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000
FXUS65 KFGZ 271625
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO EASTERN ARIZONA THIS MORNING. MORE SCATTERED
STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW PRESSURE PULLS
AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY
CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY
THROUGH EARLY NEXT WEEK.

&&

.UPDATE...
UPPER LEVEL LOW PRESSURE IS SITUATED TO OUR NORTH THIS MORNING
OVER THE CO/UT BORDER LEAVING NORTHERN ARIZONA UNDER A MUCH DRIER
WEST TO NORTHWEST FLOW. HAVE MADE MINOR UPDATES TO THE MORNING
FORECAST TO ACCOUNT FOR CURRENT SHOWER ACTIVITY IN EASTERN ARIZONA
AND UPDATE CLOUD COVER. THE FORECAST CHALLENGE TODAY WILL BE
COVERAGE OF ANY SHOWER ACTIVITY. BOUNDARY LAYER MOISTURE WILL BE
FIGHTING A DRIER AND MORE STABLE ENVIRONMENT.
REGARDLESS...COVERAGE IS EXPECTED TO BE SCATTERED OR LESS. WILL
LEAVE AFTERNOON FORECAST AS IS AND WILL CONTINUE TO ASSESS
CONVECTIVE TRENDS.

&&

.DISCUSSION...
MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER
LOW...SCATTERED SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP
THIS AFTERNOON OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY
BECOME SEVERE WITH DAMAGING HAIL AND WINDS...AS THERE IS
SUFFICIENT SHEAR AND FLOW ALOFT TO HELP SOME OF THESE STORMS
BECOME ORGANIZED. ACTIVITY IS EXPECTED TO DIE QUICKLY BY AROUND
SUNSET AS DRY MORE STABLE AIR SETS IN OVER NORTHERN ARIZONA BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. A HIGH PRESSURE RIDGE WILL
BUILD INTO THE SOUTHWEST STATES OVERNIGHT TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 18Z PACKAGE...LINGERING MOISTURE WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO NORTHERN ARIZONA TODAY. AWAY FROM
STORMS MAINLY VFR CONDITIONS. AFTER 02Z...CLEARING SKIES. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC.........MCS/TC
AVIATION.......DM

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 271625
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO EASTERN ARIZONA THIS MORNING. MORE SCATTERED
STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW PRESSURE PULLS
AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY
CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY
THROUGH EARLY NEXT WEEK.

&&

.UPDATE...
UPPER LEVEL LOW PRESSURE IS SITUATED TO OUR NORTH THIS MORNING
OVER THE CO/UT BORDER LEAVING NORTHERN ARIZONA UNDER A MUCH DRIER
WEST TO NORTHWEST FLOW. HAVE MADE MINOR UPDATES TO THE MORNING
FORECAST TO ACCOUNT FOR CURRENT SHOWER ACTIVITY IN EASTERN ARIZONA
AND UPDATE CLOUD COVER. THE FORECAST CHALLENGE TODAY WILL BE
COVERAGE OF ANY SHOWER ACTIVITY. BOUNDARY LAYER MOISTURE WILL BE
FIGHTING A DRIER AND MORE STABLE ENVIRONMENT.
REGARDLESS...COVERAGE IS EXPECTED TO BE SCATTERED OR LESS. WILL
LEAVE AFTERNOON FORECAST AS IS AND WILL CONTINUE TO ASSESS
CONVECTIVE TRENDS.

&&

.DISCUSSION...
MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER
LOW...SCATTERED SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP
THIS AFTERNOON OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY
BECOME SEVERE WITH DAMAGING HAIL AND WINDS...AS THERE IS
SUFFICIENT SHEAR AND FLOW ALOFT TO HELP SOME OF THESE STORMS
BECOME ORGANIZED. ACTIVITY IS EXPECTED TO DIE QUICKLY BY AROUND
SUNSET AS DRY MORE STABLE AIR SETS IN OVER NORTHERN ARIZONA BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. A HIGH PRESSURE RIDGE WILL
BUILD INTO THE SOUTHWEST STATES OVERNIGHT TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 18Z PACKAGE...LINGERING MOISTURE WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO NORTHERN ARIZONA TODAY. AWAY FROM
STORMS MAINLY VFR CONDITIONS. AFTER 02Z...CLEARING SKIES. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC.........MCS/TC
AVIATION.......DM

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 271625
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO EASTERN ARIZONA THIS MORNING. MORE SCATTERED
STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW PRESSURE PULLS
AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY
CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY
THROUGH EARLY NEXT WEEK.

&&

.UPDATE...
UPPER LEVEL LOW PRESSURE IS SITUATED TO OUR NORTH THIS MORNING
OVER THE CO/UT BORDER LEAVING NORTHERN ARIZONA UNDER A MUCH DRIER
WEST TO NORTHWEST FLOW. HAVE MADE MINOR UPDATES TO THE MORNING
FORECAST TO ACCOUNT FOR CURRENT SHOWER ACTIVITY IN EASTERN ARIZONA
AND UPDATE CLOUD COVER. THE FORECAST CHALLENGE TODAY WILL BE
COVERAGE OF ANY SHOWER ACTIVITY. BOUNDARY LAYER MOISTURE WILL BE
FIGHTING A DRIER AND MORE STABLE ENVIRONMENT.
REGARDLESS...COVERAGE IS EXPECTED TO BE SCATTERED OR LESS. WILL
LEAVE AFTERNOON FORECAST AS IS AND WILL CONTINUE TO ASSESS
CONVECTIVE TRENDS.

&&

.DISCUSSION...
MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER
LOW...SCATTERED SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP
THIS AFTERNOON OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY
BECOME SEVERE WITH DAMAGING HAIL AND WINDS...AS THERE IS
SUFFICIENT SHEAR AND FLOW ALOFT TO HELP SOME OF THESE STORMS
BECOME ORGANIZED. ACTIVITY IS EXPECTED TO DIE QUICKLY BY AROUND
SUNSET AS DRY MORE STABLE AIR SETS IN OVER NORTHERN ARIZONA BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. A HIGH PRESSURE RIDGE WILL
BUILD INTO THE SOUTHWEST STATES OVERNIGHT TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 18Z PACKAGE...LINGERING MOISTURE WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO NORTHERN ARIZONA TODAY. AWAY FROM
STORMS MAINLY VFR CONDITIONS. AFTER 02Z...CLEARING SKIES. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC.........MCS/TC
AVIATION.......DM

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 271625
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
925 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO EASTERN ARIZONA THIS MORNING. MORE SCATTERED
STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW PRESSURE PULLS
AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY
CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY
THROUGH EARLY NEXT WEEK.

&&

.UPDATE...
UPPER LEVEL LOW PRESSURE IS SITUATED TO OUR NORTH THIS MORNING
OVER THE CO/UT BORDER LEAVING NORTHERN ARIZONA UNDER A MUCH DRIER
WEST TO NORTHWEST FLOW. HAVE MADE MINOR UPDATES TO THE MORNING
FORECAST TO ACCOUNT FOR CURRENT SHOWER ACTIVITY IN EASTERN ARIZONA
AND UPDATE CLOUD COVER. THE FORECAST CHALLENGE TODAY WILL BE
COVERAGE OF ANY SHOWER ACTIVITY. BOUNDARY LAYER MOISTURE WILL BE
FIGHTING A DRIER AND MORE STABLE ENVIRONMENT.
REGARDLESS...COVERAGE IS EXPECTED TO BE SCATTERED OR LESS. WILL
LEAVE AFTERNOON FORECAST AS IS AND WILL CONTINUE TO ASSESS
CONVECTIVE TRENDS.

&&

.DISCUSSION...
MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER
LOW...SCATTERED SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP
THIS AFTERNOON OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY
BECOME SEVERE WITH DAMAGING HAIL AND WINDS...AS THERE IS
SUFFICIENT SHEAR AND FLOW ALOFT TO HELP SOME OF THESE STORMS
BECOME ORGANIZED. ACTIVITY IS EXPECTED TO DIE QUICKLY BY AROUND
SUNSET AS DRY MORE STABLE AIR SETS IN OVER NORTHERN ARIZONA BEHIND
THE DEPARTING LOW PRESSURE SYSTEM. A HIGH PRESSURE RIDGE WILL
BUILD INTO THE SOUTHWEST STATES OVERNIGHT TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 18Z PACKAGE...LINGERING MOISTURE WILL BRING SCATTERED
SHOWERS AND THUNDERSTORMS TO NORTHERN ARIZONA TODAY. AWAY FROM
STORMS MAINLY VFR CONDITIONS. AFTER 02Z...CLEARING SKIES. AVIATION
DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

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

&&

$$

PUBLIC.........MCS/TC
AVIATION.......DM

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF




  [top]

000
FXUS65 KPSR 271610
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
910 AM MST WED AUG 27 2014

.SYNOPSIS...
DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION TODAY...USHERING IN
A DRIER AND WARMER PATTERN ACROSS THE DESERT SOUTHWEST THROUGH AT
LEAST EARLY NEXT WEEK. HIGH TEMPERATURES WILL RETURN TO NEAR NORMAL
VALUES BY THURSDAY...PEAKING BETWEEN 105 AND 110 FRIDAY AND
SATURDAY...BEFORE RETREATING SLIGHTLY NEXT WEEK.

&&

.DISCUSSION...
TAIL END OF A SHORTWAVE TROUGH IS MOVING THROUGH GILA COUNTY THIS
MORNING...WITH A FEW LINGERING SHOWERS AND ISOLATED THUNDERSTORMS
NOTED ON SATELLITE AND RADAR. WV IMAGERY REVEALS THE PARENT
CIRCULATION ACROSS EASTERN UTAH WITH SUBSTANTIAL MID LEVEL DRYING
STRETCHING FROM SOUTH-CENTRAL ARIZONA WESTWARD INTO CENTRAL
CALIFORNIA. SURFACE DEWPOINTS HAVE BEEN SLOW TO RESPOND AND ARE
GENERALLY IN THE LOW TO MID 60S AS OF 16Z.

STRONG SUBSIDENCE AND MID LEVEL WARM ADVECTION HAS ALREADY COMMENCED
ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND WILL CONTINUE
TO SPREAD WESTWARD THIS AFTERNOON. THE HRRR ALONG WITH SEVERAL OTHER
LOCAL HI-RES MODELS INDICATE A FEW POP-UP SHOWERS ARE POSSIBLE WELL
EAST OF PHOENIX THIS AFTERNOON...BUT THE DESERTS WILL REMAIN DRY.
THE INHERITED FORECAST INDICATED 10-20 POPS FOR THIS AFTERNOON BUT
BASED ON HOW QUICKLY THE SHORTWAVE IS EXITING THE AREA...I MADE
SLIGHT REDUCTIONS TO POPS FOR LATER TODAY. ALL IN ALL IT SHOULD BE A
QUIET DAY...NO MAJOR UPDATES NECESSARY.

&&

.PREVIOUS DISCUSSION...
FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

GIVEN THE STRONG SUBSIDENCE FORECAST TO MOVE INTO THE AREA
TODAY...WEATHER CONCERNS ARE MINIMAL THROUGH THURSDAY. MOSTLY CLEAR
SKIES AND LIGHT DIURNAL WINDS ARE FORECAST AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...LEINS/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CB/MO






000
FXUS65 KPSR 271610
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
910 AM MST WED AUG 27 2014

.SYNOPSIS...
DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION TODAY...USHERING IN
A DRIER AND WARMER PATTERN ACROSS THE DESERT SOUTHWEST THROUGH AT
LEAST EARLY NEXT WEEK. HIGH TEMPERATURES WILL RETURN TO NEAR NORMAL
VALUES BY THURSDAY...PEAKING BETWEEN 105 AND 110 FRIDAY AND
SATURDAY...BEFORE RETREATING SLIGHTLY NEXT WEEK.

&&

.DISCUSSION...
TAIL END OF A SHORTWAVE TROUGH IS MOVING THROUGH GILA COUNTY THIS
MORNING...WITH A FEW LINGERING SHOWERS AND ISOLATED THUNDERSTORMS
NOTED ON SATELLITE AND RADAR. WV IMAGERY REVEALS THE PARENT
CIRCULATION ACROSS EASTERN UTAH WITH SUBSTANTIAL MID LEVEL DRYING
STRETCHING FROM SOUTH-CENTRAL ARIZONA WESTWARD INTO CENTRAL
CALIFORNIA. SURFACE DEWPOINTS HAVE BEEN SLOW TO RESPOND AND ARE
GENERALLY IN THE LOW TO MID 60S AS OF 16Z.

