Severe Thunderstorm Warning 69, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
210 PM MST TUE AUG 24 2010

.SYNOPSIS...AMPLE MOISTURE AND A FAVORABLE FLOW WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO SOUTHEAST ARIZONA THIS EVENING. A
GRADUAL DECREASE IN SHOWERS AND THUNDERSTORMS IS EXPECTED WEDNESDAY
INTO FRIDAY...FOLLOWED BY ANOTHER UPSWING IN THUNDERSTORM ACTIVITY
BY EARLY NEXT WEEK. ABOVE NORMAL HIGH TEMPERATURES WILL CONTINUE
THIS WEEK.

&&

.DISCUSSION...A BACKDOOR COLD FRONT MANAGED TO PUSH FATHER WEST
THAN PREVIOUSLY EXPECTED. THIS HAD RESULTED IN SHOWERS AND
THUNDERSTORMS DEVELOPING OVER THE LOWER DESERTS FROM PINAL AND
EASTERN PIMA WEST TO LA PAZ AND YUMA COUNTIES. BASED ON THIS...THE
MAIN AREAS OF CONCERN FOR STRONG THUNDERSTORMS WITH DAMAGING WINDS
AND LOCALLY HEAVY RAINFALL WILL BE ACROSS THE LOWER DESERTS OF
SOUTHERN ARIZONA THROUGH AT LEAST 7 PM MST. SHOWERS AND
THUNDERSTORMS ALONG THE EASTERN MOGOLLON RIM AND WHITES MOUNTAINS
WERE MORE ORGANIZED ACROSS GILA COUNTY THIS AFTERNOON...WHICH WOULD
FAVOR IMPACTING THE CENTRAL DESERTS/GREATER PHOENIX AREA/LATE THIS
AFTERNOON AND EARLY THIS EVENING. STORMS DEVELOPING ACROSS OUR
EASTERN CWA WILL REMAIN ISOLATED IN NATURE THIS AFTERNOON. THE ONLY
CONCERN WILL BE ACROSS MAINLY COCHISE COUNTY WHERE A DISTURBANCE
PASSING THROUGH THIS EVENING COULD TRIGGER MORE STORMS THERE. IF
THIS HAPPENS...MIGHT SEE SOME SHOWERS AND THUNDERSTORMS MOVE INTO
EASTERN PIMA AND PINAL COUNTIES LATE IN THE EVENING.

OTHERWISE...SOMEWHAT LESS THUNDERSTORM ACTIVITY...EXCEPT FOR THE
WESTERN DESERTS...WAS EXPECTED WEDNESDAY AND THURSDAY.
THEREAFTER...AN INCREASE IN SHOWERS AND THUNDERSTORMS CAN BE
ANTICIPATED FRIDAY AND SATURDAY AS A TROUGH OF LOW PRESSURE
INTERACTS WITH MOISTURE OVER THE AREA. GFS MODEL WAS RATHER
CONSISTENT IN ADVECTING DRIER AIR INTO MUCH OF ARIZONA SUNDAY INTO
EARLY NEXT WEEK. THIS SHOULD RESULT IN A SIGNIFICANT DECREASE IN
THUNDERSTORM ACTIVITY SUNDAY INTO WEDNESDAY OF NEXT WEEK. ABOVE
NORMAL HIGH TEMPERATURES CAN BE EXPECTED THROUGH FRIDAY...THEN
DAYTIME READINGS WILL TREND CLOSER TO NORMAL OR A FEW DEGS BELOW
NORMAL BY EARLY NEXT WEEK.

&&

.AVIATION...ISOLD-SCT TSRA/SHRA IN THE VALLEYS...AND SCT-NUMEROUS
TSRA/SHRA IN THE MOUNTAINS THIS AFTERNOON/EVENING. OUTSIDE OF THE
THUNDERSTORMS EXPECT SCT CLOUD BASES BETWEEN 5-7K FT AGL AND SCT-BKN
CLOUD DECKS OF 10-12K FT AG...WITH ELY/SELY SURFACE WINDS AT 10-15
KTS AND SOME GUSTS TO AROUND 20 KTS. WITH THE STRONGER STORMS...MVFR
CEILINGS/VSBYS EXPECTED AND WIND GUSTS TO NEAR 50 KTS. AFT 03Z
WEDNESDAY...THE SHOWERS AND STORMS WILL DIMINISH...ALTHOUGH A SLIGHT
CHANCE OF -TSRA/SHRA WILL PERSIST INTO WEDNESDAY MORNING.
DIMINISHING CLOUDINESS IS EXPECTED AFT 06Z WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...NO FIRE WEATHER CONCERNS AT THIS TIME.

&&

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

WEATHER.GOV/TUCSON

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
120 PM MST TUE AUG 24 2010

AZZ019-029>035-250600-
NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY-
UPPER GILA RIVER VALLEY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION-
TUCSON METRO/MARANA/GREEN VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY-
120 PM MST TUE AUG 24 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
ARIZONA AND SOUTHEAST ARIZONA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE REMAINED AN INCREASED RISK OF STRONG THUNDERSTORMS WITH GUSTY
WINDS IN EXCESS OF 60 MPH ALONG WITH LOCALLY HEAVY RAINFALL AND
SMALL HAIL.

THUNDERSTORMS THIS AFTERNOON HAVE DEVELOPED FARTHER WEST THAN
PREVIOUSLY EXPECTED...WITH MOST OF THE ACTIVITY LOCATED ACROSS
SOUTHEAST PINAL AND PIMA INTO WESTERN SANTA CRUZ COUNTIES AS OF 1
PM MST. BASED ON THE CURRENT LOCATION OF THE SHOWERS AND
THUNDERSTORMS AND THE FACT THAT THE STEERING FLOW ALOFT REMAINED
LIGHT...THUNDERSTORMS SHOULD BE FAVORED ACROSS THE LOWER DESERTS OF
PIMA AND PINAL COUNTIES THE REMAINDER OF THIS AFTERNOON AND EARLY
THIS EVENING.

THUNDERSTORMS DEVELOPING ACROSS GREENLEE...GRAHAM...AND COCHISE
COUNTIES SHOULD REMAIN MORE ISOLATED IN NATURE FOR MUCH OF THIS
AFTERNOON. THUNDERSTORMS MAY INCREASE IN COVERAGE THIS EVENING
ACROSS MAINLY COCHISE COUNTY AS A WEAK DISTURBANCE OVER MEXICO
PASSES BY THE REGION.

STORM MOVEMENT THIS AFTERNOON AND EVENING WILL BE TOWARD THE WEST
AT LESS THAN 10 MPH.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY IN
AFTERNOON AND EVENING HOURS THROUGH THE MIDDLE OF THE WEEK. EXPECT
GUSTY WINDS AND LOCALLY HEAVY RAINFALL WITH THE STRONGEST STORMS.
THE PATTERN WILL THEN BECOME LESS FAVORABLE FOR SHOWER AND STORM
DEVELOPMENT DURING THE LATTER HALF OF THE WEEK.

.SPOTTER INFORMATION STATEMENT...

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

WEATHER.GOV/TUCSON