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000
FXUS65 KTWC 021021
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
300 AM MST WED SEP 2 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL CREATE ELEVATED CHANCES OF SHOWERS AND THUNDERSTORMS THROUGH
SATURDAY. WE WILL THEN MAINTAIN ENOUGH MOISTURE FOR ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS INTO NEXT WEEK.

&&

.DISCUSSION...WE`VE ESTABLISHED A VERY NIFTY SOUTHWESTERLY TO
SOUTHERLY FLOW BETWEEN LARGE SCALE FEATURES AS THE PERSISTENT MEAN
TROUGH POSITION REMAINS THROUGH THE REGION TO OUR NORTHWEST (A NICE
LITTLE LOW AT THE BASE OFF THE SOUTHERN CALIFORNIA COAST) AND THE
RIDGE AXIS PHASES A TAD FURTHER EAST. THIS OPENS UP A FETCH THAT
REACHES ALL THE WAY DOWN TO THE TROPICAL ACTIVITY SOUTH OF BAJA OFF
THE WEST COAST OF MEXICO. THAT DOES NICE THINGS FOR MAINTAINING OUR
MOISTURE. IT ALSO BRINGS IN 2 EMBEDDED IMPULSES IN THIS FLOW TODAY
AND THEN AGAIN THURSDAY.

OVERALL A WELL ABOVE AVERAGE THUNDERSTORM DAY EXPECTED TODAY AS THE
FIRST IMPULSE PUSHES IN FROM THE SOUTH...WITH A TRAJECTORY FAVORING
SANTA CRUZ...EASTERN PIMA...AND WESTERN COCHISE COUNTY THIS
AFTERNOON AND MUCH OF THE REST OF THE AREA THIS EVENING. WATCH FOR
ORGANIZED OUTFLOWS AND HEAVY RAIN WITH ISOLATED WET MICROBURST
POTENTIAL. THE OUTFLOWS MAY CREATE SOME DUST ISSUES IN PORTIONS OF
PIMA AND PINAL COUNTIES.

THE FLOW WILL BE STRONG ENOUGH TO RESET THE ATMOSPHERE FOR
THURSDAY...AND WITH A SECOND IMPULSE COMING UP FROM THE SOUTH LATE
THURSDAY AFTERNOON AND EVENING...THE POTENTIAL IS THERE FOR A MORE
WIDESPREAD AND STRONGER CONVECTIVE PERIOD THAN TODAY. EVEN BETTER
STORM ORGANIZATION POSSIBLE WITH ANOTHER ELEVATED RISK FOR WET
MICROBURST ACTIVITY AND STRONG ORGANIZED OUTFLOW.

AFTER THAT DETAILS BECOME LESS CLEAR...HOWEVER IN GENERAL WE WILL
MAINTAIN THIS FAVORABLE FLOW INTO THE WEEKEND WITH EACH DAY HAVING
THE POTENTIAL FOR ABOVE AVERAGE THUNDERSTORM COVERAGE AS WE CONTINUE
TO IMPORT MOISTURE AND ENERGY FROM OUR SEPTEMBER TROPICAL SEEDING
ZONE OFF THE MEXICAN COAST.

&&

.AVIATION...VALID THRU 03/12Z.
SCATTERED TO NUMEROUS TSRA/SHRA ACROSS MUCH OF SE ARIZONA WEDNESDAY
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND GUSTS OF 35 TO
45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO TONIGHT. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY.

&&

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

&&

$$

MEYER/RASMUSSEN

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON


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000
FXUS65 KPSR 020915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED SEP 2 2015


.SYNOPSIS... LOW PRESSURE OFF THE WEST COAST THAT WILL BE MOVING
INLAND OVER THE NEXT FEW DAYS IS EXPECTED TO PULL ADDITIONAL
MOISTURE NORTHWARD INTO THE REGION...INCREASING THUNDERSTORM CHANCES
ACROSS SOUTH CENTRAL ARIZONA TODAY AND THURSDAY. A RETURN OF
SOMEWHAT DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS
AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
THUNDERSTORM CHANCES WILL THEN INCREASE SOMEWHAT EARLY NEXT WEEK AS
MOISTURE LEVELS ONCE AGAIN RISE ACROSS THE REGION.

&&

.DISCUSSION...
.TODAY THROUGH THURSDAY...

AFTER A RATHER QUIET DAY ON TUESDAY...TODAY AND THURSDAY LOOKS LIKE
THEY WILL LIKELY BE NOTICEABLY MORE ACTIVE AS FAR AS CONVECTIVE
ACTIVITY IS CONCERNED. IR SATELLITE IMAGERY IS NOW SHOWING MORE
CLOUDINESS...AND MOISTURE MOVING NORTHWARD INTO CENTRAL AND EASTERN
AZ AS AN UPPER TROF OFF THE CA COAST FINALLY BEGINS TO MOVE TO THE
EAST AS A STRONGER UPPER LOW THAT IS FORECAST TO MOVE SOUTHWARD INTO
THE PACIFIC NW ACTS AS A KICKER. ADDITIONAL MOISTURE IS ALSO BEING
TRANSPORTED NORTHWARD FROM TROPICAL DEPRESSION 14E...WHICH IS
EXPECTED TO JUST BARELY ATTAIN TROPICAL STORM STATUS FOR A BRIEF
TIME TODAY AND EARLY THURSDAY BEFORE WEAKENING...AND DISSIPATING
WELL OFF THE SOUTHERN BAJA COAST ON FRIDAY AND SATURDAY. THE LATEST
GFS IS SHOWING PWATS OVER SOUTH-CENTRAL ARIZONA RISING INTO THE 1.50-
1.7 INCH RANGE BY THIS AFTERNOON. THE COMBINATION OF THIS ADDITIONAL
MOISTURE...ALONG WITH AN EMBEDDED SHORTWAVE MOVING NORTHWARD INTO
THE REGION...AND A FAIR-GOOD VERTICAL WIND SHEAR PROFILE IS EXPECTED
TO TRIGGER SCATTERED-WIDESPREAD CONVECTIVE ACTIVITY THIS AFTERNOON
AND EVENING ACROSS SOUTH-CENTRAL AZ. THE MAIN RISKS FROM THE STORMS
TODAY WILL BE VERY STRONG WINDS...BRIEF HEAVY RAINS...AND EVEN AN
OUTSIDE CHANCE FOR SOME SMALL HAIL. HOWEVER...WIDESPREAD FLASH
FLOODING IS NOT EXPECTED DUE TO THE EXPECTED RATHER RAPID MOVEMENT
OF INDIVIDUAL THUNDERSTORM CELLS. THE COMBINATION OF INCREASED
MOISTURE LEVELS AND SOMEWHAT COOLER AIR ALOFT (500MB TEMPS IN THE -
8C TO -9C RANGE) IS EXPECTED TO KEEP HIGH TEMPS BELOW NORMAL...WITH
MOST LOWER DESERT LOCATIONS SEEING HIGHS IN THE 100-105F RANGE.

ALTHOUGH THE VERTICAL WIND SHEAR PROFILE LOOKS EVEN BETTER TOMORROW
AS THE UPPER TROF MOVES CLOSER...SOMEWHAT LOWER PWATS AND A BOUNDARY
LAYER THAT WILL LIKELY BE WORKED OVER BY TODAY/S STORMS WILL LIKELY
LIMIT THUNDERSTORM COVERAGE SOMEWHAT ON THURSDAY...BUT POPS WILL
STILL BE WELL ABOVE CLIMO LEVELS ACROSS SOUTH-CENTRAL AZ. MUCH DRIER
AIR IS EXPECTED TO PRETTY MUCH KEEP SW AZ AND SE CA THUNDERSTORM-
FREE ON BOTH DAYS.

.FRIDAY THROUGH SUNDAY... SOMEWHAT LESS CONVECTIVE ACTIVITY IS
EXPECTED DURING THIS TIME PERIOD AS SOMEWHAT DRIER AIR WORKS ITS WAY
EASTWARD INTO SOUTH-CENTRAL AZ. STILL...AT LEAST SLIGHT CHANCE POPS
ARE WARRANTED EACH DAY ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ
AS PWAT LEVELS REMAIN IN THE 1.0-1.5 INCH RANGE AND THE VERTICAL
SHEAR PROFILE REMAINS FAVORABLE THROUGH THE COLUMN.

.MONDAY THROUGH TUESDAY... ALTHOUGH FORECAST CONFIDENCE LEVELS ARE
RATHER LOW THIS FAR OUT...A INCREASE IN AVAILABLE MOISTURE AS THE
FLOW BELOW 500MB BECOMES A BIT MORE SOUTHERLY IS EXPECTED TO ALLOW
PRECIP CHANCES TO RISE A BIT DURING THIS TIME PERIOD. SOMEWHAT
WARMER AIR ALOFT AS RIDGING BUILDS BACK NORTHWARD INTO THE REGION
WILL ALSO ALLOW TEMPS TO WARM TO NEAR...OR SLIGHTLY ABOVE NORMAL
VALUES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...PERCHA



000
FXUS65 KPSR 020915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED SEP 2 2015


.SYNOPSIS... LOW PRESSURE OFF THE WEST COAST THAT WILL BE MOVING
INLAND OVER THE NEXT FEW DAYS IS EXPECTED TO PULL ADDITIONAL
MOISTURE NORTHWARD INTO THE REGION...INCREASING THUNDERSTORM CHANCES
ACROSS SOUTH CENTRAL ARIZONA TODAY AND THURSDAY. A RETURN OF
SOMEWHAT DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS
AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.
THUNDERSTORM CHANCES WILL THEN INCREASE SOMEWHAT EARLY NEXT WEEK AS
MOISTURE LEVELS ONCE AGAIN RISE ACROSS THE REGION.

&&

.DISCUSSION...
.TODAY THROUGH THURSDAY...

AFTER A RATHER QUIET DAY ON TUESDAY...TODAY AND THURSDAY LOOKS LIKE
THEY WILL LIKELY BE NOTICEABLY MORE ACTIVE AS FAR AS CONVECTIVE
ACTIVITY IS CONCERNED. IR SATELLITE IMAGERY IS NOW SHOWING MORE
CLOUDINESS...AND MOISTURE MOVING NORTHWARD INTO CENTRAL AND EASTERN
AZ AS AN UPPER TROF OFF THE CA COAST FINALLY BEGINS TO MOVE TO THE
EAST AS A STRONGER UPPER LOW THAT IS FORECAST TO MOVE SOUTHWARD INTO
THE PACIFIC NW ACTS AS A KICKER. ADDITIONAL MOISTURE IS ALSO BEING
TRANSPORTED NORTHWARD FROM TROPICAL DEPRESSION 14E...WHICH IS
EXPECTED TO JUST BARELY ATTAIN TROPICAL STORM STATUS FOR A BRIEF
TIME TODAY AND EARLY THURSDAY BEFORE WEAKENING...AND DISSIPATING
WELL OFF THE SOUTHERN BAJA COAST ON FRIDAY AND SATURDAY. THE LATEST
GFS IS SHOWING PWATS OVER SOUTH-CENTRAL ARIZONA RISING INTO THE 1.50-
1.7 INCH RANGE BY THIS AFTERNOON. THE COMBINATION OF THIS ADDITIONAL
MOISTURE...ALONG WITH AN EMBEDDED SHORTWAVE MOVING NORTHWARD INTO
THE REGION...AND A FAIR-GOOD VERTICAL WIND SHEAR PROFILE IS EXPECTED
TO TRIGGER SCATTERED-WIDESPREAD CONVECTIVE ACTIVITY THIS AFTERNOON
AND EVENING ACROSS SOUTH-CENTRAL AZ. THE MAIN RISKS FROM THE STORMS
TODAY WILL BE VERY STRONG WINDS...BRIEF HEAVY RAINS...AND EVEN AN
OUTSIDE CHANCE FOR SOME SMALL HAIL. HOWEVER...WIDESPREAD FLASH
FLOODING IS NOT EXPECTED DUE TO THE EXPECTED RATHER RAPID MOVEMENT
OF INDIVIDUAL THUNDERSTORM CELLS. THE COMBINATION OF INCREASED
MOISTURE LEVELS AND SOMEWHAT COOLER AIR ALOFT (500MB TEMPS IN THE -
8C TO -9C RANGE) IS EXPECTED TO KEEP HIGH TEMPS BELOW NORMAL...WITH
MOST LOWER DESERT LOCATIONS SEEING HIGHS IN THE 100-105F RANGE.

ALTHOUGH THE VERTICAL WIND SHEAR PROFILE LOOKS EVEN BETTER TOMORROW
AS THE UPPER TROF MOVES CLOSER...SOMEWHAT LOWER PWATS AND A BOUNDARY
LAYER THAT WILL LIKELY BE WORKED OVER BY TODAY/S STORMS WILL LIKELY
LIMIT THUNDERSTORM COVERAGE SOMEWHAT ON THURSDAY...BUT POPS WILL
STILL BE WELL ABOVE CLIMO LEVELS ACROSS SOUTH-CENTRAL AZ. MUCH DRIER
AIR IS EXPECTED TO PRETTY MUCH KEEP SW AZ AND SE CA THUNDERSTORM-
FREE ON BOTH DAYS.

.FRIDAY THROUGH SUNDAY... SOMEWHAT LESS CONVECTIVE ACTIVITY IS
EXPECTED DURING THIS TIME PERIOD AS SOMEWHAT DRIER AIR WORKS ITS WAY
EASTWARD INTO SOUTH-CENTRAL AZ. STILL...AT LEAST SLIGHT CHANCE POPS
ARE WARRANTED EACH DAY ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ
AS PWAT LEVELS REMAIN IN THE 1.0-1.5 INCH RANGE AND THE VERTICAL
SHEAR PROFILE REMAINS FAVORABLE THROUGH THE COLUMN.

.MONDAY THROUGH TUESDAY... ALTHOUGH FORECAST CONFIDENCE LEVELS ARE
RATHER LOW THIS FAR OUT...A INCREASE IN AVAILABLE MOISTURE AS THE
FLOW BELOW 500MB BECOMES A BIT MORE SOUTHERLY IS EXPECTED TO ALLOW
PRECIP CHANCES TO RISE A BIT DURING THIS TIME PERIOD. SOMEWHAT
WARMER AIR ALOFT AS RIDGING BUILDS BACK NORTHWARD INTO THE REGION
WILL ALSO ALLOW TEMPS TO WARM TO NEAR...OR SLIGHTLY ABOVE NORMAL
VALUES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 020508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 PM MST TUE SEP 1 2015


.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY THIS EVENING HAVE
REDEVELOPED...POSSIBLY DUE TO AN MCV ORIGINATING FROM SONORA. LATEST
PSR SOUNDINGS ARE NOT FAVORABLE FOR STORM DEVELOPMENT TONIGHT DUE TO
SIZABLE CIN VALUES...THOUGH THE 03Z PSR SOUNDING DID HAVE SOME
MODEST MOISTENING BETWEEN 850-700MB COMPARED TO 00Z. ANOTHER FACTOR
THAT MAY AID IN STORM DEVELOPMENT LATER TONIGHT OVER SOUTHERN ARIZONA
IS A VORT MAX CENTERED NEAR SOUTHERN SONORA THIS EVENING. MODELS SHOW
THIS FEATURE WEAKENING AS IT MOVES NORTHWARD TONIGHT...ESPECIALLY AT
500 MB BUT LESS SO AT 300/250MB. THEY DEPICT VARYING AMOUNTS OF UPPER
LEVEL DIVERGENCE AHEAD OF THE SHORT WAVE AXIS OVER ARIZONA WEDNESDAY.
THE TIMING MAY BE A BIT EARLY TO TAKE ADVANTAGE OF AS THE AXIS IS
ALMOST NORTH OF OUR CWA BY 00Z THURSDAY. HOWEVER...WOULD ANTICIPATE A
LOT MORE ACTIVITY OVER SOUTHEAST ARIZONA WEDNESDAY THAN WE HAD TODAY
GIVEN THE DYNAMICAL AID AND NOT MUCH ACTIVITY TODAY TO STABILIZE
THINGS. THUS THE KNOCK-ON EFFECTS FOR THE CENTRAL DESERTS WILL BE
ENHANCED...PROBABLY OCCURRING EARLIER IN THE DAY THAN WE OFTEN SEE.
ANTICIPATE OUR HIGHER TERRAIN AREAS WILL BE ABLE TO TAKE ADVANTAGE OF
THE FORCING AS WELL. THE MOISTURE GRADIENT WILL BE CLOSE TO THE
PHOENIX AREA...OVER WESTERN MARICOPA COUNTY SO IT LOOKS LIKE THINGS
SHOULD BE QUIET OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.

&&

.PREVIOUS DISCUSSION ISSUED 241 PM...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED
TO YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...AJ
FIRE WEATHER...PERCHA



000
FXUS65 KPSR 020508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 PM MST TUE SEP 1 2015


.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY THIS EVENING HAVE
REDEVELOPED...POSSIBLY DUE TO AN MCV ORIGINATING FROM SONORA. LATEST
PSR SOUNDINGS ARE NOT FAVORABLE FOR STORM DEVELOPMENT TONIGHT DUE TO
SIZABLE CIN VALUES...THOUGH THE 03Z PSR SOUNDING DID HAVE SOME
MODEST MOISTENING BETWEEN 850-700MB COMPARED TO 00Z. ANOTHER FACTOR
THAT MAY AID IN STORM DEVELOPMENT LATER TONIGHT OVER SOUTHERN ARIZONA
IS A VORT MAX CENTERED NEAR SOUTHERN SONORA THIS EVENING. MODELS SHOW
THIS FEATURE WEAKENING AS IT MOVES NORTHWARD TONIGHT...ESPECIALLY AT
500 MB BUT LESS SO AT 300/250MB. THEY DEPICT VARYING AMOUNTS OF UPPER
LEVEL DIVERGENCE AHEAD OF THE SHORT WAVE AXIS OVER ARIZONA WEDNESDAY.
THE TIMING MAY BE A BIT EARLY TO TAKE ADVANTAGE OF AS THE AXIS IS
ALMOST NORTH OF OUR CWA BY 00Z THURSDAY. HOWEVER...WOULD ANTICIPATE A
LOT MORE ACTIVITY OVER SOUTHEAST ARIZONA WEDNESDAY THAN WE HAD TODAY
GIVEN THE DYNAMICAL AID AND NOT MUCH ACTIVITY TODAY TO STABILIZE
THINGS. THUS THE KNOCK-ON EFFECTS FOR THE CENTRAL DESERTS WILL BE
ENHANCED...PROBABLY OCCURRING EARLIER IN THE DAY THAN WE OFTEN SEE.
ANTICIPATE OUR HIGHER TERRAIN AREAS WILL BE ABLE TO TAKE ADVANTAGE OF
THE FORCING AS WELL. THE MOISTURE GRADIENT WILL BE CLOSE TO THE
PHOENIX AREA...OVER WESTERN MARICOPA COUNTY SO IT LOOKS LIKE THINGS
SHOULD BE QUIET OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.

&&

.PREVIOUS DISCUSSION ISSUED 241 PM...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED
TO YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...AJ
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 020508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 PM MST TUE SEP 1 2015


.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY THIS EVENING HAVE
REDEVELOPED...POSSIBLY DUE TO AN MCV ORIGINATING FROM SONORA. LATEST
PSR SOUNDINGS ARE NOT FAVORABLE FOR STORM DEVELOPMENT TONIGHT DUE TO
SIZABLE CIN VALUES...THOUGH THE 03Z PSR SOUNDING DID HAVE SOME
MODEST MOISTENING BETWEEN 850-700MB COMPARED TO 00Z. ANOTHER FACTOR
THAT MAY AID IN STORM DEVELOPMENT LATER TONIGHT OVER SOUTHERN ARIZONA
IS A VORT MAX CENTERED NEAR SOUTHERN SONORA THIS EVENING. MODELS SHOW
THIS FEATURE WEAKENING AS IT MOVES NORTHWARD TONIGHT...ESPECIALLY AT
500 MB BUT LESS SO AT 300/250MB. THEY DEPICT VARYING AMOUNTS OF UPPER
LEVEL DIVERGENCE AHEAD OF THE SHORT WAVE AXIS OVER ARIZONA WEDNESDAY.
THE TIMING MAY BE A BIT EARLY TO TAKE ADVANTAGE OF AS THE AXIS IS
ALMOST NORTH OF OUR CWA BY 00Z THURSDAY. HOWEVER...WOULD ANTICIPATE A
LOT MORE ACTIVITY OVER SOUTHEAST ARIZONA WEDNESDAY THAN WE HAD TODAY
GIVEN THE DYNAMICAL AID AND NOT MUCH ACTIVITY TODAY TO STABILIZE
THINGS. THUS THE KNOCK-ON EFFECTS FOR THE CENTRAL DESERTS WILL BE
ENHANCED...PROBABLY OCCURRING EARLIER IN THE DAY THAN WE OFTEN SEE.
ANTICIPATE OUR HIGHER TERRAIN AREAS WILL BE ABLE TO TAKE ADVANTAGE OF
THE FORCING AS WELL. THE MOISTURE GRADIENT WILL BE CLOSE TO THE
PHOENIX AREA...OVER WESTERN MARICOPA COUNTY SO IT LOOKS LIKE THINGS
SHOULD BE QUIET OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.

&&

.PREVIOUS DISCUSSION ISSUED 241 PM...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED
TO YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...AJ
FIRE WEATHER...PERCHA



000
FXUS65 KPSR 020508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 PM MST TUE SEP 1 2015


.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY THIS EVENING HAVE
REDEVELOPED...POSSIBLY DUE TO AN MCV ORIGINATING FROM SONORA. LATEST
PSR SOUNDINGS ARE NOT FAVORABLE FOR STORM DEVELOPMENT TONIGHT DUE TO
SIZABLE CIN VALUES...THOUGH THE 03Z PSR SOUNDING DID HAVE SOME
MODEST MOISTENING BETWEEN 850-700MB COMPARED TO 00Z. ANOTHER FACTOR
THAT MAY AID IN STORM DEVELOPMENT LATER TONIGHT OVER SOUTHERN ARIZONA
IS A VORT MAX CENTERED NEAR SOUTHERN SONORA THIS EVENING. MODELS SHOW
THIS FEATURE WEAKENING AS IT MOVES NORTHWARD TONIGHT...ESPECIALLY AT
500 MB BUT LESS SO AT 300/250MB. THEY DEPICT VARYING AMOUNTS OF UPPER
LEVEL DIVERGENCE AHEAD OF THE SHORT WAVE AXIS OVER ARIZONA WEDNESDAY.
THE TIMING MAY BE A BIT EARLY TO TAKE ADVANTAGE OF AS THE AXIS IS
ALMOST NORTH OF OUR CWA BY 00Z THURSDAY. HOWEVER...WOULD ANTICIPATE A
LOT MORE ACTIVITY OVER SOUTHEAST ARIZONA WEDNESDAY THAN WE HAD TODAY
GIVEN THE DYNAMICAL AID AND NOT MUCH ACTIVITY TODAY TO STABILIZE
THINGS. THUS THE KNOCK-ON EFFECTS FOR THE CENTRAL DESERTS WILL BE
ENHANCED...PROBABLY OCCURRING EARLIER IN THE DAY THAN WE OFTEN SEE.
ANTICIPATE OUR HIGHER TERRAIN AREAS WILL BE ABLE TO TAKE ADVANTAGE OF
THE FORCING AS WELL. THE MOISTURE GRADIENT WILL BE CLOSE TO THE
PHOENIX AREA...OVER WESTERN MARICOPA COUNTY SO IT LOOKS LIKE THINGS
SHOULD BE QUIET OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.