STRONG SUBSIDENCE AND MID LEVEL WARM ADVECTION HAS ALREADY COMMENCED
ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND WILL CONTINUE
TO SPREAD WESTWARD THIS AFTERNOON. THE HRRR ALONG WITH SEVERAL OTHER
LOCAL HI-RES MODELS INDICATE A FEW POP-UP SHOWERS ARE POSSIBLE WELL
EAST OF PHOENIX THIS AFTERNOON...BUT THE DESERTS WILL REMAIN DRY.
THE INHERITED FORECAST INDICATED 10-20 POPS FOR THIS AFTERNOON BUT
BASED ON HOW QUICKLY THE SHORTWAVE IS EXITING THE AREA...I MADE
SLIGHT REDUCTIONS TO POPS FOR LATER TODAY. ALL IN ALL IT SHOULD BE A
QUIET DAY...NO MAJOR UPDATES NECESSARY.

&&

.PREVIOUS DISCUSSION...
FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

GIVEN THE STRONG SUBSIDENCE FORECAST TO MOVE INTO THE AREA
TODAY...WEATHER CONCERNS ARE MINIMAL THROUGH THURSDAY. MOSTLY CLEAR
SKIES AND LIGHT DIURNAL WINDS ARE FORECAST AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...LEINS/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CB/MO






000
FXUS65 KPSR 271610
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
910 AM MST WED AUG 27 2014

.SYNOPSIS...
DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION TODAY...USHERING IN
A DRIER AND WARMER PATTERN ACROSS THE DESERT SOUTHWEST THROUGH AT
LEAST EARLY NEXT WEEK. HIGH TEMPERATURES WILL RETURN TO NEAR NORMAL
VALUES BY THURSDAY...PEAKING BETWEEN 105 AND 110 FRIDAY AND
SATURDAY...BEFORE RETREATING SLIGHTLY NEXT WEEK.

&&

.DISCUSSION...
TAIL END OF A SHORTWAVE TROUGH IS MOVING THROUGH GILA COUNTY THIS
MORNING...WITH A FEW LINGERING SHOWERS AND ISOLATED THUNDERSTORMS
NOTED ON SATELLITE AND RADAR. WV IMAGERY REVEALS THE PARENT
CIRCULATION ACROSS EASTERN UTAH WITH SUBSTANTIAL MID LEVEL DRYING
STRETCHING FROM SOUTH-CENTRAL ARIZONA WESTWARD INTO CENTRAL
CALIFORNIA. SURFACE DEWPOINTS HAVE BEEN SLOW TO RESPOND AND ARE
GENERALLY IN THE LOW TO MID 60S AS OF 16Z.

STRONG SUBSIDENCE AND MID LEVEL WARM ADVECTION HAS ALREADY COMMENCED
ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND WILL CONTINUE
TO SPREAD WESTWARD THIS AFTERNOON. THE HRRR ALONG WITH SEVERAL OTHER
LOCAL HI-RES MODELS INDICATE A FEW POP-UP SHOWERS ARE POSSIBLE WELL
EAST OF PHOENIX THIS AFTERNOON...BUT THE DESERTS WILL REMAIN DRY.
THE INHERITED FORECAST INDICATED 10-20 POPS FOR THIS AFTERNOON BUT
BASED ON HOW QUICKLY THE SHORTWAVE IS EXITING THE AREA...I MADE
SLIGHT REDUCTIONS TO POPS FOR LATER TODAY. ALL IN ALL IT SHOULD BE A
QUIET DAY...NO MAJOR UPDATES NECESSARY.

&&

.PREVIOUS DISCUSSION...
FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

GIVEN THE STRONG SUBSIDENCE FORECAST TO MOVE INTO THE AREA
TODAY...WEATHER CONCERNS ARE MINIMAL THROUGH THURSDAY. MOSTLY CLEAR
SKIES AND LIGHT DIURNAL WINDS ARE FORECAST AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...LEINS/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CB/MO






000
FXUS65 KPSR 271610
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
910 AM MST WED AUG 27 2014

.SYNOPSIS...
DRIER AIR WILL CONTINUE TO MOVE INTO THE REGION TODAY...USHERING IN
A DRIER AND WARMER PATTERN ACROSS THE DESERT SOUTHWEST THROUGH AT
LEAST EARLY NEXT WEEK. HIGH TEMPERATURES WILL RETURN TO NEAR NORMAL
VALUES BY THURSDAY...PEAKING BETWEEN 105 AND 110 FRIDAY AND
SATURDAY...BEFORE RETREATING SLIGHTLY NEXT WEEK.

&&

.DISCUSSION...
TAIL END OF A SHORTWAVE TROUGH IS MOVING THROUGH GILA COUNTY THIS
MORNING...WITH A FEW LINGERING SHOWERS AND ISOLATED THUNDERSTORMS
NOTED ON SATELLITE AND RADAR. WV IMAGERY REVEALS THE PARENT
CIRCULATION ACROSS EASTERN UTAH WITH SUBSTANTIAL MID LEVEL DRYING
STRETCHING FROM SOUTH-CENTRAL ARIZONA WESTWARD INTO CENTRAL
CALIFORNIA. SURFACE DEWPOINTS HAVE BEEN SLOW TO RESPOND AND ARE
GENERALLY IN THE LOW TO MID 60S AS OF 16Z.

STRONG SUBSIDENCE AND MID LEVEL WARM ADVECTION HAS ALREADY COMMENCED
ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA AND WILL CONTINUE
TO SPREAD WESTWARD THIS AFTERNOON. THE HRRR ALONG WITH SEVERAL OTHER
LOCAL HI-RES MODELS INDICATE A FEW POP-UP SHOWERS ARE POSSIBLE WELL
EAST OF PHOENIX THIS AFTERNOON...BUT THE DESERTS WILL REMAIN DRY.
THE INHERITED FORECAST INDICATED 10-20 POPS FOR THIS AFTERNOON BUT
BASED ON HOW QUICKLY THE SHORTWAVE IS EXITING THE AREA...I MADE
SLIGHT REDUCTIONS TO POPS FOR LATER TODAY. ALL IN ALL IT SHOULD BE A
QUIET DAY...NO MAJOR UPDATES NECESSARY.

&&

.PREVIOUS DISCUSSION...
FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

GIVEN THE STRONG SUBSIDENCE FORECAST TO MOVE INTO THE AREA
TODAY...WEATHER CONCERNS ARE MINIMAL THROUGH THURSDAY. MOSTLY CLEAR
SKIES AND LIGHT DIURNAL WINDS ARE FORECAST AT ALL SITES.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...LEINS/KUHLMAN
AVIATION...LEINS
FIRE WEATHER...CB/MO





  [top]

000
FXUS65 KTWC 271601
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
901 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE MID/UPPER LOW THAT HELPED GENERATE WIDESPREAD
SHOWER AND THUNDERSTORM ACTIVITY YESTERDAY IS NOW CENTERED NEAR
THE FOUR CORNERS REGION. IT CONTINUES TO TRACK TO THE EAST AND
NORTHEAST. WATER VAPOR IMAGERY IS INDICATING A BROAD AREA OF MID-
LEVEL DRY AIR OVERSPREADING MUCH OF ARIZONA. THE TAIL END OF A
MID-LEVEL MOISTURE IS CURRENTLY SETTLING ACROSS FAR SOUTHEASTERN
PORTIONS OF THE STATE. MORNING SOUNDINGS ACROSS CENTRAL AND SOUTH
ARIZONA ARE INDICATING PRECIPITABLE WATER VALUES REMAIN SLIGHTLY
ABOVE AVERAGE. SOME DRYING ALOFT WAS NOTED ALONG WITH
STRENGTHENING WEST TO SOUTHWEST WINDS. MODEL GUIDANCE IS IN
AGREEMENT THAT CONTINUED DRYING OF THE ATMOSPHERIC COLUMN WILL
TAKE PLACE THROUGHOUT THE DAY TODAY. BASED ON THE LINGERING
MOISTURE CURRENTLY INDICATED IN SOUNDING DATA...ALONG WITH THE
MOISTURE APPARENT ON SATELLITE IMAGERY...THE FORECAST CONTINUES TO
INCLUDE THE POTENTIAL FOR THUNDERSTORMS FOR PORTIONS OF THE AREA
THIS AFTERNOON. CONVECTION IS EXPECTED TO POP OVER THE
MOUNTAINS...MAINLY EAST OF THE TUCSON TO NOGALES AREA...AND DRIFT
EASTWARD OVER VALLEY AREAS AS THE AFTERNOON PROGRESSES TOWARD
EVENING. STORMS WILL BE MORE PROGRESSIVE AND SHORT LIVED THAN
THOSE THAT OCCURRED YESTERDAY.

A MUCH DRIER AIRMASS WILL THEN SETTLE IN OVER THE REGION WITH HIGH
PRESSURE AT THE SURFACE AND ALOFT. THIS WILL LEAD TO NO THREAT OF
PRECIPITATION AND WARMING TEMPERATURES ALL ACROSS SOUTHEAST
ARIZONA THROUGH THE HOLIDAY WEEKEND.


&&

.AVIATION...VALID THRU 28/18Z
A DRIER WESTERLY FLOW ALOFT TODAY...APPARENT ON AMDAR
SOUNDINGS...WILL LIMIT THUNDERSTORM ACTIVITY TO MAINLY NEAR THE
MOUNTAINS FROM KTUS EASTWARD. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LOW...WILL NOT INCLUDE ANY
TSRA IN THE TAFS UNTIL IT LOOKS APPARENT THAT A STORM WILL
DIRECTLY IMPACT A TERMINAL. SFC WINDS VARIABLE TO 10 KTS...EXCEPT
VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS.  STORMS THAT
DEVELOP WILL DRIFT TO THE EAST AROUND 10 MPH.  THURSDAY THROUGH THE
WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY LOWER RH
LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED.  NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.


&&

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

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA


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







000
FXUS65 KTWC 271601
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
901 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE MID/UPPER LOW THAT HELPED GENERATE WIDESPREAD
SHOWER AND THUNDERSTORM ACTIVITY YESTERDAY IS NOW CENTERED NEAR
THE FOUR CORNERS REGION. IT CONTINUES TO TRACK TO THE EAST AND
NORTHEAST. WATER VAPOR IMAGERY IS INDICATING A BROAD AREA OF MID-
LEVEL DRY AIR OVERSPREADING MUCH OF ARIZONA. THE TAIL END OF A
MID-LEVEL MOISTURE IS CURRENTLY SETTLING ACROSS FAR SOUTHEASTERN
PORTIONS OF THE STATE. MORNING SOUNDINGS ACROSS CENTRAL AND SOUTH
ARIZONA ARE INDICATING PRECIPITABLE WATER VALUES REMAIN SLIGHTLY
ABOVE AVERAGE. SOME DRYING ALOFT WAS NOTED ALONG WITH
STRENGTHENING WEST TO SOUTHWEST WINDS. MODEL GUIDANCE IS IN
AGREEMENT THAT CONTINUED DRYING OF THE ATMOSPHERIC COLUMN WILL
TAKE PLACE THROUGHOUT THE DAY TODAY. BASED ON THE LINGERING
MOISTURE CURRENTLY INDICATED IN SOUNDING DATA...ALONG WITH THE
MOISTURE APPARENT ON SATELLITE IMAGERY...THE FORECAST CONTINUES TO
INCLUDE THE POTENTIAL FOR THUNDERSTORMS FOR PORTIONS OF THE AREA
THIS AFTERNOON. CONVECTION IS EXPECTED TO POP OVER THE
MOUNTAINS...MAINLY EAST OF THE TUCSON TO NOGALES AREA...AND DRIFT
EASTWARD OVER VALLEY AREAS AS THE AFTERNOON PROGRESSES TOWARD
EVENING. STORMS WILL BE MORE PROGRESSIVE AND SHORT LIVED THAN
THOSE THAT OCCURRED YESTERDAY.

A MUCH DRIER AIRMASS WILL THEN SETTLE IN OVER THE REGION WITH HIGH
PRESSURE AT THE SURFACE AND ALOFT. THIS WILL LEAD TO NO THREAT OF
PRECIPITATION AND WARMING TEMPERATURES ALL ACROSS SOUTHEAST
ARIZONA THROUGH THE HOLIDAY WEEKEND.


&&

.AVIATION...VALID THRU 28/18Z
A DRIER WESTERLY FLOW ALOFT TODAY...APPARENT ON AMDAR
SOUNDINGS...WILL LIMIT THUNDERSTORM ACTIVITY TO MAINLY NEAR THE
MOUNTAINS FROM KTUS EASTWARD. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LOW...WILL NOT INCLUDE ANY
TSRA IN THE TAFS UNTIL IT LOOKS APPARENT THAT A STORM WILL
DIRECTLY IMPACT A TERMINAL. SFC WINDS VARIABLE TO 10 KTS...EXCEPT
VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS.  STORMS THAT
DEVELOP WILL DRIFT TO THE EAST AROUND 10 MPH.  THURSDAY THROUGH THE
WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY LOWER RH
LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED.  NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.


