Severe Thunderstorm Warning 4, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
240 PM MST FRI JUL 11 2003

.SYNOPSIS...STRONG HIGH PRESSURE SHIFTING A LITTLE NORTH HAS ALLOWED
A MORE EASTERLY FLOW TO DEVELOP ACROSS THE AREA. MORE MOISTURE
SPREADING IN FROM THE EAST AND SOUTH WILL BRING SCATTERED AFTERNOON
AND EVENING THUNDERSTORMS TO THE AREA AS WELL AS TAKE A FEW DEGREES
OFF THE RECENT NEAR RECORD AFTERNOON HIGHS THROUGH SATURDAY. HIGH
PRESSURE WILL MIGRATE TO THE SOUTH FROM THE FOUR CORNERS REGION ON
SUNDAY WHICH WILL ALLOW THE ATMOSPHERE TO DRY SLIGHTLY AND
THUNDERSTORMS WILL DEVELOP FARTHER TO THE SOUTH THROUGH MID WEEK...
GENERALLY OVER EXTREME SOUTHEAST ARIZONA AND SOUTH OF THE
INTERNATIONAL BORDER.

.DISCUSSION...SEVERE THUNDERSTORM WATCH #721 IS IN EFFECT OVER
MAINLY THE EASTERN HALF OF THE COUNTY WARNING AREA (SEE SPECIFICS
BELOW) UNTIL 5 PM MST. RADARS ARE CURRENTLY DETECTING ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS OVER PORTIONS OF GRAHAM...
COCHISE...SANTA CRUZ AND EASTERN PIMA COUNTY AT THIS TIME. THIS
MORNINGS KTUS SOUNDING REFLECTED THE NEED FOR THIS WATCH WITH A JUMP
IN PRECIPATABLE WATER VALUE OF ABOUT A HALF INCH FROM YESTERDAY
EVENING (0.79 TO 1.30). MODIFYING THE SOUNDING TO REFLECT A SLIGHLTY
LOWER DEWPOINT TEMPERATURE ALONG WITH A LITTLE LESS MOIST LAYER IN
THE LOWEST 100MB OR SO STILL RESULTED IN A CAPE OF AT LEAST 1500
J/KG IF NOT CLOSER TO 2500.

MOISTURE SURGE WAS ALSO QUITE EVIDENT THIS MORNING WITH DEWPOINTS IN
THE LOWER 60S ACROSS AREAS GENERALLY FROM TUCSON SOUTH AND
WEST...BUT ALSO INTO THE PHOENIX AREA AS WELL. A LOOK AT YUMAS VAD
WIND PROFILE SHOWED 20-25 KNOT SOUTHERLY WINDS IN THE LOWEST 5K FEET.
GUAYMAS SOUNDING WAS QUITE MOIST WITH A PW OF 1.65 AND SOUTHEAST
FLOW TRANSPORTING THIS MOISTURE INTO THE GULF OF CALIFORNIA AND INTO
SOUTHEAST ARIZONA AS EVIDENCED IN THIS MORNINGS DEWPOINTS WHICH WERE
UP ABOUT 10 TO 15 DEGREES FROM 24 HOURS AGO.

AS MENTIONED EARLIER THE 500MB HIGH SHIFTS SOUTH BY SUNDAY AND
MAINTAINS THAT POSITION UNTIL AROUND TUESDAY. AS A RESULT EXPECT TO
SEE THE THREAT FOR SHOWERS AND THUNDERSTORMS DIMINISH FROM WHAT IS
EXPECTED TODAY. BASICALLY LOOKING AT 10-20ISH CHANCES FOR SHOWERS
AND THUNDERSTORMS THROUGH TUESDAY. THEN BEGINNING WEDNESDAY WE WILL
SEE A SLIGHT INCREASE IN SHOWERS AND THUNDERSTORMS (UP 10 PERCENT OR
SO) AS THE HIGH MOVES BACK OVER THE FOUR CORNERS REGION ALLOWING
MORE TRANSPORT OF MOISTURE INTO SOUTHEAST ARIZONA.

