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000
FXUS65 KPSR 022121
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
221 PM MST MON MAY 2 2016

.SYNOPSIS...
TEMPERATURES WILL QUICKLY WARM TUESDAY AND PEAK WEDNESDAY UNDER HIGH
PRESSURE. SOME LOWER DESERTS WILL APPROACH TRIPLE DIGITS. THE HEAT
WILL NOT LAST LONG AS ANOTHER STORM SYSTEM ROLLS IN FROM THE
PACIFIC. WINDS WILL INCREASE WEDNESDAY AND BE STRONGEST THURSDAY
LEADING TO AREAS OF BLOWING DUST. FRIDAY INTO THE WEEKEND WILL
FEATURE BELOW NORMAL TEMPERATURES...VARIOUS CLOUD COVER...AND MODEST
CHANCES FOR RAIN.

&&

.DISCUSSION...
CONVECTION HAS FLARED UP THIS AFTERNOON IN THE AREAS PREVIOUSLY
EXPECTED...JUST NORTH OF OUR FORECAST AREA. THIS WAS IN RESPONSE TO
THE UPPER LEVEL LOW NOW ENTERING NW ARIZONA. THIS SYSTEM IS WELL
HANDLED BY THE VARIOUS MODELING SYSTEMS AND WILL MOVE EAST TONIGHT
AND SHEAR OUT OVER NEW MEXICO TOMORROW AS THE HIGH AMPLITUDE
ANTICYCLONE CURRENTLY OVER WESTERN MONTANA ELONGATES AND ENCOMPASSES
THE ENTIRE WEST.

WARM UP CONTINUES TUESDAY AND INTO WEDNESDAY WHEN WE WILL SEE PEAK
TEMPERATURES. CURRENT FORECAST CONTINUES WITH 99 FOR PHOENIX THOUGH
GIVEN OUR TYPICAL FORECAST ERROR OF 2 DEGREES ON DAY 3 THERE IS
CERTAINLY A NON-ZERO CHANCE OF HITTING 100. THIS WOULD BE A BIT LATER
THAN THE 1981-2010 AVERAGE OF MAY 2. YUMA WILL ALSO BE CLOSE AT
FORECAST OF 98.

WINDS WILL PICK-UP WEDNESDAY AHEAD OF THE NEXT SYSTEM. CONFIDENCE ON
THE OVERALL EVOLUTION OF THE INCOMING CUT-OFF LOW IS FAIRLY HIGH AS
IT HAS BEEN FORECAST FOR MANY DAYS AT THIS POINT. SOUTH/SOUTHWEST
WINDS ON WEDNESDAY WILL LIKELY CAUSE SOME ISSUES INCLUDING BLOWING
DUST. WINDS WILL BE STRONGER ON THURSDAY AND THIS IS THE DAY WE MAY
EVENTUALLY NEED A WI.Y AND BD.Y. GEFS-BASED EXTREME FORECAST INDEX IS
HIGHLIGHTING THE PRE-FRONTAL WINDS THURSDAY TO BE IN THE 95TH
PERCENTILE WHICH HISTORICALLY CORRESPONDS TO ENOUGH WIND TO CAUSE
IMPACTS.

THE OTHER CONCERN AS THIS SYSTEM COMES IN IS WITH THE FIRE WEATHER
DANGER. IT DOES LOOK LIKE WE WILL HIT WIND AND HUMIDITY TRIGGERS FOR
A RF.W BUT FUELS ARE QUESTIONABLE AT THIS POINT GIVEN CURRENT
GREENNESS AND RECENT RAINS. WILL HOLD OFF ON ANY FW.A FOR OUR AREA
BUT IT IS HIGHLIGHTED IN THE FIRE WEATHER FORECAST.

EVENTUALLY THE SPECTER OF RAIN WILL COME WITH THE SYSTEM BUT NOT
UNTIL FRIDAY WHEN BETTER ISENTROPIC LIFT/MOISTURE FLUX/DYNAMICAL
COOLING/PVA ARRIVE. GEFS-BASED CALIBRATED POPS ARE SHOWING A BROAD
20-30 PERCENT CHANCE FOR SOME RAIN FRIDAY INTO SATURDAY THUS
INCREASED POPS A BIT. OVERALL DOESN/T APPEAR TO BE A WASHOUT EVENT BY
ANY MEANS. TEMPERATURES WILL ALSO COOL SIGNIFICANTLY...ON THE ORDER
OF 20 DEGREES FROM WEDNESDAY TO FRIDAY. HOW THE WEEKEND PLAYS OUT IS
STILL UP IN THE AIR AS MODELS NOTORIOUSLY HAVE A DIFFICULT TIME
RESOLVING THE MIGRATION OF CLOSED LOWS IN THE SOUTHWEST. OVERALL IT
WILL BE COOLER AND GENERALLY CLOUDY...RAIN CHANCES WILL LIKELY CHANGE
AS SPECIFICS ON INDIVIDUAL VORT LOBES COME INTO FOCUS IN THE DAYS
AHEAD.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW WILL PERSIST THROUGH THE FORECAST PERIOD RESULTING
IN CLEAR SKIES ACROSS ALL OF OUR TAF SITES. EXPECT WINDS TO BE
AROUND 5 KNOTS OR LESS ACROSS SOUTHEAST CALIFORNIA TAF
SITES...LEADING TO VARIABLE WINDS THROUGH THE MORNING HOURS
TOMORROW...IN SOUTH-CENTRAL AND SOUTHWEST ARIZONA TAF SITES...WINDS
WILL REMAIN BELOW 10 KNOTS AND FOLLOW NORMAL DIURNAL TRENDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
WINDS WILL INCREASE WEDNESDAY AND ONCE AGAIN THURSDAY AS A STORM
SYSTEM MOVES INTO THE SOUTHWEST. THERE WILL LIKELY BE A SEVERAL HOUR
WINDOW THURSDAY AFTERNOON WHERE WINDS AND HUMIDITY VALUES HIT
CRITICAL THRESHOLDS ACROSS PORTIONS OF MARICOPA...PINAL...AND GILA
COUNTIES. QUESTIONS REMAIN ON FUEL LEVELS DUE TO RECENT RAINS AND
CURRENT GREEN LEVELS. MUCH COOLER TEMPERATURES...LESS WIND...AND
HIGHER HUMIDITY LEVELS ARE EXPECTED FRIDAY THROUGH THE WEEKEND ALONG
WITH THE POSSIBILITY OF WETTING RAINS.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...INIGUEZ
AVIATION...VASQUEZ
FIRE WEATHER...INIGUEZ





000
FXUS65 KPSR 021644
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
944 AM MST MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
MINOR ADJUSTMENTS TO THE FORECAST THIS MORNING TO ACCOUNT FOR VARIOUS
TRENDS INCLUDING CLEAR SKY AND HIGHER HUMIDITY VALUES. TEMPERATURES
ARE PRETTY MUCH ON TRACK TO HIT FORECAST HIGHS THIS AFTERNOON. WE ARE
SEEING A PUSH OF EASTERLY WINDS ACROSS MARICOPA AND PINAL COUNTIES
THIS MORNING AND THAT SHOULD SUBSIDE BY EARLY AFTERNOON.

LAST SHORT WAVE IS ABOUT OVER LAS VEGAS THIS MORNING AND IT WILL MOVE
ACROSS NORTHERN ARIZONA TODAY. A MORE LAMINAR FLOW OVER SOUTHERN
CALIFORNIA AND SOUTHERN ARIZONA...WITH SOME MINOR WAA...WILL KEEP
PRECIPITATION CHANCES QUITE LOW. MOST OF THE CAMS ARE GENERATING A
LITTLE ACTIVITY OVER JOSHUA TREE NP AND WE WILL MAINTAIN A SLIGHT
CHANCE FOR RAIN THERE.

LOOKING AHEAD...MESSAGE OF THE DAY WILL INCLUDE WARMING TEMPERATURES
WITH THE FIRST 100 POSSIBLE FOR PHOENIX AND YUMA ON WEDNESDAY /BUT
NOT GUARANTEED AND NOT FORECAST AT THIS TIME/...STRONG WINDS THURSDAY
LIKELY GENERATING AREAS OF BLOWING DUST AND POSSIBLE DANGEROUS FIRE
WEATHER CONDITIONS...THEN THE COOL DOWN FOR THE WEEKEND WITH PERHAPS
A FEW SHOWERS. MORE DETAILS BELOW AND UPDATES THIS AFTERNOON.

PREVIOUS DISCUSSION...
HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW ALOFT WILL RESULT IN MOSTLY CLEAR SKIES THROUGH
23Z MON. LIGHT AND VARIABLE WINDS UNDER 7 KNOTS THROUGH 23ZZ MON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY AND THURSDAY...

A HIGH PRESSURE SYSTEM WILL CONTINUE OVER THE REGION ON WEDNESDAY...
HOWEVER ANOTHER PACIFIC COLD FRONT WILL APPROACH THE WEST COAST
WEDNESDAY AFTERNOON...THEN MOVE THROUGH THE REGION THURSDAY. AS A
RESULT...BREEZY SOUTHWEST WINDS WILL DEVELOP WEDNESDAY AFTERNOON AND
EVENING...BECOMING VERY WINDY THURSDAY. SINCE RELATIVE HUMIDITIES
THURSDAY WILL RANGE FROM 10 TO 15 PERCENT...RED FLAG CONDITIONS MAY
BE REACHED ON THE SOUTHWEST AND SOUTH CENTRAL AZ DESERTS THURSDAY
AFTERNOON.

FRIDAY THROUGH SUNDAY...

AFTER THE COLD FRONTAL PASSAGE THURSDAY...A COOL AND RELATIVELY
MOIST AIRMASS WILL SETTLE OVER THE REGION THIS PERIOD. BREEZY WEST
WINDS MAY DEVELOP FRIDAY AFTERNOON...BUT BECOME MUCH LIGHTER
SATURDAY AND SUNDAY. MINIMUM RELATIVE HUMIDITIES WILL INCREASE AREA-
WIDE INTO THE 17 TO 24 PERCENT RANGE. A SLIGHT CHANCE OF SHOWERS...
UNDER A RELATIVELY COOL AND MOIST AIRMASS...WILL DEVELOP FRIDAY AND
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...INIGUEZ/NOLTE
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ





000
FXUS65 KPSR 021037
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
340 AM MST MON MAY 2 2016

.UPDATE...AVIATION AND FIRE WEATHER DISCUSSIONS.

&&

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
THE CLEARING TREND THAT BEGAN LAST EVENING HAS CONTINUED OVERNIGHT.
WITH THE CALMER WINDS AND CLEARER SKIES...TEMPERATURES HAVE COOLED
TO MILD READINGS FOR EARLY MAY WITH VALUES RANGING FROM THE MID 50S
TO LOW 60S ACROSS SOUTH-CENTRAL AZ AND MID 60S ACROSS SOUTHWESTERN AZ
AND SOUTHEAST CA. WATER VAPOR LOOPS AND 500MB PLOTS SHOW REX
BLOCK...ALBEIT SHORTLIVED...OVER THE WESTERN NORTH AMERICAN
CONTINENT. THE MAIN UPPER LOW CENTER FROM THIS WEEKEND CONTINUES
TRACKING ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS THIS AM WHILE
AN ADDITIONAL TRAILING VORT LOBE ON THE WESTERN FRINGE OF THE LOW
SPINS THROUGH CENTRAL CA. THIS SHORTWAVE WILL SWING THROUGH NORTHERN
PORTIONS OF AZ TODAY ALLOWING FOR ANOTHER ROUND OF PRECIP ACTIVITY
FOR THE MOUNTAINS WHILE LEAVING THE LOWER DESERT ELEVATIONS UNDER
SOME LIMITED AFTERNOON CU FIELDS AND WARMER TEMPERATURES. TREND IN
HEIGHT RISES WILL CONTINUE THROUGHOUT THE DAY AS PACIFIC HIGH
PRESSURE BEGINS TO TRANSITION IN THE FROM THE WEST...SHUNTING OFF THE
SHORTWAVE TO THE EAST AND COMBINING WITH THE HIGH CENTER LOCATED OVER
THE CANADIAN ROCKIES. LATEST BEST PERFORMING GUIDANCE INDICATE THE
90S WILL RETURN FOR THE WESTERN FORECAST ZONES WHILE THE SOUTH-
CENTRAL AZ ZONES CAN LOOK FOR TEMPERATURES PEAKING INTO THE UPPER
80S TODAY.

HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND...
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

DRY WESTERLY FLOW ALOFT WILL RESULT IN MOSTLY CLEAR SKIES THROUGH
23Z MON. LIGHT AND VARIABLE WINDS UNDER 7 KNOTS THROUGH 23ZZ MON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY AND THURSDAY...

A HIGH PRESSURE SYSTEM WILL CONTINUE OVER THE REGION ON WEDNESDAY...
HOWEVER ANOTHER PACIFIC COLD FRONT WILL APPROACH THE WEST COAST
WEDNESDAY AFTERNOON...THEN MOVE THROUGH THE REGION THURSDAY. AS A
RESULT...BREEZY SOUTWHEST WINDS WILL DEVELOP WEDNESDAY AFTERNOON AND
EVENING...BECOMING VERY WINDY THURSDAY. SINCE RELATIVE HUMIDITIES
THURSDAY WILL RANGE FROM 10 TO 15 PERCENT...RED FLAG CONDITIONS MAY
BE REACHED ON THE SOUTWHEST AND SOUTH CENTRAL AZ DESERTS THURSDAY
AFTERNOON.

FRIDAY THROUGH SUNDAY...

AFTER THE COLD FRONTAL PASSAGE THURSDAY...A COOL AND RELATIVELY
MOIST AIRMASS WILL SETTLE OVER THE REGION THIS PERIOD. BREEZY WEST
WINDS MAY DEVELOP FRIDAY AFTERNOON...BUT BECOME MUCH LIGHTER
SATURDAY AND SUNDAY. MINIMUM RELATIVE HUMIDITIES WILL INCREASE AREA-
WIDE INTO THE 17 TO 24 PERCENT RANGE. A SLIGHT CHANCE OF SHOWERS...
UNDER A RELATIVELY COOL AND MOIST AIRMASS...WILL DEVELOP FRIDAY AND
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...NOLTE
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ





000
FXUS65 KPSR 021023
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
323 AM MST MON MAY 2 2016

.SYNOPSIS...
LOW PRESSURE WILL MAKE A SLOW EXIT TO THE EAST ACROSS NORTHERN AZ
TODAY...KEEPING THE FOCUS OF ANY LINGERING PRECIP ACTIVITY WELL NORTH
OF OUR FORECAST AREA. HIGH PRESSURE MOVING IN FROM THE WEST WILL
BUILD OVER THE DESERT SOUTHWEST THROUGH THURSDAY...RESULTING IN
MOSTLY CLEAR SKIES AND A STRONG WARMING TREND. ANOTHER PACIFIC
WEATHER SYSTEM WILL BEGIN TO MOVE INTO THE AREA FRIDAY AND FOR THE
COMING WEEKEND...BRINGING MUCH COOLER TEMPERATURES...BREEZY
CONDITIONS AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
THE CLEARING TREND THAT BEGAN LAST EVENING HAS CONTINUED OVERNIGHT.
WITH THE CALMER WINDS AND CLEARER SKIES...TEMPERATURES HAVE COOLED
TO MILD READINGS FOR EARLY MAY WITH VALUES RANGING FROM THE MID 50S
TO LOW 60S ACROSS SOUTH-CENTRAL AZ AND MID 60S ACROSS SOUTHWESTERN AZ
AND SOUTHEAST CA. WATER VAPOR LOOPS AND 500MB PLOTS SHOW REX
BLOCK...ALBEIT SHORTLIVED...OVER THE WESTERN NORTH AMERICAN
CONTINENT. THE MAIN UPPER LOW CENTER FROM THIS WEEKEND CONTINUES
TRACKING ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS THIS AM WHILE
AN ADDITIONAL TRAILING VORT LOBE ON THE WESTERN FRINGE OF THE LOW
SPINS THROUGH CENTRAL CA. THIS SHORTWAVE WILL SWING THROUGH NORTHERN
PORTIONS OF AZ TODAY ALLOWING FOR ANOTHER ROUND OF PRECIP ACTIVITY
FOR THE MOUNTAINS WHILE LEAVING THE LOWER DESERT ELEVATIONS UNDER
SOME LIMITED AFTERNOON CU FIELDS AND WARMER TEMPERATURES. TREND IN
HEIGHT RISES WILL CONTINUE THROUGHOUT THE DAY AS PACIFIC HIGH
PRESSURE BEGINS TO TRANSITION IN THE FROM THE WEST...SHUNTING OFF THE
SHORTWAVE TO THE EAST AND COMBINING WITH THE HIGH CENTER LOCATED OVER
THE CANADIAN ROCKIES. LATEST BEST PERFORMING GUIDANCE INDICATE THE
90S WILL RETURN FOR THE WESTERN FORECAST ZONES WHILE THE SOUTH-
CENTRAL AZ ZONES CAN LOOK FOR TEMPERATURES PEAKING INTO THE UPPER
80S TODAY.

