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000
FXUS65 KPSR 260350
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
850 PM MST MON MAY 25 2015

.SYNOPSIS...
DRY WEATHER ALONG WITH A WARMING TREND IS FORECAST FOR
THE REMAINDER OF THIS WEEK AND WEEKEND. AFTERNOON TEMPERATURES ON
THE LOWER DESERTS BY FRIDAY THROUGH SUNDAY WILL GENERALLY WARM TO
BETWEEN 100 AND 105 DEGREES.

&&

.DISCUSSION...
MID EVENING RADAR IMAGERY REVEALS DECAYING SHOWERS ACROSS NORTHERN
ARIZONA...MUCH LIKE THIS TIME YESTERDAY. ASIDE FROM SOME DEBRIS
CLOUDS MOVING THROUGH PORTIONS OF GILA COUNTY...SKIES WERE MOSTLY
CLEAR ACROSS THE REGION AS OF 0345Z THIS EVENING. THIS HAS ALLOWED
TEMPERATURES TO DROP OFF FAIRLY QUICKLY IN THE OUTLYING DESERT AREAS
/UPPER 70S/ BUT READINGS WITHIN THE URBAN CORE OF PHOENIX WERE STILL
IN THE MID 80S.

QUICK LOOK AT THE INCOMING 00Z DETERMINISTIC GUIDANCE SUGGESTS THE
INHERITED FORECAST IS IN GREAT SHAPE. JUST GOING TO TWEAK TEMPS BASED
ON BIAS-CORRECTED GUIDANCE AND OBSERVATIONAL TRENDS. OVERALL NO MAJOR
CHANGES NECESSARY. FORECAST BEYOND TONIGHT ALSO LOOKS IN GOOD SHAPE.

&&

.PREVIOUS DISCUSSION...
TUESDAY THROUGH WEDNESDAY...
A WEAK DISTURBANCE WILL MOVE INTO NEW MEXICO TONIGHT...FOLLOWED BY
SHORTWAVE RIDGING AND VERY STABLE CONDITIONS ON TUESDAY.

ANOTHER WEAK SHORTWAVE TROF WILL MOVE INTO THE REGION WEDNESDAY...
HOWEVER ATMOSPHERIC HEIGHT AND THICKNESS VALUES WILL APPROACH NORMAL
MEANING ANOTHER WARM AFTERNOON OF NEAR NORMAL TEMPERATURES.
WEDNESDAYS AIRMASS WILL BE DRIER...BUT MODELED SOUNDINGS OVER THE
WHITE MOUNTAINS SUPPORT PERHAPS A SLIGHT CHANCE OF LATE AFTERNOON
THUNDERSTORMS JUST OUTSIDE OUR SOUTHERN GILA COUNTY ZONE 24.

THURSDAY THROUGH MONDAY...A HIGH PRESSURE SYSTEM IS FORECAST TO
BUILD INTO THE REGION THIS PERIOD SUPPORTING DRY AND HOT WEATHER.
AFTERNOON TEMPERATURES ON THE LOWER DESERTS FRIDAY THROUGH MONDAY
WILL WARM INTO THE 100 TO 105 DEGREE RANGE.

&&

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

JUST SOME HIGH CLOUDS MOVING IN FROM THE EASTERN PACIFIC THROUGH
TUESDAY EVENING. LIGHT/DIURNALLY DRIVEN WINDS EXPECTED AT ALL SITES.
WEATHER IMPACTS SHOULD BE MINIMAL THROUGH TUESDAY EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
HIGH PRESSURE THAT WILL BE GRADUALLY BUILDING OVER THE REGION WILL
KEEP DRY CONDITIONS IN PLACE THROUGH THE FORECAST PERIOD...WITH
TEMPERATURES GRADUALLY WARMING INTO SATURDAY...BEFORE LEVELING OFF
FROM SUNDAY INTO EARLY NEXT WEEK. LOWER DESERT HIGHS WILL LIKELY
REACH 100 DEGREES AT MOST LOCATIONS BY FRIDAY...THEN RISE INTO THE
101-105 DEGREE RANGE FROM SATURDAY ONWARD INTO NEXT MONDAY. MINIMUM
RH VALUES ARE EXPECTED TO RANGE FROM AROUND 8 PERCENT TO THE MID
TEENS EACH DAY. DESPITE THESE LOW RH VALUES...THE COMBINATION OF
LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL CONTINUE TO KEEP
FIRE DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST
PERIOD.

&&

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

$$

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

DISCUSSION...LEINS/VASQUEZ
AVIATION...LEINS
FIRE WEATHER...PERCHA





000
FXUS65 KPSR 260350
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
850 PM MST MON MAY 25 2015

.SYNOPSIS...
DRY WEATHER ALONG WITH A WARMING TREND IS FORECAST FOR
THE REMAINDER OF THIS WEEK AND WEEKEND. AFTERNOON TEMPERATURES ON
THE LOWER DESERTS BY FRIDAY THROUGH SUNDAY WILL GENERALLY WARM TO
BETWEEN 100 AND 105 DEGREES.

&&

.DISCUSSION...
MID EVENING RADAR IMAGERY REVEALS DECAYING SHOWERS ACROSS NORTHERN
ARIZONA...MUCH LIKE THIS TIME YESTERDAY. ASIDE FROM SOME DEBRIS
CLOUDS MOVING THROUGH PORTIONS OF GILA COUNTY...SKIES WERE MOSTLY
CLEAR ACROSS THE REGION AS OF 0345Z THIS EVENING. THIS HAS ALLOWED
TEMPERATURES TO DROP OFF FAIRLY QUICKLY IN THE OUTLYING DESERT AREAS
/UPPER 70S/ BUT READINGS WITHIN THE URBAN CORE OF PHOENIX WERE STILL
IN THE MID 80S.

QUICK LOOK AT THE INCOMING 00Z DETERMINISTIC GUIDANCE SUGGESTS THE
INHERITED FORECAST IS IN GREAT SHAPE. JUST GOING TO TWEAK TEMPS BASED
ON BIAS-CORRECTED GUIDANCE AND OBSERVATIONAL TRENDS. OVERALL NO MAJOR
CHANGES NECESSARY. FORECAST BEYOND TONIGHT ALSO LOOKS IN GOOD SHAPE.

&&

.PREVIOUS DISCUSSION...
TUESDAY THROUGH WEDNESDAY...
A WEAK DISTURBANCE WILL MOVE INTO NEW MEXICO TONIGHT...FOLLOWED BY
SHORTWAVE RIDGING AND VERY STABLE CONDITIONS ON TUESDAY.

ANOTHER WEAK SHORTWAVE TROF WILL MOVE INTO THE REGION WEDNESDAY...
HOWEVER ATMOSPHERIC HEIGHT AND THICKNESS VALUES WILL APPROACH NORMAL
MEANING ANOTHER WARM AFTERNOON OF NEAR NORMAL TEMPERATURES.
WEDNESDAYS AIRMASS WILL BE DRIER...BUT MODELED SOUNDINGS OVER THE
WHITE MOUNTAINS SUPPORT PERHAPS A SLIGHT CHANCE OF LATE AFTERNOON
THUNDERSTORMS JUST OUTSIDE OUR SOUTHERN GILA COUNTY ZONE 24.

THURSDAY THROUGH MONDAY...A HIGH PRESSURE SYSTEM IS FORECAST TO
BUILD INTO THE REGION THIS PERIOD SUPPORTING DRY AND HOT WEATHER.
AFTERNOON TEMPERATURES ON THE LOWER DESERTS FRIDAY THROUGH MONDAY
WILL WARM INTO THE 100 TO 105 DEGREE RANGE.

&&

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

JUST SOME HIGH CLOUDS MOVING IN FROM THE EASTERN PACIFIC THROUGH
TUESDAY EVENING. LIGHT/DIURNALLY DRIVEN WINDS EXPECTED AT ALL SITES.
WEATHER IMPACTS SHOULD BE MINIMAL THROUGH TUESDAY EVENING.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
HIGH PRESSURE THAT WILL BE GRADUALLY BUILDING OVER THE REGION WILL
KEEP DRY CONDITIONS IN PLACE THROUGH THE FORECAST PERIOD...WITH
TEMPERATURES GRADUALLY WARMING INTO SATURDAY...BEFORE LEVELING OFF
FROM SUNDAY INTO EARLY NEXT WEEK. LOWER DESERT HIGHS WILL LIKELY
REACH 100 DEGREES AT MOST LOCATIONS BY FRIDAY...THEN RISE INTO THE
101-105 DEGREE RANGE FROM SATURDAY ONWARD INTO NEXT MONDAY. MINIMUM
RH VALUES ARE EXPECTED TO RANGE FROM AROUND 8 PERCENT TO THE MID
TEENS EACH DAY. DESPITE THESE LOW RH VALUES...THE COMBINATION OF
LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL CONTINUE TO KEEP
FIRE DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST
PERIOD.

&&

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

$$

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

DISCUSSION...LEINS/VASQUEZ
AVIATION...LEINS
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 252156
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 PM MST MON MAY 25 2015

.SYNOPSIS...DRY WEATHER ALONG WITH A WARMING TREND IS FORECAST FOR
THE REMAINDER OF THIS WEEK AND WEEKEND. AFTERNOON TEMPERATURES ON
THE LOWER DESERTS BY FRIDAY THROUGH SUNDAY WILL GENERALLY WARM TO
BETWEEN 100 AND 105 DEGREES.

&&

.DISCUSSION...