WITH THE POTENTIAL FOR HEAVY RAIN OVER THE MOUNTAINS THIS EVENING
HAVE ISSUED A FLASH FLOOD WATCH FOR THE BURNED AREAS OF THE
CATALINA...RINCON AND HUACHUA MOUNTAINS UNTIL 8 PM MST SINCE RUNOFF
COULD BE A PROBLEM DUE TO LOSS OF VEGETATION DUE TO RECENT FIRES.

MOLLERE

.TWC...SEVERE THUNDERSTORM WATCH #721 FOR ZONES 019-029>30-33>35
       UNTIL 5 PM MST.
       FLASH FLOOD WATCH FOR THE BURNED AREAS OF THE CATALINA...
       RINCON AND HUACHUCA MOUNTAINS UNTIL 8 PM MST.

AZZ019-029>035-120600-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1220 PM MST FRI JUL 11 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

...FIRST SEVERE THUNDERSTORM OUTBREAK OF THE SEASON POSSIBLE THIS
AFTERNOON...
...SEVERE THUNDERSTORM WATCH NUMBER 721 FOR PARTS OF SOUTHEAST
ARIZONA UNTIL 500 PM...
...FLASH FLOOD WATCH FOR BURN AREAS UNTIL 800 PM...

SYNOPSIS...A FULL MONSOON FLOW PATTERN HAS SET UP ACROSS THE REGION
TODAY. THE ATMOSPHERE HAS BECOME QUITE UNSTABLE WITH MID LEVEL WIND
FLOW IN THE 20 TO 30 KT RANGE. THIS WILL CAUSE THUNDERSTORMS TO MOVE
RATHER QUICKLY TO THE WEST AND OCCASIONALLY FORM INTO SHORT LINES OR
CLUSTERS. THUS THE RISK OF DAMAGING WINDS IS ABOVE CLIMATOLOGY...
ESPECIALLY OVER EASTERN SECTIONS OF THE REGION. THE RISK OF ONE INCH
RAINS IS SLIGHTLY BELOW CLIMATOLOGY...BUT BURN AREAS ARE HIGHLY
VULNERABLE TO FLASH FLOODING.

DISCUSSION...THE ATMOSPHERE HAS DESTABILIZED SIGNIFICANTLY OVER THE
PAST 24 HOURS. A MOISTURE SURGE UP THE GULF OF CALIFORNIA HAS
DRIVEN DEWPOINTS INTO THE 60S OVER SOUTHERN ARIZONA. PRECIPITABLE
WATERS HAVE SHOT UP INTO THE 1.2 TO 1.4 INCH RANGE AS WELL WITH
ESTIMATED AFTERNOON CAPE VALUES IN THE 2000 TO 2500 RANGE. IN
ADDITION...UPPER LEVEL SOUNDINGS INDICATED ABOUT 30KTS OF MID LEVEL
WIND SHEAR. THIS WILL TEND TO ORGANIZE THE STORMS AND PUSH THEM TO
THE WEST AT ABOUT 25 MPH. THAT WILL ONLY INCREASE THE THREAT OF
DAMAGING WINDS AND BLOWING DUST.

THE RISK OF RAINFALL IN EXCESS OF ONE INCH IS ACTUALLY SLIGHTLY
BELOW CLIMATOLOGY BECAUSE OF THE RATHER RAPID STORM MOTION. HOWEVER
THE BURN AREAS IN THE CATALINA...RINCON AND HUACHUCA MOUNTAINS ARE
EXTREMELY VULNERABLE TO FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

ENOUGH MOISTURE IS EXPECTED TO HANG ON FOR ANOTHER ROUND OF
THUNDERSTORMS SATURDAY...BEFORE HIGH PRESSURE WOBBLES BACK TO THE
SOUTH AND CLOSER TO OVERHEAD LATER IN THE WEEKEND. THIS COULD
DIMINISH THE THUNDERSTORM COVERAGE EARLY IN THE WEEK.