&&

.PREVIOUS DISCUSSION ISSUED 241 PM...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED
TO YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
ISOLATED WEAK THUNDERSTORMS OVER PINAL COUNTY AS OF 04Z POSSIBLY
ASSOCIATED WITH A WEAK DISTURBANCE FROM SONORA. THESE MAY CONTINUE TO
DRIFT NORTHWARD AND BRUSH EASTERN PORTIONS OF METRO
PHOENIX...POSSIBLY AFFECTING KIWA...BUT NOT LIKELY FOR KPHX. A MORE
SIGNIFICANT TRAILING DISTURBANCE MAY LEAD TO STORM DEVELOPMENT OVER
SOUTHEAST AND EAST-CENTRAL ARIZONA EARLIER IN THE DAY WEDNESDAY THAN
NORMAL WHICH WILL LIKELY HAVE KNOCK-ON EFFECTS FOR THE PHOENIX AREA
IN THE AFTERNOON...OUTFLOWS AND POSSIBLY DIRECT HITS FROM TSTMS.
OTHERWISE...ANTICIPATE HIGH CLOUDS TO LINGER AND SURFACE WINDS TO
FAVOR EASTERLY COMPONENTS OVERNIGHT AND MUCH OF THE DAY WEDNESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
EXPECT CLEAR SKIES FOR MUCH OF THE NIGHT FOLLOWED BY INCREASING HIGH
CLOUDS DURING THE DAY WEDNESDAY. SURFACE WINDS WILL CONTINUE TO FAVOR
SOUTHERLY COMPONENTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...INIGUEZ
AVIATION...AJ
FIRE WEATHER...PERCHA




000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 020450
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
950 PM MST TUE SEP 1 2015

.SYNOPSIS...AMPLE MOISTURE IN COMBINATION WITH SEVERAL DISTURBANCES
WILL MAINTAIN SCATTERED THUNDERSTORMS THROUGH SATURDAY. ISOLATED TO
SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS WILL THEN
PREVAIL EARLY NEXT WEEK. EXPECT BELOW AVERAGE DAYTIME TEMPERATURES
THROUGH SATURDAY FOLLOWED BY A MODEST WARMING TREND EARLY NEXT WEEK.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-55 DBZ ECHOES FROM
NEAR THE TUCSON MOUNTAINS NWWD INTO SOUTH CENTRAL PINAL COUNTY. THE
REST OF SE ARIZONA WAS VOID OF PRECIP ECHOES. THESE SHOWERS AND
THUNDERSTORMS ONGOING WEST-TO-NORTHWEST OF THE TUCSON METRO AREA
WERE AHEAD OF A REMNANT MCV/CYCLONIC CIRCULATION FEATURE APPROACHING
THE INTERNATIONAL BORDER ADJACENT SANTA CRUZ COUNTY.

BASED ON THE 02/00Z NAM12 AND SEVERAL HRRR SOLUTIONS AS WELL AS
RADAR TRENDS...HAVE MAINTAINED ISOLATED SHOWERS/TSTMS ACROSS MUCH OF
THIS FORECAST AREA THE REST OF TONIGHT INTO EARLY WED MORNING.
ADEQUATE MOISTURE IN COMBINATION WITH A MODESTLY UNSTABLE
ENVIRONMENT AND THE AFOREMENTIONED CYCLONIC CIRCULATION FEATURE
SHOULD BE SUFFICIENT TO SUPPORT AT LEAST A SLIGHT CHANCE OF
SHOWERS/TSTMS THRU DAYBREAK WED. GIVEN THE PAUCITY OF SIGNIFICANT
RAINFALL EARLIER THIS EVENING...BELIEVE THAT AMOUNTS THE REST OF
TONIGHT WILL BE CONSIDERABLY LESS THAN 24 HOURS AGO.

OTHERWISE...EXPECT MOSTLY CLOUDY SKIES ACROSS MUCH OF SE ARIZONA THE
REST OF TONIGHT. A FAIRLY ACTIVE PERIOD FOR SHOWERS/TSTMS MAY VERY
WELL BE ON TAP WED AFTERNOON/EVENING IF THE 01/12Z UNIV OF AZ WRF
NAM/GFS SOLUTIONS AND THE 02/00Z NAM12 IS REALITY. HIGH TEMPS WED
WILL AVERAGE ABOUT 2-4 DEGS F OR SO BELOW NORMAL. EVEN COOLER
DAYTIME TEMPS ARE FORECAST TO OCCUR THUR.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 03/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA INTO WEDNESDAY MORNING...THEN
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA ACROSS MUCH OF SE ARIZONA
WEDNESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND WIND
GUSTS OF 35 TO 45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...EXPECT LAYERED CLOUDS MOSTLY BETWEEN 10-15K FT AGL AND
SURFACE WIND GENERALLY LESS THAN 10 KTS INTO WEDNESDAY EVENING.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
MUCH OF SOUTHEAST ARIZONA THROUGH SATURDAY. LOCALLY HEAVY RAINFALL
AND BRIEF GUSTY WINDS WILL ACCOMPANY THE STRONGER THUNDERSTORMS.
THEREAFTER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL SUNDAY THROUGH TUESDAY. THE BEST CHANCE
OF THIS ACTIVITY WILL BE ACROSS GREENLEE...GRAHAM AND COCHISE
COUNTIES EAST OF TUCSON. DAYTIME TEMPERATURES WILL BE BELOW SEASONAL
AVERAGES DURING THE NEXT SEVERAL DAYS FOLLOWED BY A MODEST WARMING
TREND EARLY NEXT WEEK.

&&

.PREV DISCUSSION /232 PM MST/...A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING BELOW NORMAL THE
NEXT FEW DAYS.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON


  [top]

000
FXUS65 KFGZ 020355
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED BY MID
EVENING. FOR THE REMAINDER OF THE NIGHT...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED SHOWERS AND STORMS OVER MUCH OF NORTHERN
ARIZONA. PARTLY CLOUDY SKIES WILL CONTINUE.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF AFTERNOON/EVENING
THUNDERSTORMS TO BE OVER THE EASTERN MOGOLLON RIM/WHITE AND CHUSKA
MOUNTAINS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS FORECAST TO
STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF A TROUGH
LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN RAINFALL
COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...ESPECIALLY THURSDAY
AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLATED SHOWERS AND THUNDERSTORMS
UNTIL 18Z...WITH ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND
STORMS DEVELOPING AFTER 18Z. THUNDERSTORMS WILL BE MOST NUMEROUS
EAST OF A LINE EXTENDING FROM PAYSON TO CHINLE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...MCCOLLUM/TAYLOR
AVIATION...MCCOLLUM/RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 020355
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED BY MID
EVENING. FOR THE REMAINDER OF THE NIGHT...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED SHOWERS AND STORMS OVER MUCH OF NORTHERN
ARIZONA. PARTLY CLOUDY SKIES WILL CONTINUE.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF AFTERNOON/EVENING
THUNDERSTORMS TO BE OVER THE EASTERN MOGOLLON RIM/WHITE AND CHUSKA
MOUNTAINS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS FORECAST TO
STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF A TROUGH
LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN RAINFALL
COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...ESPECIALLY THURSDAY
AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLATED SHOWERS AND THUNDERSTORMS
UNTIL 18Z...WITH ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND
STORMS DEVELOPING AFTER 18Z. THUNDERSTORMS WILL BE MOST NUMEROUS
EAST OF A LINE EXTENDING FROM PAYSON TO CHINLE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...MCCOLLUM/TAYLOR
AVIATION...MCCOLLUM/RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 020355
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED BY MID
EVENING. FOR THE REMAINDER OF THE NIGHT...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED SHOWERS AND STORMS OVER MUCH OF NORTHERN
ARIZONA. PARTLY CLOUDY SKIES WILL CONTINUE.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF AFTERNOON/EVENING
THUNDERSTORMS TO BE OVER THE EASTERN MOGOLLON RIM/WHITE AND CHUSKA
MOUNTAINS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS FORECAST TO
STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF A TROUGH
LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN RAINFALL
COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...ESPECIALLY THURSDAY
AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLATED SHOWERS AND THUNDERSTORMS
UNTIL 18Z...WITH ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND
STORMS DEVELOPING AFTER 18Z. THUNDERSTORMS WILL BE MOST NUMEROUS
EAST OF A LINE EXTENDING FROM PAYSON TO CHINLE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...MCCOLLUM/TAYLOR
AVIATION...MCCOLLUM/RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 020355
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
900 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY HAD DIMINISHED BY MID
EVENING. FOR THE REMAINDER OF THE NIGHT...ENOUGH MOISTURE WILL
REMAIN FOR ISOLATED SHOWERS AND STORMS OVER MUCH OF NORTHERN
ARIZONA. PARTLY CLOUDY SKIES WILL CONTINUE.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF AFTERNOON/EVENING
THUNDERSTORMS TO BE OVER THE EASTERN MOGOLLON RIM/WHITE AND CHUSKA
MOUNTAINS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS FORECAST TO
STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF A TROUGH
LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN RAINFALL
COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...ESPECIALLY THURSDAY
AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLATED SHOWERS AND THUNDERSTORMS
UNTIL 18Z...WITH ANOTHER ROUND OF ISOLATED TO SCATTERED SHOWERS AND
STORMS DEVELOPING AFTER 18Z. THUNDERSTORMS WILL BE MOST NUMEROUS
EAST OF A LINE EXTENDING FROM PAYSON TO CHINLE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...MCCOLLUM/TAYLOR
AVIATION...MCCOLLUM/RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 012317
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
417 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...
THUNDERSTORM ACTIVITY THIS AFTERNOON HAS BEEN QUITE SUBDUED
COMPARED WITH YESTERDAY DUE TO SUBSTANTIALLY LESS INSTABILITY.
EVEN SO...RAIN RATES WITH A COUPLE OF ISOLATED CELLS UP NORTH OVER
THE SLICK ROCK HAVE BEEN HIGH ENOUGH FOR A LONG ENOUGH DURATION TO
WARRANT FLASH FLOOD WARNINGS. WITH LITTLE EXTERNAL FORCING OTHER
THAN DAYTIME HEATING..EXPECT CONVECTIVE ACTIVITY TO DECREASE
AROUND SUNSET.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF
AFTERNOON/EVENING THUNDERSTORMS TO BE OVER THE EASTERN
RIM/WHITES/CHUSKAS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS
FORECAST TO STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF
A TROUGH LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN
RAINFALL COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...
ESPECIALLY THURSDAY AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 00Z PACKAGE...EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO DIMINISH AFTER 01Z. IFR CONDITIONS AND ERRATIC GUSTY
WINDS UP TO 40 MPH ARE POSSIBLE NEAR THE STRONGER STORMS. ANOTHER
ROUND OF SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS WILL
DEVELOP AFTER 18Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...TAYLOR
AVIATION...RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 012317
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
417 PM MST TUE SEP 1 2015

.SYNOPSIS...EXPECT ANOTHER RELATIVELY QUIET DAY ON WEDNESDAY
BEFORE THUNDERSTORM ACTIVITY PICKS UP AGAIN FROM THURSDAY INTO
SATURDAY. DRIER CONDITIONS MAY RETURN NEXT WEEK.

&&

.DISCUSSION...
THUNDERSTORM ACTIVITY THIS AFTERNOON HAS BEEN QUITE SUBDUED
COMPARED WITH YESTERDAY DUE TO SUBSTANTIALLY LESS INSTABILITY.
EVEN SO...RAIN RATES WITH A COUPLE OF ISOLATED CELLS UP NORTH OVER
THE SLICK ROCK HAVE BEEN HIGH ENOUGH FOR A LONG ENOUGH DURATION TO
WARRANT FLASH FLOOD WARNINGS. WITH LITTLE EXTERNAL FORCING OTHER
THAN DAYTIME HEATING..EXPECT CONVECTIVE ACTIVITY TO DECREASE
AROUND SUNSET.

ON WEDNESDAY...LOOK FOR THE GREATEST COVERAGE OF
AFTERNOON/EVENING THUNDERSTORMS TO BE OVER THE EASTERN
RIM/WHITES/CHUSKAS...WITH LOWER COVERAGE ELSEWHERE. MOISTURE IS
FORECAST TO STREAM NORTHWARD FROM THURSDAY INTO SATURDAY AHEAD OF
A TROUGH LOCATED OVER THE WESTERN UNITED STATES. AN INCREASE IN
RAINFALL COVERAGE ACROSS NORTHERN ARIZONA IS FORECAST...
ESPECIALLY THURSDAY AND FRIDAY.

LOW RAIN CHANCES ARE MAINTAINED FROM SUNDAY INTO THE EARLY PART OF
NEXT WEEK.

&&

.AVIATION...FOR THE 00Z PACKAGE...EXPECT SHOWER AND THUNDERSTORM
ACTIVITY TO DIMINISH AFTER 01Z. IFR CONDITIONS AND ERRATIC GUSTY
WINDS UP TO 40 MPH ARE POSSIBLE NEAR THE STRONGER STORMS. ANOTHER
ROUND OF SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS WILL
DEVELOP AFTER 18Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...TAYLOR
AVIATION...RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP



000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP




000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP




000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP




000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP




000
FXUS65 KPSR 012225
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST TUE SEP 1 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AMPLE MONSOON MOISTURE REMAINS OVER THE REGION HOWEVER SLIGHTLY
COOLER CONDITIONS...COURTESY OF LAST NIGHT`S STORMS...SHOULD HELP
HOLD BACK MOST OF THE POTENTIAL FOR STORMS TODAY. COULD SEE SOME
DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX WITH ONLY THE MOST
REMOTE CHANCES OF ANYTHING MAKING IT INTO THE METRO LIKELY AFTER
PEAK TRAFFIC PERIODS. CANNOT RULE OUT SOME SHOWER ACTIVITY
OVERNIGHT...BUT CONFIDENCE IN INCLUDING IN ALL THE PHX METRO TAFS IS
LOW ATTM. WINDS WILL EVENTUALLY SWING SOUTHWEST TO WESTERLY INTO THE
AFTN...OTHERWISE REMAIN LIGHT ENOUGH TO PRODUCE PERIODS OF VRB. MID
AND HIGH CLOUDS TO CONTINUE STREAMING IN FROM THE SOUTH...VARYING
FROM SCT TO OVC IN NATURE.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT TO BKN MID AND HIGH CLOUDS WILL CONTINUE TO STREAM IN FROM THE
SOUTHWEST THROUGH THE EVENING...GNLY REMAINING ABOVE 10KFT AGL.
MAINLY SOUTHERLY WINDS TO PERSIST ACROSS THE AREA...OTHERWISE WINDS
WILL BE LIGHT ENOUGH TO PRODUCE PERIODS OF VRB.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK.
MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS
SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF
THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST
GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER
HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL
ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...NOLTE
FIRE WEATHER...MP




000
FXUS65 KPSR 012141
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
241 PM MST TUE SEP 1 2015

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...MP
FIRE WEATHER...MP




000
FXUS65 KPSR 012141
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
241 PM MST TUE SEP 1 2015

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...MP
FIRE WEATHER...MP



000
FXUS65 KPSR 012141
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
241 PM MST TUE SEP 1 2015

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
DEW POINTS CONTINUE TO RUN HIGHER AND TEMPERATURES COOLER COMPARED TO
YESTERDAY CWA-WIDE DUE TO A COMBINATION OF GULF SURGE AND PREVIOUS
THUNDERSTORM ACTIVITY. AFTERNOON CONVECTION IS MUTED AT THIS
TIME...WILL HAVE TO MONITOR FOR FURTHER DEVELOPMENT BUT OVERALL
SHOULD BE A QUIETER DAY. WILL MAINTAIN LOW END POPS FROM ABOUT
PHOENIX EAST FOR POTENTIAL OF A STRAY SHOWER OR STORM BUT FAR MORE
LIKELY THE RAIN/STORMS DON/T MATERIALIZE.

GOING FORWARD THE NEXT FEW DAYS...PRIMARY MOISTURE AXIS AS DEPICTED
BY SUB-700 HPA MIXING RATIOS WILL REMAIN ORIENTED NORTH-SOUTH JUST TO
THE WEST OF THE AZ-NM BORDER. MOISTURE LEVELS WILL INCREASE TOMORROW
AND AGAIN THURSDAY AS A MID-LEVEL TROUGH PROGRESSES INTO THE WESTERN
US...INCREASING THE SOUTHERLY FLOW AND INGESTING A BIT OF MID-LEVEL
MOISTURE FROM TROPICAL SYSTEM 14-E. THAT SYSTEM MAY BE NAMED
TONIGHT/TOMORROW BY NHC BUT THE LOW LEVEL CIRCULATION WILL REMAIN
SOUTH OF 25N BY CURRENT NHC FORECAST...AT WHICH POINT IT/LL GRADUALLY
DECAY. THE MID-LEVEL CIRCULATION WILL LIKELY SHEAR OUT IN THE
APPROACHING TROUGH AND SOME OF THAT ENERGY...ALONG WITH THE
INCREASING BOUNDARY LAYER MOISTURE...IS EXPECTED TO RESULT IN ANOTHER
UPSWING IN THUNDERSTORM ACTIVITY FOR MARICOPA COUNTY AND AREAS EAST.

THUNDERSTORM ACTIVITY WILL LIKELY PEAK WED-THU THEN TREND DOWN A BIT
FRIDAY AND FROM SATURDAY INTO EARLY NEXT WEEK PLATEAU AT A LOW GRADE
LEVEL. WE/VE BEEN TALKING ABOUT A DRYING TREND FOR A WHILE NOW AND AT
THIS POINT IT MAY BE TIME TO ACCEPT IT ISN/T RIGHT AROUND THE CORNER.
WHILE GLOBAL ENSEMBLES DUE SUGGEST PWATS DROPPING BY EARLY NEXT
WEEK...DETERMINISTIC GFS/EC RUNS KEEP THE MONSOON MOISTURE PLUME
ALONG THE AZ/NM BORDER IN PLACE THROUGH TUE/WED AND THE BROADER
TROUGH PATTERN OVER THE WEST COAST REMAINS. NOT MUCH REASON TO EXPECT
THIS ESTABLISHED PATTERN TO CHANGE AT THIS TIME THUS INCREASED POPS
FOR MARICOPA EAST /WHICH WILL BE ON THE FRINGE OF THE MOISTURE
PLUME/.

FOR SW AZ AND INTO SE CA...IT/LL LIKELY REMAIN WARM...HUMID...AND
DRY. AND WITH A STAGNANT WEATHER PATTERN...NO REAL SIGNIFICANT
TEMPERATURE SWINGS EXPECTED.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ
AVIATION...MP
FIRE WEATHER...MP



000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 012132
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
232 PM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE THUNDERSTORM
COVERAGE WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS WERE HAVING A DIFFICULT TIME
DEVELOPING TODAY DUE TO THE RAIN COOLED AIRMASS IN PLACE FROM THE
THUNDERSTORMS LAST EVENING AND OVERNIGHT. STILL EXPECTING SOME
INCREASE IN COVERAGE OF THUNDERSTORMS THROUGH THIS EVENING BUT NOT
NEARLY AS MUCH AS YESTERDAY. A DISTURBANCE EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL HELP ENHANCE THUNDERSTORM ACTIVITY
WEDNESDAY INTO THURSDAY. MODELS CONTINUED TO SUGGEST THAT A SYSTEM
APPROACHING THE SOUTHERN TIP OF BAJA WILL HELP PUSH DEEPER MOISTURE
BACK INTO THE AREA BY THE WEEKEND. THIS DEEPER MOISTURE WILL
MAINTAIN RAIN CHANCES THIS WEEK. OTHERWISE...EXPECT COOLER HIGH
TEMPERATURES THAN LAST WEEK WITH READINGS REMAINING NEAR NORMAL THE
NEXT FEW DAYS.

&&

.AVIATION...VALID THRU 03/00Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS INTO THE
EVENING THEN DEVELOP ONCE AGAIN ONLY A MORE WIDESPREAD WEDNESDAY
AFTERNOON.  BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45 KTS MAY
OCCUR WITH WITH THE STRONGER THUNDERSTORMS. OTHERWISE...CLOUD DECKS
WILL GENERALLY RANGE FROM 8-12K FT AGL AND SURFACE WIND WILL GE
MOSTLY LESS THAN 10 KTS.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY.  WITH SW FLOW ALOFT STORMS WILL GENERALLY
MOVE TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST
PART STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.
CERNIGLIA

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011658
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
958 AM MST TUE SEP 1 2015

.SYNOPSIS...AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE
AGAIN WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH
WILL THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...SURFACE TEMPERATURES HAVE BEEN RUNNING ABOUT 4 TO 6
DEGREES COOLER THIS MORNING COMPARED TO YESTERDAY AFTER THE
WIDESPREAD RAINFALL LAST EVENING AND OVERNIGHT. THESE COOLER
TEMPERATURES SHOULD TRANSLATE TO A LITTLE LATER START IN SHOWER AND
THUNDERSTORM DEVELOPMENT TODAY. THAT SAID...STILL EXPECTING A DECENT
COVERAGE IN STORMS TODAY ALTHOUGH POSSIBLY AVOIDING AREAS HIT THE
HARDEST LAST EVENING AND NIGHT. CURRENT FORECAST LOOKED ON TRACK IN
THE SHORT-TERM...SO NO UPDATES NECESSARY AT THIS TIME. PLEASE REFER
TO THE ADDITIONAL SECTIONS FOR MORE DETAILS.


&&

.AVIATION...VALID THRU 02/18Z.
EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST AND SOUTHEAST KTUS THIS
AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS MAY OCCUR WITH WITH THE STRONGER THUNDERSTORMS.
OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-12K FT AGL AND
SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

.PREV DISCUSSION...FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST
SOUTHWESTERLY FLOW BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO
OUR EAST WILL BE BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH
TROPICAL ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO
(HELLO TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD
INTO SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KFGZ 011648
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
948 AM MST TUE SEP 1 2015

.SYNOPSIS...THE MOST ACTIVE AREAS FOR SHOWER AND THUNDERSTORM
ACTIVITY WILL SHIFT A BIT EASTWARD OVER THE NEXT DAY OR TWO. A
DEEPENING LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
ENHANCE THE THREAT OF MOISTURE MOVING IN FROM THE SOUTH LATER THIS
WEEK AND INTO THE WEEKEND. DAILY SHOWER AND THUNDERSTORM ACTIVITY
WILL CONTINUE AS A RESULT...ESPECIALLY OVER THE EASTERN HALF OF
THE STATE.

&&

.UPDATE/DISCUSSION...
EXPECT LESS INTENSE STORMS OVERALL TODAY COMPARED WITH YESTERDAY
AS INSTABILITY HAS DECREASED. MOST STORMS FROM NEAR I-17/US 89
EASTWARD THIS AFTERNOON/EVENING WITH A FEW ISOLATED CELLS CAPABLE
OF VERY HEAVY RAINFALL RATES. MINOR UPDATES TO PRECIP CHANCES FOR
THIS AFTERNOON/EVENING HAVE BEEN SENT.

&&

.PREV DISCUSSION /330 AM MST/...THERE IS STILL SOME WEAK
CONVECTION OVER NORTHERN COCONINO COUNTY EARLY THIS MORNING...DUE
TO LINGERING FORCING FROM A S/WV MOVING THROUGH SOUTHERN NEVADA
AND INTO UTAH. WATER VAPOR IMAGERY SHOWS SOME SUBTLE RIDGING
MOVING IN FROM THE SOUTHWEST AHEAD OF A TROPICAL S/WV SOUTHWEST
OF SAN DIEGO. THIS MAY SUPPRESS THE WESTERN ZONES TODAY...MAYBE
EVEN SOME OF THE CENTRAL ZONES.

THE DRYING WE HAVE BEEN WAITING FOR HAS NOT REALLY MATERIALIZED. A
FAIRLY SIGNIFICANT WEST-MOVING OUTFLOW (EVEN SEEN IN WATER VAPOR
IMAGERY) DEVELOPED OVER PHOENIX EARLIER IN THE NIGHT...FEATURES
SUCH AS THIS WILL PREVENT THE BOUNDARY LAYER FROM DRYING. BEHIND
THE LOW SOUTHWEST OF SAN DIEGO...MORE PRONOUNCED DRYING FROM THE
WEST SHOULD DEVELOP WEDNESDAY AND MAYBE THURSDAY.

DESPITE THIS...MANY GFS MEMBERS STILL INSIST THAT THE BACKING FLOW
FROM HGHT FALLS IN THE GREAT BASIN WILL DRAW MOISTURE INTO ARIZONA
LATE IN THE WEEK AND OVER THE WEEKEND. IN ADDITION...MANY MODELS
ARE ALSO FORECASTING SOME TROPICAL MOISTURE INTRUSION OVER THE
WEEKEND.

IN SUMMARY...THERE IS TOO MUCH UNCERTAINTY TO REALLY DRY THINGS
OUT FROM WEST AS WAS ORIGINALLY PLANNED. ALTHOUGH ACTIVITY WILL
DECREASE OVER THE NEXT FEW DAYS...IT CANNOT BE TOTALLY RULED OUT.
THE EASTERN ZONES MAY NEVER SEE A DECREASE AT ALL...WHEN COMPARED
TO THE LAST FEW DAYS. THESE TRENDS ARE REFLECTED IN THE LATEST
POP GRIDS.