&&

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

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA


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000
FXUS65 KTWC 271516
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
816 AM MST WED AUG 27 2014

.UPDATE...QUICK UPDATE THIS MORNING TO ADJUST POPS UPWARD THIS
AFTERNOON OVER EASTERN AREAS. CHANGES ARE MINOR...WITH THE BIGGEST
DIFFERENCE THE ADDITION OF SLIGHT CHANCE POPS FOR SOME VALLEY
AREAS. MORNING TWC SOUNDING ALONG WITH LINGERING MID/UPPER LEVEL
MOISTURE NECESSITATED THE BOOST IN POPS. FULL AFD TO FOLLOW AROUND
9AM.


&&

.PREV DISCUSSION... /ISSUED 242 AM MST WED AUG 27 2014/

SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

UPDATE...CANTIN

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000
FXUS65 KTWC 271516
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
816 AM MST WED AUG 27 2014

.UPDATE...QUICK UPDATE THIS MORNING TO ADJUST POPS UPWARD THIS
AFTERNOON OVER EASTERN AREAS. CHANGES ARE MINOR...WITH THE BIGGEST
DIFFERENCE THE ADDITION OF SLIGHT CHANCE POPS FOR SOME VALLEY
AREAS. MORNING TWC SOUNDING ALONG WITH LINGERING MID/UPPER LEVEL
MOISTURE NECESSITATED THE BOOST IN POPS. FULL AFD TO FOLLOW AROUND
9AM.


&&

.PREV DISCUSSION... /ISSUED 242 AM MST WED AUG 27 2014/

SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

UPDATE...CANTIN

99/99 VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON







000
FXUS65 KPSR 271423 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
430 AM MST WED AUG 27 2014

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

&&

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

NO AVIATION CONCERNS THROUGH THURSDAY MORNING WITH ANY THUNDERSTORM
ACTIVITY REMAINING OVER THE HIGHER TERRAIN AREAS NORTH AND EAST OF
THE PHOENIX TERMINALS. THE PRESSURE GRADIENT WILL BE VERY WEAK
YIELDING LIGHT WINDS. THE ONLY MINOR UNCERTAINTY IS TIMING OF THE
NOCTURNAL WIND SHIFT LATE IN THE PERIOD...WHICH WILL LIKELY OCCUR
SOMEWHAT MORE DELAYED THAN USUAL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

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









000
FXUS65 KPSR 271423 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE PHOENIX AZ
430 AM MST WED AUG 27 2014

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

&&

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

NO AVIATION CONCERNS THROUGH THURSDAY MORNING WITH ANY THUNDERSTORM
ACTIVITY REMAINING OVER THE HIGHER TERRAIN AREAS NORTH AND EAST OF
THE PHOENIX TERMINALS. THE PRESSURE GRADIENT WILL BE VERY WEAK
YIELDING LIGHT WINDS. THE ONLY MINOR UNCERTAINTY IS TIMING OF THE
NOCTURNAL WIND SHIFT LATE IN THE PERIOD...WHICH WILL LIKELY OCCUR
SOMEWHAT MORE DELAYED THAN USUAL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

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










000
FXUS65 KPSR 271134
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
430 AM MST WED AUG 27 2014

...UPDATED AVIATION AND FIRE WEATHER...

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

NO AVIATION CONCERNS THROUGH THURSDAY MORNING WITH ANY THUNDERSTORM
ACTIVITY REMAINING OVER THE HIGHER TERRAIN AREAS NORTH AND EAST OF
THE PHOENIX TERMINALS. THE PRESSURE GRADIENT WILL BE VERY WEAK
YIELDING LIGHT WINDS. THE ONLY MINOR UNCERTAINTY IS TIMING OF THE
NOCTURNAL WIND SHIFT LATE IN THE PERIOD...WHICH WILL LIKELY OCCUR
SOMEWHAT MORE DELAYED THAN USUAL.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT AND DRY NORTHWEST FLOW WILL BUILD OVER
THE DISTRICT THROUGH EARLY NEXT WEEK. EVEN ACROSS GILA
COUNTY...CHANCES FOR THUNDERSTORMS ARE ALMOST ZERO THROUGH THE
ENTIRE PERIOD. WITH TEMPERATURES AT OR SLIGHTLY ABOVE THE SEASONAL
AVERAGE...AFTERNOON HUMIDITIES WILL RANGE FROM THE TEENS AT LOWER
ELEVATIONS TO 20-30 PERCENT OVER HIGHER TERRAIN. FAIR OVERNIGHT
RECOVERY THROUGH THE WEEKEND WILL GRADUALLY INCREASE...BECOMING GOOD
OR EXCELLENT BY EARLY NEXT WEEK. WIND SPEEDS WILL BE UNCOMMONLY LOW
THROUGH THE WEEKEND...WITH VERY LITTLE GUSTY CHARACTER.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

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







000
FXUS65 KFGZ 271005
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
305 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO PORTIONS OF NORTHERN ARIZONA THIS MORNING.  MORE
SCATTERED STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW
PRESSURE PULLS AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL
BRING DRY CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM
THURSDAY THROUGH EARLY NEXT WEEK.
&&

.DISCUSSION...
FOR TODAY...THE UPPER LOW NEAR ELY NEVADA IS SENDING ANOTHER
SHORTWAVE DISTURBANCE THROUGH NORTHERN ARIZONA THIS MORNING WHICH
HAS AIDED THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
OVER COCONINO AND YAVAPAI COUNTIES. THIS ACTIVITY WILL MOVE EAST
LATER THIS MORNING...HOWEVER THESE STORMS ARE FORECAST TO WEAKEN AS
IT MOVES INTO NAVAJO AND APACHE COUNTIES MID TO LATE MORNING.

MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER LOW...SCATTERED
SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP THIS AFTERNOON
OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY BECOME SEVERE WITH
DAMAGING HAIL AND WINDS...AS THERE IS SUFFICIENT SHEAR AND FLOW
ALOFT TO HELP SOME OF THESE STORMS BECOME ORGANIZED. ACTIVITY IS
EXPECTED TO DIE QUICKLY BY AROUND SUNSET AS DRY MORE STABLE AIR SETS
IN OVER NORTHERN ARIZONA BEHIND THE DEPARTING LOW PRESSURE SYSTEM. A
HIGH PRESSURE RIDGE WILL BUILD INTO THE SOUTHWEST STATES OVERNIGHT
TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.
&&

.AVIATION...
FOR THE 12Z PACKAGE...SCATTERED SHOWERS AND THUNDERSTORMS ARE
FORECAST ACROSS NORTHERN ARIZONA TODAY. EXPECT WIDELY SCATTERED/MVFR
AND LOCAL/IFR CONDITIONS IN HEAVIER SHOWERS. STORM COVERAGE
DECREASING AFTER 23Z. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

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

$$

PUBLIC.........TC
AVIATION.......BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF








000
FXUS65 KFGZ 271005
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
305 AM MST WED AUG 27 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING SHOWERS AND
THUNDERSTORMS TO PORTIONS OF NORTHERN ARIZONA THIS MORNING.  MORE
SCATTERED STORMS ARE EXPECTED AGAIN THIS AFTERNOON AS THE LOW
PRESSURE PULLS AWAY FROM THE AREA. A DRY WEST TO NORTHWEST FLOW WILL
BRING DRY CONDITIONS AND SLIGHTLY WARMER HIGH TEMPERATURES FROM
THURSDAY THROUGH EARLY NEXT WEEK.
&&

.DISCUSSION...
FOR TODAY...THE UPPER LOW NEAR ELY NEVADA IS SENDING ANOTHER
SHORTWAVE DISTURBANCE THROUGH NORTHERN ARIZONA THIS MORNING WHICH
HAS AIDED THE DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS
OVER COCONINO AND YAVAPAI COUNTIES. THIS ACTIVITY WILL MOVE EAST
LATER THIS MORNING...HOWEVER THESE STORMS ARE FORECAST TO WEAKEN AS
IT MOVES INTO NAVAJO AND APACHE COUNTIES MID TO LATE MORNING.

MOISTURE WILL BE SUFFICIENT IN THE LOWER LAYERS OF THE ATMOSPHERE
TODAY...AND ALONG WITH INSTABILITY AROUND THE UPPER LOW...SCATTERED
SHOWERS AND THUNDERSTORMS AREA EXPECTED TO DEVELOP THIS AFTERNOON
OVER NORTHERN ARIZONA. A FEW OF THE STORMS MAY BECOME SEVERE WITH
DAMAGING HAIL AND WINDS...AS THERE IS SUFFICIENT SHEAR AND FLOW
ALOFT TO HELP SOME OF THESE STORMS BECOME ORGANIZED. ACTIVITY IS
EXPECTED TO DIE QUICKLY BY AROUND SUNSET AS DRY MORE STABLE AIR SETS
IN OVER NORTHERN ARIZONA BEHIND THE DEPARTING LOW PRESSURE SYSTEM. A
HIGH PRESSURE RIDGE WILL BUILD INTO THE SOUTHWEST STATES OVERNIGHT
TONIGHT.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...WITH A MUCH DRIER
ATMOSPHERE...BRINGING FAIR AND WARM WEATHER TO THE NORTHLAND THROUGH
THE WEEKEND...AND INTO EARLY NEXT WEEK.
&&

.AVIATION...
FOR THE 12Z PACKAGE...SCATTERED SHOWERS AND THUNDERSTORMS ARE
FORECAST ACROSS NORTHERN ARIZONA TODAY. EXPECT WIDELY SCATTERED/MVFR
AND LOCAL/IFR CONDITIONS IN HEAVIER SHOWERS. STORM COVERAGE
DECREASING AFTER 23Z. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

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

$$

PUBLIC.........TC
AVIATION.......BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF









000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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






000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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






000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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






000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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






000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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






000
FXUS65 KTWC 270942
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
242 AM MST WED AUG 27 2014

.SYNOPSIS...A PRONOUNCED DRYING TREND CAN BE EXPECTED THE NEXT
SEVERAL DAYS AS A NORTHWESTERLY FLOW DEVELOPS OVER THE REGION. THIS
DRYING TREND WILL ALSO RESULT IN WARMER DAYTIME TEMPERATURES...WITH
HIGHS AROUND THE CENTURY MARK IN TUCSON THIS WEEKEND.

&&

.DISCUSSION...THE TAIL END OF A SYSTEM PASSING THROUGH UTAH WAS
TRIGGERING SOME THUNDERSTORMS ACROSS NORTH-CENTRAL ARIZONA EARLY
THIS MORNING. RECENT TRENDS SUGGESTED THAT THIS THUNDERSTORM
ACTIVITY WILL REMAIN WELL NORTH OF SOUTHEAST ARIZONA THIS MORNING.
HOWEVER... LINGERING MOISTURE IN COMBINATION WITH DAYTIME HEATING
WILL RESULT IN A FEW AFTERNOON AND EARLY EVENING THUNDERSTORMS
TODAY. OTHERWISE...MODELS CONTINUED TO SHOW DRIER AIR SPREADING INTO
THE AREA TODAY AND MORE SO THE NEXT FEW DAYS AS WESTERLY FLOW ALOFT
DEVELOPS OVER THE DESERT SOUTHWEST. THAT SAID...THUNDERSTORM CHANCES
WILL DIMINISH SIGNIFICANTLY STARTING TODAY. THIS DRIER AIRMASS WILL
ALSO GIVE WAY TO WARMER DAYTIME TEMPERATURES...WITH PROJECTED HIGHS
FOR TUCSON NEAR THE CENTURY MARK THIS WEEKEND.

&&

.AVIATION...VALID THRU 28/12Z.
A DRIER WESTERLY FLOW ALOFT TODAY WILL LIMIT THUNDERSTORM ACTIVITY
TO MAINLY NEAR THE MOUNTAINS. THERE IS A SMALL CHANCE THAT A
THUNDERSTORM MAY IMPACT BOTH KOLS AND KDUG BETWEEN 27/21Z AND
28/03Z. HOWEVER SINCE THE CHANCE IS LESS THAN 15%...WILL NOT INCLUDE
ANY TSRA IN THE 12Z TAF ISSUANCE. SFC WINDS VARIABLE TO 10
KTS...EXCEPT VICINITY OF AFTERNOON TSRA WHERE GUSTS TO 45 MPH ARE
POSSIBLE. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A DRYING TREND STARTS TODAY WITH AFTERNOON
THUNDERSTORMS RELEGATED TO MOSTLY NEAR THE MOUNTAINS. THURSDAY
THROUGH THE WEEKEND...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY
LOWER RH LEVELS...WARMER TEMPERATURES AND LITTLE TO NO SHOWERS OR
THUNDERSTORMS EXPECTED. NEXT WEEK WILL SEE A BIT OF A MODERATION IN
RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND WARM.

