Alert archive / Arizona / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 8, NWS Tucson, AZ
NWS Tucson, AZ issued this severe thunderstorm warning at Jul 2, 1999, 4:47 PM MST for Pima County, Arizona. It was in force for 33 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
- Jul 2, 1999, 4:47 PM MST (23:47 UTC)
- Expired
- Jul 2, 1999, 5:20 PM MST
- In force
- 33 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 23:50 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 |
|---|---|---|---|
| Jul 2, 5:13 PM MST | Thunderstorm Wind 60 | Tuscon Ryan Fld Arpt, AZ |
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, 11.8 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
- 133 J/kg
- Mixed-layer CIN
- -308 J/kg
- Mixed-layer LCL
- 2719 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -70 m²/s²
- 0-3 km storm-relative helicity
- -14 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
996 WUUS1 KTUS 022346 RRA SVRTUS AZC019-030020- BULLETIN - EAS ACTIVATION REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE TUCSON AZ 447 PM MST FRI JUL 2 1999 THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... EASTERN PIMA COUNTY IN SOUTHERN ARIZONA * UNTIL 520 PM MST * AT 444 PM MST... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 11 MILES SOUTHWEST TUCSON OR 5 MILES SOUTHEAST OF RYAN FIELD... MOVING NORTH AT 10 MPH. A SEVERE THUNDERSTORM WILL AFFECT THE RYAN FIELD AREA AND HIGHWAY 86 SOUTHWEST OF TUCSON. SEVERE THUNDERSTORM WARNING FOR DAMAGING WIND UNTIL 520 PM MST. DRB
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 Jul 2, 2:20 PM MST, 2 hours 27 minutes earlier.
Area forecast discussion, Jul 2, 2:20 PM MST, 2 hours 27 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 220 PM MST FRI JUL 2 1999 SYNOPSIS...A WEAK DISTURBANCE MOVING NORTHEAST ACROSS THE AREA THIS EVENING WILL GENERATE SOME ISOLATED THUNDERSTORMS BEFORE IT MOVES OUT AFTER MIDNIGHT. SLIGHTLY DRIER AIR BEHIND THIS SYSTEM SHOULD KEEP ANY THUNDERSTORM COVERAGE LIMITED ON SATURDAY. HOWEVER...A HIGH PRESSURE SYSTEM WILL DEVELOP OVER THE FOUR-CORNERS ON THE FOURTH OF JULY AND LINGER INTO NEXT WEEK. SUCH A PATTERN WILL BE FAVORABLE FOR MORE WIDESPREAD MONSOON THUNDERSTORMS. DISCUSSION...SHORT-TERM SITUATION FINALLY STARTING TO SHAKE OUT. MESOSCALE VORTEX CENTER LIFTING NORTHEAST TOWARD THE CWA IS ENHANCING BOTH THE ELEVATED CELLS NE AND SW OF TUCSON. CAPE'S ARE NOT ALL THAT IMPRESSIVE (AROUND 600J/KG AT MOST), THE CELLS APPEAR TO BE SOMEWHAT ELEVATED, AND THE LOWEST LAYERS ARE RELATIVELY DRY. HOWEVER, ENOUGH POSITIVE VORTICITY ADVECTION AHEAD IS PRESENT TO KEEP THE SPOTTY STUFF GOING INTO THE EVENING. IT APPEARS THE EASTERLY WAVE OVER CHIHUAHUA PROVINCE IS GOING TO GET ABSORBED OR PICKED UP BY THE VORTEX SINCE THUNDERSTORMS ON THE SIERRA MADRE ARE MOVING MORE NORTHERLY TODAY. EXPECT A DOWN DAY SATURDAY WITH AS WE GET INTO WEAK NEGATIVE VORTICITY ADVECTION. MID LEVEL FLOW IS ALSO TURNING TO THE WEST AS FAR