Alert archive / Arizona / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 69, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 10, 2002, 6:45 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 60 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
- Sep 10, 2002, 6:45 PM MST (01:45 UTC)
- Expired
- Sep 10, 2002, 7:45 PM MST
- In force
- 60 min
- Issued by
- NWS Phoenix, AZ
- Area
- Counties, with a storm outline in the text
Counties Maricopa County, AZ, Pinal County, AZ
The radar
The Phoenix radar (KIWA), 29 km from the middle of the area, began a volume at 01:47 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 |
|---|---|---|---|
| Sep 10, 7:30 PM MST | Hail 1 | Stanfield, 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.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The nearest sounding before it
Phoenix, AZ (KPSR), launched 00:00Z, 1.8 hours before the alert went out and 34 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
- 1379 J/kg
- Mixed-layer CIN
- -35 J/kg
- Mixed-layer LCL
- 1734 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 40 m²/s²
- 0-3 km storm-relative helicity
- 157 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 4.4
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 Sep 10, 3:16 PM MST, 3 hours 29 minutes earlier.
Area forecast discussion, Sep 10, 3:16 PM MST, 3 hours 29 minutes before
AZZ020>028-CAZ030>033-110545- SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 315 PAM MST TUE SEP 10 2002 .SYNOPSIS... A LOW PRESSURE SYSTEM MOVING NORTHEAST FROM NORTHERN BAJA CALIFORNIA COMBINED WITH A MOIST UNSTABLE AIRMASS MEANS SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THIS EVENING...SOME WITH HEAVY RAIN...HAIL AND STRONG WIND. THE LOW PRESSURE SYSTEM IS EXPECTED TO CONTINUE MOVING NORTHEAST AWAY FROM ARIZONA WEDNESDAY WITH GRADUALLY DRIER AIR MOVING IN THE FROM THE WEST. EVEN DRIER AIR FROM THE NORTH IS EXPECTED TO MOVE IN BY FRIDAY AND THIS WEEKEND. WARMER WEATHER IS FORECAST THROUGH THE WEEKEND AS HIGH PRESSURE ALOFT WEST OF BAJA CALIFORNIA EXPANDS NORTHEAST. .DISCUSSION... PLENTY OF MOIST AND UNSTABLE AIR CONTINUES OVER SOUTHEAST CALIFORNIA ...SOUTHWEST AND SOUTH-CENTRAL ARIZONA. TO GO ALONG WITH THIS...A WEAK LOW PRESSURE SYSTEM FROM NORTHERN BAJA CALIFORNIA IS MOVING NORTH-NORTHEAST. DYNAMICS WITH THIS SYSTEM COMBINED WITH A MOIST AND UNSTABLE AIRMASS HAS RESULTED IN THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHEAST CALIFORNIA...SOUTHWEST AND SOUTH-CENTRAL ARIZONA THIS AFTERNOON WITH CONTINUED DEVELOPMENT EXPECTED THIS EVENING. THERE IS PLENTY OF THERMODYNAMIC ENERGY AVAILABLE WITH HEATING COMBINED WITH MOMENTUM ALOFT FOR MORE SEVERE THUNDERSTORMS THROUGH THIS EVENING. THE LOW PRESSURE SYSTEM WILL CONTINUE MOVING NORTHEAST AND AWAY FROM ARIZONA WEDNESDAY WITH GRADUALLY DRIER AIR MOVING IN FROM THE WEST. THIS WILL RESULT IN A DECREASING CHANCE OF SHOWERS AND THUNDERSTORMS FROM THE WEST ESPECIALLY FOR THE DESERT AREAS. EVEN DRIER AIR FROM THE NORTH IS EXPECTED TO MOVE IN BY FRIDAY AND THIS WEEKEND. WARMER WEATHER IS FORECAST THROUGH THIS WEEKEND AS HIGH PRESSURE ALOFT WEST OF BAJA CALIFORNIA EXPANDS NORTHEAST. TEMPERATURES ARE EXPECTED TO RISE ABOVE THE AVERAGE FOR MID SEPTEMBER BY LATE THIS WEEK AND THIS WEEKEND. .PSR...NONE. ELLIS
The office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 10, 5:00 PM MST | Severe Thunderstorm Warning | PSR | Pinal | 45 min |
| Sep 10, 6:05 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 40 min |
| Sep 10, 6:14 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 31 min |
| Sep 10, 7:29 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 46 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 2002Every severe thunderstorm warning in 2002
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.