&&

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

$$

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







000
FXUS65 KPSR 270915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED AUG 27 2014

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...CB















000
FXUS65 KPSR 270915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED AUG 27 2014

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...CB















000
FXUS65 KPSR 270915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED AUG 27 2014

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...CB















000
FXUS65 KPSR 270915
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
215 AM MST WED AUG 27 2014

.SYNOPSIS...
WHILE THERE MAY STILL BE SOME LINGERING SHOWERS AND A FEW
THUNDERSTORMS ACROSS EAST-CENTRAL ARIZONA TODAY...A DRIER AND WARMER
STRETCH OF WEATHER WILL TAKE OVER LASTING AT LEAST THROUGH THE
WEEKEND. HIGH TEMPERATURES WILL CLIMB BACK TO NEAR NORMAL BY
THURSDAY PEAKING ON FRIDAY AND SATURDAY WITH SOME LOWER DESERT SPOTS
APPROACHING 110 DEGREES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST
ARIZONA.

&&

.DISCUSSION...
ALTHOUGH THE MONSOON SEASON STILL OFFICIALLY HAS ANOTHER MONTH TO
GO...THE SYNOPTIC PATTERN IS ALREADY STARTING TO LOOK MORE LIKE A
MID TO LATE SEPTEMBER REGIME. THE PACIFIC LOW PRESSURE SYSTEM THAT
MOVED OUT OF NEVADA EARLIER TODAY INTO SOUTHERN UTAH IS SLOWLY
DRAWING IN DRIER AIR ALOFT FROM THE WEST INTO SOUTHERN CALIFORNIA
AND SOUTHERN ARIZONA. HOWEVER...BELOW 700MB THE ATMOSPHERE WILL
REMAIN FAIRLY MOIST WITH MIXING RATIOS AROUND 10 G/KG UNTIL LATER
THIS AFTERNOON WHEN DRY AIR ALOFT MIXES DOWN. CURRENT WATER VAPOR
IMAGERY SHOWS A HINT OF A TRAILING VORTICITY LOBE PASSING THROUGH
CENTRAL ARIZONA WHICH HAS HELPED TO KICK OFF SOME NIGHTTIME
SHOWERS AND THUNDERSTORMS ACROSS YAVAPAI AND COCONINO COUNTIES TO
OUR NORTH. EXPECTING AT LEAST A FEW OF THESE SHOWERS TO VENTURE INTO
NORTHERN PORTIONS OF MARICOPA AND POSSIBLY INTO GILA COUNTY THROUGH
12Z. ELSEWHERE...FURTHER TO THE SOUTH AND WEST...THE DRIER AIR AND
INCREASING SUBSIDENT FLOW ALOFT IS MORE EVIDENT UNDER MAINLY CLEAR
SKIES. THERE WILL STILL BE A SLIGHT CHANCE OF SOME SHOWERS ACROSS
FAR NORTHERN MARICOPA COUNTY INTO SOUTHERN GILA COUNTY THROUGH THE
REST OF THIS MORNING INTO EARLY AFTERNOON...BUT ALL ACTIVITY SHOULD
CEASE BY SUNSET. AS THE PACIFIC LOW CONTINUES TO TRACK EASTWARD INTO
WESTERN COLORADO BY LATE THIS AFTERNOON...WINDS ALOFT WILL VEER TO
THE NORTHWEST BRINGING IN INCREASINGLY DRY AIR ABOVE 700MB WITH
SUBSIDENT FLOW ALOFT OVERTAKING THE ENTIRE CWA.

FOR THURSDAY THROUGH THE WEEKEND...ZERO POPS ARE IN THE FORECAST
DURING THE PERIOD AS A VERY DRY NORTHWESTERLY UPPER LEVEL FLOW
PATTERN PERSISTS ACROSS THE DESERT SOUTHWEST. THE SUBTROPICAL HIGH
BUILDS WESTWARD BEHIND THE EXITING PACIFIC LOW WITH THE HIGH CENTER
SETTLING JUST OFF THE SOUTHERN CALIFORNIA COAST. THIS WILL ALLOW
500MB HEIGHTS TO BUILD ACROSS OUR REGION AND FOR AN UPTICK IN
TEMPERATURES. HIGHS WILL RETURN TO NEAR SEASONAL NORMALS ALREADY ON
THURSDAY AND THEN CLIMB A COUPLE DEGREES HIGHER FOR FRIDAY AND
SATURDAY. WOULDN/T BE SURPRISED IF A FEW LOCATIONS ACROSS THE
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA DESERTS HIT 110 ON FRIDAY
AND SATURDAY.

THE UPPER RIDGE WILL BEGIN TO BREAK DOWN ON SATURDAY AS A TROUGH
MOVES INTO THE PACIFIC NORTHWEST. MODELS ARE IN EXCELLENT AGREEMENT
THIS TROUGH WILL FLATTEN THE RIDGE TO OUR SOUTHWEST...BUT KEEP US
UNDER A WESTERLY TO NORTHWESTERLY DRY UPPER LEVEL FLOW INTO NEXT
MONDAY. HIGHS SHOULD START TO TREND DOWNWARD STARTING SUNDAY AS THE
TROUGH TO OUR NORTH SLOWLY KNOCKS DOWN OUR UPPER HEIGHTS. SOME MODEL
DIFFERENCES ARE SHOWN NEAR THE END OF THE FORECAST PERIOD FOR NEXT
TUESDAY AND WEDNESDAY AS THE EUROPEAN BEGINS TO REBUILD THE
SUBTROPICAL HIGH TO OUR SOUTHEAST AND POSSIBLY ALLOWS FOR SOME
MINIMAL MOISTURE RETURN UNDER WEAK SOUTHEASTERLY FLOW. THE GFS KEEPS
THE DRIER WESTERLY FLOW ALOFT UNDER A WEAKER SUB-TROPICAL HIGH
CENTERED STILL TO OUR SOUTHWEST. TO ACCOUNT FOR THE POTENTIAL RETURN
IN MONSOONAL MOISTURE...HAVE INTRODUCED AT LEAST SOME LOW END SLIGHT
CHANCE POPS FOR TUESDAY AND WEDNESDAY ACROSS THE HIGHER TERRAIN IN
GILA COUNTY.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...KUHLMAN
AVIATION...NOLTE
FIRE WEATHER...CB















000
FXUS65 KPSR 270428
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
930 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
THUNDERSTORM COVERAGE CONTINUES TO DWINDLE THIS EVENING...WITH
ACTIVITY HOLDING OVER SOUTHERN GILA COUNTY AND ACROSS PORTIONS OF
SOUTHEASTERN AZ THIS EVENING. SCATTERED TO BROKEN CLOUD DECKS REMAIN
OVER EASTERN PORTIONS OF THE FORECAST AREA...WITH CLEAR TO MOSTLY
CLEAR SKIES EXPANDING OVER THE LOWER DESERT ELEVATIONS AND INTO
SOUTHEAST CA. EVEN WITH DRYING INTRUDING FROM THE WEST...DEEP ENOUGH
LOW LEVEL GULF MOISTURE INTERACTED WITH THE GULF BREEZE/MOUNTAIN
DRAINAGE BOUNDARIES OVER NORTHERN BAJA THIS EVENING TO FIRE OFF ONE
SINGULAR SHORT-LIVED THUNDERSTORM SOUTH OF THE BORDER AND LIGHT
SHOWER ACTIVITY JUST TO THE EAST OF EL CENTRO. JUST AS QUICKLY AS IT
POPPED UP...THE SHOWER WAS DISSIPATING.

WITH REMNANT JET ENERGY AND ELEVATED LOW-LEVEL MOISTURE SURFACE
HOLDING ACROSS THE AREA...DEWPOINTS STILL IN THE UPPER 50S TO LOW
60S...COULD SEE VERY ISOLATED POP-UP SHOWERS IN THE TURBULENT FLOW
THIS EVENING OVER THE WESTERN/SW DESERTS. THESE WILL BE SHORT-LIVED
AND OUTSIDE OF SOME ISOLATED THUNDER MENTION ACROSS NW MARICOPA...DO
NOT BELIEVE THESE WARRANT POPS ANY HIGHER THAN 10 PERCENT AT BEST.
ADJUSTMENTS TO SIGNIFICANTLY SCALE BACK MENTION EARLIER THIS
AFTERNOON WERE REFINED FURTHER...DROPPING ALL MENTION OF WEATHER OUT
OF THE PHX METRO /AZZ023/ WHILE KEEPING ISOLATED TO SCATTERED
ACTIVITY OVER THE EASTERN HIGHER TERRAIN THROUGH THE OVERNIGHT HOURS.

SAVE FOR THE INFLUENCE OF OUTFLOWS IN THE LOWER LEVEL WIND HEADINGS
ON THE 27/03Z KPSR BALLOON...THE REMAINDER OF THE COLUMN HOLDS A
WESTERLY COMPONENT. DRIER AIR WILL CONTINUE TO FILTER INTO THE
REGION AS WESTERLY FLOW AROUND THE UPPER LOW OVER UTAH EXPANDS
ACROSS THE STATE. UPPER LOW HEIGHTS WILL MAKE A GRADUAL EXIT FROM
THE FOUR CORNERS REGION WEDNESDAY...WITH RIDGING BUILDING OVER THE
REGION BY THURSDAY. REMAINDER OF THE DISCUSSION BELOW STILL APPLIES
FOR THE FORECAST SPECIFICS FOR THE REST OF THE WORK WEEK.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE
FIRE WEATHER...CB













000
FXUS65 KPSR 270428
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
930 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
THUNDERSTORM COVERAGE CONTINUES TO DWINDLE THIS EVENING...WITH
ACTIVITY HOLDING OVER SOUTHERN GILA COUNTY AND ACROSS PORTIONS OF
SOUTHEASTERN AZ THIS EVENING. SCATTERED TO BROKEN CLOUD DECKS REMAIN
OVER EASTERN PORTIONS OF THE FORECAST AREA...WITH CLEAR TO MOSTLY
CLEAR SKIES EXPANDING OVER THE LOWER DESERT ELEVATIONS AND INTO
SOUTHEAST CA. EVEN WITH DRYING INTRUDING FROM THE WEST...DEEP ENOUGH
LOW LEVEL GULF MOISTURE INTERACTED WITH THE GULF BREEZE/MOUNTAIN
DRAINAGE BOUNDARIES OVER NORTHERN BAJA THIS EVENING TO FIRE OFF ONE
SINGULAR SHORT-LIVED THUNDERSTORM SOUTH OF THE BORDER AND LIGHT
SHOWER ACTIVITY JUST TO THE EAST OF EL CENTRO. JUST AS QUICKLY AS IT
POPPED UP...THE SHOWER WAS DISSIPATING.

WITH REMNANT JET ENERGY AND ELEVATED LOW-LEVEL MOISTURE SURFACE
HOLDING ACROSS THE AREA...DEWPOINTS STILL IN THE UPPER 50S TO LOW
60S...COULD SEE VERY ISOLATED POP-UP SHOWERS IN THE TURBULENT FLOW
THIS EVENING OVER THE WESTERN/SW DESERTS. THESE WILL BE SHORT-LIVED
AND OUTSIDE OF SOME ISOLATED THUNDER MENTION ACROSS NW MARICOPA...DO
NOT BELIEVE THESE WARRANT POPS ANY HIGHER THAN 10 PERCENT AT BEST.
ADJUSTMENTS TO SIGNIFICANTLY SCALE BACK MENTION EARLIER THIS
AFTERNOON WERE REFINED FURTHER...DROPPING ALL MENTION OF WEATHER OUT
OF THE PHX METRO /AZZ023/ WHILE KEEPING ISOLATED TO SCATTERED
ACTIVITY OVER THE EASTERN HIGHER TERRAIN THROUGH THE OVERNIGHT HOURS.

SAVE FOR THE INFLUENCE OF OUTFLOWS IN THE LOWER LEVEL WIND HEADINGS
ON THE 27/03Z KPSR BALLOON...THE REMAINDER OF THE COLUMN HOLDS A
WESTERLY COMPONENT. DRIER AIR WILL CONTINUE TO FILTER INTO THE
REGION AS WESTERLY FLOW AROUND THE UPPER LOW OVER UTAH EXPANDS
ACROSS THE STATE. UPPER LOW HEIGHTS WILL MAKE A GRADUAL EXIT FROM
THE FOUR CORNERS REGION WEDNESDAY...WITH RIDGING BUILDING OVER THE
REGION BY THURSDAY. REMAINDER OF THE DISCUSSION BELOW STILL APPLIES
FOR THE FORECAST SPECIFICS FOR THE REST OF THE WORK WEEK.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

DRIER AND MORE STABLE AIR WILL CONTINUE TO FILTER INTO SOUTH-CENTRAL
AZ ALL BUT ENDING ANY CHANCES FOR SHOWER AND STORM ACTIVITY...EVEN
FOR THE CITY PERIPHERY...THIS EVENING. OUTFLOW WINDS ALREADY
TRANSITIONED WINDS TO THE TYPICAL OVERNIGHT EAST HEADINGS...WITH
SPEEDS EXPECTED 10-12KTS EARLY ON BEFORE TAPERING BACK OVERNIGHT.
THICKER STORM CLOUDS AND CIGS TO REMAIN WELL EAST OF THE TERMINALS.
PATCHES OF PASSING CU FROM THE WEST SHOULD REMAIN FEW-SCT IN
NATURE...AOA 10-12KT.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
TYPICAL DIURNAL WINDS EXPECTED FOR THE TERMINALS THIS EVENING WITH
SPEEDS GNLY AOB 8KTS. ISOLATED STORM ACTIVITY SOUTH OF THE BORDER
MAY KEEP PATCHES OF SCT-BKN CLOUDS OVER AND EAST OF KIPL FOR THE
NEXT FEW HOURS. OTHERWISE...MOSTLY CLEAR SKIES TO PREVAIL THROUGH
SUNRISE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE
FIRE WEATHER...CB












000
FXUS65 KFGZ 270344
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS EAST CENTRAL ARIZONA THIS EVENING. STORMS WILL
DECREASE FROM THE WEST TO EAST OVERNIGHT. SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE
AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND
SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT
WEEK.