TONIGHT THROUGH WEDNESDAY...ISOLATED SHWRS AND TSTMS WILL CONTINUE
THIS EVENING OVER PORTIONS OF NORTHEAST AZ JUST OUTSIDE OUR
MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY. THE WEAK DISTURBANCE WILL
MOVE INTO NEW MEXICO TONIGHT...FOLLOWED BY SHORTWAVE RIDGING AND
VERY STABLE CONDITIONS ON TUESDAY.

ANOTHER WEAK SHORTWAVE TROF WILL MOVE INTO THE REGION WEDNESDAY...
HOWEVER ATMOSPHERIC HEIGHT AND THICKNESS VALUES WILL APPROACH NORMAL
MEANING ANOTHER WARM AFTERNOON OF NEAR NORMAL TEMPERATURES.
WEDNESDAYS AIRMASS WILL BE DRIER...BUT MODELED SOUNDINGS OVER THE
WHITE MOUNTAINS SUPPORT PERHAPS A SLIGHT CHANCE OF LATE AFTERNOON
THUNDERSTORMS JUST OUTSIDE OUR SOUTHERN GILA COUNTY ZONE 24.

THURSDAY THROUGH MONDAY...A HIGH PRESSURE SYSTEM IS FORECAST TO
BUILD INTO THE REGION THIS PERIOD SUPPORTING DRY AND HOT WEATHER.
AFTERNOON TEMPERATURES ON THE LOWER DESERTS FRIDAY THROUGH MONDAY
WILL WARM INTO THE 100 TO 105 DEGREE RANGE.

&&

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

OTHER THEN A FEW HIGH CLOUDS FROM TIME-TO-TIME...MAINLY CLEAR SKIES
TO PREVAIL THROUGH THE TAF PERIOD. WEAK SFC PRESSURE GRADIENTS WITH
KEEP WINDS ON THE LIGHT SIDE...MAINLY AOB 8KTS...MOSTLY FOLLOWING
TYPICAL DIURNAL TRENDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER... THURSDAY THROUGH MONDAY... HIGH PRESSURE THAT WILL
BE GRADUALLY BUILDING OVER THE REGION WILL KEEP DRY CONDITIONS IN
PLACE THROUGH THE FORECAST PERIOD...WITH TEMPERATURES GRADUALLY
WARMING INTO SATURDAY...BEFORE LEVELING OFF FROM SUNDAY INTO EARLY
NEXT WEEK. LOWER DESERT HIGHS WILL LIKELY REACH 100 DEGREES AT MOST
LOCATIONS BY FRIDAY...THEN RISE INTO THE 101-105 DEGREE RANGE FROM
SATURDAY ONWARD INTO NEXT MONDAY. MINIMUM RH VALUES ARE EXPECTED TO
RANGE FROM AROUND 8 PERCENT TO THE MID TEENS EACH DAY. DESPITE THESE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL CONTINUE TO KEEP FIRE DANGER LEVELS AT
RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...PERCHA
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 252156
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 PM MST MON MAY 25 2015

.SYNOPSIS...DRY WEATHER ALONG WITH A WARMING TREND IS FORECAST FOR
THE REMAINDER OF THIS WEEK AND WEEKEND. AFTERNOON TEMPERATURES ON
THE LOWER DESERTS BY FRIDAY THROUGH SUNDAY WILL GENERALLY WARM TO
BETWEEN 100 AND 105 DEGREES.

&&

.DISCUSSION...

TONIGHT THROUGH WEDNESDAY...ISOLATED SHWRS AND TSTMS WILL CONTINUE
THIS EVENING OVER PORTIONS OF NORTHEAST AZ JUST OUTSIDE OUR
MOUNTAINOUS ZONE 24 SOUTHERN GILA COUNTY. THE WEAK DISTURBANCE WILL
MOVE INTO NEW MEXICO TONIGHT...FOLLOWED BY SHORTWAVE RIDGING AND
VERY STABLE CONDITIONS ON TUESDAY.

ANOTHER WEAK SHORTWAVE TROF WILL MOVE INTO THE REGION WEDNESDAY...
HOWEVER ATMOSPHERIC HEIGHT AND THICKNESS VALUES WILL APPROACH NORMAL
MEANING ANOTHER WARM AFTERNOON OF NEAR NORMAL TEMPERATURES.
WEDNESDAYS AIRMASS WILL BE DRIER...BUT MODELED SOUNDINGS OVER THE
WHITE MOUNTAINS SUPPORT PERHAPS A SLIGHT CHANCE OF LATE AFTERNOON
THUNDERSTORMS JUST OUTSIDE OUR SOUTHERN GILA COUNTY ZONE 24.

THURSDAY THROUGH MONDAY...A HIGH PRESSURE SYSTEM IS FORECAST TO
BUILD INTO THE REGION THIS PERIOD SUPPORTING DRY AND HOT WEATHER.
AFTERNOON TEMPERATURES ON THE LOWER DESERTS FRIDAY THROUGH MONDAY
WILL WARM INTO THE 100 TO 105 DEGREE RANGE.

&&

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

OTHER THEN A FEW HIGH CLOUDS FROM TIME-TO-TIME...MAINLY CLEAR SKIES
TO PREVAIL THROUGH THE TAF PERIOD. WEAK SFC PRESSURE GRADIENTS WITH
KEEP WINDS ON THE LIGHT SIDE...MAINLY AOB 8KTS...MOSTLY FOLLOWING
TYPICAL DIURNAL TRENDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER... THURSDAY THROUGH MONDAY... HIGH PRESSURE THAT WILL
BE GRADUALLY BUILDING OVER THE REGION WILL KEEP DRY CONDITIONS IN
PLACE THROUGH THE FORECAST PERIOD...WITH TEMPERATURES GRADUALLY
WARMING INTO SATURDAY...BEFORE LEVELING OFF FROM SUNDAY INTO EARLY
NEXT WEEK. LOWER DESERT HIGHS WILL LIKELY REACH 100 DEGREES AT MOST
LOCATIONS BY FRIDAY...THEN RISE INTO THE 101-105 DEGREE RANGE FROM
SATURDAY ONWARD INTO NEXT MONDAY. MINIMUM RH VALUES ARE EXPECTED TO
RANGE FROM AROUND 8 PERCENT TO THE MID TEENS EACH DAY. DESPITE THESE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL CONTINUE TO KEEP FIRE DANGER LEVELS AT
RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...VASQUEZ
AVIATION...PERCHA
FIRE WEATHER...PERCHA





000
FXUS65 KPSR 251508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
810 AM MST MON MAY 25 2015

.SYNOPSIS... ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN
ARIZONA INTO EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED
SHOWERS AND A FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS
AFTERNOON. A GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS
WEEK WITH TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND
THEN EVEN EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...CLEAR SKIES WERE NOTED ACROSS OUR FORECAST AREA...
SOUTHEAST CA TO SOUTH CENTRAL AZ THIS MORNING. HOWEVER BKN TO OVC
MID LEVEL CLOUDS ASSOCIATED WITH A WEAK DISTURBANCE WAS ALSO NOTED
ACROSS THE NORTHERN HALF OF AZ THIS MORNING. THIS DISTURBANCE IS
FORECAST TO MOVE EAST ACROSS A LARGE PART OF NORTHEAST AZ TODAY...
JUST OUTSIDE OUR PORTIONS IN SOUTHERN GILA COUNTY ZONE 24...AND
GENERATE A FEW SHOWERS AND THUNDERSTORMS.

VERY STABLE AND DRIER AIR IS FORECAST TO FOLLOW THIS SHORTWAVE LATER
THIS EVENING THROUGH TUESDAY. THEREFORE CURRENT DRY AND WARMER
FORECAST ACROSS OUR FORECAST AREA THROUGH TUESDAY LOOK OK. NO
UPDATES PLANNED.


.PREVIOUS DISCUSSION...450 AM MST...

ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...VASQUEZ/KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB




000
FXUS65 KPSR 251508
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
810 AM MST MON MAY 25 2015

.SYNOPSIS... ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN
ARIZONA INTO EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED
SHOWERS AND A FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS
AFTERNOON. A GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS
WEEK WITH TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND
THEN EVEN EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...CLEAR SKIES WERE NOTED ACROSS OUR FORECAST AREA...
SOUTHEAST CA TO SOUTH CENTRAL AZ THIS MORNING. HOWEVER BKN TO OVC
MID LEVEL CLOUDS ASSOCIATED WITH A WEAK DISTURBANCE WAS ALSO NOTED
ACROSS THE NORTHERN HALF OF AZ THIS MORNING. THIS DISTURBANCE IS
FORECAST TO MOVE EAST ACROSS A LARGE PART OF NORTHEAST AZ TODAY...
JUST OUTSIDE OUR PORTIONS IN SOUTHERN GILA COUNTY ZONE 24...AND
GENERATE A FEW SHOWERS AND THUNDERSTORMS.

VERY STABLE AND DRIER AIR IS FORECAST TO FOLLOW THIS SHORTWAVE LATER
THIS EVENING THROUGH TUESDAY. THEREFORE CURRENT DRY AND WARMER
FORECAST ACROSS OUR FORECAST AREA THROUGH TUESDAY LOOK OK. NO
UPDATES PLANNED.


.PREVIOUS DISCUSSION...450 AM MST...

ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...VASQUEZ/KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB





000
FXUS65 KPSR 251151
AFDPSR
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB






000
FXUS65 KPSR 251151 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB




000
FXUS65 KPSR 251151 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB





000
FXUS65 KPSR 251151 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB




000
FXUS65 KPSR 251151 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB





000
FXUS65 KPSR 251151
AFDPSR
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
450 AM MST MON MAY 25 2015

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

&&

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH TUESDAY MORNING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES NEXT 24 HOURS AND VFR
CONDITIONS ARE EXPECTED AT ALL TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. HUMIDITIES ARE EXPECTED TO GRADUALLY FALL OFF DAY
BY DAY PARTIALLY A RESULT OF THE INCREASING TEMPERATURES. RH VALUES
WEDNESDAY RANGE FROM AROUND 10 PERCENT TO THE UPPER TEENS AND BY THE
WEEKEND MOST DESERT LOCALES DROP INTO THE SINGLE DIGITS. DESPITE THE
LOW RH VALUES...THE COMBINATION OF LIGHT WINDS AND FAIR-GOOD
OVERNIGHT RECOVERIES WILL KEEP FIRE DANGER LEVELS AT RELATIVELY LOW
LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...KUHLMAN
AVIATION...CB
FIRE WEATHER...PERCHA/CB






000
FXUS65 KPSR 250949
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
249 AM MST MON MAY 25 2015

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH MONDAY EVENING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

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





000
FXUS65 KPSR 250949
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
249 AM MST MON MAY 25 2015

.SYNOPSIS...
ONE LAST WEAK WEATHER SYSTEM WILL MOVE ACROSS NORTHERN ARIZONA INTO
EAST-CENTRAL ARIZONA TODAY ALLOWING FOR SOME ISOLATED SHOWERS AND A
FEW THUNDERSTORMS ACROSS HIGHER TERRAIN AREAS THIS AFTERNOON. A
GRADUAL WARMING AND DRYING TREND WILL TAKE PLACE THIS WEEK WITH
TEMPERATURES RETURNING TO SEASONAL NORMALS BY THURSDAY AND THEN EVEN
EXCEEDING THE 100 DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
ONE COMPACT SHORTWAVE TROUGH EXITED THE STATE LAST EVENING WHILE
ANOTHER QUICKLY APPROACHES FROM NORTHWEST. THIS NEXT SHORTWAVE IS
DEFINITELY WEAKER...BUT STILL HAS ENOUGH FORCING ASSOCIATED WITH IT
TO GENERATE SOME ONGOING SHOWERS WEST OF FLAGSTAFF. THE FORECAST
TRACK WILL BRING THIS FEATURE THROUGH EAST-CENTRAL ARIZONA THIS
AFTERNOON WHICH SHOULD ALLOW FOR MORE SHOWER AND THUNDERSTORM
DEVELOPMENT OVER HIGHER TERRAIN AREAS NORTH AND EAST OF PHOENIX AS
SOME LINGERING MOISTURE STILL REMAINS IN PLACE. NOT REALLY EXPECTING
MUCH IF ANY SHOWER ACTIVITY OVER OUR AREA...BUT WE MAY BE ABLE TO
MANAGE TO GET SOME IN FAR EASTERN GILA COUNTY. TEMPERATURES TODAY
WILL CONTINUE THEIR UPWARD CLIMB...BUT JUST GRADUALLY AS HIGHS
SHOULD REACH INTO THE LOWER 90S OVER THE DESERTS.

THE REST OF THE WEEK WILL BE CHARACTERIZED BY DRIER
CONDITIONS...INCREASING HEIGHTS ALOFT AND CONSIDERABLE WARMING WHICH
WILL FINALLY BRING OUR TEMPERATURES BACK TO SEASONAL NORMALS BY LATE
IN THE WEEK. WHILE THERE WILL BE FAIRLY WEAK PERSISTENT WESTERLY
FLOW ALOFT...MODELS DO SHOW A WEAK SHORTWAVE TROUGH PASSING THROUGH
ON WEDNESDAY BRINGING SOME MID AND HIGH CLOUDS. REGIONAL 500MB
HEIGHTS WILL RISE FROM AROUND 574DM TODAY TO 580DM FOR TUESDAY
THROUGH THURSDAY AND THEN RISE AGAIN FOR LATE IN THE WEEK INTO THE
WEEKEND...REACHING HEIGHTS NEAR 585DM. THE 585DM 500MB HEIGHTS MOVE
IN FRIDAY NIGHT AS A FAIRLY STRONG PACIFIC RIDGE SHIFTS
NORTHEASTWARD INTO THE DESERT SOUTHWEST AND GREAT BASIN. THIS
PATTERN WILL RESULT IN HIGH TEMPERATURES RISING EACH DAY WITH MID 90S
COMMONPLACE FOR TUESDAY AND WEDNESDAY AND UPPER 90S FOR THE LATTER
PART OF THE WEEK. ONCE THE RIDGE MOVES OVERHEAD FOR THE COMING
WEEKEND...HIGHS WILL EASILY BREAK THE 100 DEGREE MARK OVER THE
DESERTS. THIS WILL BE THE WARMEST AIR SO FAR THIS YEAR...BUT WILL
STILL BE ROUGHLY 10 DEGREES SHY OF ANY RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH MONDAY EVENING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

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




000
FXUS65 KPSR 250319
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
819 PM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF WEAK WEATHER SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ANY ORGANIZED SHOWER ACTIVITY AND MEASURABLE PRECIPITATION
WILL REMAIN NORTH AND EAST OF PHOENIX ON MEMORIAL DAY. A GRADUAL
WARMING AND DRYING TREND WILL BEGIN IN THE EARLY WEEK...WITH
TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN EXCEEDING THE 100
DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
QUIET CONDITIONS PREVAIL ACROSS THE AREA THIS EVENING. THE WEAK
SHORTWAVE TROUGH THAT MOVED THROUGH THE REGION THIS AFTERNOON HAS
SHIFTED EAST...MEANWHILE THE CONVECTION THAT DEVELOPED ALONG THE RIM
HAS STARTED TO DISSIPATE WITH THE LOSS OF DAYTIME HEATING. WHILE SOME
CLOUDS ARE NOTED ON SATELLITE MAINLY ACROSS NEVADA AND NORTHWEST
ARIZONA...SKIES REMAIN MOSTLY CLEAR ACROSS THE LOWER DESERTS AS OF
03Z.

SUBSIDENCE BEHIND THE DEPARTING SHORTWAVE TROUGH SHOULD RESULT IN
MOSTLY CLEAR SKIES AND LIGHT WINDS FOR THE REST OF THE EVENING AND
OVERNIGHT HOURS. INHERITED FORECAST LOOKS VERY REPRESENTATIVE AND I
AM ONLY MAKING MINOR ADJUSTMENTS TO TEMPS AND SKY COVER BASED ON
OBSERVATIONAL TRENDS AND INCOMING SHORT-RANGE 00Z MODEL DATA.
MEANWHILE...THE FORECAST FOR MEMORIAL DAY STILL LOOKS ON TRACK WITH
HIGHS IN THE LOWER 90S.

&&

.PREVIOUS DISCUSSION...
ADDITIONAL UPSTREAM SHORTWAVES/DISTURBANCES WILL BRUSH PAST OR
THROUGH THE REGION FOR THE COMING WEEK...BUT DO LITTLE BY WAY OF
USHERING IN ANY COOLER AIRMASS TEMPERATURES OR REDUCTION IN ML AND UL
THICKNESSES. THE MEAN FLOW WILL BECOME MORE ZONAL AND ULTIMATELY
SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT ANOMALY OVER THE
WEST MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION WILL
RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER AND
DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH WILL
MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM WILL DO
LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED HEAVILY
TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH MONDAY EVENING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...LEINS/NOLTE/HIRSCH
AVIATION...LEINS
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 250319
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
819 PM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF WEAK WEATHER SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ANY ORGANIZED SHOWER ACTIVITY AND MEASURABLE PRECIPITATION
WILL REMAIN NORTH AND EAST OF PHOENIX ON MEMORIAL DAY. A GRADUAL
WARMING AND DRYING TREND WILL BEGIN IN THE EARLY WEEK...WITH
TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN EXCEEDING THE 100
DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...
QUIET CONDITIONS PREVAIL ACROSS THE AREA THIS EVENING. THE WEAK
SHORTWAVE TROUGH THAT MOVED THROUGH THE REGION THIS AFTERNOON HAS
SHIFTED EAST...MEANWHILE THE CONVECTION THAT DEVELOPED ALONG THE RIM
HAS STARTED TO DISSIPATE WITH THE LOSS OF DAYTIME HEATING. WHILE SOME
CLOUDS ARE NOTED ON SATELLITE MAINLY ACROSS NEVADA AND NORTHWEST
ARIZONA...SKIES REMAIN MOSTLY CLEAR ACROSS THE LOWER DESERTS AS OF
03Z.

SUBSIDENCE BEHIND THE DEPARTING SHORTWAVE TROUGH SHOULD RESULT IN
MOSTLY CLEAR SKIES AND LIGHT WINDS FOR THE REST OF THE EVENING AND
OVERNIGHT HOURS. INHERITED FORECAST LOOKS VERY REPRESENTATIVE AND I
AM ONLY MAKING MINOR ADJUSTMENTS TO TEMPS AND SKY COVER BASED ON
OBSERVATIONAL TRENDS AND INCOMING SHORT-RANGE 00Z MODEL DATA.
MEANWHILE...THE FORECAST FOR MEMORIAL DAY STILL LOOKS ON TRACK WITH
HIGHS IN THE LOWER 90S.