HIGH-AMPLITUDE HIGH PRESSURE WILL TAKE A FEW-DAY HOLD OVER THE
INTERMOUNTAIN WEST ALLOWING DAYTIME TEMPERATURES TO TAKE ANOTHER RUN
AT THEIR WARMEST READINGS OF THE YEAR SO FAR BY MIDWEEK. 500MB
HEIGHTS STILL PROGGED INTO THE 576-582DM RANGE AND 850MB AFTN
TEMPERATURE QUICKLY HEAD NORTH OF 20 TO 25C AFTER MONDAY. MID TO
UPPER 90 DEGREE READINGS ARE ANTICIPATED FOR THE LOWER DESERT
ELEVATIONS TUESDAY AND WEDNESDAY. WEDNESDAY STILL PINNED TO BE THE
WARMEST DAY OF THE WEEK AND QUITE POSSIBLY THE YEAR AS THE RIDGE AXIS
BEGINS TO SHIFT TO OUR EAST AS STRONG SOUTHERLY FLOW DEVELOPS INTO
THE AREA ENHANCING WAA FROM THE SUBTROPICS. CONSENSUS GUIDANCE
SUPPORTING UPPER 90S FOR MANY OF THE DESERT SITES...WITH 100S STILL
POSSIBLE FOR THE WARMEST LOCALES SUCH AS TACNA AND EL CENTRO. THE
FIRST 100F FOR PHOENIX HAS POPPED INTO SOME OF THE LATEST GRIDDED
GUIDANCE WEDNESDAY...BUT ARE FROM MODEL PERFORMERS NOT TYPICAL OF
THOSE THAT DO WELL WITH HIGH PRESSURE PATTERNS.

THURSDAY THROUGH NEXT WEEKEND...
MODEL AGREEMENT AND TRENDS...BOTH IN THE DETERMINISTIC AND ENSEMBLE
SOLUTIONS...HAVE REMAINED IN EXCELLENT AGREEMENT OVER THE PAST
SEVERAL DAYS IN ADVERTISING A DEEP PACIFIC TROUGH MOVING INTO THE
SOUTHWEST BY THE LATE WEEK/EARLY WEEKEND. TROUGHING REACHES AS FAR
SOUTH AS THE NORTHERN BAJA PENINSULA AND MAINTAINS ITS COOL
TEMPERATURE PROFILE BY THURSDAY. DAYTIME TEMPERATURES WILL BEGIN TO
COOL ACROSS THE WESTERN FORECAST ZONES AS STRONG SOUTHERLY LOW-LEVEL
WINDS DEVELOP INTO THE REGION. JET-LEVEL WINDS BEGIN TO PUSH 100KTS
THURSDAY AFTERNOON...WITH LL WINDS AT 700MB AND 850MB ENCROACHING 35
TO 45 KTS. WINDS FORECAST TO BE AT THEIR STRONGEST ON THURSDAY...WITH
AREA WIDE SUSTAINED SFC SPEEDS PUSHING 25 MPH AND GUSTS 35 MPH OR
GREATER. WITH THE WINDS COMES THE THREAT FOR DUST...SO INCLUDED
MENTION OF BLOWING DUST IN THE GRIDS FOR BOTH WEDNESDAY AND THURSDAY
AS THE SYSTEM WINDS RAMP UP INTO THE AREA. THE ONE FORECAST ELEMENT
THAT REMAINS A BIT OF A UNKNOWN QUANTITY WILL BE THE MOISTURE...AS
PWAT FIELDS APPEAR TO STRUGGLE BREAKING PAST HALF INCH READINGS.
QPF/PRECIP PLOTS FROM THE DETERMINISTIC AS WELL AS THE GEFS
REFORECAST ARE NOT OVERLY EXCITED ABOUT ANY PERIODS OF PERSISTENT
RAINFALL INTO THE AREA ON THIS SYSTEM SWINGS IN OFF THE PACIFIC AND
SETTLES OVER THE AREA BY FRIDAY.

A WELCOME COOL-DOWN WILL RESULT FOR THE SOUTHWEST AS 500MB
TEMPERATURES BEGIN TO RUN COOLER THAN -20C ACROSS THE AREA...WITH
DAYTIME HIGHS DIPPING INTO THE UPPER 70S AND LOW 80S. AS WITH
PREVIOUS SYSTEMS...THE UPPER LOW FEATURE WILL TAKE UP RESIDENCE OVER
THE WEST INTO THE WEEKEND AND POSSIBLY VERY EARLY NEXT WEEK...AS IT
BECOMES THE WESTERN END OF A CONUS WIDE OMEGA BLOCK. VORTICITY PLOTS
INDICATE IT COULD BEGIN TO LOBE OUT...ALLOWING FOR ON AND OFF ROUNDS
OF BREEZINESS AND SOME PRECIP CHANCES TO OCCUR THROUGHOUT THE
SOUTHWEST STATES.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WINDS WILL BE LIGHTER THAN NORMAL AS HIGH PRESSURE BUILDS INTO THE
REGION. OTHERWISE...SKIES WILL BE MAINLY CLEAR THROUGH TUESDAY
MORNING. FEW DIURNAL CU WITH BASES AROUND 9K FT ARE EXPECTED
MONDAY...THOUGH THEY WILL BE MOST CONCENTRATED ACROSS THE HIGHER
TERRAIN AND OUTSIDE OF THE PHOENIX VICINITY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO AVIATION WEATHER IMPACTS EXPECTED. WINDS WILL GENERALLY BE LIGHT
AND VARIABLE UNDER MAINLY CLEAR SKIES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL FIRE
WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST. CONDITIONS
WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN ALLOWING
TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...NOLTE
AVIATION...HIRSCH
FIRE WEATHER...INIGUEZ





000
FXUS65 KPSR 020412
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
912 PM MST SUN MAY 1 2016

.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...
SKIES ARE CLEARING RAPIDLY ACROSS THE DESERT SOUTHWEST THIS EVENING.
THIS IS LIKELY A RESULT OF THE STRONG HEIGHT RISES...GENERALLY
AROUND 80 METERS AT 500 MB OVER THE PAST 12 HOURS. WINDS ALSO
CONTINUE TO SUBSIDE...WHICH WILL PROMOTE FAVORABLE CONDITIONS FOR
RADIATIONAL COOLING. LOW TEMPERATURES WILL AGAIN BE AT OR BELOW
NORMAL FOR MOST SPOTS. MINOR ADJUSTMENTS WERE MADE TO THE SHORT-TERM
FORECAST THIS EVENING...MAINLY TO ACCOUNT FOR THE CLEARING SKIES AND
TO ESSENTIALLY REMOVE ANY CHANCE OF MEASURABLE PRECIPITATION.

&&

.PREVIOUS DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOREMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WINDS WILL BE LIGHTER THAN NORMAL AS HIGH PRESSURE BUILDS INTO THE
REGION. OTHERWISE...SKIES WILL BE MAINLY CLEAR THROUGH TUESDAY
MORNING. FEW DIURNAL CU WITH BASES AROUND 9K FT ARE EXPECTED MONDAY...THOUGH
THEY WILL BE MOST CONCENTRATED ACROSS THE HIGHER TERRAIN AND OUTSIDE
OF THE PHOENIX VICINITY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO AVIATION WEATHER IMPACTS EXPECTED. WINDS WILL GENERALLY BE LIGHT
AND VARIABLE UNDER MAINLY CLEAR SKIES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

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





000
FXUS65 KPSR 012049
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
150 PM MST MON MAY 2 2016


.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... CLOUDS
NEAR THE 10KFT LEVEL WILL REMAIN IN THE PHX AREA THIS AFTERNOON BUT
BEGIN TO SUBSIDE AFTER 22Z. LIGHTER WINDS AND MUCH LESS CLOUDS
OVERNIGHT AND INTO MONDAY...THOUGH THERE COULD BE A FEW STRONGER
EASTERLY BREEZES MONDAY MORNING BETWEEN 16-19Z.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKY AND LIGHT WINDS FAVORING DIURNAL PATTERNS ACROSS THE AREA
THROUGH MONDAY AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.


.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...PERCHA
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ





000
FXUS65 KPSR 012049
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
150 PM MST MON MAY 2 2016


.SYNOPSIS...
THE LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND BELOW-NORMAL
TEMPERATURES TO THE REGION OVER THE LAST FEW DAYS IS EXPECTED TO
MOVE OFF TO THE NORTHEAST TONIGHT AND MONDAY. THIS WILL ALLOW HIGH
PRESSURE TO REBUILD OVER THE DESERT SOUTHWEST FROM MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM IS STILL FORECAST TO MOVE INTO
THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING MUCH COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY...

THE COLD UPPER LOW CENTER THAT BROUGHT BELOW-NORMAL TEMPERATURES AND
SHOWERS TO THE REGION OVER THE LAST FEW DAYS IS NOW LIFTING OUT TO
THE NORTHEAST...AS ANOTHER...MUCH WEAKER SHORTWAVE MOVES INLAND INTO
CENTRAL CA/NV. AS HEIGHTS/TEMPERATURES ALOFT GRADUALLY RISE THIS
EVENING AND TONIGHT...THE SPRINKLE/LIGHT SHOWER ACTIVITY THAT IS
BEING DETECTED THIS AFTERNOON ON RADAR ACROSS SOUTH-CENTRAL AZ IS
EXPECTED TO END AROUND/AFTER SUNSET...WITH SKIES BECOMING CLEAR-
PARTLY CLOUDY OVER ALL OF OUR CWA BY LATE TONIGHT. THE WARMING
AIRMASS WILL LIKELY KEEP OVERNIGHT LOWS A BIT WARMER AT MOST
LOCATIONS THAN WHAT WAS OBSERVED LAST NIGHT...IN SPITE OF LESS CLOUD
COVER. CONTINUED WARMING ALOFT WILL ALSO ALLOW TEMPERATURES TO WARM
UP INTO THE UPPER-80S TO NEAR 90 RANGE ON MONDAY UNDER MOSTLY CLEAR
SKIES. HOWEVER...THE AFOMENTIONED SHORTWAVE...THAT IS NOW MOVING
INTO CENTRAL CA...WILL LIKELY KEEP MOST LOWER DESERT LOCATIONS BELOW
THE 90 DEGREE MARK ON MONDAY...AS IT MOVES EASTWARD OVER NORTHERN AZ.

TUESDAY THROUGH WEDNESDAY...

CURRENT GLOBAL MODEL SUITES CONTINUE TO SHOW RATHER STRONG HIGH
PRESSURE RIDGING BUILDING EASTWARD INTO THE REGION DURING THIS
PERIOD. THE COMBINATION OF 500MB HEIGHTS IN THE 578-580DM RANGE AND
1000-500MB THICKNESSES AOA 570DM...ALONG WITH MOSTLY CLEAR SKIES
WILL CERTAINLY ALLOW TEMPERATURES TO RISE WELL UP INTO THE 90S EACH
DAY...WITH WEDNESDAY LIKELY BEING THE WARMEST DAY...AS LOW-LEVEL
SOUTHERLY FLOW DEVELOPS OVER THE REGION. HOWEVER...OUTSIDE OF
PERHAPS A FEW OF THE VERY WARMEST SPOTS...IT STILL APPEARS THE MOST
LOCATIONS WILL SEE HIGHS FALL SHORT OF 100 DEGREES EACH DAY...WITH
EVEN THE WARMEST NUMERICAL GUIDANCE STILL KEEPING PHOENIX SKY HARBOR
BELOW 100 AS WELL.

THURSDAY THROUGH SUNDAY...

ALL OF THE GLOBAL MODEL SUITES...AND THE VAST MAJORITY OF THEIR
RESPECTIVE ENSEMBLE MEMBERS CONTINUE TO BRING ANOTHER COLD UPPER LOW
SOUTHWARD INTO THE REGION DURING THIS PERIOD...AS THE OVERALL LONG-
WAVE PATTERN OVER THE NORTH PACIFIC AND NORTH AMERICA UNDERGOES
SIGNIFICANT AMPLIFICATION. ALTHOUGH THIS NEW SYSTEM WILL LIKELY BE
AT LEAST AS COLD AS THE ONE THAT HAS AFFECTED US OVER THE PAST FEW
DAYS...IT APPEARS THAT IT WILL BE A SOMEWHAT DRIER ONE...LIKELY DUE
TO THE MORE NORTHERLY TRACK OF THE SYSTEM. HOWEVER THE OVERALL
IMPACTS FROM THIS NEW SYSTEM WILL LIKELY BE SIMILAR TO THE LAST ONE.
ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES BETWEEN THE
MODELS...IT NOW APPEARS THAT THIS UPPER LOW WILL BEGIN TO AFFECT OUR
CWA ON THURSDAY...BEGINNING TO COOL TEMPERATURES ACROSS THE
REGION...ESPECIALLY OVER SE CA AND THE LOWER COLORADO RIVER
VALLEY...WHILE ALSO SUBSTANTIALLY INCREASING THE WINDS AS WELL...AS
A 100+ KT JET PUSHES EASTWARD OVER THE REGION AHEAD OF THE MAIN
UPPER LOW...WITH ADVISORY-LEVEL WINDS...AREAS OF BLOWING DUST...AND
EVEN SOME FIRE WEATHER ISSUES A REAL POSSIBILITY. FURTHER
COOLING...AND EVEN A SLIGHT CHANCE FOR SHOWERS IS LIKELY FOR THE
FRIDAY-SUNDAY TIME PERIOD AS THE MAIN UPPER LOW MOVES VERY SLOWLY
EASTWARD ACROSS THE REGION...WITH AT LEAST ONE DAY OF HIGHS IN THE
70S ONCE AGAIN A POSSIBILITY FOR MANY LOWER DESERT LOCATIONS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... CLOUDS
NEAR THE 10KFT LEVEL WILL REMAIN IN THE PHX AREA THIS AFTERNOON BUT
BEGIN TO SUBSIDE AFTER 22Z. LIGHTER WINDS AND MUCH LESS CLOUDS
OVERNIGHT AND INTO MONDAY...THOUGH THERE COULD BE A FEW STRONGER
EASTERLY BREEZES MONDAY MORNING BETWEEN 16-19Z.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR SKY AND LIGHT WINDS FAVORING DIURNAL PATTERNS ACROSS THE AREA
THROUGH MONDAY AFTERNOON.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.