&&

.AVIATION...FOR THE 18Z PACKAGE...EXPECT A ROUND OF SCATTERED TO
ISOLATED SHOWERS AND THUNERSTORMS TODAY. THE GREATEST COVERAGE IS
EXPECTED IN THE WHITE MOUNTAINS REGION...WITH DECREASING COVERAGE
WESTWARD. IFR CONDITIONS AND ERRATIC GUSTY WINDS UP TO 40 MPH ARE
FORECAST NEAR THE STRONGER STORMS. THUNDERSTORM COVERAGE WILL
DIMINISH AROUND SUNSET. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...TAYLOR/PETERSON
AVIATION...RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 011648
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
948 AM MST TUE SEP 1 2015

.SYNOPSIS...THE MOST ACTIVE AREAS FOR SHOWER AND THUNDERSTORM
ACTIVITY WILL SHIFT A BIT EASTWARD OVER THE NEXT DAY OR TWO. A
DEEPENING LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
ENHANCE THE THREAT OF MOISTURE MOVING IN FROM THE SOUTH LATER THIS
WEEK AND INTO THE WEEKEND. DAILY SHOWER AND THUNDERSTORM ACTIVITY
WILL CONTINUE AS A RESULT...ESPECIALLY OVER THE EASTERN HALF OF
THE STATE.

&&

.UPDATE/DISCUSSION...
EXPECT LESS INTENSE STORMS OVERALL TODAY COMPARED WITH YESTERDAY
AS INSTABILITY HAS DECREASED. MOST STORMS FROM NEAR I-17/US 89
EASTWARD THIS AFTERNOON/EVENING WITH A FEW ISOLATED CELLS CAPABLE
OF VERY HEAVY RAINFALL RATES. MINOR UPDATES TO PRECIP CHANCES FOR
THIS AFTERNOON/EVENING HAVE BEEN SENT.

&&

.PREV DISCUSSION /330 AM MST/...THERE IS STILL SOME WEAK
CONVECTION OVER NORTHERN COCONINO COUNTY EARLY THIS MORNING...DUE
TO LINGERING FORCING FROM A S/WV MOVING THROUGH SOUTHERN NEVADA
AND INTO UTAH. WATER VAPOR IMAGERY SHOWS SOME SUBTLE RIDGING
MOVING IN FROM THE SOUTHWEST AHEAD OF A TROPICAL S/WV SOUTHWEST
OF SAN DIEGO. THIS MAY SUPPRESS THE WESTERN ZONES TODAY...MAYBE
EVEN SOME OF THE CENTRAL ZONES.

THE DRYING WE HAVE BEEN WAITING FOR HAS NOT REALLY MATERIALIZED. A
FAIRLY SIGNIFICANT WEST-MOVING OUTFLOW (EVEN SEEN IN WATER VAPOR
IMAGERY) DEVELOPED OVER PHOENIX EARLIER IN THE NIGHT...FEATURES
SUCH AS THIS WILL PREVENT THE BOUNDARY LAYER FROM DRYING. BEHIND
THE LOW SOUTHWEST OF SAN DIEGO...MORE PRONOUNCED DRYING FROM THE
WEST SHOULD DEVELOP WEDNESDAY AND MAYBE THURSDAY.

DESPITE THIS...MANY GFS MEMBERS STILL INSIST THAT THE BACKING FLOW
FROM HGHT FALLS IN THE GREAT BASIN WILL DRAW MOISTURE INTO ARIZONA
LATE IN THE WEEK AND OVER THE WEEKEND. IN ADDITION...MANY MODELS
ARE ALSO FORECASTING SOME TROPICAL MOISTURE INTRUSION OVER THE
WEEKEND.

IN SUMMARY...THERE IS TOO MUCH UNCERTAINTY TO REALLY DRY THINGS
OUT FROM WEST AS WAS ORIGINALLY PLANNED. ALTHOUGH ACTIVITY WILL
DECREASE OVER THE NEXT FEW DAYS...IT CANNOT BE TOTALLY RULED OUT.
THE EASTERN ZONES MAY NEVER SEE A DECREASE AT ALL...WHEN COMPARED
TO THE LAST FEW DAYS. THESE TRENDS ARE REFLECTED IN THE LATEST
POP GRIDS.

&&

.AVIATION...FOR THE 18Z PACKAGE...EXPECT A ROUND OF SCATTERED TO
ISOLATED SHOWERS AND THUNERSTORMS TODAY. THE GREATEST COVERAGE IS
EXPECTED IN THE WHITE MOUNTAINS REGION...WITH DECREASING COVERAGE
WESTWARD. IFR CONDITIONS AND ERRATIC GUSTY WINDS UP TO 40 MPH ARE
FORECAST NEAR THE STRONGER STORMS. THUNDERSTORM COVERAGE WILL
DIMINISH AROUND SUNSET. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...TAYLOR/PETERSON
AVIATION...RICKEY


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KPSR 011631
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
931 AM MST TUE SEP 1 2015

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
A RELATIVELY COOL AND MOIST MORNING ACROSS THE FORECAST AREA. AT 16Z
TEMPERATURES WERE QUICKLY WARMING ACROSS SE CA AND SW AZ BUT SLOWER
OVER THE PHOENIX AREA DUE TO LAST NIGHT/S STORMS. DEW POINTS WERE INT
HE MID 60S TO MID 70S. YUMA WAS REPORTING GUSTY SOUTHERLY WINDS WITH
DEW POINTS THERE AND AT EL CENTRO WELL OVER 70. KYUX VWP DEPICTING
SSE WINDS UP TO 5KFT OF 10-20 KT AND A 01.15Z RAOB THERE HAD A BL
MIXING RATIO OF ABOUT 17 G/KG. CLEARLY A SOLID SURGE UNDERWAY. DOES
NOT APPEAR THAT THERE IS ANY SHORT TERM GUIDANCE THAT IS STRONGLY
LATCHING ON TO THIS...THE HRRR IS INITIALIZING WELL BUT I/M CONCERNED
IT MIXES THE MOISTURE OUT MUCH TOO QUICKLY.

SO WHAT DOES THIS MEAN. DID MAKE SOME ADJUSTMENT ON
TEMPERATURES...GENERALLY DOWN A LITTLE BIT. LOOKING AT THE LATEST
HRRR-X RUNS AND NCAR ENS DATA...AND THE 01.12Z NAM...DON/T THINK OUR
STORM CHANCES ARE REALLY GONE FOR TODAY. WITH GOOD MOISTURE IN
PLACE...EVEN WITH SLIGHTLY REDUCED HEATING...SHOULD YIELD MLCAPE
VALUES IN EXCESS OF 500 J/KG THIS AFTERNOON AND EVENING. THERE ARE NO
CLEAR TRIGGERING/LIFTING MECHANISMS ATTM OUTSIDE OF DIURNAL
HEATING...SO TWO-OUT-OF-THREE INGREDIENTS IS ENOUGH TO WARRANT AT
LEAST A MENTION OF SHOWERS/STORMS IN THE FORECAST.

.PREVIOUS DISCUSSION...
WEDNESDAY AND THURSDAY...
THESE TWO DAYS /ESPECIALLY THURSDAY/ ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM /WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS/...WITH
THE GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR /50KTS AT 300MB/...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ/MP
AVIATION...MP
FIRE WEATHER...MP




000
FXUS65 KPSR 011631
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
931 AM MST TUE SEP 1 2015

.SYNOPSIS...
LOW END CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TODAY FROM
PHOENIX EAST...THEN INCREASE FURTHER FOR WEDNESDAY AND THURSDAY AS
LOW PRESSURE OFF THE CALIFORNIA MOVES INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL REDUCE CHANCES FOR SHOWERS AND
THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING WEEKEND.

&&

.DISCUSSION...
A RELATIVELY COOL AND MOIST MORNING ACROSS THE FORECAST AREA. AT 16Z
TEMPERATURES WERE QUICKLY WARMING ACROSS SE CA AND SW AZ BUT SLOWER
OVER THE PHOENIX AREA DUE TO LAST NIGHT/S STORMS. DEW POINTS WERE INT
HE MID 60S TO MID 70S. YUMA WAS REPORTING GUSTY SOUTHERLY WINDS WITH
DEW POINTS THERE AND AT EL CENTRO WELL OVER 70. KYUX VWP DEPICTING
SSE WINDS UP TO 5KFT OF 10-20 KT AND A 01.15Z RAOB THERE HAD A BL
MIXING RATIO OF ABOUT 17 G/KG. CLEARLY A SOLID SURGE UNDERWAY. DOES
NOT APPEAR THAT THERE IS ANY SHORT TERM GUIDANCE THAT IS STRONGLY
LATCHING ON TO THIS...THE HRRR IS INITIALIZING WELL BUT I/M CONCERNED
IT MIXES THE MOISTURE OUT MUCH TOO QUICKLY.

SO WHAT DOES THIS MEAN. DID MAKE SOME ADJUSTMENT ON
TEMPERATURES...GENERALLY DOWN A LITTLE BIT. LOOKING AT THE LATEST
HRRR-X RUNS AND NCAR ENS DATA...AND THE 01.12Z NAM...DON/T THINK OUR
STORM CHANCES ARE REALLY GONE FOR TODAY. WITH GOOD MOISTURE IN
PLACE...EVEN WITH SLIGHTLY REDUCED HEATING...SHOULD YIELD MLCAPE
VALUES IN EXCESS OF 500 J/KG THIS AFTERNOON AND EVENING. THERE ARE NO
CLEAR TRIGGERING/LIFTING MECHANISMS ATTM OUTSIDE OF DIURNAL
HEATING...SO TWO-OUT-OF-THREE INGREDIENTS IS ENOUGH TO WARRANT AT
LEAST A MENTION OF SHOWERS/STORMS IN THE FORECAST.

.PREVIOUS DISCUSSION...
WEDNESDAY AND THURSDAY...
THESE TWO DAYS /ESPECIALLY THURSDAY/ ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM /WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS/...WITH
THE GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR /50KTS AT 300MB/...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...INIGUEZ/MP
AVIATION...MP
FIRE WEATHER...MP



000
FXUS65 KPSR 011142 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-15.00 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS




000
FXUS65 KPSR 011142 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS




000
FXUS65 KPSR 011142 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-15.00 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS



000
FXUS65 KPSR 011142 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS




000
FXUS65 KPSR 011142 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-15.00 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS



000
FXUS65 KPSR 011142 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS



000
FXUS65 KPSR 011142 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
442 AM MST TUE SEP 1 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR WORKS ITS WAY
IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY IS THEN
EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE CALIFORNIA
COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION. A RETURN OF
DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE CHANCES FOR
SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE UPCOMING
WEEKEND.

&&

.DISCUSSION...
.TODAY AND TONIGHT...
AFTER A VERY ACTIVE MONDAY AFTERNOON/EVENING..A SIGNIFICANT
REDUCTION IN CONVECTIVE ACTIVITY APPEARS TO BE IN THE CARDS ACROSS
SOUTH-CENTRAL ARIZONA TODAY AND TONIGHT. THE LATEST GFS MODEL RUN IS
NOW SHOWING A REDUCTION IN PWAT VALUES OVER THE REGION TODAY...AS THE
UPPER TROF THAT IS NOW OFF THE CA COAST REPOSITIONS ITSELF A BIT
CLOSER TO THE COAST. ALSO...THE GFS 200MB STREAMLINE FORECAST IS
SHOWING THE FLOW ALOFT WILL BE BECOMING ANTICYCLONIC AND CONFLUENT
BY THIS AFTERNOON/EVENING. THESE FACTORS...ALONG WITH THE FACT THAT
THE ATMOSPHERE WAS WELL WORKED- OVER BY YESTERDAY/S STORMS IS
EXPECTED TO GREATLY LIMIT THE AMOUNT OF CONVECTIVE ACTIVITY
TODAY/TONIGHT...WITH POPS WELL DOWN IN THE SLIGHT CHANCE RANGE (AT
MOST) ACROSS THE LOWER DESERTS...WITH SOMEWHAT HIGHER POPS OVER THE
HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY...
THESE TWO DAYS (ESPECIALLY THURSDAY) ARE EXPECTED TO BE MORE ACTIVE
WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS MID-LEVEL MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E ARE SWEPT NORTHWARD INTO THE REGION
BY THE UPPER LOW TO OUR WEST. ALTHOUGH THE CENTER OF THIS TROPICAL
SYSTEM IS NOT EXPECTED TO GET EVEN REMOTELY CLOSE TO OUR REGION (THE
NHC HAS IT DISSIPATING OFF THE SOUTHERN BAJA COAST BY SAT
NIGHT)...THERE IS GOOD MODEL CONSENSUS ON THE TRACK OF THIS TROPICAL
SYSTEM (WITH A TIGHT GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE
GFS PULLING A SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR
REGION...WITH PWATS EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY
THURSDAY AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD
VERTICAL WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A
INCREASE IN CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD
ACTIVITY ON THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE
OF PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS DOWN...WITH
MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA LIKELY
SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY...
ALTHOUGH THERE WILL BE REDUCTION IN AVAILABLE MOISTURE OVER THE
REGION AS SOUTHWESTERLY FLOW ALOFT SWEEPS THE MOISTURE FROM THE
REMAINS OF TROPICAL CYCLONE 14E OFF TO THE NORTH AND EAST...MORE
SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO CONTINUE TO IMPORT AT LEAST
SOME MOISTURE INTO SOUTH-CENTRAL AZ...WITH PWATS REMAINING IN THE
1.00-1.50 INCH RANGE) DURING THE ENTIRE PERIOD. THIS LEFT-OVER
MOISTURE...COMBINED WITH FAIR-TO-GOOD VERTICAL WIND SHEAR IS EXPECTED
TO ALLOW AT LEAST SOME SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH
DAY. ON THE OTHER HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED
TO KEEP THOSE REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS
PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
GIVEN THE WIDESPREAD CONVECTION MONDAY EVENING...THE ATMOSPHERE IS
LIKELY TOO CONTAMINATED TO SUPPORT ADDITIONAL STORMS TODAY. COULD SEE
SOME DISTANT STORMS WELL EAST AND SOUTH OF PHOENIX BUT AT THIS POINT
NEARLY ALL NUMERICAL GUIDANCE SUGGESTS THE PHOENIX AREA TERMINALS
WILL BE IN THE CLEAR THIS AFTERNOON. GOING WITH THE IDEA OF SOME
AFTERNOON CU ALONG WITH TYPICAL DIURNAL WINDS,

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FEW/SCT HIGH CLOUDS SHOULD BE THE RULE ACROSS SOUTHWEST AZ/SOUTHEAST
CA THIS AFTERNOON. NO WEATHER-RELATED AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
MOISTURE WILL INCREASE ACROSS THE AREA BY THE MIDDLE OF THE WEEK
RESULTING IN ELEVATED STORM CHANCES FROM PHOENIX EASTWARD ON
THURSDAY. MOISTURE VALUES WILL WANE A BIT INTO THE WEEKEND ALTHOUGH
DAILY STORM CHANCES WILL REMAIN PRESENT THROUGH EARLY NEXT WEEK. MINIMUM
RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY ACROSS SOUTHEAST
CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER
COLORADO RIVER. FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE
INSISTENT UPON A RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND
BETTER RAIN CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...LEINS



000
FXUS65 KFGZ 011030
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST TUE SEP 01 2015

.SYNOPSIS...THE MOST ACTIVE AREAS FOR SHOWER AND THUNDERSTORM
ACTIVITY WILL SHIFT A BIT EASTWARD OVER THE NEXT DAY OR TWO. STORM
ACTIVITY WILL BE MOST COMMON OVER APACHE COUNTY.

A DEEPENING LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
ENHANCE THE THREAT OF MOISTURE MOVING IN FROM THE SOUTH LATER THIS
WEEK AND INTO THE WEEKEND. DAILY SHOWER AND THUNDERSTORM ACTIVITY
WILL CONTINUE AS A RESULT...ESPECIALLY OVER THE EASTERN HALF OF THE
STATE.

&&

.DISCUSSION...THERE IS STILL SOME WEAK CONVECTION OVER NORTHERN
COCONINO COUNTY EARLY THIS MORNING...DUE TO LINGERING FORCING FROM A
S/WV MOVING THROUGH SOUTHERN NEVADA AND INTO UTAH. WATER VAPOR
IMAGERY SHOWS SOME SUBTLE RIDGING MOVING IN FROM THE SOUTHWEST AHEAD
OF A TROPICAL S/WV SOUTHWEST OF SAN DIEGO. THIS MAY SUPPRESS THE
WESTERN ZONES TODAY...MAYBE EVEN SOME OF THE CENTRAL ZONES.

THE DRYING WE HAVE BEEN WAITING FOR HAS NOT REALLY MATERIALIZED. A
FAIRLY SIGNIFICANT WEST-MOVING OUTFLOW (EVEN SEEN IN WATER VAPOR
IMAGERY) DEVELOPED OVER PHOENIX EARLIER IN THE NIGHT...FEATURES SUCH
AS THIS WILL PREVENT THE BOUNDARY LAYER FROM DRYING. BEHIND THE LOW
SOUTHWEST OF SAN DIEGO...MORE PRONOUNCED DRYING FROM THE WEST SHOULD
DEVELOP WEDNESDAY AND MAYBE THURSDAY.

DESPITE THIS...MANY GFS MEMBERS STILL INSIST THAT THE BACKING FLOW
FROM HGHT FALLS IN THE GREAT BASIN WILL DRAW MOISTURE INTO ARIZONA
LATE IN THE WEEK AND OVER THE WEEKEND. IN ADDITION...MANY MODELS ARE
ALSO FORECASTING SOME TROPICAL MOISTURE INTRUSION OVER THE WEEKEND.

IN SUMMARY...THERE IS TOO MUCH UNCERTAINTY TO REALLY DRY THINGS OUT
FROM WEST AS WAS ORIGINALLY PLANNED. ALTHOUGH ACTIVITY WILL DECREASE
OVER THE NEXT FEW DAYS...IT CANNOT BE TOTALLY RULED OUT. THE EASTERN
ZONES MAY NEVER SEE A DECREASE AT ALL...WHEN COMPARED TO THE LAST
FEW DAYS. THESE TRENDS ARE REFLECTED IN THE LATEST POP GRIDS.

&&

.AVIATION...FOR THE 12Z PACKAGE...ISOLATED SHOWERS THIS MORNING
BECOMING SCATTERED SHOWERS AND THUNDERSTORMS AROUND NOON. STORM
COVERAGE WILL DECREASE ACROSS NORTHWESTERN ARIZONA BY AFTERNOON AS
MORE STABLE AIR MOVES IN FROM THE WEST. IFR CONDITIONS AND ERRATIC
GUSTY WINDS UP TO 40 MPH ARE FORECAST NEAR THE STRONGER STORMS.
THUNDERSTORM COVERAGE WILL DIMINISH AROUND SUNSET. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 011030
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST TUE SEP 01 2015

.SYNOPSIS...THE MOST ACTIVE AREAS FOR SHOWER AND THUNDERSTORM
ACTIVITY WILL SHIFT A BIT EASTWARD OVER THE NEXT DAY OR TWO. STORM
ACTIVITY WILL BE MOST COMMON OVER APACHE COUNTY.

A DEEPENING LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
ENHANCE THE THREAT OF MOISTURE MOVING IN FROM THE SOUTH LATER THIS
WEEK AND INTO THE WEEKEND. DAILY SHOWER AND THUNDERSTORM ACTIVITY
WILL CONTINUE AS A RESULT...ESPECIALLY OVER THE EASTERN HALF OF THE
STATE.

&&

.DISCUSSION...THERE IS STILL SOME WEAK CONVECTION OVER NORTHERN
COCONINO COUNTY EARLY THIS MORNING...DUE TO LINGERING FORCING FROM A
S/WV MOVING THROUGH SOUTHERN NEVADA AND INTO UTAH. WATER VAPOR
IMAGERY SHOWS SOME SUBTLE RIDGING MOVING IN FROM THE SOUTHWEST AHEAD
OF A TROPICAL S/WV SOUTHWEST OF SAN DIEGO. THIS MAY SUPPRESS THE
WESTERN ZONES TODAY...MAYBE EVEN SOME OF THE CENTRAL ZONES.

THE DRYING WE HAVE BEEN WAITING FOR HAS NOT REALLY MATERIALIZED. A
FAIRLY SIGNIFICANT WEST-MOVING OUTFLOW (EVEN SEEN IN WATER VAPOR
IMAGERY) DEVELOPED OVER PHOENIX EARLIER IN THE NIGHT...FEATURES SUCH
AS THIS WILL PREVENT THE BOUNDARY LAYER FROM DRYING. BEHIND THE LOW
SOUTHWEST OF SAN DIEGO...MORE PRONOUNCED DRYING FROM THE WEST SHOULD
DEVELOP WEDNESDAY AND MAYBE THURSDAY.

DESPITE THIS...MANY GFS MEMBERS STILL INSIST THAT THE BACKING FLOW
FROM HGHT FALLS IN THE GREAT BASIN WILL DRAW MOISTURE INTO ARIZONA
LATE IN THE WEEK AND OVER THE WEEKEND. IN ADDITION...MANY MODELS ARE
ALSO FORECASTING SOME TROPICAL MOISTURE INTRUSION OVER THE WEEKEND.

IN SUMMARY...THERE IS TOO MUCH UNCERTAINTY TO REALLY DRY THINGS OUT
FROM WEST AS WAS ORIGINALLY PLANNED. ALTHOUGH ACTIVITY WILL DECREASE
OVER THE NEXT FEW DAYS...IT CANNOT BE TOTALLY RULED OUT. THE EASTERN
ZONES MAY NEVER SEE A DECREASE AT ALL...WHEN COMPARED TO THE LAST
FEW DAYS. THESE TRENDS ARE REFLECTED IN THE LATEST POP GRIDS.

&&

.AVIATION...FOR THE 12Z PACKAGE...ISOLATED SHOWERS THIS MORNING
BECOMING SCATTERED SHOWERS AND THUNDERSTORMS AROUND NOON. STORM
COVERAGE WILL DECREASE ACROSS NORTHWESTERN ARIZONA BY AFTERNOON AS
MORE STABLE AIR MOVES IN FROM THE WEST. IFR CONDITIONS AND ERRATIC
GUSTY WINDS UP TO 40 MPH ARE FORECAST NEAR THE STRONGER STORMS.
THUNDERSTORM COVERAGE WILL DIMINISH AROUND SUNSET. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 011030
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST TUE SEP 01 2015

.SYNOPSIS...THE MOST ACTIVE AREAS FOR SHOWER AND THUNDERSTORM
ACTIVITY WILL SHIFT A BIT EASTWARD OVER THE NEXT DAY OR TWO. STORM
ACTIVITY WILL BE MOST COMMON OVER APACHE COUNTY.

A DEEPENING LOW PRESSURE SYSTEM OVER THE PACIFIC NORTHWEST WILL
ENHANCE THE THREAT OF MOISTURE MOVING IN FROM THE SOUTH LATER THIS
WEEK AND INTO THE WEEKEND. DAILY SHOWER AND THUNDERSTORM ACTIVITY
WILL CONTINUE AS A RESULT...ESPECIALLY OVER THE EASTERN HALF OF THE
STATE.

&&

.DISCUSSION...THERE IS STILL SOME WEAK CONVECTION OVER NORTHERN
COCONINO COUNTY EARLY THIS MORNING...DUE TO LINGERING FORCING FROM A
S/WV MOVING THROUGH SOUTHERN NEVADA AND INTO UTAH. WATER VAPOR
IMAGERY SHOWS SOME SUBTLE RIDGING MOVING IN FROM THE SOUTHWEST AHEAD
OF A TROPICAL S/WV SOUTHWEST OF SAN DIEGO. THIS MAY SUPPRESS THE
WESTERN ZONES TODAY...MAYBE EVEN SOME OF THE CENTRAL ZONES.

THE DRYING WE HAVE BEEN WAITING FOR HAS NOT REALLY MATERIALIZED. A
FAIRLY SIGNIFICANT WEST-MOVING OUTFLOW (EVEN SEEN IN WATER VAPOR
IMAGERY) DEVELOPED OVER PHOENIX EARLIER IN THE NIGHT...FEATURES SUCH
AS THIS WILL PREVENT THE BOUNDARY LAYER FROM DRYING. BEHIND THE LOW
SOUTHWEST OF SAN DIEGO...MORE PRONOUNCED DRYING FROM THE WEST SHOULD
DEVELOP WEDNESDAY AND MAYBE THURSDAY.

DESPITE THIS...MANY GFS MEMBERS STILL INSIST THAT THE BACKING FLOW
FROM HGHT FALLS IN THE GREAT BASIN WILL DRAW MOISTURE INTO ARIZONA
LATE IN THE WEEK AND OVER THE WEEKEND. IN ADDITION...MANY MODELS ARE
ALSO FORECASTING SOME TROPICAL MOISTURE INTRUSION OVER THE WEEKEND.

IN SUMMARY...THERE IS TOO MUCH UNCERTAINTY TO REALLY DRY THINGS OUT
FROM WEST AS WAS ORIGINALLY PLANNED. ALTHOUGH ACTIVITY WILL DECREASE
OVER THE NEXT FEW DAYS...IT CANNOT BE TOTALLY RULED OUT. THE EASTERN
ZONES MAY NEVER SEE A DECREASE AT ALL...WHEN COMPARED TO THE LAST
FEW DAYS. THESE TRENDS ARE REFLECTED IN THE LATEST POP GRIDS.

