Severe Thunderstorm Warning 16, NWS Phoenix, AZ

AZZ020>028-CAZ030>033-300545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
300 PM MST THU JUN 29 2000

.SYNOPSIS...
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA WILL BE UNDER A RELATIVELY
LOW PRESSURE AREA ALOFT FOR THE NEXT FEW DAYS...BETWEEN HIGH PRESSURE
CENTERS OVER NORTHERN MEXICO AND NORTHWEST ARIZONA. THIS RESULTS IN A
NORTHEAST WIND ABOVE SOUTHWEST ARIZONA...ALLOWING STORMS TO MOVE OVER
THAT AREA FROM THE HIGH TERRAIN OF NORTHERN ARIZONA...AND A SOUTHWEST
WIND ABOVE SOUTHEAST CALIFORNIA...WITH ISOLATED STORMS OVER THE HIGH
TERRAIN THERE FAILING TO REACH THE DESERTS. MOST STORMS ARE EXPECTED
TO OCCUR DURING THE AFTERNOONS AND EVENINGS.

.DISCUSSION...
SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR ALL THE AZ PORTION OF THE
PHX CWA UNTIL 8PM THIS EVENING. STORMS ARE EXPECTED TO PROPAGATE SWWD
OFF THE HIGHER TERRAIN TO THE N AND NE OF CWA. THIS LOOKS REASONABLE
...BUT CHANCES DECREASE GREATLY GOING W. THEREFORE...USING SCATTERED
TERMINOLOGY FOR ERN PARTS...DWINDLING TO SLIGHT CHANCE BY THE TIME
YOU GET TO THE COLORADO RIVER. AIRMASS VERY UNSTABLE AND MOISTURE IS
CERTAINLY NOT LACKING...WITH DEWPOINTS ON THE DESERTS IN THE 60S AND
IN 50S IN THE MOUNTAINS. REGION REMAINS IN RELATIVE LOW PRESSURE AREA
ALOFT BETWEEN HIGH CELLS OVER NW AZ AND NRN MEX. FLOW MOSTLY NELY
ACROSS AZ PORTION OF CWA...BECOMING LIGHT AND VARIABLE FAR W TO SWLY
OVER SERN CA. NELY STEERING WIND EXPECTED TO BRING STORMS OFF HIGHER
TERRAIN OF NRN AZ TO S-CNTRL AND SW DESERTS THIS EVE. P-WATER REMAINS
OVER AN INCH AND A HALF OVER MUCH OF THE AREA. UPPER-LEVEL DIFLUENCE
IN COL OVER THE AREA TO AID IN ALLOWIING GOOD VERTICAL STRUCTURE TO
STORMS MOVING OVER AREA. EXTENDED PERIOD CALLS FOR SOME DRYING IN THE
WRN PORTIONS OF THE CWA AS TROUGH PUSHES IN A BIT...BUT ERN PORTIONS
MAY BE IN FOR TROUBLE AS TROUGH PROVIDES ADDITIONAL DYNAMICS TO ACT
ON AN ALREADY IN PLA~CE MOISTURE FIELD. DO NOT BELIEVE TROUGH WILL BE
STRONG ENOUGH TO PUSH FAR ENOUGH EWD TO DRY OUT THE ERN PORTIONS OF
THE CWA.  WILT

AZZ022>024-027-028-300030-

SPECIAL WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE PHOENIX AZ
1028 AM MST THU JUN 29 2000

...THERE IS A POSSIBILITY OF HAZARDOUS WEATHER IN MARICOPA COUNTY...
SOUTHERN GILA COUNTY AND NORTHWEST PINAL COUNTY LATE THIS AFTERNOON
INTO THIS EVENING...

THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN OF
NORTHERN AND CENTRAL ARIZONA THIS AFTERNOON. SOME OF THE STORMS ARE
EXPECTED TO MOVE OFF THE HIGH TERRAIN AND TOWARD THE SOUTHWEST TO
THE LOWER DESERT OF SOUTH-CENTRAL ARIZONA THIS EVENING.

STORMS OVER THE HIGH TERRAIN OF SOUTHERN GILA COUNTY...FAR NORTHEAST
MARICOPA COUNTY AND FAR NORTHERN PINAL COUNTY ARE EXPECTED TO BRING
PRIMARILY LOCALLY HEAVY RAIN...WITH SOME HAIL AND GUSTY WIND EVENTS
ALSO POSSIBLE...BY LATE THIS AFTERNOON. STORMS MOVING OFF THE HIGHER
TERRAIN TO THE LOWER DESERTS BY THIS EVENING WILL PRODUCE LOCALLY
HEAVY RAIN AND STRONG WIND...WITH HAIL A SLIGHT POSSIBILITY.

STORM SPOTTER ACTIVATION MAY BE NECESSARY LATER TODAY.

WILT

AZZ020>028-292345-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
301 PM MST THU JUN 29 2000

...SEVERE THUNDERSTORM WATCH NUMBER 514 IS IN EFFECT UNTIL 800 PM MST
FOR SOUTH CENTRAL AND SOUTHWEST ARIZONA...

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR SOUTHWEST AND SOUTH CENTRAL ARIZONA...VALID UNTIL 800 PM MST
TONIGHT. THE SEVERE THUNDERSTORM WATCH INCLUDES LA PAZ...MARICOPA...
GILA...PINAL AND YUMA COUNTIES.  CITIES IN THE SEVERE WEATHER
WATCH INCLUDE THE GREATER PHOENIX AREA...GLOBE...SUPERIOR...
FLORENCE...CASA GRANDE...GILA BEND...YUMA...EHRENBERG...PARKER AND
QUARTZSITE.

THIS AFTERNOON...SCATTERED STRONG THUNDERSTORMS SHOULD DEVELOP OVER
SOUTHERN GILA AND NORTHEAST MARICOPA COUNTY.   SOME OF THESE
THUNDERSTORMS COULD BECOME SEVERE...WITH DAMAGING HIGH WINDS...LARGE
HAIL AND HEAVY RAINFALL...AS THEY MOVE SLOWLY TO THE SOUTHWEST.
LATER THIS AFTERNOON...MORE THUNDERSTORMS SHOULD DEVELOP WEST AND
SOUTHWEST OF PHOENIX BETWEEN GILA BEND AND YUMA...AS WELL AS THE
AREA FROM WICKENBURG WEST TO PARKER.

AS STRONG THUNDERSTORMS APPROACH...GO INDOORS.  DO NOT DRIVE IN
FLOODED ROADS.

DNR