.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS WITH TEMPERATURES ABOVE SEASONAL NORMALS TUESDAY THROUGH
THURSDAY. AN INCOMING WEATHER SYSTEM WILL CAUSE SOUTHERLY WINDS TO
INCREASE WEDNESDAY AND THURSDAY. THERE MAY BE A WINDOW THURSDAY
AFTERNOON OF STRONG WINDS AND LOW HUMIDITIES THAT REACH CRITICAL
FIRE WEATHER CONDITIONS FROM MARICOPA COUNTY AND TO THE EAST.
CONDITIONS WILL IMPROVE FRIDAY AND SATURDAY WHEN THE SYSTEM MOVES IN
ALLOWING TEMPERATURES TO COOL...HUMIDITIES TO COME UP...AND WINDS TO
DECREASE.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...PERCHA
AVIATION...INIGUEZ
FIRE WEATHER...INIGUEZ





000
FXUS65 KPSR 011544
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
845 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

A RATHER COOL MORNING...FOR THE 1ST OF MAY ACROSS OUR CWA THIS
MORNING. MOST LOWER DESERT LOCATIONS SAW LOWS IN THE UPPER 50-LOW 60
RANGE...WITH SKY HARBOR SEEING A LOW OF 59...6 DEGREES BELOW THE
NORMAL FOR THE DATE. THE UPPER LOW THAT BROUGHT US THIS COOL
WEATHER...AND THE RAINFALL YESTERDAY/LAST NIGHT IS NOW MOVING
EASTWARD ACROSS EAST-CENTRAL AZ AND IS EXPECTED TO MOVE INTO THE 4-
CORNERS REGION BY THIS EVENING. TO THE SOUTH AND WEST OF THIS LOW
CENTER...TEMPERATURES ALOFT ARE BEGINNING TO WARM...STABILIZING THE
ATMOSPHERE AND ENDING THE SHOWER ACTIVITY ACROSS MOST OF OUR CWA.
HOWEVER...LEFT-OVER MOISTURE ROTATING AROUND THE BACK SIDE OF THE
UPPER LOW CENTER IS STILL TRIGGERING A FEW SHOWERS OVER PINAL AND
SOUTHERN GILA COUNTIES...AS WELL AS EXTREME EASTERN MARICOPA COUNTY
AT THIS HOUR. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THESE
SHOWERS CONTINUING THROUGH ABOUT MIDDAY BEFORE DIMINISHING THIS
AFTERNOON. GIVEN THESE CURRENT TRENDS...IT APPEARS THAT OUR CURRENT
SHORT-TERM FORECASTS ARE HOLDING UP WELL..AND NO UPDATES ARE PLANNED
AT THIS TIME.

&&

.PREVIOUS DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...PERCHA/VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE





000
FXUS65 KPSR 011544
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
845 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

A RATHER COOL MORNING...FOR THE 1ST OF MAY ACROSS OUR CWA THIS
MORNING. MOST LOWER DESERT LOCATIONS SAW LOWS IN THE UPPER 50-LOW 60
RANGE...WITH SKY HARBOR SEEING A LOW OF 59...6 DEGREES BELOW THE
NORMAL FOR THE DATE. THE UPPER LOW THAT BROUGHT US THIS COOL
WEATHER...AND THE RAINFALL YESTERDAY/LAST NIGHT IS NOW MOVING
EASTWARD ACROSS EAST-CENTRAL AZ AND IS EXPECTED TO MOVE INTO THE 4-
CORNERS REGION BY THIS EVENING. TO THE SOUTH AND WEST OF THIS LOW
CENTER...TEMPERATURES ALOFT ARE BEGINNING TO WARM...STABILIZING THE
ATMOSPHERE AND ENDING THE SHOWER ACTIVITY ACROSS MOST OF OUR CWA.
HOWEVER...LEFT-OVER MOISTURE ROTATING AROUND THE BACK SIDE OF THE
UPPER LOW CENTER IS STILL TRIGGERING A FEW SHOWERS OVER PINAL AND
SOUTHERN GILA COUNTIES...AS WELL AS EXTREME EASTERN MARICOPA COUNTY
AT THIS HOUR. THE LATEST HRRR HIGH-RES MODEL RUN IS SHOWING THESE
SHOWERS CONTINUING THROUGH ABOUT MIDDAY BEFORE DIMINISHING THIS
AFTERNOON. GIVEN THESE CURRENT TRENDS...IT APPEARS THAT OUR CURRENT
SHORT-TERM FORECASTS ARE HOLDING UP WELL..AND NO UPDATES ARE PLANNED
AT THIS TIME.

&&

.PREVIOUS DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...PERCHA/VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE





000
FXUS65 KPSR 011208
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
508 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE





000
FXUS65 KPSR 011208
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
508 AM MST SUN MAY 1 2016


.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.

MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.

THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL BEGIN TO WEAKEN AND MAKE A SLOW EXIT TO THE EAST OVER
AZ TODAY. LIGHT RAIN SHOWER ACTIVITY WILL BE POSSIBLE DURING THE
MORNING FROM MARICOPA COUNTY EASTWARD BEFORE PRECIP ACTIVITY FOCUSES
ON THE MOUNTAINS NORTH/EAST OF PHOENIX. SCT TO BKN CLOUDS RANGING 8
TO 12KFT WILL PERSIST THROUGH EARLY AFTERNOON BEFORE DISSIPATING AND
EVENTUALLY CLEARING COMPLETELY AFTER SUNSET. TYPICAL EASTERLY AM
WINDS WILL TRANSITION SOUTH THEN WEST MIDDAY INTO THE
AFTERNOON...WITH GENERALLY LIGHT SPEEDS 6 KTS OR LESS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
FOCUS OF ANY LINGERING PRECIP ACTIVITY TODAY WILL BE WELL EAST OF THE
CO RIVER VALLEY. NOTICEABLY LIGHTER WINDS IN STORE TODAY WITH
HEADINGS VARIANT BETWEEN WEST AND NORTHWEST FOR KIPL AND NORTH AND
NORTHEAST FOR KBLH. FEW TO SCT CLOUDS GNLY AOA 10KFT WILL DISSIPATE
DURING THE DAY...WITH CLEAR SKIES POSSIBLE BY THE AFTERNOON AND FOR
THE EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
HIGH PRESSURE WILL RESULT IN A DRIER AND WARMER AIRMASS OVER THE
DISTRICTS QUICKLY WARMING TEMPERATURES TO ABOVE NORMAL READINGS WITH
MANY LOWER ELEVATION SITES HEADING INTO THE MID TO UPPER 90S. DEEP
PACIFIC TROUGH WILL APPROACH THE WEST COAST MIDWEEK SUPPORTING
INCREASING SOUTHERLY WINDS FOR WEDNESDAY AND THURSDAY. THE
COMBINATION OF STRONG WINDS...PARTICULARLY FOR THURSDAY...AND LOW
HUMIDITIES MAY SUPPORT POCKETS OF CRITICAL FIRE WEATHER CONDITIONS
ACROSS THE LOWER AZ DESERTS. CONDITIONS WILL IMPROVE ON FRIDAY AND
SATURDAY WHEN THE NEXT STORM SYSTEM WILL COOL HIGH TEMPERATURES TO
THE LOW TO MID 80S WITH MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20
PERCENT RANGE BY SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE/SAWTELLE





000
FXUS65 KPSR 010955
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 AM MST SUN MAY 1 2016

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.


MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.


THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

WITH A DRIER AND WARMER AIRMASS IN PLACE EXPECT ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY WITH THE HOTTEST DAY ON WEDNESDAY
REACHING INTO THE MID TO UPPER 90S IN THE LOWER DESERTS. EXPECT
ELEVATED FIRE DANGER ON WEDNESDAY AND THURSDAY WITH MINIMUM
HUMIDITIES FALLING TO THE 6 TO 11 PERCENT RANGE AND BREEZY SOUTHERLY
TO SOUTHWESTERLY WINDS SPREADING THROUGH THE LOWER DESERTS.
CONDITIONS WILL IMPROVE ON FRIDAY AND SATURDAY WHEN THE NEXT STORM
SYSTEM WILL COOL HIGH TEMPERATURES TO THE LOW TO MID 80S WITH
MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20 PERCENT RANGE BY
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 010955
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 AM MST SUN MAY 1 2016

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LINGER OVER THE REGION THROUGH TONIGHT...
PROVIDING BELOW NORMAL TEMPERATURES...AND A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER NORTHERN AND EASTERN ARIZONA. A HIGH PRESSURE
SYSTEM WILL SUBSEQUENTLY REBUILD OVER THE REGION MONDAY THROUGH
THURSDAY...RESULTING IN MOSTLY CLEAR SKIES AND A STRONG WARMING
TREND. ANOTHER PACIFIC WEATHER SYSTEM HOWEVER IS FORECAST TO MOVE
INTO THE AREA NEXT FRIDAY AND THE WEEKEND...BRINGING COOLER
TEMPERATURES...BREEZY CONDITIONS...AND A SLIGHT CHANCE OF SHOWERS.

&&

.DISCUSSION...

TODAY AND TONIGHT...

THE COOL LOW PRESSURE SYSTEM OVER AZ WILL LINGER OVER THE STATE
TODAY...ALBEIT MOVE SLOWLY TO THE EAST BY EARLY AFTERNOON. MODELS
FORECAST THE 500 MB CIRCULATION CENTER TO MOVE FROM OVER PHOENIX
EARLY THIS MORNING...TOWARD THE WHITE MOUNTAINS IN EAST CENTRAL AZ
BY AFTERNOON. THEREFORE A FEW LIGHT SHOWERS ARE POSSIBLE OVER THE
DESERTS NEAR PHOENIX THIS MORNING...CHANGING TO A SLIGHT CHANCE OF
SHOWERS DURING THE AFTERNOON WITH INCREASING STABILITY. MOSTLY
CLOUDY SKIES HOWEVER ARE FORECAST OVER MUCH OF SOUTHWEST AND SOUTH
CENTRAL ARIZONA TODAY...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS IN OUR MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY
THROUGH EVENING. CLEARING TO PARTIAL CLEARING SKIES ARE EXPECTED
EARLY THIS EVENING WITH SHOWERS ENDING.


MONDAY THROUGH THURSDAY...

A HIGH PRESSURE SYSTEM WILL SLOWLY BUILD OVER THE REGION THIS PERIOD
PROVIDING MOSTLY CLEAR SKIES AND MUCH WARMER AFTERNOON TEMPERATURES.
BACK MIDDLE 90S ON THE LOWER DESERTS AGAIN...OR ABOUT 5 DEGREES ABOVE
NORMAL.


THURSDAY NIGHT THROUGH SUNDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA AND AZ LATE THURSDAY AND FRIDAY. ENSEMBLE
MEMBER SPREAD APPEARS TO BE CONSOLIDATING MORE...INCREASING OUR
CONFIDENCE THAT THIS NEW WEATHER SYSTEM WILL BODILY MOVE INTO THE
REGION FRIDAY AND THE WEEKEND.  SINCE ENSEMBLE MEMBERS ARE COMING
INTO CLOSER AGREEMENT...WE CAN PLACE SOME VALUE IN THE OPERATION GFS
WHICH SHOWS THIS SYSTEM TO BE INITIALLY DRY FRIDAY AND SATURDAY...
WITH PERHAPS A BETTER CHANCE OF PRECIP SUNDAY. THEREFORE A BROAD
BRUSH FORECAST APPROACH SEEMS TO BE IN ORDER FOR NOW...KEEPING A
SLIGHT CHANCE OF SHOWERS GOING...AND MUCH COOLER TEMPERATURES
DEVELOPING.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

WITH A DRIER AND WARMER AIRMASS IN PLACE EXPECT ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY WITH THE HOTTEST DAY ON WEDNESDAY
REACHING INTO THE MID TO UPPER 90S IN THE LOWER DESERTS. EXPECT
ELEVATED FIRE DANGER ON WEDNESDAY AND THURSDAY WITH MINIMUM
HUMIDITIES FALLING TO THE 6 TO 11 PERCENT RANGE AND BREEZY SOUTHERLY
TO SOUTHWESTERLY WINDS SPREADING THROUGH THE LOWER DESERTS.
CONDITIONS WILL IMPROVE ON FRIDAY AND SATURDAY WHEN THE NEXT STORM
SYSTEM WILL COOL HIGH TEMPERATURES TO THE LOW TO MID 80S WITH
MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20 PERCENT RANGE BY
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 010355
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
855 PM MST SAT APR 30 2016

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TONIGHT INTO SUNDAY. THIS WILL RESULT IN A CHANCE OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS...PARTICULARLY OVER THE MOUNTAINS
OF EASTERN ARIZONA SUNDAY. CLEARING IS EXPECTED SUNDAY NIGHT...WITH
DRY AND MUCH WARMER WEATHER DEVELOPING NEXT WEEK. HOT WEATHER IS
EXPECTED NEXT WEEK WITH DESERT TEMPERATURES WARMING INTO THE MID TO
UPPER 90S. THERE ARE HINTS OF ANOTHER PACIFIC WEATHER SYSTEM MOVING
INTO THE REGION BY LATE NEXT WEEK OR NEXT WEEKEND.

&&

.DISCUSSION...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE PREVALENT THIS
AFTERNOON ACROSS PORTIONS OF THE AZ LOWER DESERTS...INCLUDING THE
PHOENIX AREA. THE STORMS DEVELOPED IN AN AREA CHARACTERIZED BY VERY
STRONG ASCENT AHEAD OF TIGHT VORT MAX ACROSS THE WESTERN AZ DESERTS.
LATEST WV IMAGERY AND STREAMLINE ANALYSIS SHOWS THE VORT SHEARING OUT
AS IT TRANSLATES EASTWARD ACROSS CENTRAL AZ. THE LOSS OF LARGER
SCALE ASCENT AND DIABATIC HEATING HAS CONSEQUENTLY RESULTED IN A
RAPID DECREASE IN INSTABILITY AND COVERAGE OF SHOWERS AND STORMS THIS
EVENING. LATEST HI-RES GUIDANCE INCLUDING THE HRRR CONTINUE TO SHOW
THE EXISTING ACTIVITY...MAINLY CONCENTRATED EAST OF THE PHOENIX AREA
DISSIPATING OVERNIGHT. CURRENT FORECAST HANDLES THIS WELL...THOUGH
SOME ADJUSTMENTS WERE MADE TO THE SHORT-TERM TEMPERATURES TO ACCOUNT
FOR THE RAIN-COOLED AIR EARLY THIS EVENING.

&&

.PREVIOUS DISCUSSION...
AT 2 PM A VIGOROUS UPPER LEVEL LOW PRESSURE SYSTEM WAS MOVING INTO
ARIZONA...WITH THE LOW CENTER PUSHING EASTWARD AND INTO WEST CENTRAL
AZ. BEST AREA OF PVA/DIFLUENCE AND Q-CONVERGENCE WAS FOCUSED ACROSS
WEST-CENTRAL AND SOUTH-CENTRAL ARIZONA EARLY THIS AFTERNOON AND
LATEST SPC MESOANALYSIS GRAPHIC INDICATED THAT BEST INSTABILITY WAS
ALSO IN THAT AREA WITH OVER 500 J/KG OF MLCAPE PRESENT AT 1 PM. WITH
PWAT VALUES APPROACHING THREE QUARTERS OF AN INCH OUT WEST WE HAVE A
GOOD COMBINATION OF MOISTURE...INSTABILITY AND LIFT AND NOT
SURPRISINGLY...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
AHEAD OF THE LOW...ACROSS EASTERN LA PAZ AND YUMA COUNTIES AND
WESTERN MARICOPA COUNTY. SOME OF THE STRONGEST CELLS ARE IN THE
PRIME DIFLUENT AREA AHEAD OF THE LOW CENTER OVER NERN LA PAZ COUNTY.
SO FAR STORMS HAVE BEEN SUB SEVERE AND WE HAVE COVERED THEM WITH
SIGNIFICANT WEATHER ADVISORIES AND SOCIAL MEDIA POSTS. FOR THE REST
OF THE AFTERNOON AND INTO THE EVENING THERE WILL CONTINUE TO BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL
ARIZONA...WITH SLIGHT CHANCES FURTHER WEST IN THE AREAS BEHIND THE
PASSING UPPER LOW. HIGH TEMPERATURES TODAY WILL BE ON THE COOL SIDE
AS THE UPPER LOW AND ASSOCIATED CLOUD COVER MOVES ACROSS THE
AREA...WITH MOST READINGS IN THE UPPER 70S TO LOW 80S OVER THE LOWER
DESERTS. SCATTERED SHOWERS/STORMS WILL CONTINUE TO INCREASE ACROSS
THE GREATER PHOENIX AREA DURING THE MID TO LATE AFTERNOON...THEN
CONTINUE INTO THE EVENING HOURS BEFORE STARTING TO DISSIPATE.