&&

.AVIATION...FOR THE 12Z PACKAGE...ISOLATED SHOWERS THIS MORNING
BECOMING SCATTERED SHOWERS AND THUNDERSTORMS AROUND NOON. STORM
COVERAGE WILL DECREASE ACROSS NORTHWESTERN ARIZONA BY AFTERNOON AS
MORE STABLE AIR MOVES IN FROM THE WEST. IFR CONDITIONS AND ERRATIC
GUSTY WINDS UP TO 40 MPH ARE FORECAST NEAR THE STRONGER STORMS.
THUNDERSTORM COVERAGE WILL DIMINISH AROUND SUNSET. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KTWC 011024
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
315 AM MST TUE SEP 1 2015

.SYNOPSIS...AFTER SOME LINGERING SHOWERS AND THUNDERSTORMS
IN THE EARLY MORNING HOURS...STORM COVERAGE WILL BE LESS
ACROSS PORTIONS OF THE AREA HIT THE HARDEST LAST NIGHT.
AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE AGAIN
WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH WILL
THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...OKAY THEN. IF YOU TAKE A LOOK AT WATER VAPOR IMAGERY
WE SAW A BIG COMPLEX THROUGH SONORA LATE YESTERDAY AFTERNOON...WITH
INFLUENCE FROM THE NORTHERN PERIPHERY IMPACTING OUR AREA IN THE
LATE AFTERNOON AND EARLY EVENING. AS THIS OCCURRED...A SMALL BUT
VERY STRONG COMPLEX THAT DEVELOPED EVEN FURTHER NORTH NEAR
PHOENIX AND GILA COUNTY CAN BE SEEN SENDING A GRAVITY
WAVE TO THE SOUTHWEST AND SOUTH BETWEEN 04Z-07Z. THIS INTERSECTED
WITH A REMNANT SHEAR AXIS CREATED BY THE EARLIER COMPLEX AND FIRED
THE PERSISTENT AND WIDESPREAD THUNDERSTORM AREA THROUGH EASTERN PIMA
COUNTY LATE LAST NIGHT AND EARLY THIS MORNING.

AFTER THAT SHOW (WHICH IS FINALLY DIMINISHING) IT WILL BE VERY
DIFFICULT TO MANAGE A STRONG ENOUGH TRIGGER FOR WIDESPREAD STORMS IN
SANTA CRUZ VALLEY...INCLUDING TUCSON METRO THIS AFTERNOON. FAVORED
LOCATIONS WILL BE ON THE EASTERN PERIPHERY OF LAST NIGHT`S
ACTION...PRIMARILY COCHISE AND SANTA CRUZ COUNTY.

FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST SOUTHWESTERLY FLOW
BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO OUR EAST WILL BE
BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH TROPICAL
ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO (HELLO
TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD INTO
SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

.AVIATION...VALID THRU 02/12Z.
SCATTERED -TSRA/-SHRA MAINLY NE OF KTUS THIS MORNING.
OTHERWISE...VICINITY EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST
AND SOUTHEAST KTUS THIS AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

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

&&

$$

MEYER/RASMUSSEN

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011024
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
315 AM MST TUE SEP 1 2015

.SYNOPSIS...AFTER SOME LINGERING SHOWERS AND THUNDERSTORMS
IN THE EARLY MORNING HOURS...STORM COVERAGE WILL BE LESS
ACROSS PORTIONS OF THE AREA HIT THE HARDEST LAST NIGHT.
AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE AGAIN
WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH WILL
THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...OKAY THEN. IF YOU TAKE A LOOK AT WATER VAPOR IMAGERY
WE SAW A BIG COMPLEX THROUGH SONORA LATE YESTERDAY AFTERNOON...WITH
INFLUENCE FROM THE NORTHERN PERIPHERY IMPACTING OUR AREA IN THE
LATE AFTERNOON AND EARLY EVENING. AS THIS OCCURRED...A SMALL BUT
VERY STRONG COMPLEX THAT DEVELOPED EVEN FURTHER NORTH NEAR
PHOENIX AND GILA COUNTY CAN BE SEEN SENDING A GRAVITY
WAVE TO THE SOUTHWEST AND SOUTH BETWEEN 04Z-07Z. THIS INTERSECTED
WITH A REMNANT SHEAR AXIS CREATED BY THE EARLIER COMPLEX AND FIRED
THE PERSISTENT AND WIDESPREAD THUNDERSTORM AREA THROUGH EASTERN PIMA
COUNTY LATE LAST NIGHT AND EARLY THIS MORNING.

AFTER THAT SHOW (WHICH IS FINALLY DIMINISHING) IT WILL BE VERY
DIFFICULT TO MANAGE A STRONG ENOUGH TRIGGER FOR WIDESPREAD STORMS IN
SANTA CRUZ VALLEY...INCLUDING TUCSON METRO THIS AFTERNOON. FAVORED
LOCATIONS WILL BE ON THE EASTERN PERIPHERY OF LAST NIGHT`S
ACTION...PRIMARILY COCHISE AND SANTA CRUZ COUNTY.

FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST SOUTHWESTERLY FLOW
BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO OUR EAST WILL BE
BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH TROPICAL
ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO (HELLO
TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD INTO
SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

.AVIATION...VALID THRU 02/12Z.
SCATTERED -TSRA/-SHRA MAINLY NE OF KTUS THIS MORNING.
OTHERWISE...VICINITY EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST
AND SOUTHEAST KTUS THIS AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

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

&&

$$

MEYER/RASMUSSEN

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011024
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
315 AM MST TUE SEP 1 2015

.SYNOPSIS...AFTER SOME LINGERING SHOWERS AND THUNDERSTORMS
IN THE EARLY MORNING HOURS...STORM COVERAGE WILL BE LESS
ACROSS PORTIONS OF THE AREA HIT THE HARDEST LAST NIGHT.
AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE AGAIN
WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH WILL
THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...OKAY THEN. IF YOU TAKE A LOOK AT WATER VAPOR IMAGERY
WE SAW A BIG COMPLEX THROUGH SONORA LATE YESTERDAY AFTERNOON...WITH
INFLUENCE FROM THE NORTHERN PERIPHERY IMPACTING OUR AREA IN THE
LATE AFTERNOON AND EARLY EVENING. AS THIS OCCURRED...A SMALL BUT
VERY STRONG COMPLEX THAT DEVELOPED EVEN FURTHER NORTH NEAR
PHOENIX AND GILA COUNTY CAN BE SEEN SENDING A GRAVITY
WAVE TO THE SOUTHWEST AND SOUTH BETWEEN 04Z-07Z. THIS INTERSECTED
WITH A REMNANT SHEAR AXIS CREATED BY THE EARLIER COMPLEX AND FIRED
THE PERSISTENT AND WIDESPREAD THUNDERSTORM AREA THROUGH EASTERN PIMA
COUNTY LATE LAST NIGHT AND EARLY THIS MORNING.

AFTER THAT SHOW (WHICH IS FINALLY DIMINISHING) IT WILL BE VERY
DIFFICULT TO MANAGE A STRONG ENOUGH TRIGGER FOR WIDESPREAD STORMS IN
SANTA CRUZ VALLEY...INCLUDING TUCSON METRO THIS AFTERNOON. FAVORED
LOCATIONS WILL BE ON THE EASTERN PERIPHERY OF LAST NIGHT`S
ACTION...PRIMARILY COCHISE AND SANTA CRUZ COUNTY.

FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST SOUTHWESTERLY FLOW
BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO OUR EAST WILL BE
BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH TROPICAL
ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO (HELLO
TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD INTO
SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

.AVIATION...VALID THRU 02/12Z.
SCATTERED -TSRA/-SHRA MAINLY NE OF KTUS THIS MORNING.
OTHERWISE...VICINITY EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST
AND SOUTHEAST KTUS THIS AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

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

&&

$$

MEYER/RASMUSSEN

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 011024
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
315 AM MST TUE SEP 1 2015

.SYNOPSIS...AFTER SOME LINGERING SHOWERS AND THUNDERSTORMS
IN THE EARLY MORNING HOURS...STORM COVERAGE WILL BE LESS
ACROSS PORTIONS OF THE AREA HIT THE HARDEST LAST NIGHT.
AN IMPULSE FROM THE SOUTH WILL ENHANCE STORM COVERAGE AGAIN
WEDNESDAY INTO THURSDAY. INCREASING MOISTURE FROM THE SOUTH WILL
THEN KEEP A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS INTO THE
WEEKEND.

&&

.DISCUSSION...OKAY THEN. IF YOU TAKE A LOOK AT WATER VAPOR IMAGERY
WE SAW A BIG COMPLEX THROUGH SONORA LATE YESTERDAY AFTERNOON...WITH
INFLUENCE FROM THE NORTHERN PERIPHERY IMPACTING OUR AREA IN THE
LATE AFTERNOON AND EARLY EVENING. AS THIS OCCURRED...A SMALL BUT
VERY STRONG COMPLEX THAT DEVELOPED EVEN FURTHER NORTH NEAR
PHOENIX AND GILA COUNTY CAN BE SEEN SENDING A GRAVITY
WAVE TO THE SOUTHWEST AND SOUTH BETWEEN 04Z-07Z. THIS INTERSECTED
WITH A REMNANT SHEAR AXIS CREATED BY THE EARLIER COMPLEX AND FIRED
THE PERSISTENT AND WIDESPREAD THUNDERSTORM AREA THROUGH EASTERN PIMA
COUNTY LATE LAST NIGHT AND EARLY THIS MORNING.

AFTER THAT SHOW (WHICH IS FINALLY DIMINISHING) IT WILL BE VERY
DIFFICULT TO MANAGE A STRONG ENOUGH TRIGGER FOR WIDESPREAD STORMS IN
SANTA CRUZ VALLEY...INCLUDING TUCSON METRO THIS AFTERNOON. FAVORED
LOCATIONS WILL BE ON THE EASTERN PERIPHERY OF LAST NIGHT`S
ACTION...PRIMARILY COCHISE AND SANTA CRUZ COUNTY.

FOR WEDNESDAY THROUGH THE WEEKEND...THE MODEST SOUTHWESTERLY FLOW
BETWEEN THE TROUGH TO OUR NORTHWEST AND RIDGE TO OUR EAST WILL BE
BE ABLE TO TAP INTO A LONG FETCH OF MOISTURE. WITH TROPICAL
ACTIVITY HEATING UP AGAIN OFF THE WEST COAST OF MEXICO (HELLO
TROPICAL DEPRESSION 14-E...SOON TO BECOME KEVIN)...WE`LL HEAD INTO
SEPTEMBER WATCHING FOR TROPICAL INFLUENCES PUSHING UP FROM THE
SOUTH. AN IMPULSE EMBEDDED IN THE FLOW WILL HELP ORGANIZE STORMS
WEDNESDAY INTO THURSDAY. AFTER THAT WE`LL SEE WHAT ELSE COOKS UP FOR
US FROM THAT GENERAL DIRECTION THIS WEEKEND.

&&

.AVIATION...VALID THRU 02/12Z.
SCATTERED -TSRA/-SHRA MAINLY NE OF KTUS THIS MORNING.
OTHERWISE...VICINITY EXPECT SCATTERED -TSRA/-SHRA MAINLY EAST
AND SOUTHEAST KTUS THIS AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...WE WILL MAINTAIN ENOUGH MOISTURE FOR A GOOD CHANCE
OF MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS INTO
THIS WEEKEND. FOR THE MOST PART STORMS WILL BE DECENT RAINERS
WITH WIND GUSTS IN THE 25-45 MPH RANGE...WHILE A COUPLE EACH DAY
WILL BE STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE
LIGHT WITH A WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON
OUTSIDE OF THUNDERSTORM OUTFLOWS.

&&

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

&&

$$

MEYER/RASMUSSEN

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KPSR 011011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 AM MST TUE SEPT 01 2015

.SYNOPSIS... A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR
WORKS ITS WAY IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY
IS THEN EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE
CALIFORNIA COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION.
A RETURN OF DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE
CHANCES FOR SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE
UPCOMING WEEKEND.

&&

.DISCUSSION...

.TODAY AND TONIGHT... AFTER A VERY ACTIVE MONDAY
AFTERNOON/EVENING..A SIGNIFICANT REDUCTION IN CONVECTIVE ACTIVITY
APPEARS TO BE IN THE CARDS ACROSS SOUTH-CENTRAL ARIZONA TODAY AND
TONIGHT. THE LATEST GFS MODEL RUN IS NOW SHOWING A REDUCTION IN PWAT
VALUES OVER THE REGION TODAY...AS THE UPPER TROF THAT IS NOW OFF THE
CA COAST REPOSITIONS ITSELF A BIT CLOSER TO THE COAST. ALSO...THE
GFS 200MB STREAMLINE FORECAST IS SHOWING THE FLOW ALOFT WILL BE
BECOMING ANTICYLONIC AND CONFLUENT BY THIS AFTERNOON/EVENING. THESE
FACTORS...ALONG WITH THE FACT THAT THE ATMOSPHERE WAS WELL WORKED-
OVER BY YESTERDAY/S STORMS IS EXPECTED TO GREATLY LIMIT THE AMOUNT
OF CONVECTIVE ACTIVITY TODAY/TONIGHT...WITH POPS WELL DOWN IN THE
SLIGHT CHANCE RANGE (AT MOST) ACROSS THE LOWER DESERTS...WITH
SOMEWHAT HIGHER POPS OVER THE HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY... THESE TWO DAYS (ESPECIALLY THURSDAY) ARE
EXPECTED TO BE MORE ACTIVE WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS
MID-LEVEL MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E ARE
SWEPT NORTHWARD INTO THE REGION BY THE UPPER LOW TO OUR WEST.
ALTHOUGH THE CENTER OF THIS TROPICAL SYSTEM IS NOT EXPECTED TO GET
EVEN REMOTELY CLOSE TO OUR REGION (THE NHC HAS IT DISSIPATING OFF
THE SOUTHERN BAJA COAST BY SAT NIGHT)...THERE IS GOOD MODEL
CONSENSUS ON THE TRACK OF THIS TROPICAL SYSTEM (WITH A TIGHT
GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE GFS PULLING A
SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR REGION...WITH PWATS
EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY THURSDAY
AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD VERTICAL
WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A INCREASE IN
CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD ACTIVITY ON
THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE OF
PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS
DOWN...WITH MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA
LIKELY SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY... ALTHOUGH THERE WILL BE REDUCTION IN
AVAILABLE MOISTURE OVER THE REGION AS SOUTHWESTERLY FLOW ALOFT
SWEEPS THE MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E OFF TO
THE NORTH AND EAST...MORE SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO
CONTINUE TO IMPORT AT LEAST SOME MOISTURE INTO SOUTH-CENTRAL
AZ...WITH PWATS REMAINING IN THE 1.00-15.00 INCH RANGE) DURING THE
ENTIRE PERIOD. THIS LEFT-OVER MOISTURE...COMBINED WITH FAIR-TO-GOOD
VERTICAL WIND SHEAR IS EXPECTED TO ALLOW AT LEAST SOME
SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH DAY. ON THE OTHER
HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED TO KEEP THOSE
REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 011011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 AM MST TUE SEPT 01 2015

.SYNOPSIS... A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR
WORKS ITS WAY IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY
IS THEN EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE
CALIFORNIA COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION.
A RETURN OF DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE
CHANCES FOR SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE
UPCOMING WEEKEND.

&&

.DISCUSSION...

.TODAY AND TONIGHT... AFTER A VERY ACTIVE MONDAY
AFTERNOON/EVENING..A SIGNIFICANT REDUCTION IN CONVECTIVE ACTIVITY
APPEARS TO BE IN THE CARDS ACROSS SOUTH-CENTRAL ARIZONA TODAY AND
TONIGHT. THE LATEST GFS MODEL RUN IS NOW SHOWING A REDUCTION IN PWAT
VALUES OVER THE REGION TODAY...AS THE UPPER TROF THAT IS NOW OFF THE
CA COAST REPOSITIONS ITSELF A BIT CLOSER TO THE COAST. ALSO...THE
GFS 200MB STREAMLINE FORECAST IS SHOWING THE FLOW ALOFT WILL BE
BECOMING ANTICYLONIC AND CONFLUENT BY THIS AFTERNOON/EVENING. THESE
FACTORS...ALONG WITH THE FACT THAT THE ATMOSPHERE WAS WELL WORKED-
OVER BY YESTERDAY/S STORMS IS EXPECTED TO GREATLY LIMIT THE AMOUNT
OF CONVECTIVE ACTIVITY TODAY/TONIGHT...WITH POPS WELL DOWN IN THE
SLIGHT CHANCE RANGE (AT MOST) ACROSS THE LOWER DESERTS...WITH
SOMEWHAT HIGHER POPS OVER THE HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY... THESE TWO DAYS (ESPECIALLY THURSDAY) ARE
EXPECTED TO BE MORE ACTIVE WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS
MID-LEVEL MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E ARE
SWEPT NORTHWARD INTO THE REGION BY THE UPPER LOW TO OUR WEST.
ALTHOUGH THE CENTER OF THIS TROPICAL SYSTEM IS NOT EXPECTED TO GET
EVEN REMOTELY CLOSE TO OUR REGION (THE NHC HAS IT DISSIPATING OFF
THE SOUTHERN BAJA COAST BY SAT NIGHT)...THERE IS GOOD MODEL
CONSENSUS ON THE TRACK OF THIS TROPICAL SYSTEM (WITH A TIGHT
GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE GFS PULLING A
SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR REGION...WITH PWATS
EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY THURSDAY
AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD VERTICAL
WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A INCREASE IN
CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD ACTIVITY ON
THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE OF
PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS
DOWN...WITH MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA
LIKELY SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY... ALTHOUGH THERE WILL BE REDUCTION IN
AVAILABLE MOISTURE OVER THE REGION AS SOUTHWESTERLY FLOW ALOFT
SWEEPS THE MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E OFF TO
THE NORTH AND EAST...MORE SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO
CONTINUE TO IMPORT AT LEAST SOME MOISTURE INTO SOUTH-CENTRAL
AZ...WITH PWATS REMAINING IN THE 1.00-15.00 INCH RANGE) DURING THE
ENTIRE PERIOD. THIS LEFT-OVER MOISTURE...COMBINED WITH FAIR-TO-GOOD
VERTICAL WIND SHEAR IS EXPECTED TO ALLOW AT LEAST SOME
SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH DAY. ON THE OTHER
HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED TO KEEP THOSE
REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 011011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 AM MST TUE SEPT 01 2015

.SYNOPSIS... A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR
WORKS ITS WAY IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY
IS THEN EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE
CALIFORNIA COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION.
A RETURN OF DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE
CHANCES FOR SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE
UPCOMING WEEKEND.

&&

.DISCUSSION...

.TODAY AND TONIGHT... AFTER A VERY ACTIVE MONDAY
AFTERNOON/EVENING..A SIGNIFICANT REDUCTION IN CONVECTIVE ACTIVITY
APPEARS TO BE IN THE CARDS ACROSS SOUTH-CENTRAL ARIZONA TODAY AND
TONIGHT. THE LATEST GFS MODEL RUN IS NOW SHOWING A REDUCTION IN PWAT
VALUES OVER THE REGION TODAY...AS THE UPPER TROF THAT IS NOW OFF THE
CA COAST REPOSITIONS ITSELF A BIT CLOSER TO THE COAST. ALSO...THE
GFS 200MB STREAMLINE FORECAST IS SHOWING THE FLOW ALOFT WILL BE
BECOMING ANTICYLONIC AND CONFLUENT BY THIS AFTERNOON/EVENING. THESE
FACTORS...ALONG WITH THE FACT THAT THE ATMOSPHERE WAS WELL WORKED-
OVER BY YESTERDAY/S STORMS IS EXPECTED TO GREATLY LIMIT THE AMOUNT
OF CONVECTIVE ACTIVITY TODAY/TONIGHT...WITH POPS WELL DOWN IN THE
SLIGHT CHANCE RANGE (AT MOST) ACROSS THE LOWER DESERTS...WITH
SOMEWHAT HIGHER POPS OVER THE HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY... THESE TWO DAYS (ESPECIALLY THURSDAY) ARE
EXPECTED TO BE MORE ACTIVE WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS
MID-LEVEL MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E ARE
SWEPT NORTHWARD INTO THE REGION BY THE UPPER LOW TO OUR WEST.
ALTHOUGH THE CENTER OF THIS TROPICAL SYSTEM IS NOT EXPECTED TO GET
EVEN REMOTELY CLOSE TO OUR REGION (THE NHC HAS IT DISSIPATING OFF
THE SOUTHERN BAJA COAST BY SAT NIGHT)...THERE IS GOOD MODEL
CONSENSUS ON THE TRACK OF THIS TROPICAL SYSTEM (WITH A TIGHT
GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE GFS PULLING A
SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR REGION...WITH PWATS
EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY THURSDAY
AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD VERTICAL
WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A INCREASE IN
CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD ACTIVITY ON
THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE OF
PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS
DOWN...WITH MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA
LIKELY SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY... ALTHOUGH THERE WILL BE REDUCTION IN
AVAILABLE MOISTURE OVER THE REGION AS SOUTHWESTERLY FLOW ALOFT
SWEEPS THE MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E OFF TO
THE NORTH AND EAST...MORE SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO
CONTINUE TO IMPORT AT LEAST SOME MOISTURE INTO SOUTH-CENTRAL
AZ...WITH PWATS REMAINING IN THE 1.00-15.00 INCH RANGE) DURING THE
ENTIRE PERIOD. THIS LEFT-OVER MOISTURE...COMBINED WITH FAIR-TO-GOOD
VERTICAL WIND SHEAR IS EXPECTED TO ALLOW AT LEAST SOME
SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH DAY. ON THE OTHER
HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED TO KEEP THOSE
REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 011011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 AM MST TUE SEPT 01 2015

.SYNOPSIS... A SIGNIFICANT REDUCTION IN SHOWER AND THUNDERSTORM
ACTIVITY IS EXPECTED ACROSS THE REGION TODAY AS SOMEWHAT DRIER AIR
WORKS ITS WAY IN FROM THE WEST. AN INCREASE IN THUNDERSTORM ACTIVITY
IS THEN EXPECTED ON WEDNESDAY AND THURSDAY AS LOW PRESSURE OFF THE
CALIFORNIA COAST PULLS TROPICAL MOISTURE NORTHWARD INTO THE REGION.
A RETURN OF DRIER AIR INTO THE REGION WILL THEN ONCE AGAIN REDUCE
CHANCES FOR SHOWERS AND THUNDERSTORMS FROM FRIDAY ONWARD INTO THE
UPCOMING WEEKEND.

&&

.DISCUSSION...

.TODAY AND TONIGHT... AFTER A VERY ACTIVE MONDAY
AFTERNOON/EVENING..A SIGNIFICANT REDUCTION IN CONVECTIVE ACTIVITY
APPEARS TO BE IN THE CARDS ACROSS SOUTH-CENTRAL ARIZONA TODAY AND
TONIGHT. THE LATEST GFS MODEL RUN IS NOW SHOWING A REDUCTION IN PWAT
VALUES OVER THE REGION TODAY...AS THE UPPER TROF THAT IS NOW OFF THE
CA COAST REPOSITIONS ITSELF A BIT CLOSER TO THE COAST. ALSO...THE
GFS 200MB STREAMLINE FORECAST IS SHOWING THE FLOW ALOFT WILL BE
BECOMING ANTICYLONIC AND CONFLUENT BY THIS AFTERNOON/EVENING. THESE
FACTORS...ALONG WITH THE FACT THAT THE ATMOSPHERE WAS WELL WORKED-
OVER BY YESTERDAY/S STORMS IS EXPECTED TO GREATLY LIMIT THE AMOUNT
OF CONVECTIVE ACTIVITY TODAY/TONIGHT...WITH POPS WELL DOWN IN THE
SLIGHT CHANCE RANGE (AT MOST) ACROSS THE LOWER DESERTS...WITH
SOMEWHAT HIGHER POPS OVER THE HIGHER TERRAIN EAST OF PHOENIX.