&&
.DISCUSSION...IT WAS AN ACTIVE LATE AFTERNOON AND EARLY EVENING WITH
SCATTERED THUNDERSTORMS AND ISOLATED HEAVY RAIN. MOST ACTIVITY IS
NOW IN EASTERN GILA...SOUTHERN NAVAJO AND SOUTHERN APACHE COUNTY.
THIS ACTIVITY WILL CONTINUE TO PUSH EASTWARD THIS EVENING. HAVE
UPDATED THE FORECAST TO DROP POPS AND FLASH FLOOD WATCH IN THE
WESTERN ZONES.

&&
.PREV DISCUSSION /320 PM MST/...

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD-SCT SHRA/TSRA WILL PERSIST EAST OF A
KPAN-KSJN. STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST
THROUGH 10Z. ISOLD TSRA OVER HIGHER TERRAIN AFTER 18-02Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1100 PM MST FOR AZZ013-014-016>018.

&&

$$

PUBLIC.........MAS/BAK
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 270344
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS EAST CENTRAL ARIZONA THIS EVENING. STORMS WILL
DECREASE FROM THE WEST TO EAST OVERNIGHT. SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE
AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND
SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT
WEEK.

&&
.DISCUSSION...IT WAS AN ACTIVE LATE AFTERNOON AND EARLY EVENING WITH
SCATTERED THUNDERSTORMS AND ISOLATED HEAVY RAIN. MOST ACTIVITY IS
NOW IN EASTERN GILA...SOUTHERN NAVAJO AND SOUTHERN APACHE COUNTY.
THIS ACTIVITY WILL CONTINUE TO PUSH EASTWARD THIS EVENING. HAVE
UPDATED THE FORECAST TO DROP POPS AND FLASH FLOOD WATCH IN THE
WESTERN ZONES.

&&
.PREV DISCUSSION /320 PM MST/...

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD-SCT SHRA/TSRA WILL PERSIST EAST OF A
KPAN-KSJN. STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST
THROUGH 10Z. ISOLD TSRA OVER HIGHER TERRAIN AFTER 18-02Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1100 PM MST FOR AZZ013-014-016>018.

&&

$$

PUBLIC.........MAS/BAK
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 270344
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS EAST CENTRAL ARIZONA THIS EVENING. STORMS WILL
DECREASE FROM THE WEST TO EAST OVERNIGHT. SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE
AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND
SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT
WEEK.

&&
.DISCUSSION...IT WAS AN ACTIVE LATE AFTERNOON AND EARLY EVENING WITH
SCATTERED THUNDERSTORMS AND ISOLATED HEAVY RAIN. MOST ACTIVITY IS
NOW IN EASTERN GILA...SOUTHERN NAVAJO AND SOUTHERN APACHE COUNTY.
THIS ACTIVITY WILL CONTINUE TO PUSH EASTWARD THIS EVENING. HAVE
UPDATED THE FORECAST TO DROP POPS AND FLASH FLOOD WATCH IN THE
WESTERN ZONES.

&&
.PREV DISCUSSION /320 PM MST/...

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD-SCT SHRA/TSRA WILL PERSIST EAST OF A
KPAN-KSJN. STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST
THROUGH 10Z. ISOLD TSRA OVER HIGHER TERRAIN AFTER 18-02Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1100 PM MST FOR AZZ013-014-016>018.

&&

$$

PUBLIC.........MAS/BAK
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 270344
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
845 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS EAST CENTRAL ARIZONA THIS EVENING. STORMS WILL
DECREASE FROM THE WEST TO EAST OVERNIGHT. SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE
AREA. A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND
SLIGHTLY WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT
WEEK.

&&
.DISCUSSION...IT WAS AN ACTIVE LATE AFTERNOON AND EARLY EVENING WITH
SCATTERED THUNDERSTORMS AND ISOLATED HEAVY RAIN. MOST ACTIVITY IS
NOW IN EASTERN GILA...SOUTHERN NAVAJO AND SOUTHERN APACHE COUNTY.
THIS ACTIVITY WILL CONTINUE TO PUSH EASTWARD THIS EVENING. HAVE
UPDATED THE FORECAST TO DROP POPS AND FLASH FLOOD WATCH IN THE
WESTERN ZONES.

&&
.PREV DISCUSSION /320 PM MST/...

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD-SCT SHRA/TSRA WILL PERSIST EAST OF A
KPAN-KSJN. STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST
THROUGH 10Z. ISOLD TSRA OVER HIGHER TERRAIN AFTER 18-02Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 1100 PM MST FOR AZZ013-014-016>018.

&&

$$

PUBLIC.........MAS/BAK
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KTWC 270240
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
740 PM MST TUE AUG 26 2014

.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE
OVERNIGHT WITH A PRONOUNCED DRYING TREND IS EXPECTED OVER THE NEXT
SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...QUICK UPDATE TO TRIM POPS BACK TO BETTER FIT CURRENT
TRENDS. OTHERWISE...FORECAST REMAINS ON TRACK.

&&

.AVIATION...VALID THRU 28/06Z.
TS DEVELOPMENT WILL DIMINISH OVER THE NEXT FEW HOURS FROM WEST TO
EAST AS THE UPPER TROUGH OVER NEVADA BEGINS TO EJECT ACROSS THE
NORTHERN HALF OF THE STATE. THE STRONGEST ACTIVITY WILL BE NORTH
OF THE KTUS-KSAD LINE...WITH LITTLE TO NO DEVELOPMENT EXPECTED
NEAR THE INTERNATIONAL BORDER. THAT BEING SAID...THE DEEP MOISTURE
REMAINS OVER THE AREA AND THE UPPER TROUGH SHOULD PUSH SOME ADDED
FORCING SO SOME NEW DEVELOPMENT WILL BE POSSIBLE THROUGH 12Z.
STILL...CONFIDENCE REMAINS TOO LOW AT THIS TIME TO WARRANT MENTION
IN THE TAF. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DIMINISH DURING THE OVERNIGHT HOURS. A DRYING TREND WILL GET
STARTED WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY
WARMER TEMPERATURES. THURSDAY THROUGH THE SATURDAY...THE DRYING
WILL CONTINUE WITH SIGNIFICANTLY LOWER RH LEVELS...WARMER
TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS EXPECTED. SUNDAY INTO
THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A MODERATION IN RH
LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND RATHER
WARM.

&&

.PREV DISCUSSION... /ISSUED 209 PM MST TUE AUG 26 2014/

DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.

&&

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

$$

DISCUSSION...MEADOWS

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






000
FXUS65 KTWC 270240
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
740 PM MST TUE AUG 26 2014

.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE
OVERNIGHT WITH A PRONOUNCED DRYING TREND IS EXPECTED OVER THE NEXT
SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...QUICK UPDATE TO TRIM POPS BACK TO BETTER FIT CURRENT
TRENDS. OTHERWISE...FORECAST REMAINS ON TRACK.

&&

.AVIATION...VALID THRU 28/06Z.
TS DEVELOPMENT WILL DIMINISH OVER THE NEXT FEW HOURS FROM WEST TO
EAST AS THE UPPER TROUGH OVER NEVADA BEGINS TO EJECT ACROSS THE
NORTHERN HALF OF THE STATE. THE STRONGEST ACTIVITY WILL BE NORTH
OF THE KTUS-KSAD LINE...WITH LITTLE TO NO DEVELOPMENT EXPECTED
NEAR THE INTERNATIONAL BORDER. THAT BEING SAID...THE DEEP MOISTURE
REMAINS OVER THE AREA AND THE UPPER TROUGH SHOULD PUSH SOME ADDED
FORCING SO SOME NEW DEVELOPMENT WILL BE POSSIBLE THROUGH 12Z.
STILL...CONFIDENCE REMAINS TOO LOW AT THIS TIME TO WARRANT MENTION
IN THE TAF. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DIMINISH DURING THE OVERNIGHT HOURS. A DRYING TREND WILL GET
STARTED WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY
WARMER TEMPERATURES. THURSDAY THROUGH THE SATURDAY...THE DRYING
WILL CONTINUE WITH SIGNIFICANTLY LOWER RH LEVELS...WARMER
TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS EXPECTED. SUNDAY INTO
THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A MODERATION IN RH
LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND RATHER
WARM.

&&

.PREV DISCUSSION... /ISSUED 209 PM MST TUE AUG 26 2014/

DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.

&&

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

$$

DISCUSSION...MEADOWS

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






000
FXUS65 KTWC 270240
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
740 PM MST TUE AUG 26 2014

.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE
OVERNIGHT WITH A PRONOUNCED DRYING TREND IS EXPECTED OVER THE NEXT
SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...QUICK UPDATE TO TRIM POPS BACK TO BETTER FIT CURRENT
TRENDS. OTHERWISE...FORECAST REMAINS ON TRACK.

&&

.AVIATION...VALID THRU 28/06Z.
TS DEVELOPMENT WILL DIMINISH OVER THE NEXT FEW HOURS FROM WEST TO
EAST AS THE UPPER TROUGH OVER NEVADA BEGINS TO EJECT ACROSS THE
NORTHERN HALF OF THE STATE. THE STRONGEST ACTIVITY WILL BE NORTH
OF THE KTUS-KSAD LINE...WITH LITTLE TO NO DEVELOPMENT EXPECTED
NEAR THE INTERNATIONAL BORDER. THAT BEING SAID...THE DEEP MOISTURE
REMAINS OVER THE AREA AND THE UPPER TROUGH SHOULD PUSH SOME ADDED
FORCING SO SOME NEW DEVELOPMENT WILL BE POSSIBLE THROUGH 12Z.
STILL...CONFIDENCE REMAINS TOO LOW AT THIS TIME TO WARRANT MENTION
IN THE TAF. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DIMINISH DURING THE OVERNIGHT HOURS. A DRYING TREND WILL GET
STARTED WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY
WARMER TEMPERATURES. THURSDAY THROUGH THE SATURDAY...THE DRYING
WILL CONTINUE WITH SIGNIFICANTLY LOWER RH LEVELS...WARMER
TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS EXPECTED. SUNDAY INTO
THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A MODERATION IN RH
LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND RATHER
WARM.

&&

.PREV DISCUSSION... /ISSUED 209 PM MST TUE AUG 26 2014/

DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.

&&

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

$$

DISCUSSION...MEADOWS

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






000
FXUS65 KTWC 270240
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
740 PM MST TUE AUG 26 2014

.SYNOPSIS...SHOWERS AND THUNDERSTORMS WILL CONTINUE DURING THE
OVERNIGHT WITH A PRONOUNCED DRYING TREND IS EXPECTED OVER THE NEXT
SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...QUICK UPDATE TO TRIM POPS BACK TO BETTER FIT CURRENT
TRENDS. OTHERWISE...FORECAST REMAINS ON TRACK.

&&

.AVIATION...VALID THRU 28/06Z.
TS DEVELOPMENT WILL DIMINISH OVER THE NEXT FEW HOURS FROM WEST TO
EAST AS THE UPPER TROUGH OVER NEVADA BEGINS TO EJECT ACROSS THE
NORTHERN HALF OF THE STATE. THE STRONGEST ACTIVITY WILL BE NORTH
OF THE KTUS-KSAD LINE...WITH LITTLE TO NO DEVELOPMENT EXPECTED
NEAR THE INTERNATIONAL BORDER. THAT BEING SAID...THE DEEP MOISTURE
REMAINS OVER THE AREA AND THE UPPER TROUGH SHOULD PUSH SOME ADDED
FORCING SO SOME NEW DEVELOPMENT WILL BE POSSIBLE THROUGH 12Z.
STILL...CONFIDENCE REMAINS TOO LOW AT THIS TIME TO WARRANT MENTION
IN THE TAF. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL CONTINUE TO
DIMINISH DURING THE OVERNIGHT HOURS. A DRYING TREND WILL GET
STARTED WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY
WARMER TEMPERATURES. THURSDAY THROUGH THE SATURDAY...THE DRYING
WILL CONTINUE WITH SIGNIFICANTLY LOWER RH LEVELS...WARMER
TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS EXPECTED. SUNDAY INTO
THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A MODERATION IN RH
LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE DRY AND RATHER
WARM.

