discussion, Aug 27, 2:15 PM MST, 45 minutes before
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Special weather statement, Aug 27, 12:45 PM MST, 2 hours 15 minutes before
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</html>Special weather statement, Aug 27, 12:45 PM MST, 2 hours 15 minutes before
AZZ019-029>035-280500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI AUG 27 1999...THIS PRODUCT IS NOT UPDATED
*CONDITIONAL* *CONDITIONAL*
COUNTY AREAL PROBABILITY RAIN GREATER THAN STORM
COVERAGE OF SEVERE 1.00 2.00 MOTION
COCHISE 55 10 65 30 W 10
GRAHAM 60 10 75 40 NW 10
GREENLEE 60 10 75 40 NW 10
TUCSON/ERN PIMA 60 20 80 40 W 10
TOHONO OODHAM 55 20 80 40 W 10
SOUTHEAST PINAL 55 20 80 40 W 10
WESTERN PIMA 40 20 80 40 W 10
SANTA CRUZ 60 20 80 40 W 10
SYNOPSIS...THE ATMOSPHERE IS EXTREMELY MOIST AND UNSTABLE THIS
AFTERNOON AND EVENING. HEAVY RAIN THE MAIN CONCERN WITH SEVERE
POSSIBLE. ACTIVITY WILL LINGER IN THE LOWER DESERTS WELL INTO
THE EVENING HOURS.
*****************************************************************
KEY...
AREAL COVERAGE - PERCENT OF COUNTY OR AREA THAT WILL EXPERIENCE
THUNDERSTORMS
PROB OF SEVERE - THE PROBABILITY THAT AN INDIVIDUAL STORM WILL
REACH SEVERE LEVELS (DAMAGING WIND AND/OR
LARGE HAIL)
RAIN GRTR THAN - THE PROBABILITY THAT AN INDIVIDUAL STORM WILL
PRODUCE RAIN EXCEEDING 1 INCH OR 2 INCHES IN
ANY LOCATION
STORM MOTION - GENERAL DIRECTION TO WHICH THE STORMS WILL
LIKELY MOVE AND SPEED IN MPH
NOTE...
VALID TIME IS FROM 12:45 PM TO 12 MIDNIGHT OF THE DAY OF ISSUANCE.
THIS PRODUCT IS NOT TO BE USED IN PLACE OF SEVERE THUNDERSTORM OR
FLASH FLOOD WARNINGS OR WATCHES. THIS PRODUCT IS ONLY USED FOR
OUTLOOK PURPOSES. CORRESPONDING GRAPHICS MAY BE FOUND ON THE NWS
TUCSON INTERNET PAGE AT
HTTP://WWW.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML
END/The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 26, 5:14 PM MST | Severe Thunderstorm Warning | TWC | Pima | 31 min |
| Aug 26, 7:21 PM MST | Severe Thunderstorm Warning | TWC | Pima, Santa Cruz | 49 min |
| Aug 26, 8:08 PM MST | Severe Thunderstorm Warning | TWC | Santa Cruz | 32 min |
| Aug 26, 8:49 PM MST | Flash Flood Warning | TWC | Pima | 101 min |
| Aug 27, 12:40 PM MST | Flash Flood Warning | TWC | Pima | 100 min |
| Aug 27, 1:11 PM MST | Severe Thunderstorm Warning | TWC | Pima | 44 min |
| Aug 27, 1:15 PM MST | Flash Flood Warning | TWC | Pima | 60 min |
| Aug 27, 1:55 PM MST | Severe Thunderstorm Warning | TWC | Pima | 65 min |
| Aug 27, 3:50 PM MST | Severe Thunderstorm Warning | TWC | Pinal | 45 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 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.