Alert archive / Arizona / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 694

August 17, 20004 counties in Arizona

The Storm Prediction Center issued this severe thunderstorm watch at Aug 17, 2000, 4:00 PM MST for 4 counties in Arizona. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Aug 17, 2000, 4:00 PM MST (23:00 UTC)
Expired: Aug 17, 2000, 10:00 PM MST
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Gila County, AZ, Maricopa County, AZ, Pima County, AZ, Pinal County, AZ

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Aug 17, 4:18 PM MST	Severe Thunderstorm Warning	TWC	Pima	42 min
Aug 17, 4:55 PM MST	Flash Flood Warning	TWC	Pima	5 min
Aug 17, 5:00 PM MST	Severe Thunderstorm Warning	TWC	Pima	45 min
Aug 17, 5:04 PM MST	Flash Flood Warning	TWC	Pima	26 min
Aug 17, 6:23 PM MST	Severe Thunderstorm Warning	FGZ	Gila	37 min
Aug 17, 6:33 PM MST	Flash Flood Warning	PSR	Maricopa	92 min
Aug 17, 6:41 PM MST	Flash Flood Warning	PSR	Gila	89 min
Aug 17, 7:00 PM MST	Flash Flood Warning	TWC	Pima, Pinal
Aug 17, 7:20 PM MST	Flash Flood Warning	TWC	Pima, Pinal
Aug 17, 7:29 PM MST	Flash Flood Warning	FGZ	Gila	61 min
Aug 17, 8:10 PM MST	Flash Flood Warning	TWC	Pima
Aug 17, 8:57 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	63 min

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 11.0 hours before the alert went out and 72 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 22 J/kg
Mixed-layer CIN: -358 J/kg
Mixed-layer LCL: 3161 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: -54 m²/s²
0-3 km storm-relative helicity: -37 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

529 
WWUS9 KMKC 172232
SEL4  

SEL4  
MKC WW 172226
AZZ000-180500-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 694
STORM PREDICTION CENTER NORMAN OK
326 PM MST THU AUG 17 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   CENTRAL AND SOUTHERN ARIZONA                            

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
1000 PM MST.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 60 STATUTE MILES
EITHER SIDE OF A LINE FROM 75 MILES WEST SOUTHWEST OF TUSCON
ARIZONA TO 80 MILES NORTHEAST OF PHOENIX ARIZONA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 692...WW 693...

DISCUSSION...STORMS ARE DEVELOPING TOWARD LOWER ELEVATIONS INTO
CENTRAL AZ WHERE AIRMASS HAS BECOMES MODERATELY UNSTABLE.  THIS
TREND EXPECTED TO CONTINUE WITH INCREASING WIND DAMAGE POTENTIAL AS
STORMS MOVE INTO DESERTS.


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550.  MEAN STORM
MOTION VECTOR 15020.


...HALES

320,1130 343,1120 335,1100 312,1111

Nearby

Severe Thunderstorm Watches in Arizona, 2000 Every severe thunderstorm watch in 2000

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.