.SPOTTER INFORMATION STATEMENT...

SEVERE WEATHER SPOTTER ACTIVATION IS LIKELY THIS AFTERNOON AND
EVENING. SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

PYTLAK

AZZ019-029-030-033>035-120000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1144 AM MST FRI JUL 11 2003

...SEVERE THUNDERSTORM WATCH NUMBER 721 UNTIL 500 PM MST...

THE STORM PREDICTION CENTER HAS ISSUED A SEVERE THUNDERSTORM WATCH
FOR A LARGE PORTION OF SOUTHEAST ARIZONA UNTIL 500 PM MST.  THE
WATCH INCLUDES THE FOLLOWING COUNTIES IN SOUTHEAST ARIZONA...

GREENLEE...GRAHAM...COCHISE...SANTA CRUZ...EASTERN PIMA AND
SOUTHEAST PINAL.

THIS WATCH INCLUDES THE FOLLOWING CITIES...
THE ENTIRE TUCSON METRO AREA...SAFFORD...CLIFTON...ELOY...ORACLE...
WILLCOX...SIERRA VISTA...DOUGLAS...BISBEE AND NOGALES.

THE MAIN THREAT FROM THUNDERSTORMS THIS AFTERNOON IS FROM DAMAGING
WINDS WELL IN EXCESS OF 60 MPH AND DUST STORMS WITH VISIBILITIES
NEAR ZERO IN A FEW LOCATIONS. HOWEVER...BRIEF HEAVY RAIN...FREQUENT
LIGHTNING AND SOME HAIL IS ALSO POSSIBLE.

REMEMBER THAT A SEVERE THUNDERSTORM WATCH MEANS THAT WIDESPREAD
SEVERE THUNDERSTORMS ARE POSSIBLE...BUT NOT CERTAIN AS OF YET.
REVIEW SEVERE WEATHER SAFETY RULES AND BE PREPARED TO TAKE ACTION
IF A WARNING IS ISSUED.  A FLASH FLOOD WATCH WILL ALSO BE ISSUED FOR
BURN AREAS IN SOUTHEAST ARIZONA SHORTLY.

PYTLAK

AZZ019-029-030-033>035-120000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
203 PM MST FRI JUL 11 2003

...SEVERE THUNDERSTORM WATCH FOR MUCH OF SOUTHEAST ARIZONA UNTIL 500
PM MST...

ISOLATED THUNDERSTORMS WERE DEVELOPING OVER THE MOUNTAINS OF
SOUTHEAST ARIZONA AND WERE ATTEMPTING TO MOVE INTO A FEW VALLEY
LOCATIONS. STRONGER AND MORE ORGANIZED THUNDERSTORMS WERE LINING UP
ALONG THE EASTERN MOGOLLON RIM...WHITE MOUNTAINS AND GILA MOUNTAINS
OF NEW MEXICO. MID LEVEL STEERING WINDS HAVE INCREASED SINCE LATE
MORNING AND WILL TEND TO PUSH THESE STRONGER STORMS WEST AND
SOUTHWEST INTO THE WATCH AREA BY LATE AFTERNOON. ANY STORMS WILL BE
CAPABLE OF PRODUCING DAMAGING WINDS...BLOWING DUST...BRIEF HEAVY
RAIN...AND PERHAPS SOME SMALL HAIL.

A SEVERE THUNDERSTORM WATCH MEANS THAT WIDESPREAD SEVERE WEATHER IS
POSSIBLE..BUT NOT YET CERTAIN. CONTINUE TO MONITOR WEATHER
CONDITIONS CLOSELY AND BE PREPARED TO TAKE QUICK ACTION IF SEVERE
THUNDERSTORMS DEVELOP.

PYTLAK