LATER TONIGHT INTO SUNDAY...AS THE EVENING WEARS ON AND WE MOVE INTO
SUNDAY...THE MAIN UPPER LOW CONTINUES TO SHIFT OFF TO THE
EAST/NORTHEAST AND THE DYNAMICAL FORCING BECOMES MINIMAL WITH TIME.
MID LEVEL Q CONVERGENCE BULLSEYE MOVES INTO NEW MEXICO OVERNIGHT
WITH A MORE SUBSIDENT AREA OF Q DIVERGENCE MOVING INTO THE LOWER
CENTRAL DESERTS. NVA/DVV OVERSPREAD THE AREA FROM THE WEST...AND THE
MAIN UPPER JET AXIS MOVES WELL OFF TO THE EAST AND OFFERS NO SUPPORT
FOR UVV. PRETTY MUCH...BY LATE NIGHT TONIGHT AND SUNDAY WE ARE LEFT
WITH THERMODYNAMIC SUPPORT FOR SHOWERS/CONVECTION AS COOL AIR ALOFT
REMAINS IN PLACE OVER AN AREA OF ELEVATED LOW LEVEL MOISTURE.
FORECAST CAPE VALUES HOWEVER ARE LOW COMPARED TO THIS
AFTERNOON...MOSTLY LESS THAN 200 J/KG AND THE BEST CAPE STAYS ACROSS
HIGH TERRAIN AREAS NORTH AND EAST OF PHOENIX. WE WILL CONTINUE TO
KEEP A CHANCE OF SHOWERS OR STORMS GOING OVER SRN GILA COUNTY
THROUGH THE DAY ON SUNDAY BUT LOWER POPS TO THE 15-20 PERCENT
BALLPARK OVER THE LOWER CENTRAL DESERTS WITH TIME...WITH POPS OVER
THE FAR WESTERN DESERTS AND SERN CA LOWERING INTO THE SINGLE DIGITS.
WE SHOULD SEE SOME COOLING ON SUNDAY...GIVEN THE NATURE OF THE COLD
POOL ALOFT MOVING ACROSS THE AREA AND THE CLOUD COVER...MOST
SIGNIFICANT OVER SOUTH CENTRAL AZ...AND WE WILL LOWER OUR HIGHS A
COUPLE DEGREES WITH PHOENIX DROPPING TO A HIGH OF JUST 80 ON SUNDAY.
ACTUALLY...WOULD NOT BE SURPRISED IF THE HIGH IN PHOENIX SUNDAY
REMAINS IN THE 70S.

ALTHOUGH THE MAIN LOW WILL CONTINUE TO PUSH OFF TO THE EAST SUNDAY
NIGHT...ONE MORE WEAK BAGGY TROF OVER SRN CA/SRN NV WILL SLIDE EAST
AND INTO NORTHERN ARIZONA KEEPING A SLIGHT CHANCE OF EVENING SHOWERS
IN PLAY OVER THE HIGHER TERRAIN OF JOSHUA TREE NP AS WELL AS AREAS
NORTH AND EAST OF PHOENIX. OTHERWISE EXPECT POPS IN THE SINGLE
DIGITS OVER THE LOWER AZ AND CA DESERTS.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT THROUGH SATURDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

WITH A DRIER AND WARMER AIRMASS IN PLACE EXPECT ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY WITH THE HOTTEST DAY ON WEDNESDAY
REACHING INTO THE MID TO UPPER 90S IN THE LOWER DESERTS. EXPECT
ELEVATED FIRE DANGER ON WEDNESDAY AND THURSDAY WITH MINIMUM
HUMIDITIES FALLING TO THE 6 TO 11 PERCENT RANGE AND BREEZY SOUTHERLY
TO SOUTHWESTERLY WINDS SPREADING THROUGH THE LOWER DESERTS.
CONDITIONS WILL IMPROVE ON FRIDAY AND SATURDAY WHEN THE NEXT STORM
SYSTEM WILL COOL HIGH TEMPERATURES TO THE LOW TO MID 80S WITH
MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20 PERCENT RANGE BY
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 302233 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
330 PM MST SAT APR 30 2016

.UPDATE...UPDATED FIRE WEATHER DISCUSSION.

&&

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TONIGHT INTO SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY LATE
NEXT WEEK OR NEXT WEEKEND.

&&

.DISCUSSION...
AT 2 PM A VIGOROUS UPPER LEVEL LOW PRESSURE SYSTEM WAS MOVING INTO
ARIZONA...WITH THE LOW CENTER PUSHING EASTWARD AND INTO WEST CENTRAL
AZ. BEST AREA OF PVA/DIFLUENCE AND Q-CONVERGENCE WAS FOCUSED ACROSS
WEST-CENTRAL AND SOUTH-CENTRAL ARIZONA EARLY THIS AFTERNOON AND
LATEST SPC MESOANALYSIS GRAPHIC INDICATED THAT BEST INSTABILITY WAS
ALSO IN THAT AREA WITH OVER 500 J/KG OF MLCAPE PRESENT AT 1 PM. WITH
PWAT VALUES APPROACHING THREE QUARTERS OF AN INCH OUT WEST WE HAVE A
GOOD COMBINATION OF MOISTURE...INSTABILITY AND LIFT AND NOT
SURPRISINGLY...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
AHEAD OF THE LOW...ACROSS EASTERN LA PAZ AND YUMA COUNTIES AND
WESTERN MARICOPA COUNTY. SOME OF THE STRONGEST CELLS ARE IN THE
PRIME DIFLUENT AREA AHEAD OF THE LOW CENTER OVER NERN LA PAZ COUNTY.
SO FAR STORMS HAVE BEEN SUB SEVERE AND WE HAVE COVERED THEM WITH
SIGNIFICANT WEATHER ADVISORIES AND SOCIAL MEDIA POSTS. FOR THE REST
OF THE AFTERNOON AND INTO THE EVENING THERE WILL CONTINUE TO BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL
ARIZONA...WITH SLIGHT CHANCES FURTHER WEST IN THE AREAS BEHIND THE
PASSING UPPER LOW. HIGH TEMPERATURES TODAY WILL BE ON THE COOL SIDE
AS THE UPPER LOW AND ASSOCIATED CLOUD COVER MOVES ACROSS THE
AREA...WITH MOST READINGS IN THE UPPER 70S TO LOW 80S OVER THE LOWER
DESERTS. SCATTERED SHOWERS/STORMS WILL CONTINUE TO INCREASE ACROSS
THE GREATER PHOENIX AREA DURING THE MID TO LATE AFTERNOON...THEN
CONTINUE INTO THE EVENING HOURS BEFORE STARTING TO DISSIPATE.

LATER TONIGHT INTO SUNDAY...AS THE EVENING WEARS ON AND WE MOVE INTO
SUNDAY...THE MAIN UPPER LOW CONTINUES TO SHIFT OFF TO THE
EAST/NORTHEAST AND THE DYNAMICAL FORCING BECOMES MINIMAL WITH TIME.
MID LEVEL Q CONVERGENCE BULLSEYE MOVES INTO NEW MEXICO OVERNIGHT
WITH A MORE SUBSIDENT AREA OF Q DIVERGENCE MOVING INTO THE LOWER
CENTRAL DESERTS. NVA/DVV OVERSPREAD THE AREA FROM THE WEST...AND THE
MAIN UPPER JET AXIS MOVES WELL OFF TO THE EAST AND OFFERS NO SUPPORT
FOR UVV. PRETTY MUCH...BY LATE NIGHT TONIGHT AND SUNDAY WE ARE LEFT
WITH THERMODYNAMIC SUPPORT FOR SHOWERS/CONVECTION AS COOL AIR ALOFT
REMAINS IN PLACE OVER AN AREA OF ELEVATED LOW LEVEL MOISTURE.
FORECAST CAPE VALUES HOWEVER ARE LOW COMPARED TO THIS
AFTERNOON...MOSTLY LESS THAN 200 J/KG AND THE BEST CAPE STAYS ACROSS
HIGH TERRAIN AREAS NORTH AND EAST OF PHOENIX. WE WILL CONTINUE TO
KEEP A CHANCE OF SHOWERS OR STORMS GOING OVER SRN GILA COUNTY
THROUGH THE DAY ON SUNDAY BUT LOWER POPS TO THE 15-20 PERCENT
BALLPARK OVER THE LOWER CENTRAL DESERTS WITH TIME...WITH POPS OVER
THE FAR WESTERN DESERTS AND SERN CA LOWERING INTO THE SINGLE DIGITS.
WE SHOULD SEE SOME COOLING ON SUNDAY...GIVEN THE NATURE OF THE COLD
POOL ALOFT MOVING ACROSS THE AREA AND THE CLOUD COVER...MOST
SIGNIFICANT OVER SOUTH CENTRAL AZ...AND WE WILL LOWER OUR HIGHS A
COUPLE DEGREES WITH PHOENIX DROPPING TO A HIGH OF JUST 80 ON SUNDAY.
ACTUALLY...WOULD NOT BE SURPRISED IF THE HIGH IN PHOENIX SUNDAY
REMAINS IN THE 70S.

ALTHOUGH THE MAIN LOW WILL CONTINUE TO PUSH OFF TO THE EAST SUNDAY
NIGHT...ONE MORE WEAK BAGGY TROF OVER SRN CA/SRN NV WILL SLIDE EAST
AND INTO NORTHERN ARIZONA KEEPING A SLIGHT CHANCE OF EVENING SHOWERS
IN PLAY OVER THE HIGHER TERRAIN OF JOSHUA TREE NP AS WELL AS AREAS
NORTH AND EAST OF PHOENIX. OTHERWISE EXPECT POPS IN THE SINGLE
DIGITS OVER THE LOWER AZ AND CA DESERTS.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT THROUGH SATURDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.


SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

WITH A DRIER AND WARMER AIRMASS IN PLACE EXPECT ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY WITH THE HOTTEST DAY ON WEDNESDAY
REACHING INTO THE MID TO UPPER 90S IN THE LOWER DESERTS. EXPECT
ELEVATED FIRE DANGER ON WEDNESDAY AND THURSDAY WITH MINIMUM
HUMIDITIES FALLING TO THE 6 TO 11 PERCENT RANGE AND BREEZY SOUTHERLY
TO SOUTHWESTERLY WINDS SPREADING THROUGH THE LOWER DESERTS.
CONDITIONS WILL IMPROVE ON FRIDAY AND SATURDAY WHEN THE NEXT STORM
SYSTEM WILL COOL HIGH TEMPERATURES TO THE LOW TO MID 80S WITH
MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20 PERCENT RANGE BY
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 302233 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
330 PM MST SAT APR 30 2016

.UPDATE...UPDATED FIRE WEATHER DISCUSSION.

&&

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TONIGHT INTO SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY LATE
NEXT WEEK OR NEXT WEEKEND.

&&

.DISCUSSION...
AT 2 PM A VIGOROUS UPPER LEVEL LOW PRESSURE SYSTEM WAS MOVING INTO
ARIZONA...WITH THE LOW CENTER PUSHING EASTWARD AND INTO WEST CENTRAL
AZ. BEST AREA OF PVA/DIFLUENCE AND Q-CONVERGENCE WAS FOCUSED ACROSS
WEST-CENTRAL AND SOUTH-CENTRAL ARIZONA EARLY THIS AFTERNOON AND
LATEST SPC MESOANALYSIS GRAPHIC INDICATED THAT BEST INSTABILITY WAS
ALSO IN THAT AREA WITH OVER 500 J/KG OF MLCAPE PRESENT AT 1 PM. WITH
PWAT VALUES APPROACHING THREE QUARTERS OF AN INCH OUT WEST WE HAVE A
GOOD COMBINATION OF MOISTURE...INSTABILITY AND LIFT AND NOT
SURPRISINGLY...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
AHEAD OF THE LOW...ACROSS EASTERN LA PAZ AND YUMA COUNTIES AND
WESTERN MARICOPA COUNTY. SOME OF THE STRONGEST CELLS ARE IN THE
PRIME DIFLUENT AREA AHEAD OF THE LOW CENTER OVER NERN LA PAZ COUNTY.
SO FAR STORMS HAVE BEEN SUB SEVERE AND WE HAVE COVERED THEM WITH
SIGNIFICANT WEATHER ADVISORIES AND SOCIAL MEDIA POSTS. FOR THE REST
OF THE AFTERNOON AND INTO THE EVENING THERE WILL CONTINUE TO BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL
ARIZONA...WITH SLIGHT CHANCES FURTHER WEST IN THE AREAS BEHIND THE
PASSING UPPER LOW. HIGH TEMPERATURES TODAY WILL BE ON THE COOL SIDE
AS THE UPPER LOW AND ASSOCIATED CLOUD COVER MOVES ACROSS THE
AREA...WITH MOST READINGS IN THE UPPER 70S TO LOW 80S OVER THE LOWER
DESERTS. SCATTERED SHOWERS/STORMS WILL CONTINUE TO INCREASE ACROSS
THE GREATER PHOENIX AREA DURING THE MID TO LATE AFTERNOON...THEN
CONTINUE INTO THE EVENING HOURS BEFORE STARTING TO DISSIPATE.

LATER TONIGHT INTO SUNDAY...AS THE EVENING WEARS ON AND WE MOVE INTO
SUNDAY...THE MAIN UPPER LOW CONTINUES TO SHIFT OFF TO THE
EAST/NORTHEAST AND THE DYNAMICAL FORCING BECOMES MINIMAL WITH TIME.
MID LEVEL Q CONVERGENCE BULLSEYE MOVES INTO NEW MEXICO OVERNIGHT
WITH A MORE SUBSIDENT AREA OF Q DIVERGENCE MOVING INTO THE LOWER
CENTRAL DESERTS. NVA/DVV OVERSPREAD THE AREA FROM THE WEST...AND THE
MAIN UPPER JET AXIS MOVES WELL OFF TO THE EAST AND OFFERS NO SUPPORT
FOR UVV. PRETTY MUCH...BY LATE NIGHT TONIGHT AND SUNDAY WE ARE LEFT
WITH THERMODYNAMIC SUPPORT FOR SHOWERS/CONVECTION AS COOL AIR ALOFT
REMAINS IN PLACE OVER AN AREA OF ELEVATED LOW LEVEL MOISTURE.
FORECAST CAPE VALUES HOWEVER ARE LOW COMPARED TO THIS
AFTERNOON...MOSTLY LESS THAN 200 J/KG AND THE BEST CAPE STAYS ACROSS
HIGH TERRAIN AREAS NORTH AND EAST OF PHOENIX. WE WILL CONTINUE TO
KEEP A CHANCE OF SHOWERS OR STORMS GOING OVER SRN GILA COUNTY
THROUGH THE DAY ON SUNDAY BUT LOWER POPS TO THE 15-20 PERCENT
BALLPARK OVER THE LOWER CENTRAL DESERTS WITH TIME...WITH POPS OVER
THE FAR WESTERN DESERTS AND SERN CA LOWERING INTO THE SINGLE DIGITS.
WE SHOULD SEE SOME COOLING ON SUNDAY...GIVEN THE NATURE OF THE COLD
POOL ALOFT MOVING ACROSS THE AREA AND THE CLOUD COVER...MOST
SIGNIFICANT OVER SOUTH CENTRAL AZ...AND WE WILL LOWER OUR HIGHS A
COUPLE DEGREES WITH PHOENIX DROPPING TO A HIGH OF JUST 80 ON SUNDAY.
ACTUALLY...WOULD NOT BE SURPRISED IF THE HIGH IN PHOENIX SUNDAY
REMAINS IN THE 70S.