.WEDNESDAY AND THURSDAY... THESE TWO DAYS (ESPECIALLY THURSDAY) ARE
EXPECTED TO BE MORE ACTIVE WEATHERWISE ACROSS SOUTH-CENTRAL AZ...AS
MID-LEVEL MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E ARE
SWEPT NORTHWARD INTO THE REGION BY THE UPPER LOW TO OUR WEST.
ALTHOUGH THE CENTER OF THIS TROPICAL SYSTEM IS NOT EXPECTED TO GET
EVEN REMOTELY CLOSE TO OUR REGION (THE NHC HAS IT DISSIPATING OFF
THE SOUTHERN BAJA COAST BY SAT NIGHT)...THERE IS GOOD MODEL
CONSENSUS ON THE TRACK OF THIS TROPICAL SYSTEM (WITH A TIGHT
GROUPING OF THE GFS ENSEMBLE MEMBERS)...WITH THE GFS PULLING A
SIGNIFICANT MOISTURE PLUME NORTHWARD INTO OUR REGION...WITH PWATS
EXCEEDING 1.80 INCH OVER SOUTH-CENTRAL ARIZONA BY THURSDAY
AFTERNOON. THE COMBINATION OF THIS MOISTURE ALONG WITH GOOD VERTICAL
WIND SHEAR (50KTS AT 300MB)...WITH LIKELY RESULT IN A INCREASE IN
CONVECTIVE ACTIVITY ON WEDNESDAY...AND WIDESPREAD ACTIVITY ON
THURSDAY. STORMS THAT DEVELOP WILL ONCE AGAIN BE CAPABLE OF
PRODUCING VERY STRONG WINDS AND LOCALLY HEAVY RAINS (ESPECIALLY ON
THURSDAY). THE COMBINATION OF INCREASED CLOUDINESS/RAINFALL AND
SOMEWHAT COOLER AIR ALOFT IS EXPECTED TO BRING HIGH TEMPS
DOWN...WITH MANY LOWER DESERT LOCATIONS ACROSS SOUTH-CENTRAL ARIZONA
LIKELY SEEING HIGHS ONLY IN THE 90S ON THURSDAY.

.FRIDAY THROUGH TUESDAY... ALTHOUGH THERE WILL BE REDUCTION IN
AVAILABLE MOISTURE OVER THE REGION AS SOUTHWESTERLY FLOW ALOFT
SWEEPS THE MOISTURE FROM THE REMAINS OF TROPICAL CYCLONE 14E OFF TO
THE NORTH AND EAST...MORE SOUTHERLY FLOW BELOW 700MB IS EXPECTED TO
CONTINUE TO IMPORT AT LEAST SOME MOISTURE INTO SOUTH-CENTRAL
AZ...WITH PWATS REMAINING IN THE 1.00-15.00 INCH RANGE) DURING THE
ENTIRE PERIOD. THIS LEFT-OVER MOISTURE...COMBINED WITH FAIR-TO-GOOD
VERTICAL WIND SHEAR IS EXPECTED TO ALLOW AT LEAST SOME
SHOWER/THUNDERSTORM ACTIVITY TO DEVELOP EACH DAY. ON THE OTHER
HAND...MUCH DRIER AIR OVER SE CA/SW AZ IS EXPECTED TO KEEP THOSE
REGIONS PRETTY MUCH THUNDERSTORM-FREE DURING THIS PERIOD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...PERCHA
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 010525
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL TREND DOWN FROM WEST TO EAST THE REST
OF THE NIGHT. LINGERING STORM CHANCES WILL CONTINUE EAST OF THE LOWER
COLORADO RIVER VALLEY TUESDAY THROUGH THURSDAY. MOISTURE IS EXPECTED
TO INCREASE LATE IN THE WEEK WITH WITH STORM CHANCES OVER A BROADER
AREA FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
ISOLATED WEAK STORMS LATE THIS AFTERNOON NEAR AND SOUTH OF THE
ESTRELLAS QUICKLY BLEW UP INTO MUCH MORE OVER METRO PHOENIX. THE
INITIAL STRONG STORM PRODUCED A DOWNBURST OVER THE ESTRELLAS. THEN AN
EVEN STRONGER SUBSEQUENT STORM FROM THAT OUTFLOW BLEW UP NEAR THE
STATE FAIRGROUNDS. THOSE COMBINED OUTFLOWS IN ADDITION TO OUTFLOWS FROM
PINAL COUNTY...INITIALLY SOUTH OF FLORENCE...AS WELL AS GILA COUNTY
HAVE HELPED TO CREATE WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS
NORTHEAST MARICOPA COUNTY AND PINAL COUNTY. WITH A WESTERLY COMPONENT
TO THE STEERING FLOW...STORMS ARE GENERALLY MOVING TO THE EAST BUT
BOUNDARY INTERACTIONS ARE AIDING ISOLATED REDEVELOPMENT IN AREAS
THAT ALREADY HAD STORM ACTIVITY. DESPITE AN ENVIRONMENT THAT HAD
MODEST PRECIPITABLE WATER AND SURFACE DEW POINTS...STORMS HAVE BEEN
ABLE TO PRODUCE FLASH FLOODING. AS OF THIS WRITING...THE ACTIVITY HAS
ENDED FOR MUCH OF THE METRO AREA WITH NORTHERN AND EASTERN PERIPHERY
STILL LINGERING BUT MORE ACTION OVER NORTHERN PINAL COUNTY. THIS WILL
LARGELY SETTLE DOWN BY MIDNIGHT. IT REMAINS TO BE SEEN HOW THE MCS
OVER SONORA INFLUENCES THINGS LATE TONIGHT. HRRR HAS BEEN INDICATING
LATE NIGHT DEVELOPMENT ASSOCIATED WITH THAT SYSTEM BUT IT HAS NOT
HANDLED TONIGHT/S ACTIVITY VERY WELL. STEERING FLOW SHOULD KEEP
DEBRIS CLOUDS FROM BEING TOO THICK BUT SURFACE DEW POINTS LOOK LIKE
THEY SHOULD INCREASE TUESDAY...ESPECIALLY OVER SOUTHWEST ARIZONA.
TONIGHT/S ACTIVITY SHOULD LEAVE BEHIND FAIRLY STABLE CONDITIONS FOR
TUESDAY. BUT WITH MOISTURE AVAILABLE AND PERHAPS ACTIVITY OVER
SOUTHWEST ARIZONA...SOUTH-CENTRAL ARIZONA MAY HAVE ANOTHER
OPPORTUNITY FOR STORMS TUESDAY. LOTS MORE FOR THE NIGHT SHIFT TO
EVALUATE.

&&

.PREVIOUS DISCUSSION ISSUED 233 PM...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLE
RAINFALL...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST
ARE MORE PROBABLE.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

MAIN BAND OF STORMS AS OF 05Z IS SHIFTING EASTWARD OUT OF THE METRO
PHOENIX AREA BUT ISOLATED REDEVELOPMENT CONTINUES. ANTICIPATE MOST OF
THE ACTIVITY OVER THE LOWER DESERTS WILL DISSIPATE BY 07Z-08Z.
EAST AND SOUTHEAST SURFACE WINDS SHOULD PREDOMINATE REST OF NIGHT AND
WELL INTO THE DAY TUESDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

ANTICIPATE CLEAR SKIES EXCEPT FOR SOME VERY MINOR CIRRUS. TYPICAL
WARM SEASON WIND PATTERNS WILL PREVAIL...THOUGH THE FAVORED DAYTIME
SOUTH AND SOUTHEAST WINDS MAY BE A BIT STRONGER THAN USUAL TUESDAY.
ALSO ANTICIPATE SOME ISOLATED STORMS OVER SOUTHWEST ARIZONA TUESDAY
AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/LEINS
AVIATION...AJ
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 010441
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
940 PM MST MON AUG 31 2015

.SYNOPSIS...SCATTERED THUNDERSTORMS WILL OCCUR AGAIN TUESDAY
AFTERNOON AND EVENING. A WEAK DRYING TREND AND WEAK FLOW WILL TEND
TO LIMIT MOST THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE
SECOND HALF OF THE WEEK. INCREASING MOISTURE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS THIS WEEKEND.

&&

.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WERE
OCCURRING GENERALLY NORTHEAST OF THE INTERSTATE-10 CORRIDOR AT THIS
TIME. BASED ON RADAR TRENDS AND SEVERAL HRRR SOLUTIONS...SCATTERED
SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE NEXT SEVERAL
HOURS MAINLY FROM TUCSON METRO AREA NORTH-TO-NORTHEAST ACROSS
SOUTHEAST PINAL COUNTY...GRAHAM COUNTY AND NRN GREENLEE COUNTY. THE
MAIN CONCERN WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND
BRIEF STRONG AND GUSTY WINDS. HAVE MAINTAINED ISOLATED SHOWERS/TSTMS
SOUTH-TO-SOUTHEAST OF TUCSON THE REST OF TONIGHT. HOWEVER...THE BULK
OF THE HEAVIER RAINFALL AMOUNTS WILL ALMOST CERTAINLY OCCUR WITH THE
SHOWERS/TSTMS ACROSS NERN SECTIONS. SEVERAL HRRR SOLUTIONS SUGGEST
THE BULK OF ANY SHOWERS/TSTMS WILL END AROUND SUNRISE TUE. ADEQUATE
MOISTURE WILL JUSTIFY A SLIGHT CHANCE OF SHOWERS/TSTMS TO OCCUR
MAINLY FROM TUCSON EWD/SWD LATE TUE MORNING.

PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.

&&

.AVIATION...VALID THRU 02/06Z.
SCATTERED TO PERHAPS NUMEROUS -TSRA/-SHRA MAINLY FROM KTUS VICINITY
NEWD TO THE WHITE MOUNTAINS NE OF KSAD THE REST OF TONIGHT. THESE
-TSRA/-SHRA SHOULD REMAIN NORTH OF THE KOLS/KDUG TERMINALS. THE BULK
OF THIS ACTIVITY IS EXPECTED TO END AROUND DAYBREAK TUESDAY. EXPECT
SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EWD TO THE NEW
MEXICO BORDER TUESDAY AFTERNOON AND EVENING. BRIEF MVFR CONDITIONS
AND GUSTY WINDS TO 45 KTS MAY OCCUR WITH WITH THE STRONGER
THUNDERSTORMS. OTHERWISE...CLOUD DECKS WILL GENERALLY RANGE FROM 8-
12K FT AGL AND SURFACE WIND WILL GE MOSTLY LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL
CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN THE
ACTIVITY EACH DAY. WITH SOUTHWEST FLOW ALOFT...STORMS WILL
GENERALLY MOVE TOWARD THE NORTHEAST OUTSIDE THE INFLUENCE OF
OUTFLOWS. FOR THE MOST PART STORMS WILL BE DECENT RAINERS WITH WIND
GUSTS IN THE 25-40 MPH RANGE...WHILE A COUPLE EACH DAY WILL BE
STRONGER. THROUGH MUCH OF THE COMING WEEK WINDS WILL BE LIGHT WITH A
WEST TO SOUTHWEST 10-15 MPH BREEZE EACH AFTERNOON. FROM FRIDAY
ONWARD THERE IS THE POTENTIAL FOR THE SOUTHWEST FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

.PREV DISCUSSION /230 PM MST/...THEREAFTER...THE GFS AND ECMWF
DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW PRESSURE TROUGH
DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY FLOW ALOFT
INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO ADVERTISE A
DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW INTO AT
LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND AS THE
GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE STRENGTH AND
TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST. FOR NOW...WILL
LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED THAT THERE MIGHT
BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC AS A POSSIBLE
SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA BY THE WEEKEND.
OTHERWISE...HIGH TEMPERATURES WILL BE NEAR SEASONABLE READINGS THIS
WEEK.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KFGZ 010323
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
822 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY WILL DECREASE AND GENERALLY SHIFT TO THE
EAST ON TUESDAY AND WEDNESDAY...WITH THE GREATEST CHANCES OF
THUNDERSTORMS OVER THE HIGH TERRAIN OF EASTERN ARIZONA. INCREASING
TROPICAL MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WORK WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...CONVECTION HAS DIMINISHED SIGNIFICANTLY THIS EVENING
OVER MOST OF THE CWA. THERE IS STILL ENOUGH INSTABILITY ALOFT FOR
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO CONTINUE FOR THE
NEXT COUPLE HOURS...WITH ACTIVITY GENERALLY LIMITED TO THE AREA
SOUTH OF A KGCN-KRQE LINE. HAVE KEPT POPS HIGHEST NEAR THE SOUTHERN
BORDER OF THE CWA WHERE ONGOING CONVECTION TO THE SOUTH MAY EXCITE
FURTHER DEVELOPMENT LATER TONIGHT.

STILL ON TRACK FOR SOME DRYING FROM THE WEST TUESDAY AND
WEDNESDAY...AND A RETURN OF MOISTURE LATE IN THE WEEK. HAVE RAISED
POPS A BIT MORE FOR THURSDAY AND FRIDAY...WITH GREATER CONFIDENCE IN
THE RETURN OF STORM ACTIVITY AS PER THE ENSEMBLE MODEL SOLUTIONS.

&&

.PREV DISCUSSION /359 PM MST/...IT HAS BEEN A CONVECTIVELY ACTIVE
DAY ACROSS MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING. SEVERAL
STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLD -TSRA WILL CONTINUE
OVERNIGHT...WITH MVFR CONDITIONS AND GUSTY WINDS WITH THE STRONGER
STORMS. ISOLD TO SCT -TSRA WILL DEVELOP OVER THE HIGHER TERRAIN AFT
17Z ON TUESDAY...WITH STORM MOST NUMEROUS SOUTHEAST OF A KPAN-KRQE
LINE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...BAK/RR
AVIATION...BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 010323
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
822 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY WILL DECREASE AND GENERALLY SHIFT TO THE
EAST ON TUESDAY AND WEDNESDAY...WITH THE GREATEST CHANCES OF
THUNDERSTORMS OVER THE HIGH TERRAIN OF EASTERN ARIZONA. INCREASING
TROPICAL MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WORK WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...CONVECTION HAS DIMINISHED SIGNIFICANTLY THIS EVENING
OVER MOST OF THE CWA. THERE IS STILL ENOUGH INSTABILITY ALOFT FOR
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO CONTINUE FOR THE
NEXT COUPLE HOURS...WITH ACTIVITY GENERALLY LIMITED TO THE AREA
SOUTH OF A KGCN-KRQE LINE. HAVE KEPT POPS HIGHEST NEAR THE SOUTHERN
BORDER OF THE CWA WHERE ONGOING CONVECTION TO THE SOUTH MAY EXCITE
FURTHER DEVELOPMENT LATER TONIGHT.

STILL ON TRACK FOR SOME DRYING FROM THE WEST TUESDAY AND
WEDNESDAY...AND A RETURN OF MOISTURE LATE IN THE WEEK. HAVE RAISED
POPS A BIT MORE FOR THURSDAY AND FRIDAY...WITH GREATER CONFIDENCE IN
THE RETURN OF STORM ACTIVITY AS PER THE ENSEMBLE MODEL SOLUTIONS.

&&

.PREV DISCUSSION /359 PM MST/...IT HAS BEEN A CONVECTIVELY ACTIVE
DAY ACROSS MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING. SEVERAL
STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLD -TSRA WILL CONTINUE
OVERNIGHT...WITH MVFR CONDITIONS AND GUSTY WINDS WITH THE STRONGER
STORMS. ISOLD TO SCT -TSRA WILL DEVELOP OVER THE HIGHER TERRAIN AFT
17Z ON TUESDAY...WITH STORM MOST NUMEROUS SOUTHEAST OF A KPAN-KRQE
LINE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...BAK/RR
AVIATION...BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 010323
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
822 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY WILL DECREASE AND GENERALLY SHIFT TO THE
EAST ON TUESDAY AND WEDNESDAY...WITH THE GREATEST CHANCES OF
THUNDERSTORMS OVER THE HIGH TERRAIN OF EASTERN ARIZONA. INCREASING
TROPICAL MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS LATE IN THE WORK WEEK AND INTO THE WEEKEND.

&&

.DISCUSSION...CONVECTION HAS DIMINISHED SIGNIFICANTLY THIS EVENING
OVER MOST OF THE CWA. THERE IS STILL ENOUGH INSTABILITY ALOFT FOR
WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS TO CONTINUE FOR THE
NEXT COUPLE HOURS...WITH ACTIVITY GENERALLY LIMITED TO THE AREA
SOUTH OF A KGCN-KRQE LINE. HAVE KEPT POPS HIGHEST NEAR THE SOUTHERN
BORDER OF THE CWA WHERE ONGOING CONVECTION TO THE SOUTH MAY EXCITE
FURTHER DEVELOPMENT LATER TONIGHT.

STILL ON TRACK FOR SOME DRYING FROM THE WEST TUESDAY AND
WEDNESDAY...AND A RETURN OF MOISTURE LATE IN THE WEEK. HAVE RAISED
POPS A BIT MORE FOR THURSDAY AND FRIDAY...WITH GREATER CONFIDENCE IN
THE RETURN OF STORM ACTIVITY AS PER THE ENSEMBLE MODEL SOLUTIONS.

&&

.PREV DISCUSSION /359 PM MST/...IT HAS BEEN A CONVECTIVELY ACTIVE
DAY ACROSS MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING. SEVERAL
STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 06Z PACKAGE...ISOLD -TSRA WILL CONTINUE
OVERNIGHT...WITH MVFR CONDITIONS AND GUSTY WINDS WITH THE STRONGER
STORMS. ISOLD TO SCT -TSRA WILL DEVELOP OVER THE HIGHER TERRAIN AFT
17Z ON TUESDAY...WITH STORM MOST NUMEROUS SOUTHEAST OF A KPAN-KRQE
LINE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...BAK/RR
AVIATION...BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312259
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
359 PM MST MON AUG 31 2015

.SYNOPSIS...STORM ACTIVITY IS EXPECTED TO SLOWLY MOVE EAST
THROUGH AT LEAST WEDNESDAY...WITH WESTERN YAVAPAI AND COCONINO
COUNTIES LIKELY DRYING OUT. AS EARLY AS THURSDAY...INCREASING
MOISTURE MAY LEAD TO BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS
LATE IN THE WORK WEEK.

&&

.DISCUSSION...IT HAS BEEN A CONVECTIVELY ACTIVE DAY ACROSS
MOST NORTHERN ARIZONA. SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED ACROSS THE REGION BY LATE MORNING.
SEVERAL STORMS PRODUCED VERY HEAVY RAINFALL AND THERE WAS ENOUGH
ENVIRONMENTAL SHEAR FOR A FEW ROTATING SUPERCELLS.

MOST MODEL GUIDANCE SUGGESTS SHOWER AND THUNDERSTORM ACTIVITY WILL
LARGELY DIMINISH THIS EVENING. THIS MAKES SENSE GIVEN THAT MOST
OF NORTHERN ARIZONA HAS ALREADY EXPERIENCED CONVECTIVE ACTIVITY.
THE EXCEPTION COULD BE IN SOUTHERN YAVAPAI COUNTY, BUT THERE
DOESN`T APPEAR TO BE ANY MESOSCALE MECHANISM IN PLACE AT THE
MOMENT TO GET ACTIVITY GOING THERE.

FOR TUESDAY AND WEDNESDAY...SHOWER AND THUNDERSTORM ACTIVITY IS
EXPECTED TO DECREASE AS THE ATMOSPHERE DRIES A BIT...MOSTLY ACROSS
THE WESTERN PORTIONS OF NORTHERN ARIZONA. SCATTERED SHOWERS AND
THUNDERSTORMS ARE EXPECTED IN THE WHITE MOUNTAINS REGION WITH
ISOLATED OR NO ACTIVITY ELSEWHERE.

LONG RANGE GUIDANCE SUGGESTS ANOTHER SURGE OF MOISTURE WILL MOVE
INTO NORTHERN ARIZONA THURSDAY NIGHT INTO FRIDAY. SOUTHERLY WINDS
WILL INCREASE DURING THIS TIME PERIOD AS THE PRESSURE GRADIENT
STRENGTHENS BETWEEN A HIGH ACROSS EASTERN MEXICO/SOUTHERN TEXAS
AND A PACIFIC NORTHWEST TROUGH. THE GFS CONTINUES TO BE MORE
AGGRESSIVE THAN THE ECMWF WITH REGARDS TO THE AMOUNT OF MOISTURE
RETURN, SO TRENDS WILL HAVE TO BE MONITORED TO SEE WHICH SOLUTION
IS MORE LIKELY. STORMS THAT DO DEVELOP FRIDAY AFTERNOON MAY HAVE
MODEST SHEAR VALUES AND AT LEAST LIMITED CAPE TO WORK WITH, SO
SOME STRONG STORMS CANNOT BE RULED OUT.

AS WE HEAD INTO THE WEEKEND, BOTH THE GFS AND ECMWF ARE IN AGREEMENT
THAT A DRY WESTERLY FLOW WILL SPREAD ACROSS THE REGION GREATLY
REDUCING THE CHANCE FOR PRECIPITATION. THE BEST CHANCES FOR
AFTERNOON SHOWERS AND THUNDERSTORMS LOOK TO BE MOSTLY CONFINED TO
EASTERN ARIZONA SATURDAY AND SUNDAY.

&&

.AVIATION...FOR THE 00Z PACKAGE...SCT -TSRA WILL CONTINUE THIS
EVENING...BECOMING ISOLD AFT 05Z TUESDAY. LCL IFR CONDITIONS AND
GUSTY WINDS WITH THE STRONGER STORMS.  ISOLD TO SCT -TSRA WILL
DEVELOP OVER THE HIGHER TERRAIN AFT 17Z ON TUESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/CLM
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KPSR 312133
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
233 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TONIGHT ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA LATE IN THE WEEK WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLERAINFALL...THOUGH
LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

WEATHER CONDITIONS SIMILAR TO THOSE OBSERVED OVER THE WEEKEND ONLY
SLIGHTLY SHIFTED A LITTLE FURTHER TO THE EAST. SO RESULTING FORECAST
FOR THE PHOENIX AREA TERMINALS WILL BE AGAIN FOR AT LEAST VCTS FOR A
PERIOD THIS EVENING...WITH OUTFLOW INTRUSIONS TO COME BEFORE ANY
THUNDER DEVELOPMENT. THINKING THAT ANY OUTFLOW WIND SHIFTS COULD
OCCUR AROUND 01/02Z OR SO...WITH CB AND TS/RA DEVELOPMENT POSSIBLY
FOLLOWING OVER THE REMAINDER OF THE EVENING HOURS. DEBRIS CLOUDINESS
AND A STRAY SHOWER COULD LINGER BEYOND MIDNIGHT BEFORE CONDITIONS
SCATTER OUT TOWARDS THE AM HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO DRIFT
NORTHEASTWARD AS SUBTLE TROUGHING ALOFT REMAINS OVER SOUTHEAST CA.
DAYTIME WINDS FOR KIPL TO STAY MOSTLY VRB BEFORE TAKING UP TYPICAL
SUNDOWNER WESTERLIES IN THE EVENING. ELEVATED SOUTHERLY BREEZES TO
PERSIST FOR KBLH WITH SOME AFTN GUSTINESS JUST SHY OF 20KTS OR SO.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 312133
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
233 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TONIGHT ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA LATE IN THE WEEK WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLERAINFALL...THOUGH
LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

WEATHER CONDITIONS SIMILAR TO THOSE OBSERVED OVER THE WEEKEND ONLY
SLIGHTLY SHIFTED A LITTLE FURTHER TO THE EAST. SO RESULTING FORECAST
FOR THE PHOENIX AREA TERMINALS WILL BE AGAIN FOR AT LEAST VCTS FOR A
PERIOD THIS EVENING...WITH OUTFLOW INTRUSIONS TO COME BEFORE ANY
THUNDER DEVELOPMENT. THINKING THAT ANY OUTFLOW WIND SHIFTS COULD
OCCUR AROUND 01/02Z OR SO...WITH CB AND TS/RA DEVELOPMENT POSSIBLY
FOLLOWING OVER THE REMAINDER OF THE EVENING HOURS. DEBRIS CLOUDINESS
AND A STRAY SHOWER COULD LINGER BEYOND MIDNIGHT BEFORE CONDITIONS
SCATTER OUT TOWARDS THE AM HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO DRIFT
NORTHEASTWARD AS SUBTLE TROUGHING ALOFT REMAINS OVER SOUTHEAST CA.
DAYTIME WINDS FOR KIPL TO STAY MOSTLY VRB BEFORE TAKING UP TYPICAL
SUNDOWNER WESTERLIES IN THE EVENING. ELEVATED SOUTHERLY BREEZES TO
PERSIST FOR KBLH WITH SOME AFTN GUSTINESS JUST SHY OF 20KTS OR SO.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 312133
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
233 PM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TONIGHT ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA LATE IN THE WEEK WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. A GRADUAL COOLING TREND IS ALSO
ANTICIPATED THIS WEEK THROUGH THURSDAY.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. INTERESTING TO NOTE THAT THE NCAR ENSEMBLE PICKED
UP ON THE MORNING ACTIVITY ACROSS GILA COUNTY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.

OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST THAT
ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. LATEST ACARS SOUNDINGS SHOW THAT STEERING FLOW HAS VEERED
SLIGHTLY TO THE SOUTHWEST...WHICH AT LEAST CONCEPTUALLY SHOULD FOCUS
ACTIVITY SOMEWHAT FURTHER EAST THAN IN PREVIOUS NIGHTS. A WARM LAYER
NEAR 700 MB IS ALSO EVIDENT...WHICH IS LIKELY RESULTING IN
CONSIDERABLE CONVECTIVE INHIBITION AND MOSTLY CLEAR SKIES ACROSS THE
PHOENIX AREA.

U OF A WRFS HAVE PERFORMED WELL THE PAST FEW EVENINGS AND AGAIN
INDICATE THAT SCATTERED ACTIVITY IS POSSIBLE ACROSS THE PHOENIX AREA.
FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS OF
SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE MEASURABLERAINFALL...THOUGH
LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

WEATHER CONDITIONS SIMILAR TO THOSE OBSERVED OVER THE WEEKEND ONLY
SLIGHTLY SHIFTED A LITTLE FURTHER TO THE EAST. SO RESULTING FORECAST
FOR THE PHOENIX AREA TERMINALS WILL BE AGAIN FOR AT LEAST VCTS FOR A
PERIOD THIS EVENING...WITH OUTFLOW INTRUSIONS TO COME BEFORE ANY
THUNDER DEVELOPMENT. THINKING THAT ANY OUTFLOW WIND SHIFTS COULD
OCCUR AROUND 01/02Z OR SO...WITH CB AND TS/RA DEVELOPMENT POSSIBLY
FOLLOWING OVER THE REMAINDER OF THE EVENING HOURS. DEBRIS CLOUDINESS
AND A STRAY SHOWER COULD LINGER BEYOND MIDNIGHT BEFORE CONDITIONS
SCATTER OUT TOWARDS THE AM HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO DRIFT
NORTHEASTWARD AS SUBTLE TROUGHING ALOFT REMAINS OVER SOUTHEAST CA.
DAYTIME WINDS FOR KIPL TO STAY MOSTLY VRB BEFORE TAKING UP TYPICAL
SUNDOWNER WESTERLIES IN THE EVENING. ELEVATED SOUTHERLY BREEZES TO
PERSIST FOR KBLH WITH SOME AFTN GUSTINESS JUST SHY OF 20KTS OR SO.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KTWC 312130
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND...A MOISTURE INCREASE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED TO DEVELOP THIS AFTERNOON. RAINFALL AMOUNTS HAVE GENERALLY
BEEN ON THE ORDER OF .25 TO .50 OF AN INCH...WITH A FEW OF THE
STRONGER ONES PRODUCING UP TO 1.5 INCHES IN AN HOUR. EXPECTING THIS
ACTIVITY TO DIMINISH SIGNIFICANTLY AFTER SUNDOWN. THEREAFTER...THE
GFS AND ECMWF DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW
PRESSURE TROUGH DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY
FLOW ALOFT INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO
ADVERTISE A DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW
INTO AT LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND
AS THE GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE
STRENGTH AND TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST.
FOR NOW...WILL LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED
THAT THERE MIGHT BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC
AS A POSSIBLE SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA
BY THE WEEKEND. OTHERWISE...HIGH TEMPERATURES WILL BE NEAR
SEASONABLE READINGS THIS WEEK.

&&

.AVIATION...VALID THRU 02/00Z. SCT-BKN GENERALLY 8-12 KFT WITH SCT
SHRA/TSRA THRU 01/05Z. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS WILL BE POSSIBLE IN AND AROUND THE STRONGER STORMS.  OUTSIDE OF
THUNDERSTORM INFLUENCE SURFACE WINDS WILL GENERALLY BE UNDER 10 KTS.
 SKIES WILL CLEAR AFT 01/06Z WITH CONVECTION BUILDING AGAIN AFT
01/18Z.  AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY. WITH SW FLOW ALOFT STORMS WILL GENERALLY MOVE
TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST PART
STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

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

&&
.AVIATION/FIRE WEATHER...CERNIGLIA

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KTWC 312130
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND...A MOISTURE INCREASE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED TO DEVELOP THIS AFTERNOON. RAINFALL AMOUNTS HAVE GENERALLY
BEEN ON THE ORDER OF .25 TO .50 OF AN INCH...WITH A FEW OF THE
STRONGER ONES PRODUCING UP TO 1.5 INCHES IN AN HOUR. EXPECTING THIS
ACTIVITY TO DIMINISH SIGNIFICANTLY AFTER SUNDOWN. THEREAFTER...THE
GFS AND ECMWF DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW
PRESSURE TROUGH DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY
FLOW ALOFT INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO
ADVERTISE A DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW
INTO AT LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND
AS THE GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE
STRENGTH AND TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST.
FOR NOW...WILL LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED
THAT THERE MIGHT BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC
AS A POSSIBLE SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA
BY THE WEEKEND. OTHERWISE...HIGH TEMPERATURES WILL BE NEAR
SEASONABLE READINGS THIS WEEK.

&&

.AVIATION...VALID THRU 02/00Z. SCT-BKN GENERALLY 8-12 KFT WITH SCT
SHRA/TSRA THRU 01/05Z. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS WILL BE POSSIBLE IN AND AROUND THE STRONGER STORMS.  OUTSIDE OF
THUNDERSTORM INFLUENCE SURFACE WINDS WILL GENERALLY BE UNDER 10 KTS.
 SKIES WILL CLEAR AFT 01/06Z WITH CONVECTION BUILDING AGAIN AFT
01/18Z.  AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY. WITH SW FLOW ALOFT STORMS WILL GENERALLY MOVE
TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST PART
STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

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

&&
.AVIATION/FIRE WEATHER...CERNIGLIA

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 312130
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND...A MOISTURE INCREASE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED TO DEVELOP THIS AFTERNOON. RAINFALL AMOUNTS HAVE GENERALLY
BEEN ON THE ORDER OF .25 TO .50 OF AN INCH...WITH A FEW OF THE
STRONGER ONES PRODUCING UP TO 1.5 INCHES IN AN HOUR. EXPECTING THIS
ACTIVITY TO DIMINISH SIGNIFICANTLY AFTER SUNDOWN. THEREAFTER...THE
GFS AND ECMWF DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW
PRESSURE TROUGH DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY
FLOW ALOFT INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO
ADVERTISE A DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW
INTO AT LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND
AS THE GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE
STRENGTH AND TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST.
FOR NOW...WILL LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED
THAT THERE MIGHT BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC
AS A POSSIBLE SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA
BY THE WEEKEND. OTHERWISE...HIGH TEMPERATURES WILL BE NEAR
SEASONABLE READINGS THIS WEEK.

&&

.AVIATION...VALID THRU 02/00Z. SCT-BKN GENERALLY 8-12 KFT WITH SCT
SHRA/TSRA THRU 01/05Z. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS WILL BE POSSIBLE IN AND AROUND THE STRONGER STORMS.  OUTSIDE OF
THUNDERSTORM INFLUENCE SURFACE WINDS WILL GENERALLY BE UNDER 10 KTS.
 SKIES WILL CLEAR AFT 01/06Z WITH CONVECTION BUILDING AGAIN AFT
01/18Z.  AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY. WITH SW FLOW ALOFT STORMS WILL GENERALLY MOVE
TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST PART
STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

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

&&
.AVIATION/FIRE WEATHER...CERNIGLIA

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 312130
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
230 PM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND...A MOISTURE INCREASE FROM THE SOUTH WILL
BRING A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
CONTINUED TO DEVELOP THIS AFTERNOON. RAINFALL AMOUNTS HAVE GENERALLY
BEEN ON THE ORDER OF .25 TO .50 OF AN INCH...WITH A FEW OF THE
STRONGER ONES PRODUCING UP TO 1.5 INCHES IN AN HOUR. EXPECTING THIS
ACTIVITY TO DIMINISH SIGNIFICANTLY AFTER SUNDOWN. THEREAFTER...THE
GFS AND ECMWF DIFFER ON HOW MUCH DRYING TAKES PLACES AS A LOW
PRESSURE TROUGH DEEPENS ALONG THE WEST COAST...AND THE SOUTHWESTERLY
FLOW ALOFT INCREASES ACROSS THE AREA. FOR NOW...WILL CONTINUE TO
ADVERTISE A DECREASE AND EASTERLY SHIFT IN RAIN CHANCES FOR TOMORROW
INTO AT LEAST FRIDAY. FORECAST BECOMES MORE UNCERTAIN THIS WEEKEND
AS THE GFS AND ECMWF SHOWED WIDELY DIFFERENT SOLUTIONS IN THE
STRENGTH AND TRACK OF A SYSTEM MOVING INTO THE PACIFIC NORTHWEST.
FOR NOW...WILL LEAN MORE TOWARD THE GFS SOLUTION WHICH SUGGESTED
THAT THERE MIGHT BE SOME TROPICAL INFLUENCE FROM THE EASTERN PACIFIC
AS A POSSIBLE SYSTEM HELPS PUSH DEEPER MOISTURE BACK INTO THE AREA
BY THE WEEKEND. OTHERWISE...HIGH TEMPERATURES WILL BE NEAR
SEASONABLE READINGS THIS WEEK.

&&

.AVIATION...VALID THRU 02/00Z. SCT-BKN GENERALLY 8-12 KFT WITH SCT
SHRA/TSRA THRU 01/05Z. BRIEF MVFR CONDITIONS AND GUSTY WINDS TO 45
KTS WILL BE POSSIBLE IN AND AROUND THE STRONGER STORMS.  OUTSIDE OF
THUNDERSTORM INFLUENCE SURFACE WINDS WILL GENERALLY BE UNDER 10 KTS.
 SKIES WILL CLEAR AFT 01/06Z WITH CONVECTION BUILDING AGAIN AFT
01/18Z.  AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED AFTERNOON AND EARLY EVENING THUNDERSTORMS
WILL CONTINUE THROUGH THURSDAY WITH A BIT OF AN EASTWARD SHIFT IN
THE ACTIVITY EACH DAY. WITH SW FLOW ALOFT STORMS WILL GENERALLY MOVE
TOWARD THE NE OUTSIDE THE INFLUENCE OF OUTFLOWS.  FOR THE MOST PART
STORMS WILL BE DECENT RAINERS WITH WIND GUSTS IN THE 25-40 MPH
RANGE...WHILE A COUPLE EACH DAY WILL BE STRONGER.  THROUGH MUCH OF
THE COMING WEEK WINDS WILL BE LIGHT WITH A WEST TO SOUTHWEST 10-15
MPH BREEZE EACH AFTERNOON.

FROM FRIDAY ONWARD THERE IS THE POTENTIAL FOR THE SW FLOW ALOFT TO
CAPTURE REMNANT TROPICAL SYSTEMS AND DIRECT THAT MOISTURE UP ACROSS
OUR AREA FOR PERIODS OF ENHANCEMENT TO THE PRECIPITATION POTENTIAL.

&&

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

&&
.AVIATION/FIRE WEATHER...CERNIGLIA

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KPSR 312110 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
210 PM MST MON AUG 31 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. EARLY MORNING CONVECTION ACROSS GILA COUNTY
CONTINUES TO DISSIPATE AT THIS HOUR. INTERESTING TO NOTE THAT THE
NCAR ENSEMBLE PICKED UP ON THIS ACTIVITY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.
MEANWHILE...OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST
THAT ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS
OF SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE
RAIN...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE
MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT MOST
IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT. 00Z
SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE SOUTHWESTERLY
FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL ACROSS THE
REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE ENSEMBLES
SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED TO
SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

WEATHER CONDITIONS SIMILAR TO THOSE OBSERVED OVER THE WEEKEND ONLY
SLIGHTLY SHIFTED A LITTLE FURTHER TO THE EAST. SO RESULTING FORECAST
FOR THE PHOENIX AREA TERMINALS WILL BE AGAIN FOR AT LEAST VCTS FOR A
PERIOD THIS EVENING...WITH OUTFLOW INTRUSIONS TO COME BEFORE ANY
THUNDER DEVELOPMENT. THINKING THAT ANY OUTFLOW WIND SHIFTS COULD
OCCUR AROUND 01/02Z OR SO...WITH CB AND TS/RA DEVELOPMENT POSSIBLY
FOLLOWING OVER THE REMAINDER OF THE EVENING HOURS. DEBRIS CLOUDINESS
AND A STRAY SHOWER COULD LINGER BEYOND MIDNIGHT BEFORE CONDITIONS
SCATTER OUT TOWARDS THE AM HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO DRIFT
NORTHEASTWARD AS SUBTLE TROUGHING ALOFT REMAINS OVER SOUTHEAST CA.
DAYTIME WINDS FOR KIPL TO STAY MOSTLY VRB BEFORE TAKING UP TYPICAL
SUNDOWNER WESTERLIES IN THE EVENING. ELEVATED SOUTHERLY BREEZES TO
PERSIST FOR KBLH WITH SOME AFTN GUSTINESS JUST SHY OF 20KTS OR SO.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY
ACROSS SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED
EAST OF THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE
WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER
MOISTURE...HIGHER HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY
ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...NOLTE
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 312110 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
210 PM MST MON AUG 31 2015

.UPDATE...TO AVIATION DISCUSSION...

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. EARLY MORNING CONVECTION ACROSS GILA COUNTY
CONTINUES TO DISSIPATE AT THIS HOUR. INTERESTING TO NOTE THAT THE
NCAR ENSEMBLE PICKED UP ON THIS ACTIVITY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.
MEANWHILE...OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST
THAT ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS
OF SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE
RAIN...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE
MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT MOST
IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT. 00Z
SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE SOUTHWESTERLY
FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL ACROSS THE
REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE ENSEMBLES
SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED TO
SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

WEATHER CONDITIONS SIMILAR TO THOSE OBSERVED OVER THE WEEKEND ONLY
SLIGHTLY SHIFTED A LITTLE FURTHER TO THE EAST. SO RESULTING FORECAST
FOR THE PHOENIX AREA TERMINALS WILL BE AGAIN FOR AT LEAST VCTS FOR A
PERIOD THIS EVENING...WITH OUTFLOW INTRUSIONS TO COME BEFORE ANY
THUNDER DEVELOPMENT. THINKING THAT ANY OUTFLOW WIND SHIFTS COULD
OCCUR AROUND 01/02Z OR SO...WITH CB AND TS/RA DEVELOPMENT POSSIBLY
FOLLOWING OVER THE REMAINDER OF THE EVENING HOURS. DEBRIS CLOUDINESS
AND A STRAY SHOWER COULD LINGER BEYOND MIDNIGHT BEFORE CONDITIONS
SCATTER OUT TOWARDS THE AM HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

PASSING MID AND HIGH LEVEL CLOUDS WILL CONTINUE TO DRIFT
NORTHEASTWARD AS SUBTLE TROUGHING ALOFT REMAINS OVER SOUTHEAST CA.
DAYTIME WINDS FOR KIPL TO STAY MOSTLY VRB BEFORE TAKING UP TYPICAL
SUNDOWNER WESTERLIES IN THE EVENING. ELEVATED SOUTHERLY BREEZES TO
PERSIST FOR KBLH WITH SOME AFTN GUSTINESS JUST SHY OF 20KTS OR SO.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15 PERCENT THURSDAY
ACROSS SOUTHEAST CALIFORNIA WITH VALUES ABOVE 15 PERCENT EXPECTED
EAST OF THE LOWER COLORADO RIVER. FOR FRIDAY INTO THE
WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A RETURN TO DEEPER
MOISTURE...HIGHER HUMIDITY AND BETTER RAIN CHANCES...PARTICULARLY
ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...NOLTE
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KFGZ 312043
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
143 PM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM
ACTIVITY WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN
YAVAPAI AND COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...THIS MORNING`S WATER VAPOR IMAGERY REVEALS NORTHERN
ARIZONA IS CURRENTLY LOCATED BETWEEN A WEST COAST TROUGH AND A
RIDGE OF HIGH PRESSURE EXTENDING FROM NORTH MEXICO NORTHEASTWARD
THROUGH THE CENTRAL PLAINS. BETWEEN THESE FEATURES SITS AN
ENHANCED BELT OF UPPER LEVEL WINDS, WITH A PAIR OF JET MAXIMA, AND
ASSOCIATED SHORTWAVE TROUGHS, PROPAGATING THROUGH THE FLOW.
OBSERVATIONS REVEAL SURFACE DEW POINTS REMAIN ELEVATED ACROSS
NORTHERN ARIZONA. VALUES RANGE FROM THE LOW 50`S TO THE MID 60`S,
WITH THE GREATEST DEW POINTS IN THE LOW DESERTS OF YAVAPAI COUNTY.

THIS MORNINGS UPPER AIR SOUNDING FROM NEAR FLAGSTAFF REVEALS
SLIGHTLY STRONGER WINDS THROUGHOUT THE DEPTH OF THE ATMOSPHERE AS
COMPARED TO YESTERDAY MORNINGS VALUES. THIS IS NOT SURPRISING
GIVEN THE TIGHTENING GRADIENTS BETWEEN THE TROUGH TO OUR WEST AND
RIDGE TO OUR EAST. AS A RESULT, DEEP LAYER SHEAR VALUES HAVE
INCREASED, WITH AROUND 20 KNOTS INDICATED BY THE SOUNDING. IN
ADDITION, ATMOSPHERIC INSTABILITY HAS INCREASED A BIT AS
TEMPERATURES HAVE SLIGHTLY COOLED ABOVE 500 MB. MODIFIED OBSERVED
AND FORECAST SOUNDINGS INDICATE OVER 1000 J/KG OF MIXED LAYER
CAPE MAY DEVELOP ALONG THE WESTERN MOGOLLON RIM TODAY. STORM
MOTION WILL GENERALLY BE FROM THE SOUTHWEST OR WEST AROUND 15
KNOTS.

HI-RES MODEL RUNS FROM THE UNIVERSITY OF ARIZONA FORECAST ANOTHER
CONVECTIVELY ACTIVE DAY, WITH THE MOST WIDESPREAD ACTIVITY
OCCURRING FROM THE MOGOLLON RIM NORTHWARD. IN ADDITION, THEY
INDICATE THE POTENTIAL FOR INCREASING ACTIVITY SOUTH OF THE RIM IN
THE LATE AFTERNOON AND EVENING GENERATED BY OUTFLOWS FROM PRIOR
CONVECTION. THIS TREND APPEARS TO CAPTURED IN THE EVOLUTION OF THE
SREF POP FORECAST AS WELL, BUT EXTENDING FURTHER NORTH INTO WESTERN
COCONINO COUNTY. THIS SEEMS PLAUSIBLE GIVEN THE PRESENCE OF A
WEAKENING JET MAXIMA AND SHORTWAVE TROUGH FORECAST TO MOVE
ACROSS NORTHWEST ARIZONA FROM TODAY THROUGH THE OVERNIGHT HOURS.

SO, FOR TODAY`S FORECAST, EXPECT ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. UNLIKE YESTERDAY, INCREASED
SHEAR MEANS WE COULD SEE A FEW ROTATING STORMS. FREQUENT
LIGHTNING AND FLOODING FROM HEAVY RAINFALL WILL BE THE PRIMARY
HAZARD, BUT LARGE HAIL AND STRONG DOWNBURST WINDS CANNOT BE RULED
OUT.

&&

.PREV DISCUSSION /415 AM MST/...MODELS CONTINUE TO INSIST THAT
DRIER AND MORE STABLE AIR WILL PUSH EAST ACROSS THE REGION THROUGH
THE WEEK. HOWEVER...TRENDS INDICATE THAT TUESDAY WILL LIKELY BE
MORE ACTIVE FROM WHAT WAS PREVIOUSLY THOUGHT AND THE DRYING TREND
WILL LIKELY BE STUBBORN TO MOVE EAST. EVENTUALLY...AS A STRONG
EARLY SEASON TROUGH PUSHES INTO THE PACIFIC NORTHWEST...THE DRIER
AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS DECREASING ON THIS...POPS
MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 18Z PACKAGE...SCT TO NMRS SHRA/TSRA ARE FORECAST
TODAY...MOST NUMEROUS TO THE NORTHEAST OF A LINE FROM
KGCN...KFLG...KPAN. STORMS WILL LIKELY PERSIST UNTIL 05Z TUESDAY.
LCL IFR CONDITIONS WILL OCCUR WITH THE STRONGER STORMS...WITH STRONG
SURFACE WINDS. EXPECT ISOLD -TSRA AFT 05Z TUE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/PETERSON
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312043
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
143 PM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM
ACTIVITY WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN
YAVAPAI AND COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...THIS MORNING`S WATER VAPOR IMAGERY REVEALS NORTHERN
ARIZONA IS CURRENTLY LOCATED BETWEEN A WEST COAST TROUGH AND A
RIDGE OF HIGH PRESSURE EXTENDING FROM NORTH MEXICO NORTHEASTWARD
THROUGH THE CENTRAL PLAINS. BETWEEN THESE FEATURES SITS AN
ENHANCED BELT OF UPPER LEVEL WINDS, WITH A PAIR OF JET MAXIMA, AND
ASSOCIATED SHORTWAVE TROUGHS, PROPAGATING THROUGH THE FLOW.
OBSERVATIONS REVEAL SURFACE DEW POINTS REMAIN ELEVATED ACROSS
NORTHERN ARIZONA. VALUES RANGE FROM THE LOW 50`S TO THE MID 60`S,
WITH THE GREATEST DEW POINTS IN THE LOW DESERTS OF YAVAPAI COUNTY.

THIS MORNINGS UPPER AIR SOUNDING FROM NEAR FLAGSTAFF REVEALS
SLIGHTLY STRONGER WINDS THROUGHOUT THE DEPTH OF THE ATMOSPHERE AS
COMPARED TO YESTERDAY MORNINGS VALUES. THIS IS NOT SURPRISING
GIVEN THE TIGHTENING GRADIENTS BETWEEN THE TROUGH TO OUR WEST AND
RIDGE TO OUR EAST. AS A RESULT, DEEP LAYER SHEAR VALUES HAVE
INCREASED, WITH AROUND 20 KNOTS INDICATED BY THE SOUNDING. IN
ADDITION, ATMOSPHERIC INSTABILITY HAS INCREASED A BIT AS
TEMPERATURES HAVE SLIGHTLY COOLED ABOVE 500 MB. MODIFIED OBSERVED
AND FORECAST SOUNDINGS INDICATE OVER 1000 J/KG OF MIXED LAYER
CAPE MAY DEVELOP ALONG THE WESTERN MOGOLLON RIM TODAY. STORM
MOTION WILL GENERALLY BE FROM THE SOUTHWEST OR WEST AROUND 15
KNOTS.

HI-RES MODEL RUNS FROM THE UNIVERSITY OF ARIZONA FORECAST ANOTHER
CONVECTIVELY ACTIVE DAY, WITH THE MOST WIDESPREAD ACTIVITY
OCCURRING FROM THE MOGOLLON RIM NORTHWARD. IN ADDITION, THEY
INDICATE THE POTENTIAL FOR INCREASING ACTIVITY SOUTH OF THE RIM IN
THE LATE AFTERNOON AND EVENING GENERATED BY OUTFLOWS FROM PRIOR
CONVECTION. THIS TREND APPEARS TO CAPTURED IN THE EVOLUTION OF THE
SREF POP FORECAST AS WELL, BUT EXTENDING FURTHER NORTH INTO WESTERN
COCONINO COUNTY. THIS SEEMS PLAUSIBLE GIVEN THE PRESENCE OF A
WEAKENING JET MAXIMA AND SHORTWAVE TROUGH FORECAST TO MOVE
ACROSS NORTHWEST ARIZONA FROM TODAY THROUGH THE OVERNIGHT HOURS.

SO, FOR TODAY`S FORECAST, EXPECT ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. UNLIKE YESTERDAY, INCREASED
SHEAR MEANS WE COULD SEE A FEW ROTATING STORMS. FREQUENT
LIGHTNING AND FLOODING FROM HEAVY RAINFALL WILL BE THE PRIMARY
HAZARD, BUT LARGE HAIL AND STRONG DOWNBURST WINDS CANNOT BE RULED
OUT.