&&

.PREVIOUS DISCUSSION...
ADDITIONAL UPSTREAM SHORTWAVES/DISTURBANCES WILL BRUSH PAST OR
THROUGH THE REGION FOR THE COMING WEEK...BUT DO LITTLE BY WAY OF
USHERING IN ANY COOLER AIRMASS TEMPERATURES OR REDUCTION IN ML AND UL
THICKNESSES. THE MEAN FLOW WILL BECOME MORE ZONAL AND ULTIMATELY
SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT ANOMALY OVER THE
WEST MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION WILL
RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER AND
DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH WILL
MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM WILL DO
LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED HEAVILY
TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

ASIDE FROM SOME FEW/SCT HIGH CLOUDS...WEATHER IMPACTS SHOULD BE
MINIMAL ACROSS THE REGION THROUGH MONDAY EVENING. LIGHT DIURNALLY
DRIVEN WINDS ARE EXPECTED AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...LEINS/NOLTE/HIRSCH
AVIATION...LEINS
FIRE WEATHER...PERCHA





000
FXUS65 KPSR 242039
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
138 PM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF WEAK WEATHER SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ANY ORGANIZED SHOWER ACTIVITY AND MEASURABLE PRECIPITATION
WILL REMAIN NORTH AND EAST OF PHOENIX TODAY AND MEMORIAL DAY. A
GRADUAL WARMING AND DRYING TREND WILL BEGIN IN THE EARLY WEEK...WITH
TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN EXCEEDING THE 100
DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...

LATEST UPPER VORT MAX/COMPACT SHORTWAVE OFF THE LARGER PARENT LOW
OVER NORTHWEST CO AND SOUTHERN WY CONTINUES TO CARVE ITS WAY ACROSS
OUR FORECAST AREA THIS AFTERNOON. MAIN CIRC CENTER WAS MOVING ALONG
THE INTL BORDER HEADING INTO SOUTHEAST AZ THIS AFTERNOON AND
GENERATING A WELL-DEFINED MID AND HIGH LEVEL CLOUD SHIELD OVER SOUTH-
CENTRAL AZ. LATEST SATELLITE IMAGERY ALREADY SHOWS THE THICKER
CLOUDS HEADING EAST INTO SOUTHERN GILA COUNTY AND PATCHES OF BLUE
SKY ARE NOW VISIBLE ON PHOENIX-AREA WEBCAMS. DRIER AND SLIGHTLY
SUBSIDENT FLOW ON THE BACKSIDE OF THE VORT MAX HAS KEPT SKIES MOSTLY
CLEAR OVER THE LOWER CO RIVER VALLEY AND SOUTHEAST CA...SAVE FOR A
LIMITED FEW TERRAIN DRIVEN CU. AREA TEMPERATURES ARE RUNNING A FEW
DEGREES WARMER THAN THIS TIME YESTERDAY EVEN IN SPOTS UNDERNEATH THE
THICK...BUT PASSING...CLOUD COVER. SUBTLE ANTICYCLONIC AND STABLE
FLOW WILL FOLLOW THE VORT MAX AS IT CLEARS INTO SOUTHEAST AZ
TONIGHT...LEAVING SKIES MOSTLY CLEAR AND OVERNIGHT TEMPS ON THE
MILD SIDE.

ADDITIONAL UPSTREAM SHORTWAVES/DISTURBANCES WILL BRUSH PAST OR
THROUGH THE REGION FOR THE COMING WEEK...BUT DO LITTLE BY WAY OF
USHERING IN ANY COOLER AIRMASS TEMPERATURES OR REDUCTION IN ML AND
UL THICKNESSES. THE MEAN FLOW WILL BECOME MORE ZONAL AND ULTIMATELY
SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT ANOMALY OVER THE
WEST MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION WILL
RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER AND
DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH WILL
MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM WILL
DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED HEAVILY
TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS
RISING THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED
THE 100 DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN
WELL BELOW RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED THROUGH MONDAY. SCT-BKN MID-HIGH LEVEL
CLOUD LAYERS ASSOCIATED WITH WEAK WEATHER DISTURBANCE PASSING OVER
PHX AREA TERMINALS TO GIVE WAY TO MAINLY CLEAR SKIES FROM LATER THIS
EVENING INTO MONDAY AS DRIER AIR FILTERS IN FROM THE WEST. MAINLY
CLEAR SKIES TO PREVAIL AT BOTH KIPL AND KBLH THROUGH THE TAF PERIOD.
WEAK PRESSURE GRADIENTS TO KEEP WINDS MAINLY AOB 10KTS THROUGH THE
PERIOD...MAINLY FOLLOWING TYPICAL DIURNAL PATTERNS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...NOLTE/HIRSCH
AVIATION...PERCHA
FIRE WEATHER...PERCHA





000
FXUS65 KPSR 242039
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
138 PM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF WEAK WEATHER SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ANY ORGANIZED SHOWER ACTIVITY AND MEASURABLE PRECIPITATION
WILL REMAIN NORTH AND EAST OF PHOENIX TODAY AND MEMORIAL DAY. A
GRADUAL WARMING AND DRYING TREND WILL BEGIN IN THE EARLY WEEK...WITH
TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN EXCEEDING THE 100
DEGREE MARK BY THE COMING WEEKEND.

&&

.DISCUSSION...

LATEST UPPER VORT MAX/COMPACT SHORTWAVE OFF THE LARGER PARENT LOW
OVER NORTHWEST CO AND SOUTHERN WY CONTINUES TO CARVE ITS WAY ACROSS
OUR FORECAST AREA THIS AFTERNOON. MAIN CIRC CENTER WAS MOVING ALONG
THE INTL BORDER HEADING INTO SOUTHEAST AZ THIS AFTERNOON AND
GENERATING A WELL-DEFINED MID AND HIGH LEVEL CLOUD SHIELD OVER SOUTH-
CENTRAL AZ. LATEST SATELLITE IMAGERY ALREADY SHOWS THE THICKER
CLOUDS HEADING EAST INTO SOUTHERN GILA COUNTY AND PATCHES OF BLUE
SKY ARE NOW VISIBLE ON PHOENIX-AREA WEBCAMS. DRIER AND SLIGHTLY
SUBSIDENT FLOW ON THE BACKSIDE OF THE VORT MAX HAS KEPT SKIES MOSTLY
CLEAR OVER THE LOWER CO RIVER VALLEY AND SOUTHEAST CA...SAVE FOR A
LIMITED FEW TERRAIN DRIVEN CU. AREA TEMPERATURES ARE RUNNING A FEW
DEGREES WARMER THAN THIS TIME YESTERDAY EVEN IN SPOTS UNDERNEATH THE
THICK...BUT PASSING...CLOUD COVER. SUBTLE ANTICYCLONIC AND STABLE
FLOW WILL FOLLOW THE VORT MAX AS IT CLEARS INTO SOUTHEAST AZ
TONIGHT...LEAVING SKIES MOSTLY CLEAR AND OVERNIGHT TEMPS ON THE
MILD SIDE.

ADDITIONAL UPSTREAM SHORTWAVES/DISTURBANCES WILL BRUSH PAST OR
THROUGH THE REGION FOR THE COMING WEEK...BUT DO LITTLE BY WAY OF
USHERING IN ANY COOLER AIRMASS TEMPERATURES OR REDUCTION IN ML AND
UL THICKNESSES. THE MEAN FLOW WILL BECOME MORE ZONAL AND ULTIMATELY
SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT ANOMALY OVER THE
WEST MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION WILL
RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER AND
DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH WILL
MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM WILL
DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED HEAVILY
TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS
RISING THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED
THE 100 DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN
WELL BELOW RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED THROUGH MONDAY. SCT-BKN MID-HIGH LEVEL
CLOUD LAYERS ASSOCIATED WITH WEAK WEATHER DISTURBANCE PASSING OVER
PHX AREA TERMINALS TO GIVE WAY TO MAINLY CLEAR SKIES FROM LATER THIS
EVENING INTO MONDAY AS DRIER AIR FILTERS IN FROM THE WEST. MAINLY
CLEAR SKIES TO PREVAIL AT BOTH KIPL AND KBLH THROUGH THE TAF PERIOD.
WEAK PRESSURE GRADIENTS TO KEEP WINDS MAINLY AOB 10KTS THROUGH THE
PERIOD...MAINLY FOLLOWING TYPICAL DIURNAL PATTERNS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AND WARMER CONDITIONS TO MAKE THEIR WAY INTO THE REGION
THROUGH THE PERIOD AS HIGH PRESSURE GRADUALLY STRENGTHENS OVER THE
DESERT SOUTHWEST...WITH HIGH TEMPERATURES RISING TO NEAR...OR JUST
ABOVE 100 DEGREES AT MANY LOWER DESERT LOCATIONS FROM FRIDAY ONWARD
INTO NEXT WEEKEND. ALTHOUGH HUMIDITIES ARE EXPECTED TO FALL INTO THE
HIGH SINGLE-DIGIT TO MID-TEEN RANGE EACH AFTERNOON...THE COMBINATION
OF LIGHT WINDS AND FAIR-GOOD OVERNIGHT RECOVERIES WILL KEEP FIRE
DANGER LEVELS AT RELATIVELY LOW LEVELS THROUGH THE FORECAST PERIOD.