&&

.PREV DISCUSSION... /ISSUED 209 PM MST TUE AUG 26 2014/

DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.

&&

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

$$

DISCUSSION...MEADOWS

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






000
FXUS65 KPSR 270106
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
605 PM MST TUE AUG 26 2014

.UPDATE...EARLY EVENING DISCUSSION UPDATE AND REMOVAL OF THE FLASH
FLOOD WATCH HEADLINE...

&&

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
DRY AIR INTRUSION FROM THE WEST TO SOUTHWEST NOTED CLEARLY ON
EVENING IR/WV IMAGERY ACROSS SOUTHWESTERN AND SOUTH-CENTRAL AZ THIS
EVENING. WIDELY SCATTERED ACTIVITY CONTINUES TO PERCOLATE OVER
PORTIONS OF THE LOWER DESERT LOCALES...WITH THE BEST LOOKING
ACTIVITY EXPANDING IN COVERAGE ACROSS SOUTHERN GILA COUNTY. EARLIER
STORM ACTIVITY OVER LA PAZ COUNTY HAS GRADUALLY DIMINISHED IN
COVERAGE AND INTENSITY OVER THE LAST HOUR...WITH POP-UP SHOWERS
PULSING IN AREAS WHERE SPC MESOANALYSIS DEPICT 1000-1500 J/KG
POCKETS OF SBCAPE. UPPER JET STREAK ANALYZED RUNNING SW-NE RIGHT
OVER CENTRAL AZ...WITH JET ENTRANCE ENERGY HELPING ORGANIZE THE
ACTIVITY OVER SOUTHERN GILA COUNTY.

WITH DRYING...LOSS OF DIURNAL HEATING AND THE DEPARTURE OF THE JET
ENERGY TO OUR NORTHEAST...WILL LOOK FOR ONLY ISOLATED STORM COVERAGE
TO CONTINUE INTO THE EVENING HOURS. 00Z KPSR BALLOON STILL PRESENTS
WITH SOME MINIMAL CAPE...NEAR 900 J/KG. COULD CONCEIVABLY SEE STORM
ACTIVITY RIGHT UP TO THE PERIPHERY OF THE PHX METRO BUT WIDESPREAD
ORGANIZED ACTIVITY NOT LOOKING VERY LIKELY ATTM. THE EARLIER FLASH
FLOOD WATCH WAS ALLOWED TO EXPIRE AT 5 PM MST. THE CONCERN FOR
WIDESPREAD FLASH FLOODING IS NOT AS GREAT...ESPECIALLY AS DRIER AIR
CONTINUES TO WORK INTO THE REGION. ANY ADDITIONAL STORM ACTIVITY TO
DEVELOP IN THE EVENING COULD PRODUCE BRIEF MODERATE TO HEAVY
RAINFALL...ALONG THE WITH COMBINATION THREAT FOR STRONG GUSTY
WINDS. THERE REMAINS A FAR AMOUNT OF ACTIVITY MOVING ACROSS
SOUTHEAST AZ THAT COULD SEND OUTFLOW BOUNDARIES INTO THE AREA. IN
ADDITION...SEVERAL OUTFLOW BOUNDARIES HAVE BEEN TRACKING ACROSS THE
PHX METRO FROM THE NORTH...WITH OBSERVED GUSTS NEAR 30 MPH WITH THE
BEST LOOKING OUTFLOW NEAR MESA FALCON-FIELD AT TIME OF THIS WRITING.
MAY NEED TO DEAL WITH LOCALIZED BLOWING DUST IS OUTFLOWS REMAIN
TOGETHER AND TRAVEL LONG ENOUGH INTO THE OUR FORECAST AREA FROM THE
SOUTHEAST.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

WIDELY SCATTERED STORM COVERAGE WILL PERSIST ON THE PERIPHERY OF THE
PHX METRO AND PERIODICALLY IMPACT THE TRACON GATES...BUT CONFIDENCE
IS LOW OF ANY ORGANIZED ACTIVITY FOR THE TERMINALS. WEAK ACTIVITY
OVER NW PINAL COULD CLIP KIWA...SO ADDED VCSH...BUT RADAR RETURNS
ARE QUICKLY LOOSING ANY PUNCH AS THE APPROACH THE TERMINAL. OUTFLOW
BOUNDARIES ALREADY OBSERVED MOVING IN FROM THE NORTH...WHICH COULD
BRIEFING TRANSITION WINDS AROUND AT THE TERMINALS...IF THEY COULD
OVERCOME THE STRONGER AND DRY WEST FLOW ALREADY IN PLACE ACROSS THE
REGION. ADDITIONAL OUTFLOW ACTIVITY COULD TRANSITION INTO THE AREA
FROM THE SOUTHEAST...WITH THE POSSIBILITY OF SOME VSBY REDUCING
DUST...BUT WILL CONTINUE MONITOR THE SITUATION BEFORE INTRODUCING
ANYTHING MVFR VSBYS. CONFIDENCE REMAINS LOW TO INCLUDE THUNDER IN
THE TAFS...WILL SIMPLY CARRY SCT-BKN CUMULUS DECKS MAINLY FROM
7-10K FEET. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A
DRIER MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE/CB
FIRE WEATHER...CB









000
FXUS65 KPSR 270106
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
605 PM MST TUE AUG 26 2014

.UPDATE...EARLY EVENING DISCUSSION UPDATE AND REMOVAL OF THE FLASH
FLOOD WATCH HEADLINE...

&&

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
DRY AIR INTRUSION FROM THE WEST TO SOUTHWEST NOTED CLEARLY ON
EVENING IR/WV IMAGERY ACROSS SOUTHWESTERN AND SOUTH-CENTRAL AZ THIS
EVENING. WIDELY SCATTERED ACTIVITY CONTINUES TO PERCOLATE OVER
PORTIONS OF THE LOWER DESERT LOCALES...WITH THE BEST LOOKING
ACTIVITY EXPANDING IN COVERAGE ACROSS SOUTHERN GILA COUNTY. EARLIER
STORM ACTIVITY OVER LA PAZ COUNTY HAS GRADUALLY DIMINISHED IN
COVERAGE AND INTENSITY OVER THE LAST HOUR...WITH POP-UP SHOWERS
PULSING IN AREAS WHERE SPC MESOANALYSIS DEPICT 1000-1500 J/KG
POCKETS OF SBCAPE. UPPER JET STREAK ANALYZED RUNNING SW-NE RIGHT
OVER CENTRAL AZ...WITH JET ENTRANCE ENERGY HELPING ORGANIZE THE
ACTIVITY OVER SOUTHERN GILA COUNTY.

WITH DRYING...LOSS OF DIURNAL HEATING AND THE DEPARTURE OF THE JET
ENERGY TO OUR NORTHEAST...WILL LOOK FOR ONLY ISOLATED STORM COVERAGE
TO CONTINUE INTO THE EVENING HOURS. 00Z KPSR BALLOON STILL PRESENTS
WITH SOME MINIMAL CAPE...NEAR 900 J/KG. COULD CONCEIVABLY SEE STORM
ACTIVITY RIGHT UP TO THE PERIPHERY OF THE PHX METRO BUT WIDESPREAD
ORGANIZED ACTIVITY NOT LOOKING VERY LIKELY ATTM. THE EARLIER FLASH
FLOOD WATCH WAS ALLOWED TO EXPIRE AT 5 PM MST. THE CONCERN FOR
WIDESPREAD FLASH FLOODING IS NOT AS GREAT...ESPECIALLY AS DRIER AIR
CONTINUES TO WORK INTO THE REGION. ANY ADDITIONAL STORM ACTIVITY TO
DEVELOP IN THE EVENING COULD PRODUCE BRIEF MODERATE TO HEAVY
RAINFALL...ALONG THE WITH COMBINATION THREAT FOR STRONG GUSTY
WINDS. THERE REMAINS A FAR AMOUNT OF ACTIVITY MOVING ACROSS
SOUTHEAST AZ THAT COULD SEND OUTFLOW BOUNDARIES INTO THE AREA. IN
ADDITION...SEVERAL OUTFLOW BOUNDARIES HAVE BEEN TRACKING ACROSS THE
PHX METRO FROM THE NORTH...WITH OBSERVED GUSTS NEAR 30 MPH WITH THE
BEST LOOKING OUTFLOW NEAR MESA FALCON-FIELD AT TIME OF THIS WRITING.
MAY NEED TO DEAL WITH LOCALIZED BLOWING DUST IS OUTFLOWS REMAIN
TOGETHER AND TRAVEL LONG ENOUGH INTO THE OUR FORECAST AREA FROM THE
SOUTHEAST.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

WIDELY SCATTERED STORM COVERAGE WILL PERSIST ON THE PERIPHERY OF THE
PHX METRO AND PERIODICALLY IMPACT THE TRACON GATES...BUT CONFIDENCE
IS LOW OF ANY ORGANIZED ACTIVITY FOR THE TERMINALS. WEAK ACTIVITY
OVER NW PINAL COULD CLIP KIWA...SO ADDED VCSH...BUT RADAR RETURNS
ARE QUICKLY LOOSING ANY PUNCH AS THE APPROACH THE TERMINAL. OUTFLOW
BOUNDARIES ALREADY OBSERVED MOVING IN FROM THE NORTH...WHICH COULD
BRIEFING TRANSITION WINDS AROUND AT THE TERMINALS...IF THEY COULD
OVERCOME THE STRONGER AND DRY WEST FLOW ALREADY IN PLACE ACROSS THE
REGION. ADDITIONAL OUTFLOW ACTIVITY COULD TRANSITION INTO THE AREA
FROM THE SOUTHEAST...WITH THE POSSIBILITY OF SOME VSBY REDUCING
DUST...BUT WILL CONTINUE MONITOR THE SITUATION BEFORE INTRODUCING
ANYTHING MVFR VSBYS. CONFIDENCE REMAINS LOW TO INCLUDE THUNDER IN
THE TAFS...WILL SIMPLY CARRY SCT-BKN CUMULUS DECKS MAINLY FROM
7-10K FEET. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A
DRIER MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE/CB
FIRE WEATHER...CB









000
FXUS65 KPSR 270106
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
605 PM MST TUE AUG 26 2014

.UPDATE...EARLY EVENING DISCUSSION UPDATE AND REMOVAL OF THE FLASH
FLOOD WATCH HEADLINE...

&&

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
DRY AIR INTRUSION FROM THE WEST TO SOUTHWEST NOTED CLEARLY ON
EVENING IR/WV IMAGERY ACROSS SOUTHWESTERN AND SOUTH-CENTRAL AZ THIS
EVENING. WIDELY SCATTERED ACTIVITY CONTINUES TO PERCOLATE OVER
PORTIONS OF THE LOWER DESERT LOCALES...WITH THE BEST LOOKING
ACTIVITY EXPANDING IN COVERAGE ACROSS SOUTHERN GILA COUNTY. EARLIER
STORM ACTIVITY OVER LA PAZ COUNTY HAS GRADUALLY DIMINISHED IN
COVERAGE AND INTENSITY OVER THE LAST HOUR...WITH POP-UP SHOWERS
PULSING IN AREAS WHERE SPC MESOANALYSIS DEPICT 1000-1500 J/KG
POCKETS OF SBCAPE. UPPER JET STREAK ANALYZED RUNNING SW-NE RIGHT
OVER CENTRAL AZ...WITH JET ENTRANCE ENERGY HELPING ORGANIZE THE
ACTIVITY OVER SOUTHERN GILA COUNTY.

