Severe Thunderstorm Warning 4, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST MON JUL 12 2004

SOUTHEAST ARIZONA FORECAST DISCUSSION

.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED NEAR COLORADO WILL KEEP A
MOIST EAST TO SOUTHEAST FLOW INTO ARIZONA THIS WEEK...WITH AN
INCREASE IN SHOWERS AND THUNDERSTORMS. AN UPPER LEVEL DISTURBANCE
APPROACHING THE AREA FROM THE EAST WILL SERVE TO FURTHER INCREASE
THE COVERAGE AND INTENSITY OF STORMS BY THE MIDDLE OF THE WEEK.

&&

.DISCUSSION...18Z KTUS SOUNDING STILL NOT QUITE WHAT WHAT WE WANTED
WITH SHEER AND STEERING LEVEL FLOW...TREND IS UP BUT SLOWLY. SHOULD
CONTINUE THIS TREND OVER THE NEXT 36 HOURS. AS MENTIONED THIS
MORNING...EXPECTING AN INTERESTING DAY AND INDEED WE GOT AN EARLY
START WITH LATE MORNING STORMS SHOWING STRENGTH AND TRAINING
TENDENCIES. STILL NOT SURE HOW WELL WE ARE GOING TO ORGANIZE...BUT
AS EXPECTED BOTH SEVERE AND HEAVY RAIN ARE A CONCERN. RSO FOR GOES
WEST HAS BEEN REQUESTED. THIS AFTERNOONS INITIAL STORMS GIVING
HEAVY SCATTERED COVERAGE...TO BE FOLLOWED UP BY OUTFLOW FROM THE RIM.

STRONG COMPLEX LAST NIGHT AT ENTRANCE TO GULF COMBINED WITH
PREVIOUSLY NOTED PRESSURE DIFFERENTIALS SHOULD ENHANCE SURGE
ACTIVITY INTO THE LOWER DESERTS IN THE NEXT 12 TO 18 HOURS. ALSO
STILL LOOKING AT INVERTED TROUGH...NOW APPROACHING AREA JUST SOUTH OF
THE BIG BEND AREA OF TEXAS...PUSHING INTO SOUTHEAST ARIZONA WITH
ENHANCED EASTERLY FLOW UNDER THE HIGH AROUND EARLY WEDNESDAY. ACTIVE
THROUGH SONORA AND AT LEAST SOUTHERN ARIZONA. COULD BE A VERY
INTERESTING AND BUSY WEEK. ONE OR TWO DAYS COULD BE DOWN AFTER LARGE
SCALE ORGANIZED CONVECTION...BUT NOT SURE WHICH AT THIS POINT. MAYBE
THURSDAY OR FRIDAY?

&&

.FIRE WEATHER...HIGH CENTER STRENGTHENING TO OUR EAST WILL BRING
MORE MOISTURE INTO SOUTHEAST ARIZONA FROM THE SOUTH AND EAST WITH
THE CHANCE OF SHOWERS AND THUNDERSTORMS IMPROVING THROUGH THE WEEK.
DIURNAL WIND TRENDS WILL BE COMPLICATED BY THE GUSTY OUTFLOWS FROM
THESE THUNDERSTORMS...WHILE RELATIVE HUMIDITIES ARE EXPECTED TO
GREATLY INCREASE AS THE ATMOSPHERE MOISTENS UP TO SEASONAL LEVELS.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

MEYER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1154 AM MST MON JUL 12 2004

AZZ019-029>035-130700-
NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY-COCHISE COUNTY-
SOUTHEAST PINAL COUNTY-TUCSON METRO/MARANA/GREEN VALLEY-
SANTA CRUZ COUNTY-TOHONO OODHAM NATION-WESTERN PIMA COUNTY-
1154 AM MST MON JUL 12 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...THE RISK OF BOTH SEVERE THUNDERSTORMS AND FLASH FLOODING
HAS INCREASED OVER THE REGION. A STRONG UPPER LEVEL DISTURBANCE OVER
NORTH CENTRAL MEXICO WILL CONTINUE TO MOVE TOWARD THE REGION THIS
AFTERNOON AND EVENING. A GULF SURGE HAS ALSO COMMENCED UP THE GULF OF
CALIFORNIA WHICH WILL CONTINUE TO MOISTEN AN ALREADY MOIST AND
UNSTABLE ATMOSPHERE.