&&

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

$$

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

DISCUSSION...NOLTE/HIRSCH
AVIATION...PERCHA
FIRE WEATHER...PERCHA




000
FXUS65 KPSR 241540
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
840 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA
WILL KEEP TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE
MEMORIAL DAY WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS
POSSIBLE OVER PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA
TODAY...THOUGH MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH
AND EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED
EARLY THIS WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND
EVEN EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
THE LATEST SHORTWAVE/COMPACT VORT MAX HAS REACHED THE CO RIVER
VALLEY THIS AM...INCREASING MID AND HIGH LEVEL CLOUD COVERAGE ACROSS
MUCH OF LA PAZ AND PORTIONS OF YUMA COUNTIES. CU AND CIRRUS FIELDS
THICK ENOUGH TO AT LEAST BE SAMPLED BY THE KYUX RADAR...WITH VERY
LIGHT REFLECTIVITIES ON THE ORDER OF 25DBZ OR LESS. SHORTWAVE AXIS
WILL CROSS INTO AZ AND CUT ACROSS SOUTH-CENTRAL AZ HEADING INTO
SOUTHEAST AZ BY THE AFTERNOON. FAIRLY LIMITED MOISTURE PROFILE
REMAINS WITH THIS FEATURE...DESPITE SFC DEWPOINTS PARTICULARLY
ACROSS THE CO RIVER SEEING READINGS IN THE 50S THIS AM. BLENDED TPW
IMAGERY INDICATE THE DEEPEST MOISTURE ALONG THE NORTH SIDE OF
CIRCULATION WITH A PRONOUNCED AREA OF DRYING/SUBSIDENCE ON THE S/SW
FLANK OF THE SYSTEM. WHILE NOT ONE LIKELY TO PRODUCE WETTING RAIN OR
EVEN MEASURABLE PRECIP...CAN IMAGINE WITH THE UPPER JET
DIVERGENCE/LIFT AND INCREASING CLOUD COVERAGE OVER WESTERN AZ...A
STRAY SHOWER AND PLENTY OF VIRGA WILL TRAVEL ALONG WITH THE AXIS
PASSAGE FROM WESTERN AZ...THROUGH YUMA/SW MARICOPA COUNTIES AND INTO
PIMA COUNTY FOR THE AFTERNOON. POP GRID ADJUSTMENTS MANAGED TO
SQUEAK OUT A FEW AREAS OF LIGHT RAIN/SPRINKLES OVER THE ABOVE
MENTIONED AREAS THROUGH THE DAY. STILL BELOW NORMAL UL HEIGHTS AND
COOLER AIRMASS TEMPS WILL SUPPORT ANOTHER BELOW NORMAL DAY IN TERMS
OF DAYTIME HIGHS WITH LOW TO UPPER 80S FOR MANY OF THE LOWER DESERT
ELEVATIONS.

&&

.PREVIOUS DISCUSSION /ISSUED AT 325 AM MST/PDT/...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS
WESTERN CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD
THROUGH SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND
JET-FORCED ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE
LOW SLIDES EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR
TO WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL
WILL BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS
PORTIONS OF SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION
REMAINS UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE
POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 241540
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
840 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA
WILL KEEP TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE
MEMORIAL DAY WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS
POSSIBLE OVER PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA
TODAY...THOUGH MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH
AND EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED
EARLY THIS WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND
EVEN EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
THE LATEST SHORTWAVE/COMPACT VORT MAX HAS REACHED THE CO RIVER
VALLEY THIS AM...INCREASING MID AND HIGH LEVEL CLOUD COVERAGE ACROSS
MUCH OF LA PAZ AND PORTIONS OF YUMA COUNTIES. CU AND CIRRUS FIELDS
THICK ENOUGH TO AT LEAST BE SAMPLED BY THE KYUX RADAR...WITH VERY
LIGHT REFLECTIVITIES ON THE ORDER OF 25DBZ OR LESS. SHORTWAVE AXIS
WILL CROSS INTO AZ AND CUT ACROSS SOUTH-CENTRAL AZ HEADING INTO
SOUTHEAST AZ BY THE AFTERNOON. FAIRLY LIMITED MOISTURE PROFILE
REMAINS WITH THIS FEATURE...DESPITE SFC DEWPOINTS PARTICULARLY
ACROSS THE CO RIVER SEEING READINGS IN THE 50S THIS AM. BLENDED TPW
IMAGERY INDICATE THE DEEPEST MOISTURE ALONG THE NORTH SIDE OF
CIRCULATION WITH A PRONOUNCED AREA OF DRYING/SUBSIDENCE ON THE S/SW
FLANK OF THE SYSTEM. WHILE NOT ONE LIKELY TO PRODUCE WETTING RAIN OR
EVEN MEASURABLE PRECIP...CAN IMAGINE WITH THE UPPER JET
DIVERGENCE/LIFT AND INCREASING CLOUD COVERAGE OVER WESTERN AZ...A
STRAY SHOWER AND PLENTY OF VIRGA WILL TRAVEL ALONG WITH THE AXIS
PASSAGE FROM WESTERN AZ...THROUGH YUMA/SW MARICOPA COUNTIES AND INTO
PIMA COUNTY FOR THE AFTERNOON. POP GRID ADJUSTMENTS MANAGED TO
SQUEAK OUT A FEW AREAS OF LIGHT RAIN/SPRINKLES OVER THE ABOVE
MENTIONED AREAS THROUGH THE DAY. STILL BELOW NORMAL UL HEIGHTS AND
COOLER AIRMASS TEMPS WILL SUPPORT ANOTHER BELOW NORMAL DAY IN TERMS
OF DAYTIME HIGHS WITH LOW TO UPPER 80S FOR MANY OF THE LOWER DESERT
ELEVATIONS.

&&

.PREVIOUS DISCUSSION /ISSUED AT 325 AM MST/PDT/...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS
WESTERN CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD
THROUGH SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND
JET-FORCED ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE
LOW SLIDES EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR
TO WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL
WILL BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS
PORTIONS OF SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION
REMAINS UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE
POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 241159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN MAY 24 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 241159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN MAY 24 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 241159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN MAY 24 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 241159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SUN MAY 24 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

NO AVIATION IMPACTS EXPECTED INTO MONDAY. CLEAR SKIES THIS MORNING
WILL GIVE WAY TO SOME FEW TO SCT AFTERNOON MID AND HIGH CLOUDS
MAINLY TO THE NORTH OF THE PHOENIX AREA. SOME HIGH BASED CU IS
PROBABLE ALSO OVER HIGH TERRAIN AREAS THIS AFTERNOON AS A WEAK UPPER
LEVEL DISTURBANCE PASSES THROUGH SOUTHERN ARIZONA. A VERY WEAK
PRESSURE GRADIENT WILL KEEP WINDS LESS THAN 10 KTS THROUGH THE
PERIOD WHILE FOLLOWING TYPICAL DIURNAL PATTERNS IN THE PHOENIX AREA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 241025
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

VERY LITTLE TO NO AVIATION IMPACTS THROUGH SUNDAY EVENING. MOST
DIURNAL CU HAS DISSIPATED...AND ONLY OCCASIONAL SCT MID/HIGH CLOUDS
WILL PASS BY TERMINALS SUNDAY. SFC WINDS AT PHOENIX AERODROMES WILL
BE SEASONABLY LIGHT WITH VERY TYPICAL WIND SHIFT TIMING. GUSTY W/SW
WINDS OVER SOUTHEAST CALIFORNIA SHOULD GENERALLY WEAKEN DURING THE
OVERNIGHT HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 241025
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

VERY LITTLE TO NO AVIATION IMPACTS THROUGH SUNDAY EVENING. MOST
DIURNAL CU HAS DISSIPATED...AND ONLY OCCASIONAL SCT MID/HIGH CLOUDS
WILL PASS BY TERMINALS SUNDAY. SFC WINDS AT PHOENIX AERODROMES WILL
BE SEASONABLY LIGHT WITH VERY TYPICAL WIND SHIFT TIMING. GUSTY W/SW
WINDS OVER SOUTHEAST CALIFORNIA SHOULD GENERALLY WEAKEN DURING THE
OVERNIGHT HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 241025
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

VERY LITTLE TO NO AVIATION IMPACTS THROUGH SUNDAY EVENING. MOST
DIURNAL CU HAS DISSIPATED...AND ONLY OCCASIONAL SCT MID/HIGH CLOUDS
WILL PASS BY TERMINALS SUNDAY. SFC WINDS AT PHOENIX AERODROMES WILL
BE SEASONABLY LIGHT WITH VERY TYPICAL WIND SHIFT TIMING. GUSTY W/SW
WINDS OVER SOUTHEAST CALIFORNIA SHOULD GENERALLY WEAKEN DURING THE
OVERNIGHT HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 241025
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 AM MST SUN MAY 24 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER AND THUNDERSTORM ACTIVITY IS POSSIBLE OVER
PARTS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA TODAY...THOUGH
MEASURABLE PRECIPITATION WILL GENERALLY REMAIN NORTH AND EAST OF
PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED EARLY THIS
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN
EXCEEDING THE 100 DEGREE MARK BY THE WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WEAKENING UPPER LOW ACROSS WESTERN
CO WITH ANOTHER COMPACT VORT MAX DIVING SOUTHEASTWARD THROUGH
SOUTHERN CA. MODELS CONTINUE TO INDICATE THAT VORTICITY AND JET-FORCED
ASCENT WILL BE PREVALENT ACROSS SOUTHERN AZ TODAY AS THE LOW SLIDES
EASTWARD. WEAK WV TRANSPORT WILL BE AN INHIBITING FACTOR TO
WIDESPREAD PRECIPITATION. HOWEVER...A FEW NCEP NMM-BASED WRFS
SUGGEST THAT INSTABILITY ASSOCIATED WITH THE MID-LEVEL COLD POOL WILL
BE SUFFICIENT TO GENERATE ISOLATED THUNDERSTORMS ACROSS PORTIONS OF
SOUTHWESTERN AZ THIS AFTERNOON. MEASURABLE PRECIPITATION REMAINS
UNLIKELY IN THESE AREAS BUT A FEW LIGHTNING STRIKES ARE POSSIBLE.

