Severe Thunderstorm Warning 76, NWS Tucson, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
1000 AM MST SAT AUG 28 2010

.SYNOPSIS...A RATHER STRONG TROUGH OF LOW PRESSURE WILL MOVE INTO
THE WESTERN U.S. THROUGH SUNDAY. INITIALLY THIS MAY INCREASE
THUNDERSTORM INTENSITY TODAY...ESPECIALLY NORTH AND EAST OF TUCSON.
HOWEVER BY SUNDAY THIS SAME TROUGH WILL INDUCE A DRIER SOUTHWEST
FLOW WHICH WILL TEMPORARILY SHUNT THE DEEPER MOISTURE SOUTH AND EAST
OF THE REGION. AS THE TROUGH WEAKENS AND UPPER LEVEL HIGH OVER THE
SOUTHERN PLAINS BUILDS BACK TO THE WEST. A MORE TYPICAL MONSOON
PATTERN WILL RESUME FOR THE START OF THE NEW MONTH.

&&

.DISCUSSION...VISIBLE SATELLITE IMAGERY THIS MORNING SHOWED
SCATTERED MID-LEVEL CLOUDS N AND E OF TUCSON AND THEN SOUTH OF THE
INTERNATIONAL BORDER. ELSEWHERE ABUNDANT SUNSHINE PREVAILED. WATER
VAPOR IMAGERY SHOWED DEPARTING LOW OVER NE ARIZONA WITH PLENTY OF
MID-UPPER LEVEL DRY AIR ADVECTING IN BEHIND THIS SYSTEM. MORNING
TUCSON SOUNDING SHOWED WESTERLY FLOW THROUGH MOST OF THE COLUMN.
PRECIPITABLE WATER VALUES ARE DOWN AROUND 0.15"-0.50" FROM FRIDAY
MORNING WITH VALUES IN THE 1"-1.30" RANGE. SURFACE DEWPOINTS THIS
MORNING WERE IN THE UPPER 50S TO THE UPPER 60S WITH VALUES UP THE
COLORADO RIVER IN THE 70S AS GULF SURGE CONTINUES.

NOW TO THE 12Z MODELS. GFS INITIALIZED WAY TOO MUCH CLOUD COVER/QPF
OVER SOUTHEAST ARIZONA WHILE THE NAM HAD A SLIGHTLY BETTER
INITIALIZATION. THEY BOTH HAVE DIFFERENT SOLUTIONS FOR LATER TODAY
INTO TONIGHT WITH NAM KEEPING MOST OF THE ACTIVITY EAST OF A PICACHO
PEAK TO SASABE LINE WITH SMALL MCS DEVELOPING JUST EAST OF TUCSON.
THIS WAS NOT SEEN ON THE 06Z NAM. GFS HAS AREAL COVERAGE OF ACTIVITY
ACROSS MOST OF SOUTHEAST ARIZONA STARTING THIS MORNING AND
CONTINUING INTO THE EVENING. HAVE YET TO LOOK AT THE UOFA WRF RUNS.

SO IN A NUTSHELL...MODELS HAVING SOME PROBLEMS TODAY AND NOT MUCH TO
HANG YOUR HAT ON TO CHANGE THE CURRENT FORECAST WHICH CALLS FOR
ISOLD TO SCATTERED STORMS THIS AFTERNOON INTO THIS EVENING. WITH THE
DRIER MID LEVEL AIR MOVING IN...THE THREAT FOR ISOLD SEVERE STORMS
INCREASES ACROSS THE AREA.

&&

.AVIATION...ISOLD-SCTD SHRA/TS WILL BE DVLPG AFT 18Z. SOME STORMS
MAY PRODUCE LCLY HVY RAIN...ALG WITH MVFR CIGS/VSBYS. NORMAL DIURNAL
WIND TRENDS OUTSIDE OF STRONG GUSTY OUTFLOWS FROM THUNDERSTORMS.
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
NATIONAL WEATHER SERVICE TUCSON AZ
113 PM MST SAT AUG 28 2010

AZZ019-029-030-033>035-290700-
NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY-
UPPER GILA RIVER VALLEY-TUCSON METRO/MARANA/GREEN VALLEY-
SANTA CRUZ COUNTY-COCHISE COUNTY-
113 PM MST SAT AUG 28 2010

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

DRIER AIR ALOFT HAS MOVED IN FROM THE WEST. HOWEVER AT THE SURFACE
SUFFICIENT MOISTURE REMAINS. COMBINED WITH THE AFTERNOON HEATING
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE DEVELOPING AND LASTING
INTO THE EARLIER EVENING HOURS. LOCALLY HEAVY RAIN AND WIND GUSTS
TO 50 MPH ARE POSSIBLE WITH THE STRONGEST STORMS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE WILL BE A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.

.SPOTTER INFORMATION STATEMENT...

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

AZZ031-032-290700-
WESTERN PIMA COUNTY-TOHONO OODHAM NATION-
113 PM MST SAT AUG 28 2010

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

DRIER AIR HAS MOVED IN ALOFT WHICH WILL LIMIT THE CHANCES OF
THUNDERSTORM DEVELOPMENT. HOWEVER WITH SUFFICIENT MOISTURE
REMAINING AT THE SURFACE...CAN'T RULE OUT THUNDERSTORM
DEVELOPMENT. ACROSS EASTERN PORTIONS OF THE TOHONO OODHAM
NATION...SOME OF THE STORMS THAT DEVELOP WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAIN.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY.

.SPOTTER INFORMATION STATEMENT...

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

WEATHER.GOV/TUCSON

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
200 PM MST SAT AUG 28 2010

AZZ035-282145-
COCHISE COUNTY AZ-
200 PM MST SAT AUG 28 2010

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN COCHISE COUNTY UNTIL 245
PM MST...

AT 153 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 6 MILES EAST OF HUACHUCA CITY...OR 8 MILES NORTH
OF SIERRA VISTA...MOVING EAST AT 10 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.

AREAS AFFECTED BY THIS STORM INCLUDE...NICKSVILLE...FAIRBANK...
CHARLESTON...HEREFORD...TOMBSTONE AND JUNCTION OF HIGHWAYS 80 AND 90.

LAT...LON 3199 10991 3139 10993 3143 11025 3185 11036
TIME...MOT...LOC 2100Z 275DEG 5KT 3166 11023