Severe Thunderstorm Warning 110, NWS Phoenix, AZ

AZZ020>028-CAZ030>033-150545-

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 PM MST SUN AUG 14 2005

SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION

.SYNOPSIS...
A COUPLE OF LOW PRESSURE SYSTEMS MOVING INTO REGION WILL RESULT IN A
CHANCE FOR SHOWERS AND THUNDERSTORMS OVERNIGHT AND MONDAY ACROSS
SOUTH CENTRAL ARIZONA...AND PORTIONS OF SOUTHWEST ARIZONA. A SLIGHT
CHANCE OF MOUNTAIN SHOWERS AND THUNDERSTORMS IS ALSO POSSIBLE IN
SOUTHEAST CALIFORNIA. A DRIER AND MORE STABLE AIRMASS WILL MOVE INTO
THE REGION TUESDAY THROUGH SATURDAY...PRODUCING MOSTLY SUNNY AND
WARMER WEATHER. HOWEVER A SLIGHT CHANCE FOR AFTERNOON THUNDERSTORMS
WILL CONTINUE OVER THE MOUNTAINS OF SOUTH CENTRAL ARIZONA.

&&

.DISCUSSION...
THE FLOW ALOFT IS BECOMING EVEN MORE DYNAMICAL TODAY AS A COUPLE OF
SHORTWAVE FEATURES APPROACH THE AREA. THE FORMER UPPER LEVEL CENTRAL
BAJA CA CUTOFF LOW WAS MOVING INTO SOUTHEAST AZ THIS MORNING...WHILE
A LARGE PACIFIC TROF WILL APPROACH SOUTHERN CA LATER IN THE DAY. A
SORT OF ONE TWO PUNCH SO TO SPEAK FOR OUR AZ FORECAST ZONES IN
SOUTHWEST AND SOUTH CENTRAL AZ.

THE FORMER BAJA CA CUTOFF LOW WAS MOVING INTO SOUTHEAST AZ (BEST
SEEN IN THE VAPOR IMAGERY)...AND ADVECTING A MUCH HIGHER 700-500 MB
THETA-E AIRMASS INTO SOUTH CENTRAL AZ. INCREASING JET DYNAMICS ACROSS
THE EASTERN THIRD OF AZ WILL PROVIDE A CHANCE FOR SHOWER AND
THUNDERSTORM ACTIVITY OVER MUCH OF SOUTH CENTRAL AND PARTS OF
SOUTHWEST AZ THE REMAINDER OF THE AFTERNOON AND EVENING. SHOWERS AND
THUNDERSTORMS...SOME SEVERE...HAVE ALREADY BEEN ON THE UPSWING IN
REMOTE PARTS OF WESTERN MARICOPA COUNTY.

AS THE AIRMASS IN PARTS OF SOUTHWEST AND SOUTH CENTRAL AZ BECOMES
NEARLY SATURATED THIS EVENING...THE PACIFIC LOW PRESSURE SYSTEM
MOVING TOWARD SOUTHERN CA WILL SPREAD AND INCREASINGLY BROAD
DIFLUENT UPPER LEVEL FLOW ACROSS MUCH OF AZ TONIGHT AND MONDAY
MORNING TO CONTINUE THE RAIN CHANCES OVERNIGHT.

DRYING AND A MORE STABLE AIRMASS FOLLOWS LATER MONDAY...TUESDAY...
AND SUBSEQUENT DAYS...ALONG WITH WARMER AFTERNOON TEMPERATURES.