ALTHOUGH THE MAIN LOW WILL CONTINUE TO PUSH OFF TO THE EAST SUNDAY
NIGHT...ONE MORE WEAK BAGGY TROF OVER SRN CA/SRN NV WILL SLIDE EAST
AND INTO NORTHERN ARIZONA KEEPING A SLIGHT CHANCE OF EVENING SHOWERS
IN PLAY OVER THE HIGHER TERRAIN OF JOSHUA TREE NP AS WELL AS AREAS
NORTH AND EAST OF PHOENIX. OTHERWISE EXPECT POPS IN THE SINGLE
DIGITS OVER THE LOWER AZ AND CA DESERTS.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT THROUGH SATURDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.


SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...

WITH A DRIER AND WARMER AIRMASS IN PLACE EXPECT ABOVE NORMAL
TEMPERATURES THROUGH THURSDAY WITH THE HOTTEST DAY ON WEDNESDAY
REACHING INTO THE MID TO UPPER 90S IN THE LOWER DESERTS. EXPECT
ELEVATED FIRE DANGER ON WEDNESDAY AND THURSDAY WITH MINIMUM
HUMIDITIES FALLING TO THE 6 TO 11 PERCENT RANGE AND BREEZY SOUTHERLY
TO SOUTHWESTERLY WINDS SPREADING THROUGH THE LOWER DESERTS.
CONDITIONS WILL IMPROVE ON FRIDAY AND SATURDAY WHEN THE NEXT STORM
SYSTEM WILL COOL HIGH TEMPERATURES TO THE LOW TO MID 80S WITH
MINIMUM HUMIDITIES IN THE MID TEEN TO MID 20 PERCENT RANGE BY
SATURDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 302211
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST SAT APR 30 2016

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TONIGHT INTO SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY LATE
NEXT WEEK OR NEXT WEEKEND.

&&

.DISCUSSION...
AT 2 PM A VIGOROUS UPPER LEVEL LOW PRESSURE SYSTEM WAS MOVING INTO
ARIZONA...WITH THE LOW CENTER PUSHING EASTWARD AND INTO WEST CENTRAL
AZ. BEST AREA OF PVA/DIFLUENCE AND Q-CONVERGENCE WAS FOCUSED ACROSS
WEST-CENTRAL AND SOUTH-CENTRAL ARIZONA EARLY THIS AFTERNOON AND
LATEST SPC MESOANALYSIS GRAPHIC INDICATED THAT BEST INSTABILITY WAS
ALSO IN THAT AREA WITH OVER 500 J/KG OF MLCAPE PRESENT AT 1 PM. WITH
PWAT VALUES APPROACHING THREE QUARTERS OF AN INCH OUT WEST WE HAVE A
GOOD COMBINATION OF MOISTURE...INSTABILITY AND LIFT AND NOT
SURPRISINGLY...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
AHEAD OF THE LOW...ACROSS EASTERN LA PAZ AND YUMA COUNTIES AND
WESTERN MARICOPA COUNTY. SOME OF THE STRONGEST CELLS ARE IN THE
PRIME DIFLUENT AREA AHEAD OF THE LOW CENTER OVER NERN LA PAZ COUNTY.
SO FAR STORMS HAVE BEEN SUB SEVERE AND WE HAVE COVERED THEM WITH
SIGNIFICANT WEATHER ADVISORIES AND SOCIAL MEDIA POSTS. FOR THE REST
OF THE AFTERNOON AND INTO THE EVENING THERE WILL CONTINUE TO BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS SOUTH CENTRAL
ARIZONA...WITH SLIGHT CHANCES FURTHER WEST IN THE AREAS BEHIND THE
PASSING UPPER LOW. HIGH TEMPERATURES TODAY WILL BE ON THE COOL SIDE
AS THE UPPER LOW AND ASSOCIATED CLOUD COVER MOVES ACROSS THE
AREA...WITH MOST READINGS IN THE UPPER 70S TO LOW 80S OVER THE LOWER
DESERTS. SCATTERED SHOWERS/STORMS WILL CONTINUE TO INCREASE ACROSS
THE GREATER PHOENIX AREA DURING THE MID TO LATE AFTERNOON...THEN
CONTINUE INTO THE EVENING HOURS BEFORE STARTING TO DISSIPATE.

LATER TONIGHT INTO SUNDAY...AS THE EVENING WEARS ON AND WE MOVE INTO
SUNDAY...THE MAIN UPPER LOW CONTINUES TO SHIFT OFF TO THE
EAST/NORTHEAST AND THE DYNAMICAL FORCING BECOMES MINIMAL WITH TIME.
MID LEVEL Q CONVERGENCE BULLSEYE MOVES INTO NEW MEXICO OVERNIGHT
WITH A MORE SUBSIDENT AREA OF Q DIVERGENCE MOVING INTO THE LOWER
CENTRAL DESERTS. NVA/DVV OVERSPREAD THE AREA FROM THE WEST...AND THE
MAIN UPPER JET AXIS MOVES WELL OFF TO THE EAST AND OFFERS NO SUPPORT
FOR UVV. PRETTY MUCH...BY LATE NIGHT TONIGHT AND SUNDAY WE ARE LEFT
WITH THERMODYNAMIC SUPPORT FOR SHOWERS/CONVECTION AS COOL AIR ALOFT
REMAINS IN PLACE OVER AN AREA OF ELEVATED LOW LEVEL MOISTURE.
FORECAST CAPE VALUES HOWEVER ARE LOW COMPARED TO THIS
AFTERNOON...MOSTLY LESS THAN 200 J/KG AND THE BEST CAPE STAYS ACROSS
HIGH TERRAIN AREAS NORTH AND EAST OF PHOENIX. WE WILL CONTINUE TO
KEEP A CHANCE OF SHOWERS OR STORMS GOING OVER SRN GILA COUNTY
THROUGH THE DAY ON SUNDAY BUT LOWER POPS TO THE 15-20 PERCENT
BALLPARK OVER THE LOWER CENTRAL DESERTS WITH TIME...WITH POPS OVER
THE FAR WESTERN DESERTS AND SERN CA LOWERING INTO THE SINGLE DIGITS.
WE SHOULD SEE SOME COOLING ON SUNDAY...GIVEN THE NATURE OF THE COLD
POOL ALOFT MOVING ACROSS THE AREA AND THE CLOUD COVER...MOST
SIGNIFICANT OVER SOUTH CENTRAL AZ...AND WE WILL LOWER OUR HIGHS A
COUPLE DEGREES WITH PHOENIX DROPPING TO A HIGH OF JUST 80 ON SUNDAY.
ACTUALLY...WOULD NOT BE SURPRISED IF THE HIGH IN PHOENIX SUNDAY
REMAINS IN THE 70S.

ALTHOUGH THE MAIN LOW WILL CONTINUE TO PUSH OFF TO THE EAST SUNDAY
NIGHT...ONE MORE WEAK BAGGY TROF OVER SRN CA/SRN NV WILL SLIDE EAST
AND INTO NORTHERN ARIZONA KEEPING A SLIGHT CHANCE OF EVENING SHOWERS
IN PLAY OVER THE HIGHER TERRAIN OF JOSHUA TREE NP AS WELL AS AREAS
NORTH AND EAST OF PHOENIX. OTHERWISE EXPECT POPS IN THE SINGLE
DIGITS OVER THE LOWER AZ AND CA DESERTS.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT THROUGH SATURDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

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

WITH A LOW PRESSURE STORM SYSTEM SWEEPING THROUGH THE REGION ON
SATURDAY AFTERNOON AND EVENING EXPECT SOME SCATTERED RAIN SHOWERS
AND THUNDERSTORMS AND VERY BREEZY SOUTH TO SOUTHWEST WINDS WITH
PERIODIC GUSTS OF 20 TO 25KTS. THROUGH ABOUT 03Z. EXPECT THE LOWEST
CIGS TO VARY FROM 7K TO 11K FT. EXPECT WEST TO SOUTHWEST WINDS TO
TAPER OFF TO 7 TO 10KTS. TONIGHT WITH BROKEN CIGS AT ABOUT 9K FT.
LIGHT EASTERLY COMPONENT WINDS WILL BE FAVORED BEGINNING LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING.


SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

VERY BREEZY TO WINDY NORTHERLY COMPONENT WINDS WITH SOME GUSTS TO
20KTS. ARE EXPECTED FOR KBLH ALONG WITH RAIN SHOWERS AND
THUNDERSTORMS IN THE VICINITY THROUGH EARLY EVENING. BROKEN TO
OVERCAST CIGS FROM 7 TO 11K FT. ARE ALSO LIKELY THROUGH THIS
EVENING. WINDY WEST AND NORTHWESTERLY WINDS WITH GUSTS OF 25 TO
30KTS ARE EXPECTED FOR KIPL WITH CLEAR TO PARTLY CLOUDY SKIES.
LIGHTER WESTERLY TO NORTHWESTERLY WINDS ARE EXPECTED FOR BOTH SITES
BY 03 TO 04Z.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A WARMER AIRMASS WILL TRANSITION INTO THE AREA FROM THE WEST...WITH
HIGH TEMPERATURES PEAKING INTO THE MID TO UPPER 90S BY
WEDNESDAY AND THURSDAY FOR MANY LOWER DESERT SITES. MINIMUM
HUMIDITIES WILL DRY BELOW 15 PERCENT FOR MONDAY...BELOW 10 PERCENT
FOR TUESDAY AND WIDESPREAD SINGLE DIGIT PERCENTAGES POSSIBLE BY
MIDWEEK. OVERNIGHT RECOVERIES WILL RANGE FROM FAIR TO MODEST
THROUGHOUT THE WEEK. AFTER A FEW DAY BREAK FROM ELEVATED
WINDS...BREEZY SOUTH AND SOUTHWESTERLY WINDS IN THE WESTERN DISTRICTS
WILL RETURN AFTER WEDNESDAY AND SPREAD ACROSS THE REGION THURSDAY AND
FRIDAY AS ANOTHER LOW PRESSURE AREA APPROACHES FROM THE PACIFIC.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...NOLTE





000
FXUS65 KPSR 301538
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
835 AM MST SAT APR 30 2016

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TODAY AND SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY NEXT
WEEKEND.

&&

.DISCUSSION...
RATHER VIGOROUS UPPER LOW CONTINUED TO TAKE AIM ON ARIZONA THIS
MORNING WITH THE LOW CENTER DRIVING SOUTH THROUGH FAR SRN NEVADA AND
SWINGING TOWARDS THE EAST AND INTO FAR WEST CENTRAL ARIZONA. BY THIS
AFTERNOON THE LOW CENTER IS PROGGED TO BE OVER WEST CENTRAL AZ WITH
ALL OF THE BEST DYNAMICS...INCLUDING MIDLEVEL Q CONVERGENCE...PVA...
UPPER DIFLUENCE AND UPPER JET SUPPORT...FOCUSING ON SOUTH CENTRAL
ARIZONA DURING THE EARLY TO MID AFTERNOON HOURS. SO FAR...AS OF 8
AM...RADAR INDICATED THAT ALL OF THE CONVECTION WAS TO THE NORTH OF
OUR AREA...OVER NRN AZ AND SRN NEVADA. CURRENT SPC MESOANALYSIS
GRAPHICS SHOWED NO MLCAPE OVER THE LOWER DESERTS...BUT AFTER 18Z WE
SHOULD START SEEING 100-250 J/KG CAPE WORKING INTO PORTIONS OF SERN
CA AND THE WESTERN DESERTS.

LATEST SUITE OF MESOSCALE MODELS...INCLUDING HRRR...WRF4KM AND SSEO
STORM SCALE ENSEMBLE OF OPPORTUNITY...INDICATED THAT CONVECTION
WOULD REALLY START BREAKING OUT ACROSS SOUTH CENTRAL AZ AFTER ABOUT
20Z THIS AFTERNOON...WITH SCATTERED SHOWERS AND EMBEDDED
THUNDERSTORMS ACROSS MUCH OF THE AREA INTO THE EVENING HOURS. LESS
CONVECTION WOULD BE FOCUSED OVER SERN CA AND FAR WESTERN AZ AS
DYNAMICS WOULD BE DECREASING BEHIND THE UPPER LOW CENTER. CURRENT
POPS HAVE BEEN TWEAKED AGAIN AND RANGE BETWEEN 20 AND 40 PERCENT
OVER SOUTH CENTRAL AZ DURING THE AFTERNOON HOURS TODAY. CAPE THIS
AFTERNOON IS NOT FORECAST TO BE EXCESSIVE...MOSTLY BELOW 400
J/KG...BUT WITH RATHER STRONG DYNAMICS IT WILL NOT TAKE AS MUCH TO
GENERATE SOME MODERATELY STRONG THUNDERSTORMS. THUS WE CAN EXPECT
SOME GUSTY WINDS OVER 40 MPH THIS AFTERNOON ALONG WITH BRIEF
MODERATE TO HEAVY RAIN. MAYBE SOME BLOWING DUST AS WELL. THIS
AFTERNOON AND EVENING MIGHT BECOME A BIT INTERESTING CONVECTIVELY
SPEAKING.

.PREVIOUS DISCUSSION...
TODAY AND SUNDAY...

THE FLUID DYNAMICS OF THE EVOLVING WEATHER SYSTEM OVER THE SOUTHWEST
U.S. CHANGED FRIDAY EVENING AS A NUMBER OF NEW AND SMALLER
DISTURBANCES HAVE UNEXPECTEDLY SPUN UP UNDER A STRONG NORTHERLY JET
STREAM OVER THE PACIFIC NORTHWEST. THIS IS BEST SEEN IN THE 300/250
MB 00Z SAT PLOT DATA ACROSS WA/OR/ID.  IN OTHER WORDS...WHAT WAS ONCE
THOUGHT TO BE ONE VERY CLEAN AND UNILATERAL SYSTEM MOVING SOUTH AND
PIVOTING OUT OF SOUTHERN CA SATURDAY NIGHT...AND EXPOSING SOUTH
CENTRAL AZ INCLUDING PHOENIX TO A CHANCE OF THUNDERSTORMS SUNDAY...
HAS NOW CHANGED.

THE INITIAL DISTURBANCE...CLEARLY SEEN IN IR SATELLITE IMAGERY OVER
SOUTHERN NEVADA AND PRODUCING THUNDERSTORMS AT MIDNIGHT...WILL NOW
BE DRIVEN INTO CENTRAL AZ BY EVENING. STRONG 500/300MB HEIGHT
FALLS...MID LEVEL DYNAMICS...AND IMPORTED MOISTURE FROM NEVADA WILL
RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...GENERALLY FROM THE COLORADO RIVER VALLEY NEAR BLYTHE...EAST
TO WICKENBURG...PHOENIX...AND SURROUNDING DESERTS AND MOUNTAINS.

MODELED SOUNDINGS NOW SUGGEST THE CONVECTIVE TRIGGER TEMP AT PHOENIX
IS 75 DEG F (A HIGH TEMP OF 84 IS FORECAST)...66 DEG AT WICKENBURG
(A HIGH OF 75 IS FCST)...61 DEG AT GLOBE (A HIGH OF 75 IS FCST)...
AND 75 AT BLYTHE (A HIGH OF 82 IS FCST). THESE CONVECTIVE TRIGGER
TEMPS WILL GENERALLY DEVELOP BETWEEN NOON AND 2 PM.  ALSO...MODELED
SOUNDINGS DEPICT CONVECTIVE CLOUD BASES ON THE HIGH SIDE...ROUGHLY
12-14 THSD FT SUGGESTING THE POSSIBILITY OF MODERATELY STRONG
DOWNBURST WINDS AND EVERYTHING THAT COMES WITH IT INCLUDING LOCALLY
DENSE BLOWING DUST.

THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS EVENING
WITH THE LOSS OF DAYTIME HEATING...BUT CONTINUE AGAIN SUNDAY OVER
PORTIONS OF SOUTH CENTRAL AZ FROM PHOENIX NORTH AND EAST...
PARTICULARLY OVER THE MOUNTAINS AS A SECOND AND WEAKER DISTURBANCE
ROTATES INTO THE REGION FROM THE NORTH.

IN SUMMARY...PERHAPS THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS
WITH GUSTY WINDS WILL BE THIS AFTERNOON AND EVENING...NOT SUNDAY.