&&

.PREV DISCUSSION /415 AM MST/...MODELS CONTINUE TO INSIST THAT
DRIER AND MORE STABLE AIR WILL PUSH EAST ACROSS THE REGION THROUGH
THE WEEK. HOWEVER...TRENDS INDICATE THAT TUESDAY WILL LIKELY BE
MORE ACTIVE FROM WHAT WAS PREVIOUSLY THOUGHT AND THE DRYING TREND
WILL LIKELY BE STUBBORN TO MOVE EAST. EVENTUALLY...AS A STRONG
EARLY SEASON TROUGH PUSHES INTO THE PACIFIC NORTHWEST...THE DRIER
AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS DECREASING ON THIS...POPS
MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 18Z PACKAGE...SCT TO NMRS SHRA/TSRA ARE FORECAST
TODAY...MOST NUMEROUS TO THE NORTHEAST OF A LINE FROM
KGCN...KFLG...KPAN. STORMS WILL LIKELY PERSIST UNTIL 05Z TUESDAY.
LCL IFR CONDITIONS WILL OCCUR WITH THE STRONGER STORMS...WITH STRONG
SURFACE WINDS. EXPECT ISOLD -TSRA AFT 05Z TUE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/PETERSON
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312043
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
143 PM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM
ACTIVITY WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN
YAVAPAI AND COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...THIS MORNING`S WATER VAPOR IMAGERY REVEALS NORTHERN
ARIZONA IS CURRENTLY LOCATED BETWEEN A WEST COAST TROUGH AND A
RIDGE OF HIGH PRESSURE EXTENDING FROM NORTH MEXICO NORTHEASTWARD
THROUGH THE CENTRAL PLAINS. BETWEEN THESE FEATURES SITS AN
ENHANCED BELT OF UPPER LEVEL WINDS, WITH A PAIR OF JET MAXIMA, AND
ASSOCIATED SHORTWAVE TROUGHS, PROPAGATING THROUGH THE FLOW.
OBSERVATIONS REVEAL SURFACE DEW POINTS REMAIN ELEVATED ACROSS
NORTHERN ARIZONA. VALUES RANGE FROM THE LOW 50`S TO THE MID 60`S,
WITH THE GREATEST DEW POINTS IN THE LOW DESERTS OF YAVAPAI COUNTY.

THIS MORNINGS UPPER AIR SOUNDING FROM NEAR FLAGSTAFF REVEALS
SLIGHTLY STRONGER WINDS THROUGHOUT THE DEPTH OF THE ATMOSPHERE AS
COMPARED TO YESTERDAY MORNINGS VALUES. THIS IS NOT SURPRISING
GIVEN THE TIGHTENING GRADIENTS BETWEEN THE TROUGH TO OUR WEST AND
RIDGE TO OUR EAST. AS A RESULT, DEEP LAYER SHEAR VALUES HAVE
INCREASED, WITH AROUND 20 KNOTS INDICATED BY THE SOUNDING. IN
ADDITION, ATMOSPHERIC INSTABILITY HAS INCREASED A BIT AS
TEMPERATURES HAVE SLIGHTLY COOLED ABOVE 500 MB. MODIFIED OBSERVED
AND FORECAST SOUNDINGS INDICATE OVER 1000 J/KG OF MIXED LAYER
CAPE MAY DEVELOP ALONG THE WESTERN MOGOLLON RIM TODAY. STORM
MOTION WILL GENERALLY BE FROM THE SOUTHWEST OR WEST AROUND 15
KNOTS.

HI-RES MODEL RUNS FROM THE UNIVERSITY OF ARIZONA FORECAST ANOTHER
CONVECTIVELY ACTIVE DAY, WITH THE MOST WIDESPREAD ACTIVITY
OCCURRING FROM THE MOGOLLON RIM NORTHWARD. IN ADDITION, THEY
INDICATE THE POTENTIAL FOR INCREASING ACTIVITY SOUTH OF THE RIM IN
THE LATE AFTERNOON AND EVENING GENERATED BY OUTFLOWS FROM PRIOR
CONVECTION. THIS TREND APPEARS TO CAPTURED IN THE EVOLUTION OF THE
SREF POP FORECAST AS WELL, BUT EXTENDING FURTHER NORTH INTO WESTERN
COCONINO COUNTY. THIS SEEMS PLAUSIBLE GIVEN THE PRESENCE OF A
WEAKENING JET MAXIMA AND SHORTWAVE TROUGH FORECAST TO MOVE
ACROSS NORTHWEST ARIZONA FROM TODAY THROUGH THE OVERNIGHT HOURS.

SO, FOR TODAY`S FORECAST, EXPECT ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. UNLIKE YESTERDAY, INCREASED
SHEAR MEANS WE COULD SEE A FEW ROTATING STORMS. FREQUENT
LIGHTNING AND FLOODING FROM HEAVY RAINFALL WILL BE THE PRIMARY
HAZARD, BUT LARGE HAIL AND STRONG DOWNBURST WINDS CANNOT BE RULED
OUT.

&&

.PREV DISCUSSION /415 AM MST/...MODELS CONTINUE TO INSIST THAT
DRIER AND MORE STABLE AIR WILL PUSH EAST ACROSS THE REGION THROUGH
THE WEEK. HOWEVER...TRENDS INDICATE THAT TUESDAY WILL LIKELY BE
MORE ACTIVE FROM WHAT WAS PREVIOUSLY THOUGHT AND THE DRYING TREND
WILL LIKELY BE STUBBORN TO MOVE EAST. EVENTUALLY...AS A STRONG
EARLY SEASON TROUGH PUSHES INTO THE PACIFIC NORTHWEST...THE DRIER
AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS DECREASING ON THIS...POPS
MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 18Z PACKAGE...SCT TO NMRS SHRA/TSRA ARE FORECAST
TODAY...MOST NUMEROUS TO THE NORTHEAST OF A LINE FROM
KGCN...KFLG...KPAN. STORMS WILL LIKELY PERSIST UNTIL 05Z TUESDAY.
LCL IFR CONDITIONS WILL OCCUR WITH THE STRONGER STORMS...WITH STRONG
SURFACE WINDS. EXPECT ISOLD -TSRA AFT 05Z TUE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/PETERSON
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 312043
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
143 PM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM
ACTIVITY WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN
YAVAPAI AND COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...THIS MORNING`S WATER VAPOR IMAGERY REVEALS NORTHERN
ARIZONA IS CURRENTLY LOCATED BETWEEN A WEST COAST TROUGH AND A
RIDGE OF HIGH PRESSURE EXTENDING FROM NORTH MEXICO NORTHEASTWARD
THROUGH THE CENTRAL PLAINS. BETWEEN THESE FEATURES SITS AN
ENHANCED BELT OF UPPER LEVEL WINDS, WITH A PAIR OF JET MAXIMA, AND
ASSOCIATED SHORTWAVE TROUGHS, PROPAGATING THROUGH THE FLOW.
OBSERVATIONS REVEAL SURFACE DEW POINTS REMAIN ELEVATED ACROSS
NORTHERN ARIZONA. VALUES RANGE FROM THE LOW 50`S TO THE MID 60`S,
WITH THE GREATEST DEW POINTS IN THE LOW DESERTS OF YAVAPAI COUNTY.

THIS MORNINGS UPPER AIR SOUNDING FROM NEAR FLAGSTAFF REVEALS
SLIGHTLY STRONGER WINDS THROUGHOUT THE DEPTH OF THE ATMOSPHERE AS
COMPARED TO YESTERDAY MORNINGS VALUES. THIS IS NOT SURPRISING
GIVEN THE TIGHTENING GRADIENTS BETWEEN THE TROUGH TO OUR WEST AND
RIDGE TO OUR EAST. AS A RESULT, DEEP LAYER SHEAR VALUES HAVE
INCREASED, WITH AROUND 20 KNOTS INDICATED BY THE SOUNDING. IN
ADDITION, ATMOSPHERIC INSTABILITY HAS INCREASED A BIT AS
TEMPERATURES HAVE SLIGHTLY COOLED ABOVE 500 MB. MODIFIED OBSERVED
AND FORECAST SOUNDINGS INDICATE OVER 1000 J/KG OF MIXED LAYER
CAPE MAY DEVELOP ALONG THE WESTERN MOGOLLON RIM TODAY. STORM
MOTION WILL GENERALLY BE FROM THE SOUTHWEST OR WEST AROUND 15
KNOTS.

HI-RES MODEL RUNS FROM THE UNIVERSITY OF ARIZONA FORECAST ANOTHER
CONVECTIVELY ACTIVE DAY, WITH THE MOST WIDESPREAD ACTIVITY
OCCURRING FROM THE MOGOLLON RIM NORTHWARD. IN ADDITION, THEY
INDICATE THE POTENTIAL FOR INCREASING ACTIVITY SOUTH OF THE RIM IN
THE LATE AFTERNOON AND EVENING GENERATED BY OUTFLOWS FROM PRIOR
CONVECTION. THIS TREND APPEARS TO CAPTURED IN THE EVOLUTION OF THE
SREF POP FORECAST AS WELL, BUT EXTENDING FURTHER NORTH INTO WESTERN
COCONINO COUNTY. THIS SEEMS PLAUSIBLE GIVEN THE PRESENCE OF A
WEAKENING JET MAXIMA AND SHORTWAVE TROUGH FORECAST TO MOVE
ACROSS NORTHWEST ARIZONA FROM TODAY THROUGH THE OVERNIGHT HOURS.

SO, FOR TODAY`S FORECAST, EXPECT ANOTHER ROUND OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS. UNLIKE YESTERDAY, INCREASED
SHEAR MEANS WE COULD SEE A FEW ROTATING STORMS. FREQUENT
LIGHTNING AND FLOODING FROM HEAVY RAINFALL WILL BE THE PRIMARY
HAZARD, BUT LARGE HAIL AND STRONG DOWNBURST WINDS CANNOT BE RULED
OUT.

&&

.PREV DISCUSSION /415 AM MST/...MODELS CONTINUE TO INSIST THAT
DRIER AND MORE STABLE AIR WILL PUSH EAST ACROSS THE REGION THROUGH
THE WEEK. HOWEVER...TRENDS INDICATE THAT TUESDAY WILL LIKELY BE
MORE ACTIVE FROM WHAT WAS PREVIOUSLY THOUGHT AND THE DRYING TREND
WILL LIKELY BE STUBBORN TO MOVE EAST. EVENTUALLY...AS A STRONG
EARLY SEASON TROUGH PUSHES INTO THE PACIFIC NORTHWEST...THE DRIER
AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS DECREASING ON THIS...POPS
MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 18Z PACKAGE...SCT TO NMRS SHRA/TSRA ARE FORECAST
TODAY...MOST NUMEROUS TO THE NORTHEAST OF A LINE FROM
KGCN...KFLG...KPAN. STORMS WILL LIKELY PERSIST UNTIL 05Z TUESDAY.
LCL IFR CONDITIONS WILL OCCUR WITH THE STRONGER STORMS...WITH STRONG
SURFACE WINDS. EXPECT ISOLD -TSRA AFT 05Z TUE. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...RR/PETERSON
AVIATION...BAK


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KTWC 311648
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
947 AM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND A MOISTURE INCREASE FROM THE SOUTH WILL BRING
A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...RADAR WAS SHOWING A FEW LINGERING SHOWERS IN THE WHITE
MOUNTAINS THIS MORNING...WITH CLOUDS ALREADY STARTING TO BUILD UP IN
THE MOUNTAINS ELSEWHERE ACROSS SOUTHEAST ARIZONA. STILL LOOKING AT A
RATHER ACTIVE DAY THUNDERSTORM WISE ACROSS THE AREA...WITH LOCALLY
HEAVY RAINFALL AND STRONG WINDS BEING THE MAIN CONCERNS TODAY.
CURRENT FORECAST SEEMED TO HANDLE THE TRENDS WELL...SO NO UPDATES
NECESSARY THIS MORNING. PLEASE REFER TO THE ADDITIONAL SECTIONS IN
THIS PRODUCT FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 01/18Z.
BECOMING SCT-BKN IN THE AFTERNOON...DECKS GENERALLY 8 TO 12 KFT. SCT
SHRA/TSRA WILL AGAIN BE POSSIBLE THIS AFTERNOON. BRIEF MVFR
CONDITIONS AND GUSTY WINDS TO 45 KTS WILL BE POSSIBLE IN AND AROUND
THE STRONGER STORMS.  OUTSIDE OF THUNDERSTORM INFLUENCE SURFACE
WINDS WILL GENERALLY BE UNDER 10 KTS...THOUGH SOME WEST-SOUTHWEST
AFTERNOON BREEZINESS IS NOT OUT OF THE QUESTION. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS
IN STORE FOR TODAY...WITH THE ACTIVITY SHIFTING A BIT MORE EAST.
GENERALLY FROM ZONES 503...504 AND 536 EAST. PRIME CONCERN TODAY IS
STRONG WINDS AND HEAVY RAIN DUE TO SLOW MOTIONS.  THIS BASIC IDEA
WILL CONTINUE EARLY THIS WEEK...WITH DAILY AFTERNOON AND EVENING
STORMS EXPECTED.  STARTING TUESDAY STORMS WILL TEND TO BE MORE
FOCUSED OVER EASTERN ZONES...WITH DIMINISHED THUNDERSTORM ACTIVITY
FROM WEDNESDAY ON.  THUNDERSTORMS ARE EXPECTED TO BE WET AND AS IS
TYPICAL MAY PRODUCE STRONG...GUSTY AND ERRATIC WINDS WITH THE
STRONGER THUNDERSTORMS.

OUTSIDE OF THUNDERSTORMS GENERALLY LIGHT TERRAIN DRIVEN WINDS ARE
EXPECTED...WITH A WEST TO SOUTHWEST FLOW WILL DEVELOPING TODAY
ACROSS ARIZONA. THE STRONGEST WINDS WILL BE ACROSS ZONE
150...PEAKING IN THE 15-20 MPH RANGE.

&&

.PREV DISCUSSION...THE MID LEVEL AND STORM FLOW REMAIN WEAK WITH THE
TROUGHINESS THROUGH THE REGION NORTH OF US NOT DIGGING MUCH...AND
THE NEARBY RIDGE CONTINUING TO WEAKEN WITH THE REMNANT CENTER
HANGING ON IN CHIHUAHUA. WE HAVE PLENTY OF MOISTURE FOR THE TIME
BEING WITH PRECIPITABLE WATER LEVELS ACROSS THE SOUTHERN HALF OF THE
STATE RANGING FROM 1 INCH NEAR THE NEW MEXICO BORDER TO 1.6 INCHES
IN SOUTH CENTRAL AREAS WEST AND NORTHWEST OF TUCSON.

FOR TODAY WE SHOULD BENEFIT FROM A LITTLE MORE COOLING IN THE MID
LEVELS AS THE HIGH PRESSURE CONTINUES TO WEAKEN. THIS SHOULD SUPPORT
VALLEY STORMS A LITTLE BETTER COMPARED TO YESTERDAY. WE HAD BUILT UP
SOLID ELEVATED CONVECTIVE POTENTIAL BY YESTERDAY AFTERNOON...WE JUST
DIDN`T HAVE QUITE ENOUGH TO OVERCOME THE INHIBITION IN SOME VALLEY
LOCATIONS. EXPECT BETTER COVERAGE TODAY WITH INCREASED SUPPORT FOR
VALLEY STORMS EAST OF SELLS. THIS IS SUPPORTED WELL BY 00Z UOFA WRF
RUNS.

FOR TUESDAY AND WEDNESDAY WE`LL CONTINUE TO SEE SOME MOISTURE
EROSION FROM THE WEST...WITH AREAS IMMEDIATELY UPSTREAM IN THE WEAK
BUT CONTINUING WESTERLY TO SOUTHWESTERLY FLOW STARTING TO LOSE
MOISTURE. MAIN AREA OF FOCUS EAST OF TUCSON TUESDAY AND WEDNESDAY
AFTERNOONS.

BY THURSDAY THE WEAKER MOISTURE FIELDS WILL HAVE TAKEN THEIR TOLL
WITH MORE LIMITED COVERAGE...STILL FAVORING AREAS EAST OF TUCSON.

LATER IN THE WEEK AND INTO THE WEEKEND...SEPTEMBER IS HERE AND IT`S
TIME TO WATCH FOR TROPICAL INFLUENCES. THE ACTIVITY OFF THE WEST
COAST OF MEXICO HAS BEEN PICKING UP STEAM AGAIN...GENERATING 3 NAMED
STORMS OVER THE PAST WEEK. AS IS OFTEN THE CASE IN AUGUST...THESE
STORMS HAVE BEEN MAKING A BEELINE FOR THE CENTRAL PACIFIC WITHOUT
DOING MUCH FOR OUR AREA. ANOTHER IS COOKING ABOUT 650 MILES SOUTH-
SOUTHWEST OF MANZANILLO WITH AN AREA OF LOW PRESSURE BECOMING BETTER
ORGANIZED SINCE YESTERDAY. CONDITIONS ARE CONDUCIVE FOR CONTINUED
DEVELOPMENT WITH THIS STORM EXPECTED TO BECOME A DEPRESSION DURING
THE NEXT DAY OR TWO. IF IT ENDS UP GETTING A NAME...IT WILL BE
KEVIN. WITH THE MEAN TROUGH POSITION HANGING ON THROUGH THE NORTHERN
AND CENTRAL GREAT BASIN...WE MIGHT BE ABLE TO COAX SOME TROPICAL
INFLUENCES IN OUR GENERAL DIRECTION BY THEN. AT THE VERY LEAST
MEDIUM RANGE MODELS ONCE AGAIN INCREASE OUR MOISTURE BY NEXT WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON



000
FXUS65 KTWC 311648
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
947 AM MST MON AUG 31 2015

.SYNOPSIS...ANOTHER GOOD CHANCE OF SHOWERS AND THUNDERSTORMS TODAY.
A WEAK DRYING TREND AND WEAK FLOW WILL TEND TO LIMIT MOST
THUNDERSTORM ACTIVITY TO AREAS EAST OF TUCSON THE SECOND HALF OF THE
WEEK. BY THIS WEEKEND A MOISTURE INCREASE FROM THE SOUTH WILL BRING
A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS.

&&

.DISCUSSION...RADAR WAS SHOWING A FEW LINGERING SHOWERS IN THE WHITE
MOUNTAINS THIS MORNING...WITH CLOUDS ALREADY STARTING TO BUILD UP IN
THE MOUNTAINS ELSEWHERE ACROSS SOUTHEAST ARIZONA. STILL LOOKING AT A
RATHER ACTIVE DAY THUNDERSTORM WISE ACROSS THE AREA...WITH LOCALLY
HEAVY RAINFALL AND STRONG WINDS BEING THE MAIN CONCERNS TODAY.
CURRENT FORECAST SEEMED TO HANDLE THE TRENDS WELL...SO NO UPDATES
NECESSARY THIS MORNING. PLEASE REFER TO THE ADDITIONAL SECTIONS IN
THIS PRODUCT FOR MORE DETAILS.

&&

.AVIATION...VALID THRU 01/18Z.
BECOMING SCT-BKN IN THE AFTERNOON...DECKS GENERALLY 8 TO 12 KFT. SCT
SHRA/TSRA WILL AGAIN BE POSSIBLE THIS AFTERNOON. BRIEF MVFR
CONDITIONS AND GUSTY WINDS TO 45 KTS WILL BE POSSIBLE IN AND AROUND
THE STRONGER STORMS.  OUTSIDE OF THUNDERSTORM INFLUENCE SURFACE
WINDS WILL GENERALLY BE UNDER 10 KTS...THOUGH SOME WEST-SOUTHWEST
AFTERNOON BREEZINESS IS NOT OUT OF THE QUESTION. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...ANOTHER ROUND OF SCATTERED SHOWERS AND THUNDERSTORMS
IN STORE FOR TODAY...WITH THE ACTIVITY SHIFTING A BIT MORE EAST.
GENERALLY FROM ZONES 503...504 AND 536 EAST. PRIME CONCERN TODAY IS
STRONG WINDS AND HEAVY RAIN DUE TO SLOW MOTIONS.  THIS BASIC IDEA
WILL CONTINUE EARLY THIS WEEK...WITH DAILY AFTERNOON AND EVENING
STORMS EXPECTED.  STARTING TUESDAY STORMS WILL TEND TO BE MORE
FOCUSED OVER EASTERN ZONES...WITH DIMINISHED THUNDERSTORM ACTIVITY
FROM WEDNESDAY ON.  THUNDERSTORMS ARE EXPECTED TO BE WET AND AS IS
TYPICAL MAY PRODUCE STRONG...GUSTY AND ERRATIC WINDS WITH THE
STRONGER THUNDERSTORMS.

OUTSIDE OF THUNDERSTORMS GENERALLY LIGHT TERRAIN DRIVEN WINDS ARE
EXPECTED...WITH A WEST TO SOUTHWEST FLOW WILL DEVELOPING TODAY
ACROSS ARIZONA. THE STRONGEST WINDS WILL BE ACROSS ZONE
150...PEAKING IN THE 15-20 MPH RANGE.

&&

.PREV DISCUSSION...THE MID LEVEL AND STORM FLOW REMAIN WEAK WITH THE
TROUGHINESS THROUGH THE REGION NORTH OF US NOT DIGGING MUCH...AND
THE NEARBY RIDGE CONTINUING TO WEAKEN WITH THE REMNANT CENTER
HANGING ON IN CHIHUAHUA. WE HAVE PLENTY OF MOISTURE FOR THE TIME
BEING WITH PRECIPITABLE WATER LEVELS ACROSS THE SOUTHERN HALF OF THE
STATE RANGING FROM 1 INCH NEAR THE NEW MEXICO BORDER TO 1.6 INCHES
IN SOUTH CENTRAL AREAS WEST AND NORTHWEST OF TUCSON.

FOR TODAY WE SHOULD BENEFIT FROM A LITTLE MORE COOLING IN THE MID
LEVELS AS THE HIGH PRESSURE CONTINUES TO WEAKEN. THIS SHOULD SUPPORT
VALLEY STORMS A LITTLE BETTER COMPARED TO YESTERDAY. WE HAD BUILT UP
SOLID ELEVATED CONVECTIVE POTENTIAL BY YESTERDAY AFTERNOON...WE JUST
DIDN`T HAVE QUITE ENOUGH TO OVERCOME THE INHIBITION IN SOME VALLEY
LOCATIONS. EXPECT BETTER COVERAGE TODAY WITH INCREASED SUPPORT FOR
VALLEY STORMS EAST OF SELLS. THIS IS SUPPORTED WELL BY 00Z UOFA WRF
RUNS.

FOR TUESDAY AND WEDNESDAY WE`LL CONTINUE TO SEE SOME MOISTURE
EROSION FROM THE WEST...WITH AREAS IMMEDIATELY UPSTREAM IN THE WEAK
BUT CONTINUING WESTERLY TO SOUTHWESTERLY FLOW STARTING TO LOSE
MOISTURE. MAIN AREA OF FOCUS EAST OF TUCSON TUESDAY AND WEDNESDAY
AFTERNOONS.

BY THURSDAY THE WEAKER MOISTURE FIELDS WILL HAVE TAKEN THEIR TOLL
WITH MORE LIMITED COVERAGE...STILL FAVORING AREAS EAST OF TUCSON.

LATER IN THE WEEK AND INTO THE WEEKEND...SEPTEMBER IS HERE AND IT`S
TIME TO WATCH FOR TROPICAL INFLUENCES. THE ACTIVITY OFF THE WEST
COAST OF MEXICO HAS BEEN PICKING UP STEAM AGAIN...GENERATING 3 NAMED
STORMS OVER THE PAST WEEK. AS IS OFTEN THE CASE IN AUGUST...THESE
STORMS HAVE BEEN MAKING A BEELINE FOR THE CENTRAL PACIFIC WITHOUT
DOING MUCH FOR OUR AREA. ANOTHER IS COOKING ABOUT 650 MILES SOUTH-
SOUTHWEST OF MANZANILLO WITH AN AREA OF LOW PRESSURE BECOMING BETTER
ORGANIZED SINCE YESTERDAY. CONDITIONS ARE CONDUCIVE FOR CONTINUED
DEVELOPMENT WITH THIS STORM EXPECTED TO BECOME A DEPRESSION DURING
THE NEXT DAY OR TWO. IF IT ENDS UP GETTING A NAME...IT WILL BE
KEVIN. WITH THE MEAN TROUGH POSITION HANGING ON THROUGH THE NORTHERN
AND CENTRAL GREAT BASIN...WE MIGHT BE ABLE TO COAX SOME TROPICAL
INFLUENCES IN OUR GENERAL DIRECTION BY THEN. AT THE VERY LEAST
MEDIUM RANGE MODELS ONCE AGAIN INCREASE OUR MOISTURE BY NEXT WEEKEND.

