Severe Thunderstorm Warning 76, NWS Tucson, AZ

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST THU AUG 14 2003

.SYNOPSIS...A STRONG LOW PRESSURE SYSTEM WILL MOVE FROM TEXAS INTO
ARIZONA OVER THE NEXT COUPLE OF DAYS...BRINGING AN INCREASE IN
THUNDERSTORMS ACROSS THE AREA. EXPECT COOLER AFTERNOONS TO GO ALONG
WITH THE INCREASE IN CLOUD COVER AND THUNDERSTORMS.

.DISCUSSION...EVERYTHING KIND OF SET UP SIMILAR TO WHAT MM5 SHOWED
THIS MORNING EXCEPT FOR OUTFLOW BOUNDARY THAT PUSHED INTO TUCSON
AREA. STORMS IN WHITE MOUNTAINS MOVING SOUTHWEST 15 OR 20 KNOTS AND
WILL INTERACT WITH MOIST BOUNDARY LAYER AWAITING IN LOW DESERTS TO
FIRE OFF LARGE AREA OF STORMS OVER THE LOW DESERTS TONIGHT. LEADING
THUNDERSTORMS HAVE DEVELOPED OVER SOUTHEAST PINAL COUNTY AHEAD OF
STORMS IN WHITE MOUNTAINS SHOWING SUPERCELL CHARACTERISTICS WITH
OTHER THUNDERSTORMS IN CENTRAL PIMA COUNTY. FLASH FLOOD AND SEVERE
WATCHES SHOULD EASILY VERIFY TODAY. REASON IS THAT WE ARE IN LEFT
FRONT QUADRANT OF THIS LOW WITH ALL THE ASSOCIATED DYNAMICS. HEAVY
RAIN THAT FELL IN PARTS OF PIMA AND PINAL COUNTIES LAST NIGHT MAKE
ANTECEDENT CONDITIONS FOR FLASH FLOODING PRIME...ESPECIALLY GIVEN
THAT WE SAW FLASHY SIGNATURES ON THE GAUGES DURING LAST NIGHTS
STORMS.

COLD POOL MOVES INTO AREA TOMORROW AND STORMS SHOULD HAVE NO
PROBLEMS DEVELOPING WITH SURFACE HEATING. THEY WILL NOT BE AS WELL
ORGANIZED...BUT WITH PLENTY OF MOISTURE WILL STILL HAVE SIMILAR
PROBLEMS ALTHOUGH MORE LIKE PULSE STORMS THAN SUPERCELLS.

NO RADICAL CHANGE SEEN THROUGH THE WEEKEND...ALTHOUGH WOULD EXPECT
LOWER CHANCES OF RAIN ESPECIALLY IF THIS LOW TAPS SOME DRY MID LEVEL
AIR. BUT MOISTURE WILL BE REINFORCED NEXT WEEK BY TROPICAL SYSTEM IN
GULF OF MEXICO.

.TWC...SEVERE THUNDERSTORM WATCH UNTIL 900 PM AZZ029-031>034
       FLASH FLOOD WATCH UNTIL MIDNIGHT AZZ029-031>034.

AZZ019-029>035-151400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
12 NOON MST THU AUG 14 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

...FLASH FLOOD WATCH IN EFFECT FROM 2 PM MST THIS AFTERNOON UNTIL 12
MIDNIGHT TONIGHT FOR SOUTHEAST PINAL COUNTY...ALL OF PIMA COUNTY AND
SANTA CRUZ COUNTY...

SYNOPSIS...THUNDERSTORMS SHOULD FORM ON THE RIM TODAY AND MOVE
SOUTHWEST ACROSS THE AREA THIS EVENING. THE POTENTIAL FOR SEVERE
THUNDERSTORMS AND PRECIPITATION IN EXCESS OF ONE INCH IT IS ABOVE
CLIMATOLOGY...ESPECIALLY FROM TUCSON WEST.

DISCUSSION...A FEW LIGHT SHOWERS WERE PRESENT SOUTHEAST OF TUCSON
THIS MORNING AS DEBRIS CLOUD COVER FROM WEDNESDAY NIGHT CONVECTION
CONTINUES TO MOVE SOUTHWEST. THE UPPER LOW THAT WAS IN TEXAS OVER
THE PAST TWO DAYS HAS MIGRATED WEST AND IS SITUATED THIS AFTERNOON
IN CHIHUAHUA MEXICO. MODERATE NORTHEAST FLOW AHEAD OF THIS SYSTEM
WILL MOVE STORMS THAT DEVELOP ON THE RIM COUNTRY DOWN INTO THE LOWER
VALLEYS THIS AFTERNOON AND EVENING AND INTO THE LOW DESERTS WEST OF
TUCSON TONIGHT. THE THREAT OF SEVERE WEATHER (I.E. DAMAGING WINDS
AND HAIL) WILL BE HIGHER THAN NORMAL FROM TUCSON WEST BUT NEAR
CLIMATOLOGY IN THE EAST...WHERE SOME DRIER AIR HAS MOVED IN. A VERY
MOIST ATMOSPHERE IS IN PLACE FROM TUCSON WEST...WHERE PRECIPITABLE
WATER VALUES RANGE FROM 1.50 INCHES TO TWO INCHES. THIS AREA WILL
SEE THE BEST CHANCE OF HEAVY RAIN. THUS THE CHANCE OF ONE INCH
PRECIPITATION IS RATHER HIGH FROM TUCSON WEST...WHERE A FLASH FLOOD
WATCH IS IN EFFECT UNTIL 12 MIDNIGHT...BUT NEAR CLIMATOLOGY EAST OF
TUCSON. MOVEMENT OF THE STORMS WILL BE GENERALLY WEST TO SOUTHWEST
AROUND 10 TO 15 MPH.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

THE UPPER LOW IN CHIHUAHUA MEXICO WILL MOVE INTO THE STATE FRIDAY
AND WILL CONTINUE TO HELP FOCUS THUNDERSTORM DEVELOPMENT FRIDAY AND
FRIDAY NIGHT. THE UPSWING IN THUNDERSTORM COVERAGE WILL CONTINUE AND
THE CHANCE FOR HEAVY RAIN WILL REMAIN AT A LEVEL HIGHER THAN NORMAL.

.SPOTTER INFORMATION STATEMENT...

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

AZZ029-031>034-150400-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
153 PM MST THU AUG 14 2003

THE STORM PREDICTION CENTER HAS ISSUED SEVERE THUNDERSTORM WATCH
NUMBER 859 FOR SOUTH CENTRAL ARIZONA EFFECTIVE UNTIL 900 PM MST.
THIS WATCH INCLUDES SOUTHEAST PINAL...SANTA CRUZ AND PIMA COUNTIES.

THIS WATCH INCLUDES THE ENTIRE TUCSON METRO AREA...AJO...SELLS...
ELOY...ORACLE...AND NOGALES.

CONDITIONS HAVE BECOME FAVORABLE FOR LARGE HAIL UP TO 2 INCHES IN
DIAMETER...WIND GUSTS UP TO 80 MPH...AND TORRENTIAL RAINS IN THIS
AREA. A FLASH FLOOD WATCH IS ALSO IN EFFECT FOR THIS SAME AREA UNTIL
MIDNIGHT TONIGHT. BE PREPARED TO TAKE QUICK ACTION IF A WARNING IS
ISSUED.

PYTLAK