WITH DRYING...LOSS OF DIURNAL HEATING AND THE DEPARTURE OF THE JET
ENERGY TO OUR NORTHEAST...WILL LOOK FOR ONLY ISOLATED STORM COVERAGE
TO CONTINUE INTO THE EVENING HOURS. 00Z KPSR BALLOON STILL PRESENTS
WITH SOME MINIMAL CAPE...NEAR 900 J/KG. COULD CONCEIVABLY SEE STORM
ACTIVITY RIGHT UP TO THE PERIPHERY OF THE PHX METRO BUT WIDESPREAD
ORGANIZED ACTIVITY NOT LOOKING VERY LIKELY ATTM. THE EARLIER FLASH
FLOOD WATCH WAS ALLOWED TO EXPIRE AT 5 PM MST. THE CONCERN FOR
WIDESPREAD FLASH FLOODING IS NOT AS GREAT...ESPECIALLY AS DRIER AIR
CONTINUES TO WORK INTO THE REGION. ANY ADDITIONAL STORM ACTIVITY TO
DEVELOP IN THE EVENING COULD PRODUCE BRIEF MODERATE TO HEAVY
RAINFALL...ALONG THE WITH COMBINATION THREAT FOR STRONG GUSTY
WINDS. THERE REMAINS A FAR AMOUNT OF ACTIVITY MOVING ACROSS
SOUTHEAST AZ THAT COULD SEND OUTFLOW BOUNDARIES INTO THE AREA. IN
ADDITION...SEVERAL OUTFLOW BOUNDARIES HAVE BEEN TRACKING ACROSS THE
PHX METRO FROM THE NORTH...WITH OBSERVED GUSTS NEAR 30 MPH WITH THE
BEST LOOKING OUTFLOW NEAR MESA FALCON-FIELD AT TIME OF THIS WRITING.
MAY NEED TO DEAL WITH LOCALIZED BLOWING DUST IS OUTFLOWS REMAIN
TOGETHER AND TRAVEL LONG ENOUGH INTO THE OUR FORECAST AREA FROM THE
SOUTHEAST.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

WIDELY SCATTERED STORM COVERAGE WILL PERSIST ON THE PERIPHERY OF THE
PHX METRO AND PERIODICALLY IMPACT THE TRACON GATES...BUT CONFIDENCE
IS LOW OF ANY ORGANIZED ACTIVITY FOR THE TERMINALS. WEAK ACTIVITY
OVER NW PINAL COULD CLIP KIWA...SO ADDED VCSH...BUT RADAR RETURNS
ARE QUICKLY LOOSING ANY PUNCH AS THE APPROACH THE TERMINAL. OUTFLOW
BOUNDARIES ALREADY OBSERVED MOVING IN FROM THE NORTH...WHICH COULD
BRIEFING TRANSITION WINDS AROUND AT THE TERMINALS...IF THEY COULD
OVERCOME THE STRONGER AND DRY WEST FLOW ALREADY IN PLACE ACROSS THE
REGION. ADDITIONAL OUTFLOW ACTIVITY COULD TRANSITION INTO THE AREA
FROM THE SOUTHEAST...WITH THE POSSIBILITY OF SOME VSBY REDUCING
DUST...BUT WILL CONTINUE MONITOR THE SITUATION BEFORE INTRODUCING
ANYTHING MVFR VSBYS. CONFIDENCE REMAINS LOW TO INCLUDE THUNDER IN
THE TAFS...WILL SIMPLY CARRY SCT-BKN CUMULUS DECKS MAINLY FROM
7-10K FEET. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A
DRIER MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE/CB
FIRE WEATHER...CB









000
FXUS65 KPSR 270106
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
605 PM MST TUE AUG 26 2014

.UPDATE...EARLY EVENING DISCUSSION UPDATE AND REMOVAL OF THE FLASH
FLOOD WATCH HEADLINE...

&&

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
DRY AIR INTRUSION FROM THE WEST TO SOUTHWEST NOTED CLEARLY ON
EVENING IR/WV IMAGERY ACROSS SOUTHWESTERN AND SOUTH-CENTRAL AZ THIS
EVENING. WIDELY SCATTERED ACTIVITY CONTINUES TO PERCOLATE OVER
PORTIONS OF THE LOWER DESERT LOCALES...WITH THE BEST LOOKING
ACTIVITY EXPANDING IN COVERAGE ACROSS SOUTHERN GILA COUNTY. EARLIER
STORM ACTIVITY OVER LA PAZ COUNTY HAS GRADUALLY DIMINISHED IN
COVERAGE AND INTENSITY OVER THE LAST HOUR...WITH POP-UP SHOWERS
PULSING IN AREAS WHERE SPC MESOANALYSIS DEPICT 1000-1500 J/KG
POCKETS OF SBCAPE. UPPER JET STREAK ANALYZED RUNNING SW-NE RIGHT
OVER CENTRAL AZ...WITH JET ENTRANCE ENERGY HELPING ORGANIZE THE
ACTIVITY OVER SOUTHERN GILA COUNTY.

WITH DRYING...LOSS OF DIURNAL HEATING AND THE DEPARTURE OF THE JET
ENERGY TO OUR NORTHEAST...WILL LOOK FOR ONLY ISOLATED STORM COVERAGE
TO CONTINUE INTO THE EVENING HOURS. 00Z KPSR BALLOON STILL PRESENTS
WITH SOME MINIMAL CAPE...NEAR 900 J/KG. COULD CONCEIVABLY SEE STORM
ACTIVITY RIGHT UP TO THE PERIPHERY OF THE PHX METRO BUT WIDESPREAD
ORGANIZED ACTIVITY NOT LOOKING VERY LIKELY ATTM. THE EARLIER FLASH
FLOOD WATCH WAS ALLOWED TO EXPIRE AT 5 PM MST. THE CONCERN FOR
WIDESPREAD FLASH FLOODING IS NOT AS GREAT...ESPECIALLY AS DRIER AIR
CONTINUES TO WORK INTO THE REGION. ANY ADDITIONAL STORM ACTIVITY TO
DEVELOP IN THE EVENING COULD PRODUCE BRIEF MODERATE TO HEAVY
RAINFALL...ALONG THE WITH COMBINATION THREAT FOR STRONG GUSTY
WINDS. THERE REMAINS A FAR AMOUNT OF ACTIVITY MOVING ACROSS
SOUTHEAST AZ THAT COULD SEND OUTFLOW BOUNDARIES INTO THE AREA. IN
ADDITION...SEVERAL OUTFLOW BOUNDARIES HAVE BEEN TRACKING ACROSS THE
PHX METRO FROM THE NORTH...WITH OBSERVED GUSTS NEAR 30 MPH WITH THE
BEST LOOKING OUTFLOW NEAR MESA FALCON-FIELD AT TIME OF THIS WRITING.
MAY NEED TO DEAL WITH LOCALIZED BLOWING DUST IS OUTFLOWS REMAIN
TOGETHER AND TRAVEL LONG ENOUGH INTO THE OUR FORECAST AREA FROM THE
SOUTHEAST.

&&

.PREVIOUS DISCUSSION /ISSUED AT 145 PM MST/PDT...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

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

WIDELY SCATTERED STORM COVERAGE WILL PERSIST ON THE PERIPHERY OF THE
PHX METRO AND PERIODICALLY IMPACT THE TRACON GATES...BUT CONFIDENCE
IS LOW OF ANY ORGANIZED ACTIVITY FOR THE TERMINALS. WEAK ACTIVITY
OVER NW PINAL COULD CLIP KIWA...SO ADDED VCSH...BUT RADAR RETURNS
ARE QUICKLY LOOSING ANY PUNCH AS THE APPROACH THE TERMINAL. OUTFLOW
BOUNDARIES ALREADY OBSERVED MOVING IN FROM THE NORTH...WHICH COULD
BRIEFING TRANSITION WINDS AROUND AT THE TERMINALS...IF THEY COULD
OVERCOME THE STRONGER AND DRY WEST FLOW ALREADY IN PLACE ACROSS THE
REGION. ADDITIONAL OUTFLOW ACTIVITY COULD TRANSITION INTO THE AREA
FROM THE SOUTHEAST...WITH THE POSSIBILITY OF SOME VSBY REDUCING
DUST...BUT WILL CONTINUE MONITOR THE SITUATION BEFORE INTRODUCING
ANYTHING MVFR VSBYS. CONFIDENCE REMAINS LOW TO INCLUDE THUNDER IN
THE TAFS...WILL SIMPLY CARRY SCT-BKN CUMULUS DECKS MAINLY FROM
7-10K FEET. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A
DRIER MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...NOLTE
PREVIOUS DISCUSSION...AJ/MO
AVIATION...NOLTE/CB
FIRE WEATHER...CB









000
FXUS65 KFGZ 262221
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
320 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS TO THE NORTHLAND TONIGHT.  STORMS WILL DECREASE FROM
SOUTHWEST TO NORTHEAST OVERNIGHT...WITH SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE AREA.
A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND SLIGHTLY
WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...BRIEF DISCUSSION WITH ONGOING CONVECTIVE ACTIVITY...
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPED OVER NORTHERN ARIZONA
TODAY...WITH THE STRONGEST ACTIVITY PERISTING SOUTH OF INTERSTATE 40
WHERE INSTABILITY HAS BEEN GREATEST. ACTIVITY HAS DIMINISHED OVER THE
PAST COUPLE HOURS OVER WESTERN AZ AS SUBSIDENCE AND DRIER AIR STARTS
TO WORK ON THE ATMOSPHERE...BUT EXPECT STORMS TO PERSIST AHEAD OF THE
SHORTWAVE AXIS WHERE INSTABILITY IN EXCESS OF 1000J/KG...AND 0-6KM
BULK SHEAR 30-40KTS WIND SHEAR STILL POSE A THREAT OF STRONG TO SVR
STORMS AND HEAVY RAINFALL. FLASH FLOOD WATCH TO CONTINUE AS ISSUED.

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCT TO NMRS SHRA/TSRA AND ISOLD +TSRA WILL
PERSIST EAST OF A KPGA-KFGZ LINE 00-05Z...WITH -SHRA TO THE WEST.
STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST 05Z-10Z. ISOLD
TO SCT SHRA/-TSRA WILL CONTINUE THROUGH 10Z-18Z WED GENERALLY NE OF
A LINE FROM KPGA-KRQE...WITH REDEVELOPMENT OF -TSRA OVR NRN AZ HIGHER
TERRAIN AFTER 18Z WED. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........BAK
AVIATION.......BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 262221
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
320 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS TO THE NORTHLAND TONIGHT.  STORMS WILL DECREASE FROM
SOUTHWEST TO NORTHEAST OVERNIGHT...WITH SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE AREA.
A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND SLIGHTLY
WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...BRIEF DISCUSSION WITH ONGOING CONVECTIVE ACTIVITY...
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPED OVER NORTHERN ARIZONA
TODAY...WITH THE STRONGEST ACTIVITY PERISTING SOUTH OF INTERSTATE 40
WHERE INSTABILITY HAS BEEN GREATEST. ACTIVITY HAS DIMINISHED OVER THE
PAST COUPLE HOURS OVER WESTERN AZ AS SUBSIDENCE AND DRIER AIR STARTS
TO WORK ON THE ATMOSPHERE...BUT EXPECT STORMS TO PERSIST AHEAD OF THE
SHORTWAVE AXIS WHERE INSTABILITY IN EXCESS OF 1000J/KG...AND 0-6KM
BULK SHEAR 30-40KTS WIND SHEAR STILL POSE A THREAT OF STRONG TO SVR
STORMS AND HEAVY RAINFALL. FLASH FLOOD WATCH TO CONTINUE AS ISSUED.

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCT TO NMRS SHRA/TSRA AND ISOLD +TSRA WILL
PERSIST EAST OF A KPGA-KFGZ LINE 00-05Z...WITH -SHRA TO THE WEST.
STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST 05Z-10Z. ISOLD
TO SCT SHRA/-TSRA WILL CONTINUE THROUGH 10Z-18Z WED GENERALLY NE OF
A LINE FROM KPGA-KRQE...WITH REDEVELOPMENT OF -TSRA OVR NRN AZ HIGHER
TERRAIN AFTER 18Z WED. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........BAK
AVIATION.......BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 262221
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
320 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS TO THE NORTHLAND TONIGHT.  STORMS WILL DECREASE FROM
SOUTHWEST TO NORTHEAST OVERNIGHT...WITH SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE AREA.
A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND SLIGHTLY
WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...BRIEF DISCUSSION WITH ONGOING CONVECTIVE ACTIVITY...
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPED OVER NORTHERN ARIZONA
TODAY...WITH THE STRONGEST ACTIVITY PERISTING SOUTH OF INTERSTATE 40
WHERE INSTABILITY HAS BEEN GREATEST. ACTIVITY HAS DIMINISHED OVER THE
PAST COUPLE HOURS OVER WESTERN AZ AS SUBSIDENCE AND DRIER AIR STARTS
TO WORK ON THE ATMOSPHERE...BUT EXPECT STORMS TO PERSIST AHEAD OF THE
SHORTWAVE AXIS WHERE INSTABILITY IN EXCESS OF 1000J/KG...AND 0-6KM
BULK SHEAR 30-40KTS WIND SHEAR STILL POSE A THREAT OF STRONG TO SVR
STORMS AND HEAVY RAINFALL. FLASH FLOOD WATCH TO CONTINUE AS ISSUED.

