Severe Thunderstorm Warning 11, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 AM MST WED JUL 14 2004

SOUTHEAST ARIZONA FORECAST DISCUSSION

.SYNOPSIS...HIGH PRESSURE ALOFT CENTERED OVER COLORADO WILL KEEP A
MOIST EAST TO SOUTHEAST FLOW INTO ARIZONA THROUGH FRIDAY. AN UPPER
LEVEL DISTURBANCE WILL APPROACH THE AREA FROM THE SOUTHEAST TODAY
AND INCREASE RAINFALL AS IT TAPS INTO MOISTURE FROM TROPICAL STORM
BLAS SOUTHWEST OF BAJA. THE RISK OF THUNDERSTORMS SHOULD DECREASE
SOMEWHAT LATE IN THE WEEK AS THE UPPER HIGH MOVES SOUTH AND CLOSES
OFF SOME OF THE MOISTURE SUPPLY.
&&

.DISCUSSION...SATELLITE IMAGERY THIS MORNING SHOWED EXTENSIVE CLOUD
COVER OVER WESTERN HALF OF ARIZONA WITH CLOUDS THINNING/CLEARING THE
CLOSER YOU GET TO THE NEW MEXICO STATE LINE. WATER VAPOR IMAGERY AND
UPPER AIR PLOTS SHOWED WEAKENING INVERTED TROF OVER CHIHUAHUA
MEXICO...MOVING WEST. ISOLATED THUNDERSTORMS HAVE DEVELOPED OVER
SOUTHWEST NEW MEXICO WHERE THE UPPER LEVEL DEFORMATION ZONE IS
LOCATED. 12Z TUCSON CONTAMINATED WITH LAST NIGHTS ACTIVITY BUT STILL
SHOWED A PRECIPITABLE WATER VALUE JUST UNDER TWO INCHES. WITH VERY
MOIST ATMOSPHERE IN PLACE...THERE IS A HIGH POTENTIAL FOR FLASH
FLOODING RAINS LATER THIS AFTERNOON AND TONIGHT. HOWEVER THE BUG IN
THE MIX TODAY IS THAT HEATING WILL BE CUT BACK DUE TO COOLER
BOUNDARY LAYER AND CLOUD COVER (WHICH HAS INCREASED OVER THE LAST
HOUR EAST OF TUCSON). CURRENT THINKING FOR FLASH FLOOD WATCH AREA
WOULD BE EAST OF A ELOY-SELLS LINE FOR THIS AFTERNOON AND
EVENING...AND THEN WEST OF THE ELOY-SELLS LINE FOR TONIGHT INTO THE
WEE HOURS OF THURSDAY MORNING. SEVERE THUNDERSTORM THREAT IS LOWER
TODAY THAN YESTERDAY DUE TO LESS SHEAR...BUT STILL MAY HAVE A
ISOLATED DAMAGING WIND EVENT. THE REST OF THE FORECAST CYCLE WILL BE
MENTIONED IN THE AFTERNOON DISCUSSION.
&&

.FIRE WEATHER...HUMIDITIES CONTINUE TO IMPROVE WITH WINDS REMAINING
ON THE LIGHT SIDE EXCEPT NEAR TSTMS. THE MAIN CONCERN IS STARTING TO
INVOLVE BURN AREA FLASH FLOOD POTENTIAL WHICH WILL CONTINUE TO BE
MONITORED CLOSELY.
&&

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

JRG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1154 AM MST WED JUL 14 2004

AZZ019-029-030-033>035-150700-
NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY-COCHISE COUNTY-
SOUTHEAST PINAL COUNTY-TUCSON METRO/MARANA/GREEN VALLEY-
SANTA CRUZ COUNTY-
1154 AM MST WED JUL 14 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

...FLASH FLOOD WATCH 200 PM UNTIL 1000 PM...

SYNOPSIS...THE RISK OF EXCESSIVE RAINFALL IS HIGH THIS AFTERNOON
AND EVENING. A WEAKENING UPPER LEVEL DISTURBANCE OVER NORTHERN
CHIHUAHUA WILL MOVE INTO SOUTHEAST ARIZONA TONIGHT WHERE TROPICAL
MOISTURE IS IN PLACE. CLOUD COVER AND RATHER WARM TEMPERATURES
ALOFT WILL KEEP THE RISK OF SEVERE THUNDERSTORMS BELOW CLIMATOLOGY...
HOWEVER ISOLATED SMALL HAIL AND WET MICROBURSTS ARE POSSIBLE WITH THE
STRONGEST STORMS.