SOUTH AS 25N LATITUDE AT PRESENT. HOWEVER THE HIGH PRECIP WATERS GO NOWHERE AND 500MB TEMPS STAY ON THE COOLISH SIDE. STICKING WITH GOING ISOLATED WORDING IS THE SAFEST COURSE OF ACTION. SUNDAY AND ESPECIALLY MONDAY ARE LOOKING INTERESTING, OR BAD DEPENDING ON HOW MUCH TIME YOU'RE PLANNING TO BE OUTDOORS. NEW AVN CONFIRMED LAST NIGHT'S MRF BY SURGING HIGH THETA-E AIR INTO SE AZ AS 4-CORNER HIGH DEVELOPS. BY SUNDAY EVENING, EASTERLY FLOW IS SETUP FROM TOP TO BOTTOM. CANADIAN MODEL, AND TO A LESSER EXTENT THE AVN, EVEN TAKES THE STRONG TROPICAL WAVE IN THE GULF OF CAMPECHE AND SWINGS IT'S REMNANTS TOWARD SE AZ BY 12Z MON. EVEN IF THIS DOESN'T HAPPEN, IT STILL LOOKS LIKE THE LATTER HALF OF THE WEEKEND, AND VIRTUALLY ALL OF NEXT WEEK FOR THAT MATTER, WILL BE WET. WE'LL USE AREAL COVERAGE WORDING SINCE CONFIDENCE IS HIGH. PYTLAK .TWC...NONE.
In the hours before
Special weather statement, Jul 2, 12:45 PM MST, 4 hours 2 minutes before
PHXSPSTUS
TTAA00 KTUS DDHHMM
AZZ019-029>035-030500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 2 1999...THIS PRODUCT IS NOT UPDATED
*CONDITIONAL* *CONDITIONAL*
COUNTY AREAL PROBABILITY RAIN GREATER THAN STORM
COVERAGE OF SEVERE 1.00 2.00 MOTION
COCHISE 35 10 30 0 N 10
GRAHAM 20 0 0 0 N 10
GREENLEE 20 0 0 0 N 10
TUCSON/ERN PIMA 15 0 5 0 N 10
TOHONO OODHAM 10 0 0 0 N 10
SOUTHEAST PINAL 10 0 0 0 N 10
WESTERN PIMA 10 0 0 0 N 10
SANTA CRUZ 40 10 30 0 N 10
SYNOPSIS...WIDESPREAD CLOUD COVER THIS MORNING HAS REDUCED HEATING AND
THIS MAY LIMIT THUNDERSTORM DEVELOPMENT THIS AFTERNOON. A WEAK
DISTURBANCE IS MOVING NORTHEAST ACROSS PIMA COUNTY AND MAY TRIGGER
ISOLATED CONVECTION NORTHEAST OF IT. RAINFALL TOTALS ARE EXPECTED TO
BE ON THE LIGHT SIDE...BUT THE BEST CHANCE FOR RAINFALL ON THE
VALLEY FLOORS IS ALONG THE MEXICO BORDER.
*****************************************************************
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://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML
END/Special weather statement, Jul 2, 12:45 PM MST, 4 hours 2 minutes before
PHXSPSTUS
TTAA00 KTUS DDHHMM
AZZ019-029>035-030500-
SPECIAL WEATHER STATEMENT...SOUTHEAST ARIZONA CONVECTIVE OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1245 PM MST FRI JUL 2 1999...THIS PRODUCT IS NOT UPDATED
*CONDITIONAL* *CONDITIONAL*
COUNTY AREAL PROBABILITY RAIN GREATER THAN STORM
COVERAGE OF SEVERE 1.00 2.00 MOTION
COCHISE 35 10 30 0 N 10
GRAHAM 20 0 0 0 N 10
GREENLEE 20 0 0 0 N 10
TUCSON/ERN PIMA 15 0 5 0 N 10
TOHONO OODHAM 10 0 0 0 N 10
SOUTHEAST PINAL 10 0 0 0 N 10
WESTERN PIMA 10 0 0 0 N 10
SANTA CRUZ 40 10 30 0 N 10
SYNOPSIS...WIDESPREAD CLOUD COVER THIS MORNING HAS REDUCED HEATING AND
THIS MAY LIMIT THUNDERSTORM DEVELOPMENT THIS AFTERNOON. A WEAK
DISTURBANCE IS MOVING NORTHEAST ACROSS PIMA COUNTY AND MAY TRIGGER
ISOLATED CONVECTION NORTHEAST OF IT. RAINFALL TOTALS ARE EXPECTED TO
BE ON THE LIGHT SIDE...BUT THE BEST CHANCE FOR RAINFALL ON THE
VALLEY FLOORS IS ALONG THE MEXICO BORDER.
