Severe Thunderstorm Warning 77, NWS Phoenix, AZ

AZZ020>028-CAZ030>033-262245-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1020 AM MST SAT OCT 26 2002

.SYNOPSIS...
A RATHER STRONG UPPER LEVEL STORM SYSTEM WILL MOVE SLOWLY EAST
ACROSS ARIZONA THIS WEEKEND. BELOW NORMAL DAYTIME HIGHS ARE EXPECTED
TODAY...WITH EVEN COOLER DAYTIME HIGHS EXPECTED SUNDAY OVER SOUTH
CENTRAL ARIZONA. SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR
TODAY AND TONIGHT...ESPECIALLY OVER SOUTHWEST AND SOUTH-CENTRAL
ARIZONA. THE CHANCE FOR SHOWERS AND POSSIBLE THUNDERSTORMS WILL
CONTINUE THROUGH AT LEAST MIDDAY SUNDAY OVER THE LOWER DESERT OF
SOUTH CENTRAL ARIZONA...AND THROUGH LATE AFTERNOON OR EARLY EVENING
OVER THE HIGHER TERRAIN OF SOUTH CENTRAL ARIZONA. DRY CONDITIONS AND
NEAR NORMAL TEMPERATURES ARE EXPECTED NEXT WEEK AS HIGH PRESSURE
BUILDS OVER THE SOUTHWEST UNITED STATES.

.DISCUSSION...
SHOWERS AND A FEW THUNDERSTORMS OCCURRING THIS MORNING OVER SW AND
S-CNTRL AZ...INCLUDING THE GREATER PHOENIX METRO AREA. ACTIVE WX
AREA IS IN LEFT EXIT REGION OF A 100 KT 300 MB JET CENTERED OVER THE
NORTHERN GULF OF CALIFORNIA AS OF 16Z. THIS JET MAX IS PROGGED TO
PROPAGATE TOWARD THE ENE TODAY...AND BE OVER SW NEW MEXICO BY THIS
EVENING. 12Z PLOT DATA INDICATES COOLER MID-TROPOSPHERIC TEMPS TO
OUR WEST...WITH -21 C 500 MB TEMP AT SAN DIEGO WHILE TUCSON WAS -15
C. PRECIPITABLE WATER ON THE INCREASE THANKS TO DEEP-LAYER SOUTH
FLOW...WITH GOES TPW IMAGES INDICATING .75-.9 OVER MOST OF LOWER
DESERT AS OF 15Z ...AND ADDITIONAL MOISTENING WILL BE POSSIBLE TODAY
INTO THIS EVENING. GIVEN STRENGTH OF UPPER JET AND DESTABILIZING
TREND... POTENTIAL FOR SMALL HAIL AND STRONG GUSTY WINDS WILL EXIST
WITH STORMS TODAY...ESPECIALLY MIDDAY INTO EARLY THIS AFTERNOON.
TONIGHT...ANOTHER UPPER JET STREAK MOVES SOUTH ALONG THE CENTRAL
CALIFORNIA COASTLINE WHILE THE 500 MB LOW CENTER DRIFTS SLOWLY
ACROSS NORTHWEST AZ. ETA/AVN FORECAST MOIST LAYER TO DEEPEN WHILE
UVV INCREASES OVER SOUTH CENTRAL AZ TONIGHT AS SFC FRONT CURRENTLY
OVER FAR WESTERN AZ MOVES INTO THAT AREA. UPPER JET CONFIGURATION
NOT AS FAVORABLE FOR STORMS TONIGHT...BUT THREAT FOR SHOWERS AND
STORMS WILL CONTINUE OVER SOUTH CENTRAL AZ INTO EARLY SUNDAY THANKS
TO LOW-LEVEL CONVERGENCE...FURTHER DESTABILIZATION...AND MOISTURE
INCREASE. S-CNTRL AZ PORTION OF CWA SHOULD RECEIVE THE MOST RAIN
FROM THIS SYSTEM...WITH ONE QUARTER TO ONE HALF INCH AMOUNTS
POSSIBLE OVER THE SOUTH CENTRAL LOWER DESERT WHILE ONE HALF TO THREE
QUARTERS OF AN INCH AMOUNTS WILL BE POSSIBLE OVER PORTIONS OF THE
SOUTH CENTRAL AZ HIGHER TERRAIN. CURRENT ZONES IN DECENT SHAPE. NO
UPDATES.

.PSR...NONE.

AZZ022>024-027-028-270100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
1033 AM MST SAT OCT 26 2002

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH-CENTRAL ARIZONA

.DAY ONE...TODAY

ISOLATED THUNDERSTORMS...WITH SMALL HAIL...STRONG GUSTY WINDS...
BRIEF MODERATE RAIN...AND INTENSE CLOUD TO GROUND LIGHTNING...ARE
POSSIBLE OVER SOUTH CENTRAL ARIZONA...INCLUDING THE GREATER PHOENIX
METROPOLITAN AREA...GILA BEND...CASA GRANDE...AND GLOBE...TODAY.
INDIVIDUAL STORMS WILL MOVE TOWARD THE NORTHEAST AT 25 MPH.

.INSTRUCTIONS TO SPOTTERS...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.