CLEARING SKIES ARE FORECAST FOR SUNDAY NIGHT.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT AND FRIDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
EASTERLY WINDS...VAR BETWEEN NE AND SE AT TIMES...WILL BEGIN TO VEER
TO SOUTH AND EVENTUALLY WESTERLY HEADINGS MIDDAY THRU THIS AFTERNOON.
ANOTHER STORM SYSTEM WILL TRANSITION IN FROM THE NORTHWEST AND
SUPPORT SHOWER/THUNDER DEVELOPMENT IN THE AFTERNOON ALONG WITH
WIDESPREAD BREEZINESS. PRECIP COVERAGE AT THIS TIME LOOKS TO BE
SPOTTY...SO CONTINUED VC MENTIONING IN THE 12Z TAFS. GUSTS INTO THE
20 TO 25KT RANGE WILL BE POSSIBLE...WITH MORE ERRATIC AND SLIGHTLY
STRONGER WINDS IN THE VICINITY OF SHOWERS/THUNDER. BEST WINDOW FOR
PRECIP ACTIVITY STILL LOOKS TO BE 30/22Z THROUGH 01/03Z. CLOUDS WILL
CONTINUE TO INCREASE THIS MORNING...DEVELOPING INTO SCT AND BKN MID
LEVEL COVERAGE 7 TO 9KFT OR SO.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
ELEVATED WEST WINDS TO CONTINUE FOR KIPL THROUGHOUT THE DAY...WITH
GUSTS OF 25KTS POSSIBLE. SOUTHERLY WINDS WILL TRANSITION TO
NORTHWESTERLY FOR KBLH AS ANOTHER STORM SYSTEM PASSES THROUGH THE
REGION. SHOWER/STORM CHANCES GENERALLY REMAIN EAST OF THE CO RIVER
THROUGHOUT THE DAY...BUT GUSTY STORM WINDS CANNOT BE RULED OUT FOR
KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A WARMER AIRMASS WILL TRANSITION INTO THE AREA FROM THE WEST...WITH
HIGH TEMPERATURES PEAKING INTO THE MID TO UPPER 90S BY
WEDNESDAY AND THURSDAY FOR MANY LOWER DESERT SITES. MINIMUM
HUMIDITIES WILL DRY BELOW 15 PERCENT FOR MONDAY...BELOW 10 PERCENT
FOR TUESDAY AND WIDESPREAD SINGLE DIGIT PERCENTAGES POSSIBLE BY
MIDWEEK. OVERNIGHT RECOVERIES WILL RANGE FROM FAIR TO MODEST
THROUGHOUT THE WEEK. AFTER A FEW DAY BREAK FROM ELEVATED
WINDS...BREEZY SOUTH AND SOUTHWESTERLY WINDS IN THE WESTERN DISTRICTS
WILL RETURN AFTER WEDNESDAY AND SPREAD ACROSS THE REGION THURSDAY AND
FRIDAY AS ANOTHER LOW PRESSURE AREA APPROACHES FROM THE PACIFIC.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE





000
FXUS65 KPSR 301255
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
555 AM MST SAT APR 30 2016

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TODAY AND SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY NEXT
WEEKEND.

&&

.DISCUSSION...

TODAY AND SUNDAY...

THE FLUID DYNAMICS OF THE EVOLVING WEATHER SYSTEM OVER THE SOUTHWEST
U.S. CHANGED FRIDAY EVENING AS A NUMBER OF NEW AND SMALLER
DISTURBANCES HAVE UNEXPECTEDLY SPUN UP UNDER A STRONG NORTHERLY JET
STREAM OVER THE PACIFIC NORTHWEST. THIS IS BEST SEEN IN THE 300/250
MB 00Z SAT PLOT DATA ACROSS WA/OR/ID.  IN OTHER WORDS...WHAT WAS ONCE
THOUGHT TO BE ONE VERY CLEAN AND UNILATERAL SYSTEM MOVING SOUTH AND
PIVOTING OUT OF SOUTHERN CA SATURDAY NIGHT...AND EXPOSING SOUTH
CENTRAL AZ INCLUDING PHOENIX TO A CHANCE OF THUNDERSTORMS SUNDAY...
HAS NOW CHANGED.

THE INITIAL DISTURBANCE...CLEARLY SEEN IN IR SATELLITE IMAGERY OVER
SOUTHERN NEVADA AND PRODUCING THUNDERSTORMS AT MIDNIGHT...WILL NOW
BE DRIVEN INTO CENTRAL AZ BY EVENING. STRONG 500/300MB HEIGHT
FALLS...MID LEVEL DYNAMICS...AND IMPORTED MOISTURE FROM NEVADA WILL
RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...GENERALLY FROM THE COLORADO RIVER VALLEY NEAR BLYTHE...EAST
TO WICKENBURG...PHOENIX...AND SURROUNDING DESERTS AND MOUNTAINS.

MODELED SOUNDINGS NOW SUGGEST THE CONVECTIVE TRIGGER TEMP AT PHOENIX
IS 75 DEG F (A HIGH TEMP OF 84 IS FORECAST)...66 DEG AT WICKENBURG
(A HIGH OF 75 IS FCST)...61 DEG AT GLOBE (A HIGH OF 75 IS FCST)...
AND 75 AT BLYTHE (A HIGH OF 82 IS FCST). THESE CONVECTIVE TRIGGER
TEMPS WILL GENERALLY DEVELOP BETWEEN NOON AND 2 PM.  ALSO...MODELED
SOUNDINGS DEPICT CONVECTIVE CLOUD BASES ON THE HIGH SIDE...ROUGHLY
12-14 THSD FT SUGGESTING THE POSSIBILITY OF MODERATELY STRONG
DOWNBURST WINDS AND EVERYTHING THAT COMES WITH IT INCLUDING LOCALLY
DENSE BLOWING DUST.

THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS EVENING
WITH THE LOSS OF DAYTIME HEATING...BUT CONTINUE AGAIN SUNDAY OVER
PORTIONS OF SOUTH CENTRAL AZ FROM PHOENIX NORTH AND EAST...
PARTICULARLY OVER THE MOUNTAINS AS A SECOND AND WEAKER DISTURBANCE
ROTATES INTO THE REGION FROM THE NORTH.

IN SUMMARY...PERHAPS THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS
WITH GUSTY WINDS WILL BE THIS AFTERNOON AND EVENING...NOT SUNDAY.

CLEARING SKIES ARE FORECAST FOR SUNDAY NIGHT.

MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.

THURSDAY NIGHT AND FRIDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
EASTERLY WINDS...VAR BETWEEN NE AND SE AT TIMES...WILL BEGIN TO VEER
TO SOUTH AND EVENTUALLY WESTERLY HEADINGS MIDDAY THRU THIS AFTERNOON.
ANOTHER STORM SYSTEM WILL TRANSITION IN FROM THE NORTHWEST AND
SUPPORT SHOWER/THUNDER DEVELOPMENT IN THE AFTERNOON ALONG WITH
WIDESPREAD BREEZINESS. PRECIP COVERAGE AT THIS TIME LOOKS TO BE
SPOTTY...SO CONTINUED VC MENTIONING IN THE 12Z TAFS. GUSTS INTO THE
20 TO 25KT RANGE WILL BE POSSIBLE...WITH MORE ERRATIC AND SLIGHTLY
STRONGER WINDS IN THE VICINITY OF SHOWERS/THUNDER. BEST WINDOW FOR
PRECIP ACTIVITY STILL LOOKS TO BE 30/22Z THROUGH 01/03Z. CLOUDS WILL
CONTINUE TO INCREASE THIS MORNING...DEVELOPING INTO SCT AND BKN MID
LEVEL COVERAGE 7 TO 9KFT OR SO.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
ELEVATED WEST WINDS TO CONTINUE FOR KIPL THROUGHOUT THE DAY...WITH
GUSTS OF 25KTS POSSIBLE. SOUTHERLY WINDS WILL TRANSITION TO
NORTHWESTERLY FOR KBLH AS ANOTHER STORM SYSTEM PASSES THROUGH THE
REGION. SHOWER/STORM CHANCES GENERALLY REMAIN EAST OF THE CO RIVER
THROUGHOUT THE DAY...BUT GUSTY STORM WINDS CANNOT BE RULED OUT FOR
KBLH.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A WARMER AIRMASS WILL TRANSITION INTO THE AREA FROM THE WEST...WITH
HIGH TEMPERATURES PEAKING INTO THE MID TO UPPER 90S BY
WEDNESDAY AND THURSDAY FOR MANY LOWER DESERT SITES. MINIMUM
HUMIDITIES WILL DRY BELOW 15 PERCENT FOR MONDAY...BELOW 10 PERCENT
FOR TUESDAY AND WIDESPREAD SINGLE DIGIT PERCENTAGES POSSIBLE BY
MIDWEEK. OVERNIGHT RECOVERIES WILL RANGE FROM FAIR TO MODEST
THROUGHOUT THE WEEK. AFTER A FEW DAY BREAK FROM ELEVATED
WINDS...BREEZY SOUTH AND SOUTHWESTERLY WINDS IN THE WESTERN DISTRICTS
WILL RETURN AFTER WEDNESDAY AND SPREAD ACROSS THE REGION THURSDAY AND
FRIDAY AS ANOTHER LOW PRESSURE AREA APPROACHES FROM THE PACIFIC.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...NOLTE





000
FXUS65 KPSR 301004
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
305 AM MST SAT APR 30 2016

.SYNOPSIS...
A NEW LOW PRESSURE SYSTEM WILL MOVE INTO THE REGION FROM THE NORTH
TODAY AND SUNDAY. THIS WILL PROVIDE BREEZY CONDITIONS...MORE
COOLING...AND A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS...PARTICULARLY OVER NORTHERN AND CENTRAL ARIZONA.
CLEARING IS EXPECTED SUNDAY NIGHT...WITH DRY AND MUCH WARMER WEATHER
DEVELOPING NEXT WEEK. HOT WEATHER IS EXPECTED NEXT WEEK WITH DESERT
TEMPERATURES WARMING INTO THE MID TO UPPER 90S. THERE ARE HINTS OF
ANOTHER PACIFIC WEATHER SYSTEM MOVING INTO THE REGION BY NEXT
WEEKEND.

&&

.DISCUSSION...

TODAY AND SUNDAY...

THE FLUID DYNAMICS OF THE EVOLVING WEATHER SYSTEM OVER THE SOUTHWEST
U.S. CHANGED FRIDAY EVENING AS A NUMBER OF NEW AND SMALLER
DISTURBANCES HAVE UNEXPECTEDLY SPUN UP UNDER A STRONG NORTHERLY JET
STREAM OVER THE PACIFIC NORTHWEST. THIS IS BEST SEEN IN THE 300/250
MB 00Z SAT PLOT DATA ACROSS WA/OR/ID.  IN OTHER WORDS...WHAT WAS ONCE
THOUGHT TO BE ONE VERY CLEAN AND UNILATERAL SYSTEM MOVING SOUTH AND
PIVOTING OUT OF SOUTHERN CA SATURDAY NIGHT...AND EXPOSING SOUTH
CENTRAL AZ INCLUDING PHOENIX TO A CHANCE OF THUNDERSTORMS SUNDAY...
HAS NOW CHANGED.

THE INITIAL DISTURBANCE...CLEARLY SEEN IN IR SATELLITE IMAGERY OVER
SOUTHERN NEVADA AND PRODUCING THUNDERSTORMS AT MIDNIGHT...WILL NOW
BE DRIVEN INTO CENTRAL AZ BY EVENING. STRONG 500/300MB HEIGHT
FALLS...MID LEVEL DYNAMICS...AND IMPORTED MOISTURE FROM NEVADA WILL
RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...GENERALLY FROM THE COLORADO RIVER VALLEY NEAR BLYTHE...EAST
TO WICKENBURG...PHOENIX...AND SURROUNDING DESERTS AND MOUNTAINS.

MODELED SOUNDINGS NOW SUGGEST THE CONVECTIVE TRIGGER TEMP AT PHOENIX
IS 75 DEG F (A HIGH TEMP OF 84 IS FORECAST)...66 DEG AT WICKENBURG
(A HIGH OF 75 IS FCST)...61 DEG AT GLOBE (A HIGH OF 75 IS FCST)...
AND 75 AT BLYTHE (A HIGH OF 82 IS FCST). THESE CONVECTIVE TRIGGER
TEMPS WILL GENERALLY DEVELOP BETWEEN NOON AND 2 PM.  ALSO...MODELED
SOUNDINGS DEPICT CONVECTIVE CLOUD BASES ON THE HIGH SIDE...ROUGHLY
12-14 THSD FT SUGGESTING THE POSSIBILITY OF MODERATELY STRONG
DOWNBURST WINDS AND EVERYTHING THAT COMES WITH IT INCLUDING LOCALLY
DENSE BLOWING DUST.

THE CHANCE OF SHOWERS AND THUNDERSTORMS WILL DIMINISH THIS EVENING
WITH THE LOSS OF DAYTIME HEATING...BUT CONTINUE AGAIN SUNDAY OVER
PORTIONS OF SOUTH CENTRAL AZ FROM PHOENIX NORTH AND EAST...
PARTICULARLY OVER THE MOUNTAINS AS A SECOND AND WEAKER DISTURBANCE
ROTATES INTO THE REGION FROM THE NORTH.

IN SUMMARY...PERHAPS THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS
WITH GUSTY WINDS WILL BE THIS AFTERNOON AND EVENING...NOT SUNDAY.

CLEARING SKIES ARE FORECAST FOR SUNDAY NIGHT.


MONDAY THROUGH THURSDAY...

DRY WESTERLY FLOW WILL DEVELOP MONDAY...FOLLOWED BY A BUILDING HIGH
PRESSURE SYSTEM TUE...WED...AND MOST OF THURSDAY. THIS WILL RESULT
IN MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES.


THURSDAY NIGHT AND FRIDAY...

MODELS HAVE BEEN FORECASTING ANOTHER PACIFIC WEATHER SYSTEM TO
APPROACH SOUTHERN CA LATE THURSDAY AND FRIDAY. ENSEMBLE SPREAD
CONTINUES BO BE WIDE WITH RESPECT TO TIMING AND INTENSITY. HOWEVER
ITS A NEAR CERTAINTY THAT ANOTHER PACIFIC SYSTEM WILL MOVE INTO THE
REGION BY THE END OF NEXT WEEK AND WEEKEND FOR MORE COOLING...
WIND...AND A THREAT OF SHOWERS. FOR NOW WE FEEL COMFORTABLE
INTRODUCING JUST A SLIGHT CHANCE OF SHOWERS AREA-WIDE FRIDAY AND
SATURDAY WITH NO SPECIFICS NOR RESOLUTION.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
TYPICAL EARLY EVENING BREEZINESS WILL SUBSIDE OVERNIGHT...ULTIMATELY
GIVING WAY TO DOWNSLOPE EASTERLY FLOW BETWEEN 08Z AND 10Z. LATEST
MODEL GUIDANCE INDICATES INSTABILITY WILL INCREASE SATURDAY
AFTERNOON...RESULTING IN WIDESPREAD BREEZINESS AND A CHANCE OF
CONVECTION. GUSTS WILL GENERALLY REACH 25 KT...EXCEPT HIGHER IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS. STORMS ARE MOST LIKELY IN A
PERIOD FROM AROUND 23Z SATURDAY TO 03Z SUNDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WINDS WILL SUBSIDE LATER ON THIS EVENING AT KIPL/KBLH...BEFORE
INCREASING ONCE AGAIN DURING THE MORNING. MAIN AVIATION WEATHER
CONCERN APPEARS TO BE A CHANCE OF THUNDERSTORMS...GENERALLY FROM KBLH
EASTWARD SATURDAY AFTERNOON. ANY STORMS THAT DEVELOP WILL BE CAPABLE
OF PRODUCING WIND GUSTS TO 40 KT.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...