*****************************************************************
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://NIMBO.WRH.NOAA.GOV/TUCSON/SWO/SWO.SHTML
END/Special weather statement, Jul 2, 2:30 PM MST, 2 hours 17 minutes before
AZZ019-029>035-031000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST FRI JUL 2 1999 ...OUTLOOK FOR THE FOURTH OF JULY WEEKEND... THE START OF THE WEEKEND WILL FEATURE ISOLATED AFTERNOON AND EVENING THUNDERSTORMS...MOSTLY OVER THE MOUNTAINS SOUTH AND EAST OF TUCSON. TOWARD THE END OF THE WEEKEND...THE WIND PATTERN THROUGHOUT THE ATMOSPHERE WILL BECOME MORE FAVORABLE FOR WIDESPREAD MONSOON ACTIVITY IN SOUTHEAST ARIZONA. THUS THE CHANCE OF THUNDERSTORMS WILL INCREASE ON THE FOURTH OF JULY...WITH AN EVEN BETTER CHANCE ON MONDAY. TEMPERATURES WILL BE ON THE WARM SIDE WITH HIGHS RANGING FROM NEAR 80 IN THE MOUNTAINS TO 108 IN THE WESTERN DESERTS. LOWS WILL BE IN THE 50S IN THE MOUNTAINS TO LOWER 80S IN THE DESERTS. PEOPLE WITH OUTDOOR ACTIVITIES SHOULD KEEP A WATCH ON WEATHER CONDITIONS AND BRING ALONG A WEATHER RADIO. WITH THE START OF THE MONSOON COMES THE THREAT OF FLASH FLOODING AND SEVERE THUNDERSTORMS. PYTLAK
Special weather statement, Jul 2, 2:30 PM MST, 2 hours 17 minutes before
AZZ019-029>035-031000- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST FRI JUL 2 1999 ...OUTLOOK FOR THE FOURTH OF JULY WEEKEND... THE START OF THE WEEKEND WILL FEATURE ISOLATED AFTERNOON AND EVENING THUNDERSTORMS...MOSTLY OVER THE MOUNTAINS SOUTH AND EAST OF TUCSON. TOWARD THE END OF THE WEEKEND...THE WIND PATTERN THROUGHOUT THE ATMOSPHERE WILL BECOME MORE FAVORABLE FOR WIDESPREAD MONSOON ACTIVITY IN SOUTHEAST ARIZONA. THUS THE CHANCE OF THUNDERSTORMS WILL INCREASE ON THE FOURTH OF JULY...WITH AN EVEN BETTER CHANCE ON MONDAY. TEMPERATURES WILL BE ON THE WARM SIDE WITH HIGHS RANGING FROM NEAR 80 IN THE MOUNTAINS TO 108 IN THE WESTERN DESERTS. LOWS WILL BE IN THE 50S IN THE MOUNTAINS TO LOWER 80S IN THE DESERTS. PEOPLE WITH OUTDOOR ACTIVITIES SHOULD KEEP A WATCH ON WEATHER CONDITIONS AND BRING ALONG A WEATHER RADIO. WITH THE START OF THE MONSOON COMES THE THREAT OF FLASH FLOODING AND SEVERE THUNDERSTORMS. PYTLAK
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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.