&&

.AVIATION...
DISCUSSION FOR 00Z TAFS. TAFS MOST LIKELY TO EXPERIENCE STORM
ACTIVITY WITHIN NEXT 12 HOURS ARE KIWA AND KPHX...LEAST LIKELY IS
KIPL. STRONG BUT ISOLATED STORMS DEVELOPED SOUTH AND WEST OF THE
PHOENIX METRO AREA BETWEEN 19Z-22Z. STORM DEVELOPMENT OVER YUMA AND
LA PAZ COUNTIES IS LIKELY TO CONTINUE EARLY IN THE TAF
PERIOD...THEREBY THREATENING KBLH AND KYUM. CONDITIONS ARE STILL
CONDUCIVE FOR STORMS TO AFFECT KPHX AND KIWA BETWEEN 00Z-06Z WITH A
STRAY SHOWER OR THUNDERSTORM POSSIBLE DURING THE LATE NIGHT AND
MORNING HOURS.

SEE TAFS PHXTAFPHX...PHXTAFIWA...PHXTAFYUM...LAXTAFBLH...LAXTAFIPL
FOR DETAILS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.
CA...NONE.

&&

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX

VASQUEZ

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
602 AM MST SUN AUG 14 2005

AZZ020>028-CAZ030>033-150100-
GREATER PHOENIX AREA-IMPERIAL COUNTY-JOSHUA TREE NATIONAL PARK/JTNP/-
LOWER COLORADO RIVER VALLEY AZ-LOWER COLORADO RIVER VALLEY CA-
NORTHWEST AND NORTH CENTRAL PINAL COUNTY-NORTHWEST MARICOPA COUNTY-
RIVERSIDE COUNTY/EASTERN DESERTS-
SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS-
SOUTHWEST DESERTS-SOUTHWEST MARICOPA COUNTY-WEST CENTRAL DESERTS-
YUMA/MARTINEZ LAKE AND VICINITY-
602 AM MST (602 AM PDT) SUN AUG 14 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH-CENTRAL AND
SOUTHWEST ARIZONA.

.DAY ONE...TODAY

A LOW PRESSURE SYSTEM FROM THE NORTHERN GULF OF CALIFORNIA IS
MOVING TOWARD ARIZONA TODAY AND WILL BRING AN INCREASE IN
SHOWERS AND THUNDERSTORMS BY THIS AFTERNOON AND TONIGHT MAINLY TO
SOUTH-CENTRAL ARIZONA INCLUDING THE GREATER PHOENIX AREA. SOME OF
THESE STORMS WILL PRODUCE VERY HEAVY RAIN WITH AN INCREASING
POSSIBILITY OF FLASH FLOODING ESPECIALLY SOUTHEAST AND EAST OF
PHOENIX EASTWARD ACROSS SOUTHERN GILA COUNTY WHERE MUDSLIDES ARE
ALSO POSSIBLE. STRONG GUSTY DAMAGING WINDS ARE ALSO POSSIBLE WITH
SOME OF THE THUNDERSTORMS...AS WELL AS BLOWING DESERT DUST WITH A
SUDDEN REDUCTION IN VISIBILITY.

IF YOU GET CAUGHT IN A DUST STORM...PULL OFF THE ROAD AS FAR AS
POSSIBLE...PUT YOUR VEHICLE IN PARK...TURN YOUR LIGHTS ALL THE
WAY OFF...AND TAKE YOUR FOOT OFF THE BRAKE.

STAY AWAY FROM FLOODED ROADS EVEN IF YOU THINK IT IS ONLY A SMALL
AMOUNT OF WATER. THE DEPTH OF THE WATER MAY BE GREATER THAN YOU
THINK...AND RUNNING WATER HAS GREAT FORCE. TURN AROUND AND FIND A
SAFE WAY TO GET TO YOUR DESTINATION.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

SHOWERS AND THUNDERSTORMS WILL DECREASE FROM THE SOUTH BY MONDAY
AFTERNOON. HOWEVER...ROADS MAY STILL BE FLOODED WITH WATER RUNNING IN
NORMALLY DRY WASHES AND CREEKS MAINLY IN SOUTH-CENTRAL ARIZONA
INCLUDING THE GREATER PHOENIX AREA.

.SPOTTER INFORMATION STATEMENT...

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

ELLIS