DISCUSSION...AS EXPECTED OVER THE PAST COUPLE OF DAYS...A MORE
ACTIVE MONSOON PATTERN IS ABOUT TO GET UNDERWAY. SURFACE DEWPOINTS
REMAIN ON THE LOW SIDE FOR MID JULY...BUT THE MID AND UPPER LEVELS
OF THE ATMOSPHERE HAVE BECOME QUITE MOIST AND UNSTABLE.
PRECIPITABLE WATERS WERE ALREADY BETWEEN 1.2 AND 1.6
INCHES ACROSS SOUTHEAST ARIZONA LATE THIS MORNING. PLENTY OF SOLAR
HEATING IS ALSO EXPECTED TO AID IN DESTABILIZATION THROUGHOUT
SOUTHEAST ARIZONA. THE ONLY INGREDIENT WHICH MAY PREVENT AN OUTBREAK
OF SEVERE THUNDERSTORMS IS THAT MID LEVEL WIND SHEAR REMAINS ON THE
WEAK SIDE. HOWEVER THE LATEST UPPER AIR SOUNDING INDICATES THAT THE
MID LEVELS WINDS HAVE INCREASED SOMEWHAT SINCE EARLIER THIS
MORNING...ENOUGH SO THAT THE THUNDERSTORMS TODAY WILL BE SOMEWHAT
LONGER LIVED...STRONGER AND MORE ORGANIZED. THE INCREASING FLOW
WILL ALSO CAUSE SOME CELL TRAINING AND MAY CAUSE THE STORMS TO
CONSOLIDATE INTO A MESOSCALE CONVECTIVE SYSTEM BY TONIGHT. THIS
WOULD THEN TEND TO PUSH INTO THE WESTERN DESERTS AFTER SUNSET. THUS
THE RISK OF DAMAGING WINDS...LARGE HAIL AND FLASH FLOODING WILL ALL
BE SLIGHTLY ABOVE CLIMATOLOGY THIS AFTERNOON AND EVENING ACROSS ALL
OF SOUTHEAST ARIZONA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THE RISK OF NUMEROUS AND POSSIBLY STRONG THUNDERSTORMS WILL CONTINUE
THROUGH THURSDAY. THE LARGE UPPER LEVEL DISTURBANCE IS EXPECTED
TO MOVE INTO THE GULF OF CALIFORNIA BY TUESDAY BEFORE TURNING
NORTHWEST TOWARD SOUTHERN CALIFORNIA. A TROPICAL DEPRESSION HAS
ALSO FORMED SOUTHWEST OF MEXICO...WITH MOISTURE FROM THIS SYSTEM
FEEDING TOWARD THE GULF OF CALIFORNIA. THERE IS A CHANCE THAT
CONSIDERABLE CLOUD COVER WILL HOLD DOWN THE AMOUNT OF INSTABILITY AND
THUS REDUCE THE THREAT OF SEVERE THUNDERSTORMS AND FLASH FLOODING ON
ANY GIVEN DAY. HOWEVER...THE UPCOMING WEEK GENERALLY LOOKS ACTIVE IN
TERMS OF THUNDERSTORM DEVELOPMENT. THUNDERSTORM COVERAGE SHOULD
DECREASE A BIT BY THE END OF THE WEEK ONCE THIS UPPER LEVEL
DISTURBANCE FINALLY LIFTS OUT OF THE REGION.

.SPOTTER INFORMATION STATEMENT...

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

PYTLAK