Severe Thunderstorm Warning 91, NWS Phoenix, AZ

AZZ020>025-CAZ030>033-061130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST/PDT FRI SEP 5 1997

...MODERATE RISK FOR SEVERE THUNDERSTORMS OVER CENTRAL AND EASTERN
RIVERSIDE...NORTHWEST IMPERIAL...NORTHERN YUMA AND WESTERN LA PAZ
COUNTIES THIS AFTERNOON AND EVENING...

...SLIGHT RISK FOR SEVERE THUNDERSTORMS OVER MARICOPA AND NORTHWEST
PINAL COUNTIES TONIGHT...

A STRONG UPPER LEVEL DISTURBANCE WILL MOVE EAST ACROSS SOUTH-CENTRAL
CALIFORNIA THIS AFTERNOON AND EVENING.  THE AIRMASS OVER FAR
SOUTHEAST CALIFORNIA IS VERY MOIST AND UNSTABLE. THUNDERSTORMS...
SOME SEVERE WITH DAMAGING WINDS...HAIL...AND VERY HEAVY RAIN
RESULTING IN LOCALIZED FLOODING...CAN BE EXPECTED OVER PORTIONS OF
CENTRAL AND EASTERN RIVERSIDE AND NORTHWEST IMPERIAL COUNTIES IN
CALIFORNIA...AS WELL AS OVER PORTIONS OF NORTHERN YUMA AND WESTERN
LA PAZ COUNTIES IN ARIZONA...THIS AFTERNOON AND TONIGHT.  THE JOSHUA
TREE NATIONAL PARK AND THE SALTON SEA STATE RECREATIONAL AREA ARE
INCLUDED IN THE MODERATE RISK AREA.  INDIVIDUAL STORMS WILL MOVE TO
THE NORTHEAST AT 20 MPH.

THE ATMOSPHERE IS ALSO QUITE UNSTABLE OVER SOUTH-CENTRAL ARIZONA.  A
WEAK UPPER LEVEL DISTURBANCE OVER NORTHERN MEXICO WILL MOVE WEST
TOWARD SOUTHEAST ARIZONA THIS AFTERNOON.  SCATTERED THUNDERSTORMS
WILL DEVELOP OVER EAST-CENTRAL AND SOUTHEAST ARIZONA THIS AFTERNOON
AND REDEVELOP TOWARD THE WEST AND NORTHWEST.  OUTFLOW FROM THESE
STORMS WILL GENERATE BLOWING DUST THAT MAY MOVE OVER PORTIONS OF
MARICOPA AND NORTHERN PINAL COUNTIES LATE THIS AFTERNOON OR EVENING.
SCATTERED THUNDERSTORMS...SOME SEVERE...MAY AFFECT PORTIONS
OF THE GREATER PHOENIX METRO...AS WELL AS CASA GRANDE AND GILA BEND
...TONIGHT.  DAMAGING STRAIGHT LINE WINDS AND BRIEF HEAVY RAIN ARE
POSSIBLE WITH THE STRONGEST STORMS.  INDIVIDUAL STORMS WILL MOVE TO
THE NORTHWEST AT 10 MPH.

THUNDERSTORMS WILL ALSO AFFECT SOME LOCATIONS IN SOUTHERN GILA
COUNTY THIS AFTERNOON AND EVENING.  BRIEF HEAVY RAIN AND GUSTY WINDS
CAN BE EXPECTED WITH THE STRONGER STORMS...BUT STORMS ARE EXPECTED
TO STAY BELOW SEVERE LIMITS.

....................................................................

FOR THE PURPOSES OF THIS OUTLOOK...SEVERE WEATHER REFERS TO ANY OF
THE FOLLOWING...DAMAGING WINDS IN EXCESS OF 57 MPH...HAIL 3/4 INCH
IN DIAMETER OR LARGER...AND LOCALLY HEAVY RAINFALL WHICH RESULTS IN
RUNNING WASHES OR FLOODING.

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                              IN CALIFORNIA

MARICOPA            YUMA                IMPERIAL
NORTHWEST PINAL     LA PAZ              CENTRAL AND EASTERN RIVERSIDE
SOUTHERN GILA
....................................................................

GREEN