IN TERMS OF PRECIPITATION...MODEL CONSENSUS SUGGESTS THE BEST CHANCE
WILL AGAIN BE WELL NORTH AND EAST OF PHOENIX. ACROSS THE LOWER
ELEVATIONS...A DRY SUB-CLOUD LAYER WILL LIKELY RESULT IN AREAS OF
VIRGA WHERE CU FIELDS ARE THE MOST ORGANIZED. WITH ONE LOW EXITING
THE WEST AND ANOTHER MOVING THROUGH AZ...TEMPERATURES WILL AGAIN BE
BELOW NORMAL...BUT A FEW DEGREES WARMER THAN THOSE OBSERVED SATURDAY.

EARLY THIS WEEK...THE MEAN FLOW WILL BECOME MORE ZONAL AND
ULTIMATELY SOUTHWESTERLY WHILE THE PERSISTENT NEGATIVE HEIGHT
ANOMALY MIGRATES EASTWARD AND DISSOLVES. HEIGHTS ACROSS THE REGION
WILL RISE STEADILY THROUGH THE WEEK...HERALDING A RETURN TO WARMER
AND DRIER CONDITIONS. GFS/ECMWF INDICATE THAT A WEAK PACIFIC TROUGH
WILL MOVE THROUGH THE DESERT SOUTHWEST WEDNESDAY...BUT THIS SYSTEM
WILL DO LITTLE TO TEMPER THE BUILDING HEAT. FORECAST IS WEIGHTED
HEAVILY TOWARDS THE OPERATIONAL AND ENSEMBLE-BASED ECMWF...WHICH ARE
EXHIBITING VERY LOW SPREAD AND ARE OFTEN TOP PERFORMERS IN THESE
TYPES OF SCENARIOS. WHAT THIS EQUATES TO IS LOWER DESERT HIGHS RISING
THROUGH THE 90S THROUGH MIDWEEK. HIGH TEMPERATURES MAY EXCEED THE 100
DEGREE MARK AS EARLY AS FRIDAY IN PHOENIX BUT WILL REMAIN WELL BELOW
RECORDS.

&&

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

VERY LITTLE TO NO AVIATION IMPACTS THROUGH SUNDAY EVENING. MOST
DIURNAL CU HAS DISSIPATED...AND ONLY OCCASIONAL SCT MID/HIGH CLOUDS
WILL PASS BY TERMINALS SUNDAY. SFC WINDS AT PHOENIX AERODROMES WILL
BE SEASONABLY LIGHT WITH VERY TYPICAL WIND SHIFT TIMING. GUSTY W/SW
WINDS OVER SOUTHEAST CALIFORNIA SHOULD GENERALLY WEAKEN DURING THE
OVERNIGHT HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 240255
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
755 PM MST SAT MAY 23 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER PARTS OF SOUTH-
CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION WILL GENERALLY
REMAIN EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS
EXPECTED NEXT WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S
AND EVEN ABOVE THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
THE LARGE SCALE WRN CONUS NEGATIVE HEIGHT ANOMALY REMAINS STUCK IN
PLACE THIS EVENING...WITH ONE SHORTWAVE LIFTING NORTH THROUGH WRN
COLORADO WHILE A SECONDARY PV ANOMALY DESCENDS SOUTHEAST ALONG THE
CALIFORNIA COAST. GIVEN THIS CONFIGURATION....THE FORECAST AREA WILL
REMAIN IN A SUBSIDENCE REGIME THROUGH THE NIGHT WITH DIURNAL CU
ALREADY LARGELY DISSIPATING...AND HAVE CLEANED UP SKY COVER GRIDS AS
A RESULT. MOST OTHER SALIENT WEATHER PARAMETERS ONLY NEEDED
SLIGHT ADJUSTMENTS TO ACCOUNT FOR SHORT TERM TRENDS.

THE AFOREMENTIONED COMPACT PV ANOMALY HEADING TOWARDS ARIZONA ON
SUNDAY STILL LOOKS TO CARRY A FAIR AMOUNT OF DYNAMICAL
ENERGY...HOWEVER MOST RECENT MODEL OUTPUT STILL SUGGESTS VERY
LIMITED MOISTURE PROFILES (5-6 G/KG BOUNDARY LAYER MIXING RATIOS).
OTHER THAN ALONG THE RIM WHERE SCT SHOWERS WILL DEVELOP...SOME HIGH
RESOLUTION MODELS WANT TO SHOW ADDITIONAL ISOLD SHOWERS THROUGH
PARTS OF CENTRAL AND SOUTHEAST ARIZONA IN ASSOCIATION WITH THE SMALL
COLD CORE. FEEL SOME VIRGA AND A EXTREMELY ISOLATED SHOWER COULD BE
POSSIBLE WITH THE DRY SUBCLOUD LAYER...BUT NOT ENOUGH EVIDENCE
EXISTS TO MAKE SUBSTANTIAL INCREASES TO POPS IN THIS EVENINGS
UPDATE.

&&

.PREVIOUS DISCUSSION...
/223 PM MST SAT MAY 23 2015/
TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

VERY LITTLE TO NO AVIATION IMPACTS THROUGH SUNDAY EVENING. MOST
DIURNAL CU HAS DISSIPATED...AND ONLY OCCASIONAL SCT MID/HIGH CLOUDS
WILL PASS BY TERMINALS SUNDAY. SFC WINDS AT PHOENIX AERODROMES WILL
BE SEASONABLY LIGHT WITH VERY TYPICAL WIND SHIFT TIMING. GUSTY W/SW
WINDS OVER SOUTHEAST CALIFORNIA SHOULD GENERALLY WEAKEN DURING THE
OVERNIGHT HOURS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&

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

&&

$$

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

DISCUSSION...MO/PERCHA
AVIATION...MO
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 232123 AAA
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
223 PM MST SAT MAY 23 2015

.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

SPOTTY CU COVERAGE OVER THE SOUTH-CENTRAL AZ AND SOUTHEAST CA
DESERTS WILL DISSIPATE AND CLEAR AFTER SUNSET THIS EVENING. WHILE
WINDS HAVE BEEN LIGHTER TODAY THAN OBSERVED OVER THE PREVIOUS
AFTERNOON... THEIR HEADINGS HAVE BEEN MORE VARIABLE IN THE NATURE.
BROADLY... WINDS WILL MAINTAIN SOME WESTERLY COMPONENT BUT SQUIRRELY
VARIABLE HEADINGS CANNOT BE RULED OUT. EXPECT SUNDOWNER WINDS INTO
KIPL THIS EVENING...WITH GUSTS INTO THE 20KT RANGE POSSIBLE TOWARDS
EARLY SUNDAY AM.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&  KUHLMAN

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

$$

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

DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...NOLTE/MO





000
FXUS65 KPSR 232123 AAA
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
223 PM MST SAT MAY 23 2015

.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

SPOTTY CU COVERAGE OVER THE SOUTH-CENTRAL AZ AND SOUTHEAST CA
DESERTS WILL DISSIPATE AND CLEAR AFTER SUNSET THIS EVENING. WHILE
WINDS HAVE BEEN LIGHTER TODAY THAN OBSERVED OVER THE PREVIOUS
AFTERNOON... THEIR HEADINGS HAVE BEEN MORE VARIABLE IN THE NATURE.
BROADLY... WINDS WILL MAINTAIN SOME WESTERLY COMPONENT BUT SQUIRRELY
VARIABLE HEADINGS CANNOT BE RULED OUT. EXPECT SUNDOWNER WINDS INTO
KIPL THIS EVENING...WITH GUSTS INTO THE 20KT RANGE POSSIBLE TOWARDS
EARLY SUNDAY AM.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&  KUHLMAN

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

$$

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

DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...NOLTE/MO




000
FXUS65 KPSR 232123
AFDPSR
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
223 PM MST SAT MAY 23 2015

.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

SPOTTY CU COVERAGE OVER THE SOUTH-CENTRAL AZ AND SOUTHEAST CA
DESERTS WILL DISSIPATE AND CLEAR AFTER SUNSET THIS EVENING. WHILE
WINDS HAVE BEEN LIGHTER TODAY THAN OBSERVED OVER THE PREVIOUS
AFTERNOON... THEIR HEADINGS HAVE BEEN MORE VARIABLE IN THE NATURE.
BROADLY... WINDS WILL MAINTAIN SOME WESTERLY COMPONENT BUT SQUIRRELY
VARIABLE HEADINGS CANNOT BE RULED OUT. EXPECT SUNDOWNER WINDS INTO
KIPL THIS EVENING...WITH GUSTS INTO THE 20KT RANGE POSSIBLE TOWARDS
EARLY SUNDAY AM.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AND WARMER CONDITIONS WILL DEVELOP INTO THE REGION OVER THE
COMING WEEK AND RESULT IN OUR WARMEST TEMPERATURES SO FAR THIS YEAR
BY NEXT WEEKEND. THE WEATHER PATTERN WILL STILL REMAIN SOMEWHAT
ACTIVE OVERHEAD...AS A FEW WEAK DISTURBANCES BRUSH PAST OR THROUGH
THE AREA. HOWEVER...THESE WILL BE ON THE DRY SIDE. TEMPERATURES WILL
GRADUALLY WARM CLOSER TOWARD SEASONAL NORMALS. AS A RESULT...
AFTERNOON RELATIVE HUMIDITY VALUES WILL FALL BACK INTO THE TEENS
FOLLOWING FAIR TO GOOD OVERNIGHT RECOVERY. HOWEVER...WINDS WILL
GENERALLY REMAIN LIGHT FOLLOWING TYPICAL DAILY PATTERNS LEADING TO
MINIMAL FIRE WEATHER CONCERNS.