&&

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

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON




000
FXUS65 KPSR 311612
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
912 AM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. EARLY MORNING CONVECTION ACROSS GILA COUNTY
CONTINUES TO DISSIPATE AT THIS HOUR. INTERESTING TO NOTE THAT THE
NCAR ENSEMBLE PICKED UP ON THIS ACTIVITY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.
MEANWHILE...OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST
THAT ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS
OF SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE
RAIN...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE
MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT MOST
IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT. 00Z
SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE SOUTHWESTERLY
FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL ACROSS THE
REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE ENSEMBLES
SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED TO
SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...CB
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 311612
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
912 AM MST MON AUG 31 2015

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THAT THE RIDGE HAS DRIFTED SLIGHTLY
TO THE EAST...BUT OVERALL VERY LITTLE HAS CHANGED SYNOPTICALLY OVER
THE PAST FEW DAYS. EARLY MORNING CONVECTION ACROSS GILA COUNTY
CONTINUES TO DISSIPATE AT THIS HOUR. INTERESTING TO NOTE THAT THE
NCAR ENSEMBLE PICKED UP ON THIS ACTIVITY AND CONSEQUENTLY MORE
WEIGHT WAS ASSIGNED TO THIS GUIDANCE THROUGH THE EVENING.
MEANWHILE...OTHER CONVECTIVE ALLOWING GUIDANCE CONTINUES TO SUGGEST
THAT ISOLATED/SCATTERED THUNDERSTORMS WILL AGAIN DEVELOP ACROSS THE
PHOENIX AREA AND POINTS EASTWARD THIS EVENING...AIDED BY SUFFICIENT
LOW-LEVEL MOISTURE...BOUNDARY PROPAGATION FROM THE SOUTH AND
RELATIVELY COOL TEMPERATURES ALOFT ASSOCIATED WITH A TROUGH TO THE
WEST. FORECAST POPS WERE INCREASED TO 20-30 PERCENT ACROSS PORTIONS
OF SOUTH-CENTRAL AZ FOR TONIGHT. MOST AREAS WILL NOT SEE
RAIN...THOUGH LIGHTNING...GUSTY WINDS AND AREAS OF BLOWING DUST ARE
MORE PROBABLE.

&&

.PREVIOUS DISCUSSION...
SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT MOST
IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT. 00Z
SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE SOUTHWESTERLY
FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL ACROSS THE
REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE ENSEMBLES
SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED TO
SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...HIRSCH
AVIATION...CB
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KFGZ 311112
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM ACTIVITY
WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN YAVAPAI AND
COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...LITTLE HAS BEEN DONE TO SCOUR OUT LOW LEVEL MOISTURE
OVERNIGHT...EXCEPT ALONG THE FAR WESTERN BORDERS OF THE CWA. ANOTHER
ACTIVE DAY IS EXPECTED TODAY...PERHAPS EVEN MORE SO THAN SUNDAY.
THIS IS DUE A WEAK S/WV OVER SOCAL THAT WILL MOVE INTO WESTERN
ARIZONA THIS AFTERNOON...COURTESY OF A MID-LEVEL JET SEEN ON WATER
VAPOR IN THE SAME AREA. THIS WILL PROVIDE MORE THAN ENOUGH DYNAMICS
AND COOLING ALOFT TO ACT ON OUR PRE-EXISTING MOISTURE OVER CENTRAL
AND EASTERN ARIZONA. MODEL SOUNDING PROFILES INDICATE A BIT MORE
SHEAR AND CAPE FROM SUNDAY...SO FAIRLY WIDESPREAD COVERAGE IS
EXPECTED...WITH A FEW SEVERE STORMS.

MODELS CONTINUE TO INSIST THAT DRIER AND MORE STABLE AIR WILL PUSH
EAST ACROSS THE REGION THROUGH THE WEEK. HOWEVER...TRENDS INDICATE
THAT TUESDAY WILL LIKELY BE MORE ACTIVE FROM WHAT WAS PREVIOUSLY
THOUGHT AND THE DRYING TREND WILL LIKELY BE STUBBORN TO MOVE EAST.
EVENTUALLY...AS A STRONG EARLY SEASON TROUGH PUSHES INTO THE PACIFIC
NORTHWEST...THE DRIER AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS
DECREASING ON THIS...POPS MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE FORECAST FOR TODAY AS AN UPPER LEVEL TROUGH HELPS
TO CONVECT THE AIR MASS. IFR CONDITIONS WILL OCCUR NEAR THE STRONGER
STORMS WITH THREATS OF LARGE HAIL...LOCALIZED FLASH FLOODING...ALONG
WITH ERRATIC AND GUSTY SURFACE WINDS FROM 40 TO 50 MPH. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 311112
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM ACTIVITY
WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN YAVAPAI AND
COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...LITTLE HAS BEEN DONE TO SCOUR OUT LOW LEVEL MOISTURE
OVERNIGHT...EXCEPT ALONG THE FAR WESTERN BORDERS OF THE CWA. ANOTHER
ACTIVE DAY IS EXPECTED TODAY...PERHAPS EVEN MORE SO THAN SUNDAY.
THIS IS DUE A WEAK S/WV OVER SOCAL THAT WILL MOVE INTO WESTERN
ARIZONA THIS AFTERNOON...COURTESY OF A MID-LEVEL JET SEEN ON WATER
VAPOR IN THE SAME AREA. THIS WILL PROVIDE MORE THAN ENOUGH DYNAMICS
AND COOLING ALOFT TO ACT ON OUR PRE-EXISTING MOISTURE OVER CENTRAL
AND EASTERN ARIZONA. MODEL SOUNDING PROFILES INDICATE A BIT MORE
SHEAR AND CAPE FROM SUNDAY...SO FAIRLY WIDESPREAD COVERAGE IS
EXPECTED...WITH A FEW SEVERE STORMS.

MODELS CONTINUE TO INSIST THAT DRIER AND MORE STABLE AIR WILL PUSH
EAST ACROSS THE REGION THROUGH THE WEEK. HOWEVER...TRENDS INDICATE
THAT TUESDAY WILL LIKELY BE MORE ACTIVE FROM WHAT WAS PREVIOUSLY
THOUGHT AND THE DRYING TREND WILL LIKELY BE STUBBORN TO MOVE EAST.
EVENTUALLY...AS A STRONG EARLY SEASON TROUGH PUSHES INTO THE PACIFIC
NORTHWEST...THE DRIER AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS
DECREASING ON THIS...POPS MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE FORECAST FOR TODAY AS AN UPPER LEVEL TROUGH HELPS
TO CONVECT THE AIR MASS. IFR CONDITIONS WILL OCCUR NEAR THE STRONGER
STORMS WITH THREATS OF LARGE HAIL...LOCALIZED FLASH FLOODING...ALONG
WITH ERRATIC AND GUSTY SURFACE WINDS FROM 40 TO 50 MPH. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 311112
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM ACTIVITY
WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN YAVAPAI AND
COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...LITTLE HAS BEEN DONE TO SCOUR OUT LOW LEVEL MOISTURE
OVERNIGHT...EXCEPT ALONG THE FAR WESTERN BORDERS OF THE CWA. ANOTHER
ACTIVE DAY IS EXPECTED TODAY...PERHAPS EVEN MORE SO THAN SUNDAY.
THIS IS DUE A WEAK S/WV OVER SOCAL THAT WILL MOVE INTO WESTERN
ARIZONA THIS AFTERNOON...COURTESY OF A MID-LEVEL JET SEEN ON WATER
VAPOR IN THE SAME AREA. THIS WILL PROVIDE MORE THAN ENOUGH DYNAMICS
AND COOLING ALOFT TO ACT ON OUR PRE-EXISTING MOISTURE OVER CENTRAL
AND EASTERN ARIZONA. MODEL SOUNDING PROFILES INDICATE A BIT MORE
SHEAR AND CAPE FROM SUNDAY...SO FAIRLY WIDESPREAD COVERAGE IS
EXPECTED...WITH A FEW SEVERE STORMS.

MODELS CONTINUE TO INSIST THAT DRIER AND MORE STABLE AIR WILL PUSH
EAST ACROSS THE REGION THROUGH THE WEEK. HOWEVER...TRENDS INDICATE
THAT TUESDAY WILL LIKELY BE MORE ACTIVE FROM WHAT WAS PREVIOUSLY
THOUGHT AND THE DRYING TREND WILL LIKELY BE STUBBORN TO MOVE EAST.
EVENTUALLY...AS A STRONG EARLY SEASON TROUGH PUSHES INTO THE PACIFIC
NORTHWEST...THE DRIER AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS
DECREASING ON THIS...POPS MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE FORECAST FOR TODAY AS AN UPPER LEVEL TROUGH HELPS
TO CONVECT THE AIR MASS. IFR CONDITIONS WILL OCCUR NEAR THE STRONGER
STORMS WITH THREATS OF LARGE HAIL...LOCALIZED FLASH FLOODING...ALONG
WITH ERRATIC AND GUSTY SURFACE WINDS FROM 40 TO 50 MPH. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




000
FXUS65 KFGZ 311112
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
415 AM MST MON AUG 31 2015

.SYNOPSIS...EXPECT ANOTHER ROUND OF SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS TODAY. SOME STORMS TODAY MAY CONTAIN LARGE HAIL
AND TORRENTIAL RAINFALL...AS WELL AS DAMAGING WINDS. STORM ACTIVITY
WILL SLOWLY MOVE EAST THROUGH THE WEEK...WITH WESTERN YAVAPAI AND
COCONINO COUNTIES LIKELY DRYING OUT.

&&

.DISCUSSION...LITTLE HAS BEEN DONE TO SCOUR OUT LOW LEVEL MOISTURE
OVERNIGHT...EXCEPT ALONG THE FAR WESTERN BORDERS OF THE CWA. ANOTHER
ACTIVE DAY IS EXPECTED TODAY...PERHAPS EVEN MORE SO THAN SUNDAY.
THIS IS DUE A WEAK S/WV OVER SOCAL THAT WILL MOVE INTO WESTERN
ARIZONA THIS AFTERNOON...COURTESY OF A MID-LEVEL JET SEEN ON WATER
VAPOR IN THE SAME AREA. THIS WILL PROVIDE MORE THAN ENOUGH DYNAMICS
AND COOLING ALOFT TO ACT ON OUR PRE-EXISTING MOISTURE OVER CENTRAL
AND EASTERN ARIZONA. MODEL SOUNDING PROFILES INDICATE A BIT MORE
SHEAR AND CAPE FROM SUNDAY...SO FAIRLY WIDESPREAD COVERAGE IS
EXPECTED...WITH A FEW SEVERE STORMS.

MODELS CONTINUE TO INSIST THAT DRIER AND MORE STABLE AIR WILL PUSH
EAST ACROSS THE REGION THROUGH THE WEEK. HOWEVER...TRENDS INDICATE
THAT TUESDAY WILL LIKELY BE MORE ACTIVE FROM WHAT WAS PREVIOUSLY
THOUGHT AND THE DRYING TREND WILL LIKELY BE STUBBORN TO MOVE EAST.
EVENTUALLY...AS A STRONG EARLY SEASON TROUGH PUSHES INTO THE PACIFIC
NORTHWEST...THE DRIER AIR MAY WIN OUT. HOWEVER...CONFIDENCE IS
DECREASING ON THIS...POPS MAY NEED TO BE RAISED LATER THIS WEEK.

&&

.AVIATION...FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ARE FORECAST FOR TODAY AS AN UPPER LEVEL TROUGH HELPS
TO CONVECT THE AIR MASS. IFR CONDITIONS WILL OCCUR NEAR THE STRONGER
STORMS WITH THREATS OF LARGE HAIL...LOCALIZED FLASH FLOODING...ALONG
WITH ERRATIC AND GUSTY SURFACE WINDS FROM 40 TO 50 MPH. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

PUBLIC...PETERSON
AVIATION...BOHLIN


FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KPSR 311106 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
405 AM MST MON AUG 31 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ALOFT
OVER SOUTHERN CALIFORNIA AND PORTIONS OF THE ARIZONA
DESERTS...MEANWHILE A SERIES OF CONVECTIVE COMPLEXES CONTINUE TO
DECAY OVER SOUTHERN SONORA. A FEW GRAVITY WAVES ARE EVIDENT ACROSS
THE REGION...ONE OF WHICH APPEARED TO MOVE THROUGH THE PHOENIX METRO
AROUND 06Z. HOWEVER CONDITIONS REMAIN RELATIVELY QUIET AS OF 0930Z
WITH ONLY SOME DEBRIS MID CLOUDS ACROSS THE AREA. NATURALLY THE CLOUD
COVER HAS ALLOWED TEMPERATURES TO REMAIN ON THE MILD SIDE WITH MOST
DESERT LOCALES ONLY IN THE MID/UPPER 80S.

SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT
MOST IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT.
00Z SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE
SOUTHWESTERLY FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL
ACROSS THE REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE
ENSEMBLES SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED
TO SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...CB
FIRE WEATHER...CB/HIRSCH



000
FXUS65 KPSR 311106 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
405 AM MST MON AUG 31 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ALOFT
OVER SOUTHERN CALIFORNIA AND PORTIONS OF THE ARIZONA
DESERTS...MEANWHILE A SERIES OF CONVECTIVE COMPLEXES CONTINUE TO
DECAY OVER SOUTHERN SONORA. A FEW GRAVITY WAVES ARE EVIDENT ACROSS
THE REGION...ONE OF WHICH APPEARED TO MOVE THROUGH THE PHOENIX METRO
AROUND 06Z. HOWEVER CONDITIONS REMAIN RELATIVELY QUIET AS OF 0930Z
WITH ONLY SOME DEBRIS MID CLOUDS ACROSS THE AREA. NATURALLY THE CLOUD
COVER HAS ALLOWED TEMPERATURES TO REMAIN ON THE MILD SIDE WITH MOST
DESERT LOCALES ONLY IN THE MID/UPPER 80S.

SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT
MOST IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT.
00Z SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE
SOUTHWESTERLY FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL
ACROSS THE REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE
ENSEMBLES SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED
TO SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...CB
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 311106 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
405 AM MST MON AUG 31 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ALOFT
OVER SOUTHERN CALIFORNIA AND PORTIONS OF THE ARIZONA
DESERTS...MEANWHILE A SERIES OF CONVECTIVE COMPLEXES CONTINUE TO
DECAY OVER SOUTHERN SONORA. A FEW GRAVITY WAVES ARE EVIDENT ACROSS
THE REGION...ONE OF WHICH APPEARED TO MOVE THROUGH THE PHOENIX METRO
AROUND 06Z. HOWEVER CONDITIONS REMAIN RELATIVELY QUIET AS OF 0930Z
WITH ONLY SOME DEBRIS MID CLOUDS ACROSS THE AREA. NATURALLY THE CLOUD
COVER HAS ALLOWED TEMPERATURES TO REMAIN ON THE MILD SIDE WITH MOST
DESERT LOCALES ONLY IN THE MID/UPPER 80S.

SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT
MOST IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT.
00Z SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE
SOUTHWESTERLY FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL
ACROSS THE REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE
ENSEMBLES SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED
TO SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...CB
FIRE WEATHER...CB/HIRSCH




000
FXUS65 KPSR 311106 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
405 AM MST MON AUG 31 2015

.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AGAIN TODAY ACROSS THE
PHOENIX AREA AND POINTS EAST...ALTHOUGH A SLIGHT DRYING TREND IS
EXPECTED BY THE MIDDLE OF THE WEEK. MOISTURE IS EXPECTED TO RETURN TO
THE AREA BEFORE THIS WEEKEND WITH ADDITIONAL SHOWERS/STORMS POSSIBLE
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL GRADUALLY RETREAT THIS
WEEK...EVENTUALLY RESIDING WITHIN A DEGREE OR TWO OF NORMAL FROM
WEDNESDAY ONWARD.

&&

.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS SOUTHWESTERLY FLOW ALOFT
OVER SOUTHERN CALIFORNIA AND PORTIONS OF THE ARIZONA
DESERTS...MEANWHILE A SERIES OF CONVECTIVE COMPLEXES CONTINUE TO
DECAY OVER SOUTHERN SONORA. A FEW GRAVITY WAVES ARE EVIDENT ACROSS
THE REGION...ONE OF WHICH APPEARED TO MOVE THROUGH THE PHOENIX METRO
AROUND 06Z. HOWEVER CONDITIONS REMAIN RELATIVELY QUIET AS OF 0930Z
WITH ONLY SOME DEBRIS MID CLOUDS ACROSS THE AREA. NATURALLY THE CLOUD
COVER HAS ALLOWED TEMPERATURES TO REMAIN ON THE MILD SIDE WITH MOST
DESERT LOCALES ONLY IN THE MID/UPPER 80S.

SOUTHWESTERLY FLOW ALOFT WILL PREVAIL AGAIN TODAY COURTESY OF
LONGWAVE TROUGHING OFF THE WEST COAST BUT AS HAS BEEN THE CASE THE
PAST SEVERAL DAYS...THIS WON`T NECESSARILY RESULT IN QUIET WEATHER.
MID/UPPER LEVEL FLOW ISN`T PARTICULARLY STRONG TO BEGIN WITH BUT
MOST IMPORTANTLY...WINDS IN THE 925-700MB LAYER REMAIN OUT OF THE
SOUTH/SOUTHEAST. HARD TO EFFECTIVELY SCOUR OUT LOW LEVEL MOISTURE
WHEN IT SIMPLY ADVECTS BACK INTO THE AREA EACH EVENING/OVERNIGHT.
00Z SOUNDINGS AND BLENDED TPW IMAGERY SUGGEST THAT DESPITE
SOUTHWESTERLY FLOW ALOFT...PWATS REMAIN AT OR SLIGHTLY ABOVE NORMAL
ACROSS THE REGION THIS MORNING. HI-RES MODELS AND THEIR RESPECTIVE
ENSEMBLES SUGGEST A SIMILAR CONVECTIVE REGIME THIS AFTERNOON COMPARED
TO SATURDAY AND SUNDAY. STORMS WILL BE MOST LIKELY TO THE
NORTH/SOUTH/EAST OF PHOENIX...WITH OUTFLOWS LIKELY TO DROP INTO THE
DESERTS FROM ALL DIRECTIONS AND SPAWN ISOLATED STORMS OVER THE PHX
METRO AREA. UNTIL THE BOUNDARY LAYER HAS SUFFICIENTLY DRIED OUT OR
HAS BEEN SUFFICIENTLY OVERTURNED...I DON`T SEE ANY REASON WHY IT
WON`T BE ACTIVE. MADE SOME UPWARD ADJUSTMENTS TO POPS THIS
AFTERNOON/EVENING. ACROSS THE WESTERN HALF OF THE FORECAST AREA WHERE
THE BOUNDARY LAYER HAS ACTUALLY DRIED OUT /AND HAS BEEN DRY THE PAST
FEW DAYS/...STORM CHANCES REMAIN SLIM TO NIL.

FORECAST CONFIDENCE TUESDAY THROUGH THURSDAY IS LOW. DETERMINISTIC
GUIDANCE TAKEN AT FACE VALUE WOULD SUGGEST A DOWNWARD TREND IN STORMS
THROUGH MID WEEK...HOWEVER PROBABILISTIC TOOLS SUGGEST THE BL WILL
REMAIN MOIST WITH MODEST INSTABILITY ACROSS THE REGION. OF COURSE THE
MISSING INGREDIENT IS A TRIGGER TO KICK OFF STORMS IN THE FIRST PLACE
AND NONE OF THE DETERMINISTIC GUIDANCE INDICATE MUCH IN THE WAY OF
INVERTED TROUGHS OR LARGER SCALE FEATURES. WILL HANG ONTO SOMEWHAT
ELEVATED POPS /HIGHER THAN CLIMO/ THROUGH MID WEEK ON THE PREMISE
THAT STORMS WILL BE TRIGGERED BY COLLIDING OUTFLOWS.

FORECAST CONFIDENCE ISN`T MUCH HIGHER LATER IN THE FORECAST PERIOD.
IT WOULD APPEAR THAT MOISTURE WILL BE DRAWN INTO THE REGION FROM THE
TROPICS LATE IN THE WEEK /FRIDAY-SATURDAY/ ALTHOUGH EXACTLY WHERE
THIS AXIS OF DEEPEST MOISTURE RESIDES IS STILL UP FOR DEBATE.
00Z DETERMINISTIC GFS AND ECMWF SUGGEST ANOMALOUSLY HIGH PWATS AND
MIXING RATIOS WILL OVERSPREAD MUCH OF THE DESERT SOUTHWEST WHEREAS
GEFS AND NAEFS KEEP THIS MOISTURE SOUTH OF THE INTERNATIONAL BORDER
AND SHIFT IT TOWARD THE AZ/NM BORDER. GIVEN THE MAGNITUDE OF THE
700-300MB FLOW DURING THIS TIME PERIOD /AROUND 30-40KTS/...I`M
SKEPTICAL THE MOISTURE WILL REMAIN CONFINED TO THE BORDER AND POINTS
SOUTH. DEWPOINTS HAVE BEEN BUMPED UP LATE IN THE WEEK AND POPS HAVE
ALSO BEEN ELEVATED A BIT OVER INHERITED VALUES /MORE IN LINE WITH
CLIMO/. COULD END UP SEEING ELEVATED RAIN CHANCES LATE IN THE WEEK
INTO THE WEEKEND...BUT COULD JUST AS EASILY SEE INCREASE CLOUD COVER
AND DRY CONDITIONS DEPENDING ON WHERE THE MOISTURE AXIS POSITIONS
ITSELF. THUS CONFIDENCE IN PRECIP CHANCES IS LOW. FAIRLY HIGH
CONFIDENCE IN LOWER TEMPERATURES LATE IN THE WEEK WITH SOME OF THE
RAW UN-CORRECTED GUIDANCE POINTING TO HIGHS IN THE UPPER 90S. LOWERED
TEMPERATURES A FEW DEGREES FROM FRIDAY ONWARD ACCORDINGLY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...

DESPITE FLOW ALOFT BECOMING MORE SOUTHWESTERLY...LOWER LEVEL FLOW
REMAINS MORE SOUTHERLY AND THE BOUNDARY LAYER MOISTURE WILL REMAIN
IN PLACE FOR AT LEAST THE NEXT 24 HOURS. THUS ANOTHER ROUND OF
CONVECTION IS LIKELY ACROSS THE GREATER PHOENIX AREA LATER THIS
AFTERNOON AND THIS EVENING. CONDITIONS ARE SIMILAR TO YESTERDAY AND
TIMING OF STORMS MAY BE SIMILAR. WE WILL CONTINUE THE PREVIOUS TAF
THINKING AND INCLUDE VCTS IN THE AREA TAFS AFTER ABOUT 02Z...ALSO
MENTIONING A WIND SHIFT AS STORMS INITIALLY FIRE OVER HIGHER TERRAIN
TO THE SOUTHEAST OF CENTRAL PHOENIX. HIGH BASED CUMULUS TO FORM
LATER THIS AFTERNOON AND SHOULD STORMS MOVE THROUGH CIGS WILL LIKELY
STAY ELEVATED...MAINLY AOA 8K FEET.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

NO SIGNIFICANT AVIATION IMPACTS EXPECTED NEXT 24 HOURS AS FLOW ALOFT
REMAINS DRY SOUTHWESTERLY. MAY SEE SOME SCT-BKN CIRRUS AT TIMES WITH
LITTLE OR NO LOWER CLOUD DECKS EXPECTED. WINDS TO FAVOR THE WEST AT
KIPL NEXT 24 HOURS...AND THE SOUTH AT KBLH. A FEW AFTERNOON GUSTS TO
20KT POSSIBLE ALSO AT KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LOW PRESSURE SYSTEM ACROSS THE PACIFIC NORTHWEST WILL DISPLACE THE
MONSOON HIGH SLIGHTLY TO THE SOUTH AND EAST THROUGH THE WEEK. THE
TREND WILL BE TOWARDS COOLER CONDITIONS ACROSS THE DESERT SOUTHWEST
WITH HIGH TEMPERATURES NEAR OR SLIGHTLY BELOW SEASONAL NORMALS EACH
DAY. HOWEVER SUFFICIENT MOISTURE WILL LINGER ACROSS EASTERN ARIZONA
TO KEEP AT LEAST A SLIGHT CHANCE FOR THUNDERSTORMS FROM PHOENIX EAST
WEDNESDAY INTO THURSDAY. MINIMUM RH VALUES WILL FALL BELOW 15
PERCENT WEDNESDAY AND THURSDAY ACROSS SOUTHEAST CALIFORNIA WITH
VALUES ABOVE 15 PERCENT EXPECTED EAST OF THE LOWER COLORADO RIVER.
FOR FRIDAY INTO THE WEEKEND...LATEST GUIDANCE MORE INSISTENT UPON A
RETURN TO DEEPER MOISTURE...HIGHER HUMIDITY AND BETTER RAIN
CHANCES...PARTICULARLY ACROSS SOUTH CENTRAL ARIZONA.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...LEINS
AVIATION...CB
FIRE WEATHER...CB/HIRSCH



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