Alert archive / Arizona / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 5, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 6, 1999, 3:16 PM MST for Pinal County, Arizona. It was in force for 64 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 6, 1999, 3:16 PM MST (22:16 UTC)
- Expired
- Jul 6, 1999, 4:20 PM MST
- In force
- 64 min
- Issued by
- NWS Phoenix, AZ
- Area
- Whole counties
County Pinal County, AZ
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 6, 3:18 PM MST | Tornado F0 | Florence Jct, AZ | Numerous sightings from Florence and Florence Jct as considerable dust and debris was carried aloft. |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 6, 1:15 PM MST | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Phoenix, AZ (KPSR), launched 12:00Z, 10.3 hours before the alert went out and 82 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
- 236 J/kg
- Mixed-layer CIN
- -208 J/kg
- Mixed-layer LCL
- 2182 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- -41 m²/s²
- 0-3 km storm-relative helicity
- -2 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 Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 6, 2:50 PM MST, 26 minutes earlier.
Area forecast discussion, Jul 6, 2:50 PM MST, 26 minutes before
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 250 PM MST TUE JUL 6 1999 .SYNOPSIS... HIGH PRESSURE ALOFT WILL REMAIN OVER THE COLORADO AND 4 CORNERS AREA THROUGH THIS WEEK. THIS WILL KEEP A MOIST SOUTHEAST TO EASTERLY FLOW OVER THE REGION WHICH WILL SPREAD THE MOISTURE WESTWARD. AS A RESULT SKIES WILL REMAIN PARTLY CLOUDY OVER THE REGION WITH SCATTERED AFTERNOON AND EVENING THUNDERSTORMS IN SOUTH CENTRAL ARIZONA BECOMING ISOLATED IN SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. .DISCUSSION... MODELS KEEP UPPER HIGH OVER COLORADO / 4 CORNERS AREA FOR NEXT FEW DAYS. THIS KEEPS MOIST SOUTHEAST TO EAST FLOW OVER REGION. SATELLITE PHOTOS SHOW THAT MOISTURE HAS ALREADY SPREAD INTO SW AZ AND PORTIONS OF SE CA TODAY. IN ADDITION...A 4,000 FT. DEEP GULF SURGE OCCURRED INT0 YUMA TODAY. MODELS SHOW COUPLE VORMAXS OVER THE NORTHERN GULF WHICH MODELS TAKE A PIECE OF AND ROTATE INTO THE JOSHUA TREE AREA TONIGHT/WEDNESDAY WITH SOME PVA EXTENDING UP INTO SW/SOUTH CENTRAL AZ. THIS SHOULD HELP TO DEVELOP A THUNDERSTORMS TONIGHT OVER CENTRAL DESERTS AND POSSIBLY ISOLATED IN SW AZ/SE CA AREA. ALTHOUGH AIRMASS STILL NOT THAT UNSTABLE OVER THE WESTERN...BUT UNSTABLE OVER THE EAST PORTION OF CWA. SOME THUNDERSTORMS POSSIBLY SEVERE OVER SOUTHEAST AZ AND CENTRAL DESERTS UNTIL 03Z TONIGHT. OTHERWISE...SCATTERED AFTERNOON/ EVENING THUNDERSTORMS SOUTH CENTRAL AZ NEXT FEW DAYS AND ISOLATED IN WESTERN CWA ESPECIALLY WEDNESDAY/THURSDAY. THUNDERSTORMS OVER SOUTH CENTRAL AZ WILL BE PROPAGATING WESTWARD INTO THE CENTRAL DESERTS WITH THE EASTERLY FLOW ALOFT. 12Z PHX SOUNDING REMAINS AN INVERTED V FOR GUSTY WINDS WITH THE STORMS. MRF EXTENDED KEEP UPPER HIGH NORTH OF REGION FOR CONTINUED MOIST EASTERLY FLOW FOR LITTLE CHANGE IN CURRENT PATTERN. UK MODEL HOWEVER SHIFTS HIGH CENTER TO VICINITY LAS BY WEEKEND WHICH...IF IT OCCURS...WOULD BRING STORMS DOWN OFF RIM INTO CENTRAL DESERTS RATHER THAN FROM THE EAST. SEE SEL7 FOR SEVERE THUNDERSTORM WATCH BOX. DKS
The office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 6, 2:00 PM MST | Severe Thunderstorm Warning | PSR | Gila | 60 min |
| Jul 6, 3:10 PM MST | Severe Thunderstorm Warning | PSR | Pinal | 65 min |
| Jul 6, 3:21 PM MST | Tornado Warning | PSR | Pinal | 34 min |
| Jul 6, 4:09 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 91 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.