&&  KUHLMAN

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

$$

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

DISCUSSION...PERCHA
AVIATION...NOLTE
FIRE WEATHER...NOLTE/MO






000
FXUS65 KPSR 231930
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1230 PM MST SAT MAY 23 2015

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...PERCHA
AVIATION...KUHLMAN
FIRE WEATHER...MO




000
FXUS65 KPSR 231930
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1230 PM MST SAT MAY 23 2015

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...PERCHA
AVIATION...KUHLMAN
FIRE WEATHER...MO





000
FXUS65 KPSR 231930
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1230 PM MST SAT MAY 23 2015

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THROUGH THE REMAINDER OF THE MEMORIAL DAY
WEEKEND. ISOLATED SHOWER ACTIVITY IS POSSIBLE OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA...THOUGH MEASURABLE PRECIPITATION
WILL GENERALLY REMAIN WELL NORTH AND EAST OF PHOENIX. A GRADUAL
WARMING AND DRYING TREND IS EXPECTED NEXT WEEK...WITH TEMPERATURES
RETURNING TO THE UPPER 90S AND EVEN ABOVE THE 100 DEGREE MARK BY
NEXT WEEKEND.

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY... A UNSEASONABLY STRONG...AND COOL PACIFIC
UPPER LOW CENTER THAT BROUGHT WELL-BELOW NORMAL TEMPERATURES TO THE
DESERT SOUTHWEST OVER THE LAST FEW DAYS IS NOW CENTERED OVER EAST-
CENTRAL UTAH THIS AFTERNOON...AND IS FORECAST TO MOVE INTO CO/WY
TONIGHT AND ON SUNDAY. IN THE WAKE OF THIS LOW CENTER...COOL...BUT
RELATIVELY DRY NORTHWESTERLY FLOW CONTINUES OVER OUR CWA. THE COOL
AIR OVER THE REGION...WITH 850MB TEMPS IN THE 14-16C RANGE...WILL BE
KEEPING MOST LOWER DESERT HIGHS WELL DOWN IN THE 80S THIS AFTERNOON.
AFTER ANOTHER COOL NIGHT TONIGHT...WITH MOST LOWER DESERT LOCATIONS
SEEING LOWS ONCE AGAIN FALLING INTO THE 55-65 DEGREE RANGE...A NEW
SHORTWAVE...THAT IS NOW MOVING INTO NORTHERN CA...IS EXPECTED TO
ROTATE SOUTHWARD AND EASTWARD AROUND THE MAIN LOW CENTER ACROSS
SOUTHERN AZ ON SUNDAY. ALTHOUGH THIS NEXT SYSTEM IS QUITE DRY...WITH
PWATS ONLY RISING INTO THE 0.40-0.50 INCH RANGE...GOOD DIFFLUENCE
AHEAD OF THE SHORTWAVE AND DECENT MID-LEVEL COOLING (500MB TEMPS
FALLING TO AS LOW AS -18C)...ALONG WITH GOOD UPSLOPE FLOW...SHOULD
BE ENOUGH TO TRIGGER A FEW SHOWERS AND THUNDERSTORM OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ON SUNDAY AFTERNOON...AS THE UPPER LOW
PASSES OVER OUR REGION. ALONG WITH THE SHOWER CHANCES...THIS
SHORTWAVE WILL ALSO KEEP OUR TEMPERATURES WELL BELOW NORMAL AGAIN ON
SUNDAY. GIVEN THAT FACT THAT THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE WILL BE ALMOST AS COOL AS THE ONE WE ARE SEEING
TODAY...HIGH ON SUNDAY WILL LIKELY BE HARD-PRESSED TO GET OUT OF THE
MID-80S ACROSS THE LOWER DESERTS...JUST A COUPLE OF DEGREES WARMER
THEN WHAT WE ARE FORECASTING FOR TODAY.

MONDAY WILL LIKELY BE OUR LAST DAY OF SIGNIFICANTLY BELOW NORMAL
TEMPERATURES...AS ANOTHER...WEAKER SHORTWAVE BRUSHES BY TO OUR NORTH
AND EAST. THIS NEXT SHORTWAVE COULD ONCE AGAIN PRODUCE A SHOWER OR
TWO OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX ON MONDAY
AFTERNOON...BUT THE VAST MAJORITY OF MEASURABLE RAINFALL IS EXPECTED
TO REMAIN WELL TO OUR NORTH...OVER THE RIM COUNTY AND WHITE
MOUNTAINS. HIGHS ON MONDAY ARE EXPECTED TO RISE INTO THE LOW 90S AT
MOST LOWER DESERT LOCATIONS.

TUESDAY THROUGH SATURDAY... A GRADUAL WARMING TREND IS EXPECTED
THROUGH THIS PERIOD AS THE FLOW ALOFT BECOMES MORE ZONAL AS THE MAIN
LONG-WAVE TROF SHIFTS OFF TO OUR NORTH AND EAST. LOWER DESERT HIGHS
ARE EXPECTED TO RISE INTO THE UPPER 90S BY FRIDAY...AND INTO THE
100S NEXT SATURDAY...AS RIDGING BECOMES ESTABLISHED OVER THE REGION
BEHIND THE LAST WEAK UPPER TROF THAT WILL BE MOVING EASTWARD ACROSS
THE GREAT BASIN ON THURSDAY AND FRIDAY.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...PERCHA
AVIATION...KUHLMAN
FIRE WEATHER...MO




000
FXUS65 KPSR 231554
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
855 AM MST SAT MAY 23 2015

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION... A VERY PLEASANT MORNING TODAY...ESPECIALLY FOR LATE-
MAY ACROSS THE REGION! THIS MORNING/S LOW OF 64 AT SKY HARBOR IS 7
DEGREES BELOW THE NORMAL OF 71 FOR THE DATE...WITH MAY LOCATIONS IN
THE MORE RURAL LOWER DESERT LOCATIONS SEEING LOWS IN THE 50S. EVEN
BETTER...THE FORECAST HIGH TODAY AT SKY HARBOR OF 83 IS A FULL 14
DEGREES BELOW THE AVERAGE OF 97. CONSIDERING THAT WE CAN HAVE HIGHS
WELL OVER 100 THIS TIME OF YEAR...THIS WX IS A REAL BREAK FOR US.
THE NEXT UPSTREAM SHORTWAVE...WHICH IS EXPECTED TO HOLD TEMPERATURES
DOWN AGAIN ON SUNDAY...CAN BE SEEN ON LATEST IR SATELLITE IMAGERY
JUST ENTERING EXTREME NORTHERN CA. THE LATEST (12Z) GFS MODEL SUITE
CONTINUES TO TAKE THIS NEXT SHORTWAVE EASTWARD ACROSS SOUTHERN AZ
DURING THE DAY ON SUNDAY. THE AIRMASS ASSOCIATED WITH THIS NEW
SHORTWAVE APPEARS IT WILL BE NEARLY AS COOL AS THE ONE THAT IS OVER
THE REGION TODAY. AS FAR AS THE VERY SHORT TERM IS CONCERNED...OTHER
THAN SOME VERY MINOR ADJUSTMENTS TO THE HOURLY TEMP AND DEWPOINTS
GRIDS...INHERITED FORECASTS ARE LOOKING JUST FINE.

&&

.PREVIOUS DISCUSSION... LATEST STREAMLINE ANALYSIS SHOWS THE
PERSISTENT CYCLONIC FLOW ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH
A LOW PRESSURE SYSTEM CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS
EVIDENT ON WV IMAGERY AHEAD OF THE LOW ACROSS SOUTHEASTERN
AZ...THOUGH DEEPER MOISTURE FURTHER WEST IS CURRENTLY OVERSPREADING
THE MOHAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...PERCHA/HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...MO




000
FXUS65 KPSR 231159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SAT MAY 23 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...MO





000
FXUS65 KPSR 231159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SAT MAY 23 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...MO




000
FXUS65 KPSR 231159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SAT MAY 23 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...MO




000
FXUS65 KPSR 231159
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
459 AM MST SAT MAY 23 2015

.UPDATE...UPDATED AVIATION DISCUSSION...