A DRIER AND WARMER AIRMASS WILL STEADILY MOVE INTO THE REGION WITH
BELOW NORMAL HIGH TEMPS ON MONDAY WARMING TO ABOVE NORMAL ON TUESDAY
AND WELL ABOVE NORMAL ON WEDNESDAY WHEN HIGHS IN THE UPPER 90S...
AND ELEVATED FIRE WEATHER DANGER...IS EXPECTED. MINIMUM HUMIDITIES
IN THE MID TEENS TO LOWER 20S PERCENT RANGE ON MONDAY WILL BECOME
EVEN DRIER BY WEDNESDAY WHEN THEY WILL FALL TO THE SINGLE DIGITS.
EXPECT FAIR TO GOOD OVERNIGHT RECOVERIES ON MONDAY TO BECOME FAIR BY
TUESDAY WITH SOME IMPROVEMENT POSSIBLE ON FRIDAY. BREEZY SOUTH AND
SOUTHWESTERLY WINDS IN THE WESTERN ZONES ARE IN STORE FOR WEDNESDAY
AND IN CENTRAL AND EASTERN ZONES ON THURSDAY AND FRIDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...HIRSCH
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 300340
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
840 PM MST FRI APR 29 2016

.SYNOPSIS...
DRY NORTHWEST FLOW ALOFT WILL INCREASE OVER THE REGION THROUGH
SATURDAY. WARMER AFTERNOON TEMPERATURES ARE ALSO FORECAST.
HOWEVER...ANOTHER PACIFIC LOW PRESSURE SYSTEM IS EXPECTED TO MOVE
INTO THE REGION SATURDAY NIGHT AND SUNDAY...DEVELOPING BREEZY
CONDITIONS AND A THREAT FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE OF PRECIPITATION WILL OCCUR OVER THE SOUTH CENTRAL ARIZONA
DESERTS AND MOUNTAINS...MAINLY IN THE VICINITY OF PHOENIX. CLEARING
IS EXPECTED SUNDAY NIGHT...WITH HIGH PRESSURE AND MUCH WARMER
WEATHER NEXT WEEK.

&&

.DISCUSSION...
CYCLONIC FLOW PREVAILS ACROSS THE WESTERN CONUS WITH ONE UPPER LOW
ACROSS CO AND ANOTHER VORT MAX UPSTREAM ACROSS NORTHERN CA. FORECAST
IS IN GOOD SHAPE IN THE SHORT-TERM. LOW TEMPERATURES OVERNIGHT ARE
AGAIN GENERALLY EXPECTED TO BE NEAR OR SLIGHTLY BELOW NORMAL. ONLY
MINOR ADJUSTMENTS WERE MADE TO THE SHORT-TERM TEMPERATURES AND
DEWPOINTS. HOWEVER...SIGNIFICANT CHANGES WERE MADE TO THE SATURDAY
AFTERNOON THROUGH SUNDAY EVENING PERIOD.

HI-RES CONVECTIVE ALLOWING MODELS ARE TRENDING TOWARDS A MORE ACTIVE
SATURDAY AFTERNOON AND EVENING AS THE AFOREMENTIONED VORT MAX DROPS
SOUTHEASTWARD TOWARDS LAKE HAVASU. GLOBAL MODELS INDICATE A LARGE
AREA OF ASCENT WILL DEVELOP ACROSS SOUTH-CENTRAL AZ AHEAD OF THE LOW.
CONVECTIVE PARAMETERS ALSO SUGGEST THE POSSIBILITY OF A FEW
THUNDERSTORMS. POPS WERE INCREASED TO AROUND 30 PERCENT FOR THE
PHOENIX AREA AND THE CHARACTER OF THE PRECIP WAS CHANGED TO SCATTERED
COVERAGE TO CONVEY GREATER CERTAINTY.

MODELS SHOW THE LOW FILLING RAPIDLY SUNDAY AND DRIFTING TOWARDS THE
FOUR CORNERS. SUBSIDENT FLOW IS THEN EXPECTED TO DEVELOP BEHIND THE
LOW. MUCH OF THE PRECIPITATION WILL BE RELEGATED TO AREAS NORTH AND
EAST OF PHOENIX AND POPS WERE LOWERED ACROSS A LARGE PORTION OF THE
LOWER DESERTS.

&&

.PREVIOUS DISCUSSION...
FAST ON THE HEELS OF THE CURRENTLY EXITING LOW PRESSURE SYSTEM WILL
BE ANOTHER PACIFIC LOW MOVING IN FROM THE NORTHWEST DURING THE DAY ON
SATURDAY. MODEL GUIDANCE...INCLUDING OPERATIONAL RUNS OF THE
NAM/GFS/ECMWF AS WELL AS GEFS ENSEMBLE GUIDANCE...REMAINS CONSISTENT
IN THE TIMING AND TRACK OF THIS NEXT LOW...AND CONFIDENCE IN THE
FORECAST IS HIGH FOR BOTH PRECIP AND AN EXPECTED COOL DOWN. PROGS
MOVE THE UPPER LOW CENTER INTO FAR SRN NV AND FAR WCNTRL ARIZONA BY
SATURDAY AFTERNOON...AND THE BEST QG FORCING APPEARS TO MOVE INTO
SOUTHERN ARIZONA DURING THE DAY SATURDAY BEFORE THE DEEPER MOISTURE
ARRIVES. AS SUCH...WE HAVE POPS STARTING UP SATURDAY AFTERNOON BUT
MAINLY SLIGHT CHANCES OVER SERN CA AS WELL AS NORTHERN PORTIONS OF LA
PAZ AND MARICOPA COUNTIES. CANNOT RULE OUT A THUNDERSTORM DEVELOPING
SATURDAY AFTERNOON AS LIFTED INDICES DROP TO AROUND ZERO. OVERNIGHT
SATURDAY NIGHT AS THE UPPER LOW MOVES ACROSS SOUTH CENTRAL
ARIZONA...MAIN FORCING SHIFTS INTO THE EASTERN PORTION OF THE STATE
AND POPS ACROSS SOUTH CENTRAL AZ RISE INTO THE 20-30 PERCENT BALL
PARK...WITH SLIGHT CHANCES LINGERING FURTHER TO THE WEST. WIND SHOULD
NOT BE AS MUCH OF AN ISSUE WITH THIS SYSTEM AS WITH SOME OF THE
EARLIER ONES...BUT ONCE AGAIN FAVORED AREAS IN IMPERIAL
COUNTY...MAINLY FROM THE IMPERIAL VALLEY SOUTHWESTWARD...COULD REACH
TO NEAR WIND ADVISORY CRITERIA ON SATURDAY AS THE LOW APPROACHES. FOR
NOW WE WILL HIGHLIGHT THIS THREAT VIA SOCIAL MEDIA INSTEAD OF A WIND
ADVISORY.

ON SUNDAY THE MAIN UPPER LOW SHIFTS EAST AND INTO NEW MEXICO...AND
DYNAMICS/Q CONVERGENCE SHIFT EAST WITH THE UPPER LOW...AND JET
DYNAMICS ALSO DECREASE MARKEDLY AS THE UPPER JET AXIS SHIFTS OFF TO
THE SOUTHEAST OF PHOENIX. SO THE QG FORCING DECREASES BUT
THERMODYNAMIC EFFECTS INCREASE AS COOL AIR ALOFT AND LOWER LEVEL
MOISTURE SPREAD INTO THE CENTRAL DESERTS. WE WILL SEE HIGH TEMPS
COOL DOWN TO NEAR 80 OR INTO THE UPPER 70S OVER SOUTH CENTRAL
AZ...WITH HIGHS INTO THE MID 80S OVER THE WARMER WESTERN DESERTS.

SUNDAY NIGHT INTO MONDAY...UPPER LOW IS FORECAST TO CONTINUE TO PUSH
OFF TO THE NORTHEAST AS RIDGING ALOFT BUILDS ALONG THE SRN CA COAST.
DRIER MORE SUBSIDENT WEST/NORTHWEST FLOW ALOFT SPREADS ACROSS THE
AREA FOR MOSTLY SUNNY SKIES ALONG WITH WARMER HIGH TEMPERATURES.
HIGHS WILL CLIMB INTO THE MID 80S TO AROUND 90 MONDAY. EXPECT A DRY
DAY ALTHOUGH THERE MAY BE ENOUGH LINGERING MOISTURE TO ALLOW FOR A
SLIGHT CHANCE OF A SHOWER OR AFTERNOON STORM OVER THE HIGHER TERRAIN
EAST OF GLOBE.

TUESDAY THROUGH FRIDAY...

A HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION THIS PERIOD FOR
MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES. IN OTHER WORDS...
BACK TO NORMAL SPRING-TIME WEATHER...WITH OUCH...DESERT TEMPERATURES
IN THE 90S AGAIN. ITS ALSO CONCEIVABLE THAT PHOENIX CAN REACH ITS
FIRST 100 DEG TEMP OF THE YEAR THURSDAY UNDER SOUTH WINDS/WARM
ADVECTION. ALTHOUGH GUIDANCE DISPLAYS DECREASING MODEL-TO-MODEL
CONSISTENCY...AND ENSEMBLE MEMBER SPREAD IS STILL HIGH...IT LOOKS
MORE LIKELY THAT WE WILL SEE SHOWERS AND MAYBE THUNDERSTORMS SPREAD
INTO THE AREA FRIDAY AS A DEEP UPPER LOW SETS UP JUST INLAND ALONG
THE WEST COAST. THUS POPS HAVE BEEN RAISED INTO THE SLIGHT CHANCE
CATEGORY ON FRIDAY ACROSS SOUTHEAST CALIFORNIA...AS WELL AS PORTIONS
OF SOUTHERN GILA COUNTY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
TYPICAL EARLY EVENING BREEZINESS WILL SUBSIDE OVERNIGHT...ULTIMATELY
GIVING WAY TO DOWNSLOPE EASTERLY FLOW BETWEEN 08Z AND 10Z. LATEST
MODEL GUIDANCE INDICATES INSTABILITY WILL INCREASE SATURDAY
AFTERNOON...RESULTING IN WIDESPREAD BREEZINESS AND A CHANCE OF
CONVECTION. GUSTS WILL GENERALLY REACH 25 KT...EXCEPT HIGHER IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS. STORMS ARE MOST LIKELY IN A
PERIOD FROM AROUND 23Z SATURDAY TO 03Z SUNDAY.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WINDS WILL SUBSIDE LATER ON THIS EVENING AT KIPL/KBLH...BEFORE
INCREASING ONCE AGAIN DURING THE MORNING. MAIN AVIATION WEATHER
CONCERN APPEARS TO BE A CHANCE OF THUNDERSTORMS...GENERALLY FROM KBLH
EASTWARD SATURDAY AFTERNOON. ANY STORMS THAT DEVELOP WILL BE CAPABLE
OF PRODUCING WIND GUSTS TO 40 KT.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...

A DRIER AND WARMER AIRMASS WILL STEADILY MOVE INTO THE REGION WITH
BELOW NORMAL HIGH TEMPS ON MONDAY WARMING TO ABOVE NORMAL ON TUESDAY
AND WELL ABOVE NORMAL ON WEDNESDAY WHEN HIGHS IN THE UPPER 90S...
AND ELEVATED FIRE WEATHER DANGER...IS EXPECTED. MINIMUM HUMIDITIES
IN THE MID TEENS TO LOWER 20S PERCENT RANGE ON MONDAY WILL BECOME
EVEN DRIER BY WEDNESDAY WHEN THEY WILL FALL TO THE SINGLE DIGITS.
EXPECT FAIR TO GOOD OVERNIGHT RECOVERIES ON MONDAY TO BECOME FAIR BY
TUESDAY WITH SOME IMPROVEMENT POSSIBLE ON FRIDAY. BREEZY SOUTH AND
SOUTHWESTERLY WINDS IN THE WESTERN ZONES ARE IN STORE FOR WEDNESDAY
AND IN CENTRAL AND EASTERN ZONES ON THURSDAY AND FRIDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...CB/VASQUEZ
AVIATION...HIRSCH
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 292153
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
253 PM MST FRI APR 29 2016

.UPDATE...UPDATED FIRE WEATHER DISCUSSION.

.SYNOPSIS...
DRY NORTHWEST FLOW ALOFT WILL INCREASE OVER THE REGION THROUGH
SATURDAY. WARMER AFTERNOON TEMPERATURES ARE ALSO FORECAST.
HOWEVER...ANOTHER PACIFIC LOW PRESSURE SYSTEM IS EXPECTED TO MOVE
INTO THE REGION SATURDAY NIGHT AND SUNDAY...DEVELOPING BREEZY
CONDITIONS AND A THREAT FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE OF PRECIPITATION WILL OCCUR OVER THE SOUTH CENTRAL ARIZONA
DESERTS AND MOUNTAINS...MAINLY IN THE VICINITY OF PHOENIX. CLEARING
IS EXPECTED SUNDAY NIGHT...WITH HIGH PRESSURE AND MUCH WARMER
WEATHER NEXT WEEK.

&&

.DISCUSSION...
UPPER LEVEL LOW PRESSURE SYSTEM CONTINUED TO PUSH OFF TOWARDS THE
NORTHEAST THIS AFTERNOON WITH THE LOW CENTER MOVING EAST/NORTHEAST
OF THE FOUR CORNERS AND INTO SERN COLORADO. DRY SUBSIDENT AND
SLIGHTLY CYCLONIC NORTHWEST FLOW ALOFT WAS OVERSPREADING THE
DESERTS...ALLOWING FOR SOME THINNING OF THE THICKER MID CLOUD DECKS
THAT WERE IN PLACE THIS MORNING ACROSS SOUTH CENTRAL ARIZONA. RADAR
AT 2 PM SHOWED JUST A FEW LIGHT SHOWERS OVER HIGHER TERRAIN
NORTHEAST OF PHOENIX...WITH HIGH BASED CUMULUS OVER THE LOWER
CENTRAL DESERTS. TEMPERATURES EARLY THIS AFTERNOON WERE RUNNING 3-8
DEGREES AHEAD OF YESTERDAY AS SOME OF THE WARM AIR ALOFT WAS
TRANSLATING TO THE SURFACE. STILL...HIGHS TODAY WILL STAY BELOW
SEASONAL NORMALS...ONLY RISING INTO THE LOW 80S OVER THE GREATER
PHOENIX AREA.

FAST ON THE HEELS OF THE CURRENTLY EXITING LOW PRESSURE SYSTEM WILL
BE ANOTHER PACIFIC LOW MOVING IN FROM THE NORTHWEST DURING THE DAY
ON SATURDAY. MODEL GUIDANCE...INCLUDING OPERATIONAL RUNS OF THE
NAM/GFS/ECMWF AS WELL AS GEFS ENSEMBLE GUIDANCE...REMAINS CONSISTENT
IN THE TIMING AND TRACK OF THIS NEXT LOW...AND CONFIDENCE IN THE
FORECAST IS HIGH FOR BOTH PRECIP AND AN EXPECTED COOL DOWN. PROGS
MOVE THE UPPER LOW CENTER INTO FAR SRN NV AND FAR WCNTRL ARIZONA BY
SATURDAY AFTERNOON...AND THE BEST QG FORCING APPEARS TO MOVE INTO
SOUTHERN ARIZONA DURING THE DAY SATURDAY BEFORE THE DEEPER MOISTURE
ARRIVES. AS SUCH...WE HAVE POPS STARTING UP SATURDAY AFTERNOON BUT
MAINLY SLIGHT CHANCES OVER SERN CA AS WELL AS NORTHERN PORTIONS OF
LA PAZ AND MARICOPA COUNTIES. CANNOT RULE OUT A THUNDERSTORM
DEVELOPING SATURDAY AFTERNOON AS LIFTED INDICES DROP TO AROUND ZERO.
OVERNIGHT SATURDAY NIGHT AS THE UPPER LOW MOVES ACROSS SOUTH CENTRAL
ARIZONA...MAIN FORCING SHIFTS INTO THE EASTERN PORTION OF THE STATE
AND POPS ACROSS SOUTH CENTRAL AZ RISE INTO THE 20-30 PERCENT BALL
PARK...WITH SLIGHT CHANCES LINGERING FURTHER TO THE WEST. WIND
SHOULD NOT BE AS MUCH OF AN ISSUE WITH THIS SYSTEM AS WITH SOME OF
THE EARLIER ONES...BUT ONCE AGAIN FAVORED AREAS IN IMPERIAL
COUNTY...MAINLY FROM THE IMPERIAL VALLEY SOUTHWESTWARD...COULD REACH
TO NEAR WIND ADVISORY CRITERIA ON SATURDAY AS THE LOW APPROACHES.
FOR NOW WE WILL HIGHLIGHT THIS THREAT VIA SOCIAL MEDIA INSTEAD OF A
WIND ADVISORY.