DISCUSSION...TROPICAL MOISTURE MOVED NORTH INTO THE REGION OVER THE
PAST 36 HOURS FROM THE GULF OF CALIFORNIA. PRECIPITABLE WATER IS
ALMOST DOUBLE THE NORMAL LEVEL FOR MID JULY. ISOLATED THUNDERSTORMS
WERE ALREADY DEVELOPING OVER SOUTHEAST ARIZONA...DESPITE
CONSIDERABLE CLOUD COVER. THE UPPER AIR SOUNDING FROM LATE THIS
MORNING ALSO SHOWED AN INCREASE IN EAST WIND SHEAR...WHICH IS
CAUSING THE INITIAL STORMS TO TRAIN. ALL OF THIS STRONGLY SUGGESTS A
POTENTIALLY SERIOUS FLASH FLOOD SITUATION. THE LACK OF DAYTIME
HEATING SHOULD KEEP STORM UPDRAFTS FROM BECOMING TOO STRONG...BUT
THE INCREASE IN MID LEVEL WIND SHEAR AND EXCESSIVE MOISTURE CONTENT
IN THE ATMOSPHERE COULD CAUSE A COUPLE OF STORMS TO PRODUCE WET
MICROBURSTS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE RISK OF STRONG THUNDERSTORMS WILL DIMINISH SOMEWHAT BY THE END
OF THE WEEK AS HIGH PRESSURE OVER SOUTHERN COLORADO SHIFTS INTO NEW
MEXICO. THIS WILL REDUCE EAST FLOW OVER THE REGION AND WILL CAUSE
SOME WARMING ALOFT.  AN UPSWING IS THEN POSSIBLE EARLY NEXT WEEK AS
THE HIGH AGAIN TRIES TO SHIFT BACK TO THE NORTH.

.SPOTTER INFORMATION STATEMENT...

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

AZZ031-032-150700-
TOHONO OODHAM NATION-WESTERN PIMA COUNTY-
1154 AM MST WED JUL 14 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL ARIZONA

.DAY ONE...TODAY

...FLASH FLOOD WATCH 600 PM UNTIL 300 AM...

SYNOPSIS...THE RISK OF EXCESSIVE RAINFALL IS HIGH THIS AFTERNOON
AND EVENING. A WEAKENING UPPER LEVEL DISTURBANCE OVER NORTHERN
CHIHUAHUA WILL MOVE INTO SOUTHEAST ARIZONA TONIGHT WHERE TROPICAL
MOISTURE IS IN PLACE. CLOUD COVER AND RATHER WARM TEMPERATURES
ALOFT WILL KEEP THE RISK OF SEVERE THUNDERSTORMS BELOW CLIMATOLOGY...
HOWEVER ISOLATED SMALL HAIL AND WET MICROBURSTS ARE POSSIBLE WITH THE
STRONGEST STORMS.

DISCUSSION...TROPICAL MOISTURE MOVED NORTH INTO THE REGION OVER THE
PAST 36 HOURS FROM THE GULF OF CALIFORNIA. PRECIPITABLE WATER IS
ALMOST DOUBLE THE NORMAL LEVEL FOR MID JULY. ISOLATED THUNDERSTORMS
WERE ALREADY DEVELOPING OVER SOUTHEAST ARIZONA...DESPITE
CONSIDERABLE CLOUD COVER. THE UPPER AIR SOUNDING FROM LATE THIS
MORNING ALSO SHOWED AN INCREASE IN EAST WIND SHEAR...WHICH IS
CAUSING THE INITIAL STORMS TO TRAIN. ALL OF THIS STRONGLY SUGGESTS A
POTENTIALLY SERIOUS FLASH FLOOD SITUATION. THE LACK OF DAYTIME
HEATING SHOULD KEEP STORM UPDRAFTS FROM BECOMING TOO STRONG...BUT
THE INCREASE IN MID LEVEL WIND SHEAR AND EXCESSIVE MOISTURE CONTENT
IN THE ATMOSPHERE COULD CAUSE A COUPLE OF STORMS TO PRODUCE WET
MICROBURSTS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE RISK OF STRONG THUNDERSTORMS WILL DIMINISH SOMEWHAT BY THE END
OF THE WEEK AS HIGH PRESSURE OVER SOUTHERN COLORADO SHIFTS INTO NEW
MEXICO. THIS WILL REDUCE EAST FLOW OVER THE REGION AND WILL CAUSE
SOME WARMING ALOFT.  AN UPSWING IS THEN POSSIBLE EARLY NEXT WEEK AS
THE HIGH AGAIN TRIES TO SHIFT BACK TO THE NORTH.

.SPOTTER INFORMATION STATEMENT...

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

PYTLAK