&&

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

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

GENERALLY CLEAR SKIES THROUGH THE PERIOD EXCEPT FOR A FEW HIGHER
BASED CU THIS AFTERNOON OVER HIGHER TERRAIN AREAS. WINDS WILL BE
LIGHTER THAN THE PAST SEVERAL DAYS...BUT STILL CARRY A MORE DOMINANT
WESTERLY COMPONENT OVERALL. WILL LIKELY SEE SOME BREEZY AFTERNOON
WINDS...BUT MOSTLY ACROSS SOUTHEAST CALIFORNIA.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...KUHLMAN
FIRE WEATHER...MO





000
FXUS65 KPSR 231011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
311 AM MST SAT MAY 23 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
VERY LITTLE AVIATION CONCERN THROUGH SATURDAY AFTERNOON WITH ONLY
OCCASIONAL CLOUDS AOA 8K FT. GUSTY W/SW WINDS WILL PERSIST INTO
THE EVENING...BEFORE QUICKLY WEAKENING. THE SHIFT TO THE TRADITIONAL
LATE NIGHT EASTERLY DRAINAGE WIND DIRECTION WILL LIKELY BE MORE
DELAYED THAN USUAL...WITH ONLY MODERATE CONFIDENCE IN TIMING. EXPECT
A FEW HIGHER BASED CU TOMORROW AFTERNOON ALONG WITH SOMEWHAT WEAKER
WEST WINDS.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GUSTY W/SW SFC WINDS WILL BE THE PRIMARY AVIATION CONCERN
THIS EVENING...HOWEVER SPEEDS WILL DECREASE QUICKLY LATER THIS
EVENING AND NOT BE PROBLEMATIC SATURDAY. CHANCES FOR SHOWERS AT KBLH
PRETTY MUCH OVER...BUT THERE MAY BE A SOME SCT CU/SC DECKS NEAR 7-8K
FEET INTO THE EARLY MORNING HOURS. OTHERWISE NO AVIATION CONCERNS
SATURDAY AS SKIES WILL BE MOSTLY CLEAR AND WINDS WILL BE LESS AS
COMPARED TO TODAY...AND STILL FAVORING THE SOUTHWEST TO WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO/CB
FIRE WEATHER...MO





000
FXUS65 KPSR 231011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
311 AM MST SAT MAY 23 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
VERY LITTLE AVIATION CONCERN THROUGH SATURDAY AFTERNOON WITH ONLY
OCCASIONAL CLOUDS AOA 8K FT. GUSTY W/SW WINDS WILL PERSIST INTO
THE EVENING...BEFORE QUICKLY WEAKENING. THE SHIFT TO THE TRADITIONAL
LATE NIGHT EASTERLY DRAINAGE WIND DIRECTION WILL LIKELY BE MORE
DELAYED THAN USUAL...WITH ONLY MODERATE CONFIDENCE IN TIMING. EXPECT
A FEW HIGHER BASED CU TOMORROW AFTERNOON ALONG WITH SOMEWHAT WEAKER
WEST WINDS.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GUSTY W/SW SFC WINDS WILL BE THE PRIMARY AVIATION CONCERN
THIS EVENING...HOWEVER SPEEDS WILL DECREASE QUICKLY LATER THIS
EVENING AND NOT BE PROBLEMATIC SATURDAY. CHANCES FOR SHOWERS AT KBLH
PRETTY MUCH OVER...BUT THERE MAY BE A SOME SCT CU/SC DECKS NEAR 7-8K
FEET INTO THE EARLY MORNING HOURS. OTHERWISE NO AVIATION CONCERNS
SATURDAY AS SKIES WILL BE MOSTLY CLEAR AND WINDS WILL BE LESS AS
COMPARED TO TODAY...AND STILL FAVORING THE SOUTHWEST TO WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO/CB
FIRE WEATHER...MO




000
FXUS65 KPSR 231011
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
311 AM MST SAT MAY 23 2015

.SYNOPSIS...
A SERIES OF LOW PRESSURE SYSTEMS MOVING THROUGH ARIZONA WILL KEEP
TEMPERATURES BELOW NORMAL THIS WEEKEND. SHOWER ACTIVITY IS
POSSIBLE...THOUGH PRECIPITATION WILL GENERALLY REMAIN WELL NORTH AND
EAST OF PHOENIX. A GRADUAL WARMING AND DRYING TREND IS EXPECTED NEXT
WEEK...WITH TEMPERATURES RETURNING TO THE UPPER 90S AND EVEN ABOVE
THE 100 DEGREE MARK BY NEXT WEEKEND.

&&

.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS THE PERSISTENT CYCLONIC FLOW
ACROSS THE DESERT SOUTHWEST ASSOCIATED WITH A LOW PRESSURE SYSTEM
CENTERED NEAR THE AZ/UT BORDER. A DRY SLOT IS EVIDENT ON WV IMAGERY AHEAD
OF THE LOW ACROSS SOUTHEASTERN AZ...THOUGH DEEPER MOISTURE FURTHER
WEST IS CURRENTLY OVERSPREADING THE MOJAVE DESERT.

OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT IN THE SHORT-TERM.
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL DRIFT NORTHEASTWARD
TODAY WHILE WEAKENING. CONSENSUS OF CONVECTIVE ALLOWING GUIDANCE
INDICATES THAT SHOWER ACTIVITY WILL BE FOCUSED ACROSS NORTHERN AZ
THIS AFTERNOON. ACROSS THE LOWER DESERTS...A FEW CLOUDS CAN BE
EXPECTED BUT THE BIG STORY WILL REMAIN THE WELL-BELOW NORMAL
TEMPERATURES WITH HIGHS GENERALLY IN THE LOWER 80S AND ROUGHLY 15
DEGREES BELOW NORMAL.

NEXT IN THE SERIES OF SHORT-WAVE TROUGHS WILL DIVE SOUTHEASTWARD
INTO SOUTHERN AZ SUNDAY. THIS VORT MAX WILL BE COMPACT BUT PRODUCE
STRONG FORCING FOR ASCENT IN A CONCENTRATED AREA ACROSS SOUTHEASTERN
AZ. BEST CHANCE FOR CONVECTION WILL BE IN THESE AREAS AND AGAIN
ACROSS NORTHERN-CENTRAL AZ IN THE VICINITY OF THE DEEPER MOISTURE.
HOWEVER...BOTH THE GFS AND NAM-WRF HAVE TRENDED STRONGER WITH THIS
SYSTEM AND IT BEARS WATCHING.

SHORT-WAVE RIDGE WILL MAKE A RETURN TO THE REGION MONDAY...HERALDING
WARMER CONDITIONS AND A RETURN TO THE 90S FOR MANY LOCATIONS. STEADY
HEIGHT RISES THROUGH THE WEEK IN A QUASI-ZONAL FLOW WILL YIELD A
GRADUAL WARMING TREND...WITH TEMPERATURES RECOVERING TO NEAR NORMAL
BY MID-LATE WEEK. MODELS SUGGEST A WEAK PACIFIC TROUGH WILL DRIFT EASTWARD
INTO THE INTERMOUNTAIN WEST LATE IN THE WEEK...BUT IT IS UNLIKELY TO
HAVE MUCH OF AN IMPACT IN TERMS OF SENSIBLE WEATHER. THEREAFTER...A
RIDGE IS LIKELY TO DEVELOP ACROSS THE REGION...WHICH WILL LIKELY
BOOST TEMPERATURES ABOVE THE 100 DEGREE MARK BY SATURDAY. FORECAST
TEMPERATURES WERE WEIGHTED HEAVILY TOWARDS THE OPERATIONAL AND
ENSEMBLE ECMWF WHICH HAVE PERFORMED WELL RECENTLY AND ARE OFTEN TOP
PERFORMERS IN THESE TYPES OF SETUPS.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
VERY LITTLE AVIATION CONCERN THROUGH SATURDAY AFTERNOON WITH ONLY
OCCASIONAL CLOUDS AOA 8K FT. GUSTY W/SW WINDS WILL PERSIST INTO
THE EVENING...BEFORE QUICKLY WEAKENING. THE SHIFT TO THE TRADITIONAL
LATE NIGHT EASTERLY DRAINAGE WIND DIRECTION WILL LIKELY BE MORE
DELAYED THAN USUAL...WITH ONLY MODERATE CONFIDENCE IN TIMING. EXPECT
A FEW HIGHER BASED CU TOMORROW AFTERNOON ALONG WITH SOMEWHAT WEAKER
WEST WINDS.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GUSTY W/SW SFC WINDS WILL BE THE PRIMARY AVIATION CONCERN
THIS EVENING...HOWEVER SPEEDS WILL DECREASE QUICKLY LATER THIS
EVENING AND NOT BE PROBLEMATIC SATURDAY. CHANCES FOR SHOWERS AT KBLH
PRETTY MUCH OVER...BUT THERE MAY BE A SOME SCT CU/SC DECKS NEAR 7-8K
FEET INTO THE EARLY MORNING HOURS. OTHERWISE NO AVIATION CONCERNS
SATURDAY AS SKIES WILL BE MOSTLY CLEAR AND WINDS WILL BE LESS AS
COMPARED TO TODAY...AND STILL FAVORING THE SOUTHWEST TO WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
A FEW WEAK WEATHER DISTURBANCES WILL MOVE THROUGH THE DISTRICT NEXT
WEEK...HOWEVER DRY WEATHER WILL STILL PREVAIL. A GRADUAL WARMING
TREND WILL ALSO GRACE THE REGION BRINGING TEMPERATURES CLOSER TO THE
SEASONAL NORMAL. AS A RESULT...AFTERNOON RELATIVE HUMIDITY VALUES
WILL FALL BACK INTO THE TEENS FOLLOWING FAIR TO GOOD OVERNIGHT
RECOVERY. HOWEVER...WINDS WILL GENERALLY REMAIN LIGHT FOLLOWING
TYPICAL DAILY PATTERNS LEADING TO MINIMAL FIRE WEATHER CONCERNS.

&&

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

$$

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

DISCUSSION...HIRSCH
AVIATION...MO/CB
FIRE WEATHER...MO




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