ON SUNDAY THE MAIN UPPER LOW SHIFTS EAST AND INTO NEW MEXICO...AND
DYNAMICS/Q CONVERGENCE SHIFT EAST WITH THE UPPER LOW...AND JET
DYNAMICS ALSO DECREASE MARKEDLY AS THE UPPER JET AXIS SHIFTS OFF TO
THE SOUTHEAST OF PHOENIX. SO THE QG FORCING DECREASES BUT
THERMODYNAMIC EFFECTS INCREASE AS COOL AIR ALOFT AND LOWER LEVEL
MOISTURE SPREAD INTO THE CENTRAL DESERTS. AS SUCH WE HAVE A 20-30
PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS OVER SOUTH CENTRAL AZ
SUNDAY...WITH A LINGERING 10 PERCENT CHANCE OVER THE WESTERN DESERTS
INTO SERN CA. WE WILL SEE HIGH TEMPS COOL DOWN TO NEAR 80 OR INTO
THE UPPER 70S OVER SOUTH CENTRAL AZ...WITH HIGHS INTO THE MID 80S
OVER THE WARMER WESTERN DESERTS.

SUNDAY NIGHT INTO MONDAY...UPPER LOW IS FORECAST TO CONTINUE TO PUSH
OFF TO THE NORTHEAST AS RIDGING ALOFT BUILDS ALONG THE SRN CA COAST.
DRIER MORE SUBSIDENT WEST/NORTHWEST FLOW ALOFT SPREADS ACROSS THE
AREA FOR MOSTLY SUNNY SKIES ALONG WITH WARMER HIGH TEMPERATURES.
HIGHS WILL CLIMB INTO THE MID 80S TO AROUND 90 MONDAY. EXPECT A DRY
DAY ALTHOUGH THERE MAY BE ENOUGH LINGERING MOISTURE TO ALLOW FOR A
SLIGHT CHANCE OF A SHOWER OR AFTERNOON STORM OVER THE HIGHER TERRAIN
EAST OF GLOBE.

TUESDAY THROUGH FRIDAY...

A HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION THIS PERIOD FOR
MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES. IN OTHER WORDS...
BACK TO NORMAL SPRING-TIME WEATHER...WITH OUCH...DESERT TEMPERATURES
IN THE 90S AGAIN. ITS ALSO CONCEIVABLE THAT PHOENIX CAN REACH ITS
FIRST 100 DEG TEMP OF THE YEAR THURSDAY UNDER SOUTH WINDS/WARM
ADVECTION. ALTHOUGH GUIDANCE DISPLAYS DECREASING MODEL-TO-MODEL
CONSISTENCY...AND ENSEMBLE MEMBER SPREAD IS STILL HIGH...IT LOOKS
MORE LIKELY THAT WE WILL SEE SHOWERS AND MAYBE THUNDERSTORMS SPREAD
INTO THE AREA FRIDAY AS A DEEP UPPER LOW SETS UP JUST INLAND ALONG
THE WEST COAST. THUS POPS HAVE BEEN RAISED INTO THE SLIGHT CHANCE
CATEGORY ON FRIDAY ACROSS SOUTHEAST CALIFORNIA...AS WELL AS PORTIONS
OF SOUTHERN GILA COUNTY.

&&

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

BREEZY WEST TO SOUTHWESTERLY WINDS WITH GUSTS OF 14 TO 22KTS ARE
EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING ALONG WITH PARTLY
CLOUDY SKIES AND OCCASIONAL CIGS OF 8 TO 9K FT. WEST WINDS WILL
BECOME LIGHT THIS EVENING WITH MOSTLY SCATTERED SKIES. EASTERLY
COMPONENT OR LIGHT AND VARIABLE WINDS SHOULD BEGIN IN THE VERY EARLY
MORNING HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

FOR THIS AFTERNOON SKIES WILL BE CLEAR TO PARTLY CLOUDY WITH LIGHT
AND VARIABLE WINDS. DURING THE LATE AFTERNOON AND EARLY EVENING
WESTERLY COMPONENT WINDS OF 10 TO 15 KTS CAN BE EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...

A DRIER AND WARMER AIRMASS WILL STEADILY MOVE INTO THE REGION WITH
BELOW NORMAL HIGH TEMPS ON MONDAY WARMING TO ABOVE NORMAL ON TUESDAY
AND WELL ABOVE NORMAL ON WEDNESDAY WHEN HIGHS IN THE UPPER 90S...
AND ELEVATED FIRE WEATHER DANGER...IS EXPECTED. MINIMUM HUMIDITIES
IN THE MID TEENS TO LOWER 20S PERCENT RANGE ON MONDAY WILL BECOME
EVEN DRIER BY WEDNESDAY WHEN THEY WILL FALL TO THE SINGLE DIGITS.
EXPECT FAIR TO GOOD OVERNIGHT RECOVERIES ON MONDAY TO BECOME FAIR BY
TUESDAY WITH SOME IMPROVEMENT POSSIBLE ON FRIDAY. BREEZY SOUTH AND
SOUTHWESTERLY WINDS IN THE WESTERN ZONES ARE IN STORE FOR WEDNESDAY
AND IN CENTRAL AND EASTERN ZONES ON THURSDAY AND FRIDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





000
FXUS65 KPSR 292150
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 PM MST FRI APR 29 2016

.UPDATE...UPDATED FIRE WEATHER DISCUSSION.

.SYNOPSIS...
DRY NORTHWEST FLOW ALOFT WILL INCREASE OVER THE REGION THROUGH
SATURDAY. WARMER AFTERNOON TEMPERATURES ARE ALSO FORECAST.
HOWEVER...ANOTHER PACIFIC LOW PRESSURE SYSTEM IS EXPECTED TO MOVE
INTO THE REGION SATURDAY NIGHT AND SUNDAY...DEVELOPING BREEZY
CONDITIONS AND A THREAT FOR SHOWERS AND THUNDERSTORMS. THE BEST
CHANCE OF PRECIPITATION WILL OCCUR OVER THE SOUTH CENTRAL ARIZONA
DESERTS AND MOUNTAINS...MAINLY IN THE VICINITY OF PHOENIX. CLEARING
IS EXPECTED SUNDAY NIGHT...WITH HIGH PRESSURE AND MUCH WARMER
WEATHER NEXT WEEK.

&&

.DISCUSSION...
UPPER LEVEL LOW PRESSURE SYSTEM CONTINUED TO PUSH OFF TOWARDS THE
NORTHEAST THIS AFTERNOON WITH THE LOW CENTER MOVING EAST/NORTHEAST
OF THE FOUR CORNERS AND INTO SERN COLORADO. DRY SUBSIDENT AND
SLIGHTLY CYCLONIC NORTHWEST FLOW ALOFT WAS OVERSPREADING THE
DESERTS...ALLOWING FOR SOME THINNING OF THE THICKER MID CLOUD DECKS
THAT WERE IN PLACE THIS MORNING ACROSS SOUTH CENTRAL ARIZONA. RADAR
AT 2 PM SHOWED JUST A FEW LIGHT SHOWERS OVER HIGHER TERRAIN
NORTHEAST OF PHOENIX...WITH HIGH BASED CUMULUS OVER THE LOWER
CENTRAL DESERTS. TEMPERATURES EARLY THIS AFTERNOON WERE RUNNING 3-8
DEGREES AHEAD OF YESTERDAY AS SOME OF THE WARM AIR ALOFT WAS
TRANSLATING TO THE SURFACE. STILL...HIGHS TODAY WILL STAY BELOW
SEASONAL NORMALS...ONLY RISING INTO THE LOW 80S OVER THE GREATER
PHOENIX AREA.

FAST ON THE HEELS OF THE CURRENTLY EXITING LOW PRESSURE SYSTEM WILL
BE ANOTHER PACIFIC LOW MOVING IN FROM THE NORTHWEST DURING THE DAY
ON SATURDAY. MODEL GUIDANCE...INCLUDING OPERATIONAL RUNS OF THE
NAM/GFS/ECMWF AS WELL AS GEFS ENSEMBLE GUIDANCE...REMAINS CONSISTENT
IN THE TIMING AND TRACK OF THIS NEXT LOW...AND CONFIDENCE IN THE
FORECAST IS HIGH FOR BOTH PRECIP AND AN EXPECTED COOL DOWN. PROGS
MOVE THE UPPER LOW CENTER INTO FAR SRN NV AND FAR WCNTRL ARIZONA BY
SATURDAY AFTERNOON...AND THE BEST QG FORCING APPEARS TO MOVE INTO
SOUTHERN ARIZONA DURING THE DAY SATURDAY BEFORE THE DEEPER MOISTURE
ARRIVES. AS SUCH...WE HAVE POPS STARTING UP SATURDAY AFTERNOON BUT
MAINLY SLIGHT CHANCES OVER SERN CA AS WELL AS NORTHERN PORTIONS OF
LA PAZ AND MARICOPA COUNTIES. CANNOT RULE OUT A THUNDERSTORM
DEVELOPING SATURDAY AFTERNOON AS LIFTED INDICES DROP TO AROUND ZERO.
OVERNIGHT SATURDAY NIGHT AS THE UPPER LOW MOVES ACROSS SOUTH CENTRAL
ARIZONA...MAIN FORCING SHIFTS INTO THE EASTERN PORTION OF THE STATE
AND POPS ACROSS SOUTH CENTRAL AZ RISE INTO THE 20-30 PERCENT BALL
PARK...WITH SLIGHT CHANCES LINGERING FURTHER TO THE WEST. WIND
SHOULD NOT BE AS MUCH OF AN ISSUE WITH THIS SYSTEM AS WITH SOME OF
THE EARLIER ONES...BUT ONCE AGAIN FAVORED AREAS IN IMPERIAL
COUNTY...MAINLY FROM THE IMPERIAL VALLEY SOUTHWESTWARD...COULD REACH
TO NEAR WIND ADVISORY CRITERIA ON SATURDAY AS THE LOW APPROACHES.
FOR NOW WE WILL HIGHLIGHT THIS THREAT VIA SOCIAL MEDIA INSTEAD OF A
WIND ADVISORY.

ON SUNDAY THE MAIN UPPER LOW SHIFTS EAST AND INTO NEW MEXICO...AND
DYNAMICS/Q CONVERGENCE SHIFT EAST WITH THE UPPER LOW...AND JET
DYNAMICS ALSO DECREASE MARKEDLY AS THE UPPER JET AXIS SHIFTS OFF TO
THE SOUTHEAST OF PHOENIX. SO THE QG FORCING DECREASES BUT
THERMODYNAMIC EFFECTS INCREASE AS COOL AIR ALOFT AND LOWER LEVEL
MOISTURE SPREAD INTO THE CENTRAL DESERTS. AS SUCH WE HAVE A 20-30
PERCENT CHANCE OF SHOWERS OR THUNDERSTORMS OVER SOUTH CENTRAL AZ
SUNDAY...WITH A LINGERING 10 PERCENT CHANCE OVER THE WESTERN DESERTS
INTO SERN CA. WE WILL SEE HIGH TEMPS COOL DOWN TO NEAR 80 OR INTO
THE UPPER 70S OVER SOUTH CENTRAL AZ...WITH HIGHS INTO THE MID 80S
OVER THE WARMER WESTERN DESERTS.

SUNDAY NIGHT INTO MONDAY...UPPER LOW IS FORECAST TO CONTINUE TO PUSH
OFF TO THE NORTHEAST AS RIDGING ALOFT BUILDS ALONG THE SRN CA COAST.
DRIER MORE SUBSIDENT WEST/NORTHWEST FLOW ALOFT SPREADS ACROSS THE
AREA FOR MOSTLY SUNNY SKIES ALONG WITH WARMER HIGH TEMPERATURES.
HIGHS WILL CLIMB INTO THE MID 80S TO AROUND 90 MONDAY. EXPECT A DRY
DAY ALTHOUGH THERE MAY BE ENOUGH LINGERING MOISTURE TO ALLOW FOR A
SLIGHT CHANCE OF A SHOWER OR AFTERNOON STORM OVER THE HIGHER TERRAIN
EAST OF GLOBE.

TUESDAY THROUGH FRIDAY...

A HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION THIS PERIOD FOR
MOSTLY CLEAR SKIES AND MUCH WARMER TEMPERATURES. IN OTHER WORDS...
BACK TO NORMAL SPRING-TIME WEATHER...WITH OUCH...DESERT TEMPERATURES
IN THE 90S AGAIN. ITS ALSO CONCEIVABLE THAT PHOENIX CAN REACH ITS
FIRST 100 DEG TEMP OF THE YEAR THURSDAY UNDER SOUTH WINDS/WARM
ADVECTION. ALTHOUGH GUIDANCE DISPLAYS DECREASING MODEL-TO-MODEL
CONSISTENCY...AND ENSEMBLE MEMBER SPREAD IS STILL HIGH...IT LOOKS
MORE LIKELY THAT WE WILL SEE SHOWERS AND MAYBE THUNDERSTORMS SPREAD
INTO THE AREA FRIDAY AS A DEEP UPPER LOW SETS UP JUST INLAND ALONG
THE WEST COAST. THUS POPS HAVE BEEN RAISED INTO THE SLIGHT CHANCE
CATEGORY ON FRIDAY ACROSS SOUTHEAST CALIFORNIA...AS WELL AS PORTIONS
OF SOUTHERN GILA COUNTY.

&&

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

BREEZY WEST TO SOUTHWESTERLY WINDS WITH GUSTS OF 14 TO 22KTS ARE
EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING ALONG WITH PARTLY
CLOUDY SKIES AND OCCASIONAL CIGS OF 8 TO 9K FT. WEST WINDS WILL
BECOME LIGHT THIS EVENING WITH MOSTLY SCATTERED SKIES. EASTERLY
COMPONENT OR LIGHT AND VARIABLE WINDS SHOULD BEGIN IN THE VERY EARLY
MORNING HOURS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

FOR THIS AFTERNOON SKIES WILL BE CLEAR TO PARTLY CLOUDY WITH LIGHT
AND VARIABLE WINDS. DURING THE LATE AFTERNOON AND EARLY EVENING
WESTERLY COMPONENT WINDS OF 10 TO 15 KTS CAN BE EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...

A DRIER AND WARMER AIRMASS WILL STEADILY MOVE INTO THE REGION WITH
BELOW NORMAL HIGH TEMPS ON MONDAY WARMING TO ABOVE NORMAL ON TUESDAY
AND WELL ABOVE NORMAL ON WEDNESDAY WHEN HIGHS IN THE UPPER 90S...
AND ELEVATED FIRE WEATHER DANGER...IS EXPECTED. MINIMUM HUMIDITIES
IN THE MID TEENS TO LOWER 20S ON MONDAY WILL BECOME EVEN DRIER BY
WEDNESDAY WHEN THEY WILL FALL TO THE SINGLE DIGITS. EXPECT FAIR TO
GOOD OVERNIGHT RECOVERIES ON MONDAY TO BECOME FAIR BY TUESDAY WITH
SOME IMPROVEMENT POSSIBLE ON FRIDAY. BREEZY SOUTH AND SOUTHWESTERLY
WINDS IN THE WESTERN ZONES ARE IN STORE FOR WEDNESDAY AND IN CENTRAL
AND EASTERN ZONES ON THURSDAY AND FRIDAY.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION IS NOT EXPECTED.

&&

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

$$

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

DISCUSSION...CB/VASQUEZ
AVIATION...SAWTELLE
FIRE WEATHER...SAWTELLE





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