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCT TO NMRS SHRA/TSRA AND ISOLD +TSRA WILL
PERSIST EAST OF A KPGA-KFGZ LINE 00-05Z...WITH -SHRA TO THE WEST.
STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST 05Z-10Z. ISOLD
TO SCT SHRA/-TSRA WILL CONTINUE THROUGH 10Z-18Z WED GENERALLY NE OF
A LINE FROM KPGA-KRQE...WITH REDEVELOPMENT OF -TSRA OVR NRN AZ HIGHER
TERRAIN AFTER 18Z WED. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........BAK
AVIATION.......BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KFGZ 262221
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
320 PM MST TUE AUG 25 2014

.SYNOPSIS...
A LOW PRESSURE TROUGH WILL CONTINUE TO BRING NUMEROUS SHOWERS AND
THUNDERSTORMS TO THE NORTHLAND TONIGHT.  STORMS WILL DECREASE FROM
SOUTHWEST TO NORTHEAST OVERNIGHT...WITH SCATTERED STORMS EXPECTED
AGAIN ON WEDNESDAY AS THE LOW PRESSURE AREA PULLS AWAY FROM THE AREA.
A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS AND SLIGHTLY
WARMER HIGH TEMPERATURES FROM THURSDAY THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...BRIEF DISCUSSION WITH ONGOING CONVECTIVE ACTIVITY...
NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPED OVER NORTHERN ARIZONA
TODAY...WITH THE STRONGEST ACTIVITY PERISTING SOUTH OF INTERSTATE 40
WHERE INSTABILITY HAS BEEN GREATEST. ACTIVITY HAS DIMINISHED OVER THE
PAST COUPLE HOURS OVER WESTERN AZ AS SUBSIDENCE AND DRIER AIR STARTS
TO WORK ON THE ATMOSPHERE...BUT EXPECT STORMS TO PERSIST AHEAD OF THE
SHORTWAVE AXIS WHERE INSTABILITY IN EXCESS OF 1000J/KG...AND 0-6KM
BULK SHEAR 30-40KTS WIND SHEAR STILL POSE A THREAT OF STRONG TO SVR
STORMS AND HEAVY RAINFALL. FLASH FLOOD WATCH TO CONTINUE AS ISSUED.

RECENT HRRR RUNS CONSISTENT WITH DOWNSWING IN ACTIVITY FROM SOUTHWEST
TO NORTHEAST ACROSS THE CWA THIS EVENING AS DRY AIR AND SUBSIDENCE
WORKS IN FROM THE WEST...WITH PRIMARY IMPACTS LIMITED TO NE AZ AFTER
06Z. CURRENT TRENDS SUPPORT THESE FORECASTS.

ON WEDNESDAY...LINGERING BOUNDARY LAYER MOISTURE WILL BE ADEQUATE FOR
SCATTERED SHOWERS AND THUNDERSTORMS TO REDEVELOP...MOST NUMEROUS OVER
AND NORTHEAST OF THE MOGOLLON RIM.

THURSDAY THROUGH THE WEEKEND...MODELS CONTINUE TO BE CONSISTENT WITH
STRONG RIDGING OVER THE SOUTHWEST...BRINGING FAIR AND WARM WEATHER
TO THE NORTHLAND THROUGH THE WEEKEND...AND INTO EARLY NEXT WEEK.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCT TO NMRS SHRA/TSRA AND ISOLD +TSRA WILL
PERSIST EAST OF A KPGA-KFGZ LINE 00-05Z...WITH -SHRA TO THE WEST.
STORMS WILL DECREASE FROM THE SOUTHWEST TO NORTHEAST 05Z-10Z. ISOLD
TO SCT SHRA/-TSRA WILL CONTINUE THROUGH 10Z-18Z WED GENERALLY NE OF
A LINE FROM KPGA-KRQE...WITH REDEVELOPMENT OF -TSRA OVR NRN AZ HIGHER
TERRAIN AFTER 18Z WED. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........BAK
AVIATION.......BAK

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF



000
FXUS65 KTWC 262109
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
209 PM MST TUE AUG 26 2014

.SYNOPSIS...DEEP MOISTURE WILL GENERATE SHOWERS AND THUNDERSTORMS
THROUGH THE EVENING. A PRONOUNCED DRYING TREND IS EXPECTED OVER
THE NEXT SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.


&&

.AVIATION...
SCATTERED TO NUMEROUS SHRA/TSRA+ WILL CONTINUE THRU 27/02Z BEFORE
TAPERING OFF AND ENDING BY 27/08Z.  EXPECT SCT-BKN 6-10KFT AGL
AND BKN LAYERS ABOVE WITH LCL MVFR CONDS NEAR STRONGEST TSRA+.  AFT
27/08Z CONDS BECOMING FEW-SCT060 WITH SCT-BKN LAYERS ABV 12KFT AGL.
SFC WINDS VARIABLE TO 10 KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO
45 MPH ARE POSSIBLE.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS AND THUNDERSTORMS EARLY THIS
EVENING WILL TAPER OFF AND END AROUND OR SHORTLY AFTER MIDNIGHT.  A
DRYING TREND WILL GET STARTED WEDNESDAY WITH MUCH LESS CONVECTION
EXPECTED AND SLIGHTLY WARMER TEMPERATURES.  THURSDAY THROUGH THE
SATURDAY...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY LOWER RH
LEVELS...WARMER TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS
EXPECTED.  SUNDAY INTO THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A
MODERATION IN RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE
DRY AND RATHER WARM.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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






000
FXUS65 KTWC 262109
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
209 PM MST TUE AUG 26 2014

.SYNOPSIS...DEEP MOISTURE WILL GENERATE SHOWERS AND THUNDERSTORMS
THROUGH THE EVENING. A PRONOUNCED DRYING TREND IS EXPECTED OVER
THE NEXT SEVERAL DAYS AS DRY NORTHWESTERLY FLOW OVERSPREADS ARIZONA.

&&

.DISCUSSION...A MID/UPPER LEVEL TROUGH CONTINUES TO TRACK EASTWARD
THIS AFTERNOON. DEEP MOISTURE AND INSTABILITY AHEAD OF THE TROUGH
IS BEING ENHANCED...WITH WIDESPREAD THUNDERSTORM ACTIVITY BEING
OBSERVED ACROSS MUCH OF THE STATE. STRONG DYNAMIC LIFT IS TAKING
PLACE OVER NORTHERN ARIZONA AND SOUTHERN UTAH...WITH SOME
SIGNIFICANT DEEP CONVECTION TAKING PLACE. THE WEATHER OF SOUTHEAST
ARIZONA IS BEING DRIVEN BY SURFACE BASED INSTABILITY AND LINGERING
DEEP MOISTURE. THUNDERSTORMS HAVE BEEN DEVELOPING FOR SEVERAL
HOURS...AND ARE EXPECTED TO CONTINUE TO DEVELOP THROUGHOUT THE
AFTERNOON AND EVENING. MOST STORMS HAVE INITIALLY BEEN STUCK
ALONG/OVER TERRAIN AREAS. HEAVY RAINFALL HAS BEEN OBSERVED WITH
MANY OF THE STORMS. AS THE REMAINDER OF THE DAY PROGRESSES SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO FILL IN MANY LOWER ELEVATION
AREAS AS WELL. A FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH 8 PM
AND LOCAL FLOODING IS CERTAINLY POSSIBLE.

THE TROUGH WILL CONTINUE ITS PROGRESSION OVER ARIZONA TONIGHT INTO
EARLY THURSDAY. INITIALLY...THE TROUGH WILL ACT TO DEVELOP
CONVECTION OVER THE AREA...ALTHOUGH THE THREAT OF HEAVIEST
PRECIPITATION WILL SHIFT NORTHWARD. A MUCH DRIER AIRMASS WILL
ADVECT OVER ARIZONA ON THE BACKSIDE OF THE TROUGH BEGINNING AS
EARLY AS WEDNESDAY AFTERNOON. THE DRY NORTHWEST FLOW ALOFT WILL BE
ENHANCED THROUGH THE REMAINDER OF THE WEEK AS A MID/UPPER RIDGE OF
HIGH PRESSURE BUILDS TO OUR WEST ALONG THE WEST COAST. UNDER THIS
REGIME PRECIPITATION CHANCES WILL PLUMMET AND TEMPERATURES WILL
CREEP UPWARD.

LONG RANGE MODELS SHOW LITTLE CHANGE IN THIS OVERALL PATTERN UNTIL
PERHAPS THE MIDDLE OF NEXT WEEK.


&&

.AVIATION...
SCATTERED TO NUMEROUS SHRA/TSRA+ WILL CONTINUE THRU 27/02Z BEFORE
TAPERING OFF AND ENDING BY 27/08Z.  EXPECT SCT-BKN 6-10KFT AGL
AND BKN LAYERS ABOVE WITH LCL MVFR CONDS NEAR STRONGEST TSRA+.  AFT
27/08Z CONDS BECOMING FEW-SCT060 WITH SCT-BKN LAYERS ABV 12KFT AGL.
SFC WINDS VARIABLE TO 10 KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO
45 MPH ARE POSSIBLE.  AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...
WIDESPREAD SHOWERS AND THUNDERSTORMS EARLY THIS
EVENING WILL TAPER OFF AND END AROUND OR SHORTLY AFTER MIDNIGHT.  A
DRYING TREND WILL GET STARTED WEDNESDAY WITH MUCH LESS CONVECTION
EXPECTED AND SLIGHTLY WARMER TEMPERATURES.  THURSDAY THROUGH THE
SATURDAY...THE DRYING WILL CONTINUE WITH SIGNIFICANTLY LOWER RH
LEVELS...WARMER TEMPERATURES AND NO SHOWERS OR THUNDERSTORMS
EXPECTED.  SUNDAY INTO THE MIDDLE OF NEXT WEEK WILL SEE A BIT OF A
MODERATION IN RH LEVELS BUT AT THIS TIME IT IS STILL EXPECTED TO BE
DRY AND RATHER WARM.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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







000
FXUS65 KPSR 262046
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

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






000
FXUS65 KPSR 262046
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

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






000
FXUS65 KPSR 262046
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

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






000
FXUS65 KPSR 262046
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST TUE AUG 26 2014

.SYNOPSIS...
AFTER TODAY...STORM ACTIVITY WILL BEGIN TO TREND DOWNWARD OVER
ARIZONA AS A LOW PRESSURE SYSTEM STARTS TO SHIFT EASTWARD.
MUCH DRIER AIR WILL MOVE INTO THE REGION FROM THE NORTH WITH DRY
CONDITIONS EXPECTED THURSDAY THROUGH TUESDAY.

&&

.DISCUSSION...
A STRONG STORM PASSED THROUGH PARKER AROUND MIDDAY AND VERY STRONG
STORMS DEVELOPED JUST NORTH OF LA PAZ COUNTY SHORTLY THEREAFTER.
GOOD CAPE AIDED BY DYNAMICAL FORCING...ASSOCIATED WITH AN UPPER
LOW...CAME TOGETHER. MAIN DYNAMICAL FEATURE IS A JET CENTERED OVER
NORTHWEST ARIZONA. WITH SOME LIFT DRIVEN BY RIGHT ENTRANCE REGION
DYNAMICS STILL TO AFFECT AN AREA STRETCHING FROM PARKER TO
WICKENBURG THIS AFTERNOON...THE FLASH FLOOD WATCH WAS EXPANDED
THERE. THE WATCH WAS ALSO EXPANDED IN TIME TO END AT 5 PM AS HI RES
MODEL GUIDANCE INDICATES STORM ACTIVITY CONTINUING PAST 2
PM...MAINLY OVER SOUTHERN GILA COUNTY. ANOTHER FACTOR IN ADDITION TO
THE SLOWLY DEPARTING JET OVER NORTHWEST ARIZONA IS ANOTHER JET
STREAK ALREADY MOVING ACROSS SOUTHERN ARIZONA PER MODELS. HRRR WAS
SLOW TO CATCH ON TO LA PAZ AND MOHAVE COUNTY ACTIVITY AND OTHER HI
RES MODELS HAVE PRETTY MUCH MISSED IT. HOWEVER...LATEST HRRR SHOWS
ACTIVITY LINGERING OVER LA PAZ COUNTY THROUGH 23Z AND DECREASING
AFTER THAT. IT ALSO SHOWS NORTHERNMOST MARICOPA COUNTY AND GILA
COUNTY BEING ACTIVE WITH MORE SPOTTY ACTIVITY OVER PHOENIX AREA AND
PINAL COUNTY. STORMS WILL NOT ONLY HAVE THE CAPABILITY OF PRODUCING
HEAVY RAIN BUT THERE IS ENOUGH CAPE AND SHEAR...MAINLY WEST OF
PHOENIX...TO BE CONCERNED ABOUT SEVERE POTENTIAL. DYNAMICAL FORCING
SHIFTS NORTHEASTWARD TONIGHT. THIS COMBINED WITH LOSS OF SURFACE
HEATING WILL MEAN A DOWN TREND FOR STORM CHANCES TONIGHT.


WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

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






000
FXUS65 KPSR 261948 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB







000
FXUS65 KPSR 261948 CCA
AFDPSR

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 5 PM THIS AFTERNOON AZZ021>022...AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB






000
FXUS65 KPSR 261945 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB










000
FXUS65 KPSR 261945 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB










000
FXUS65 KPSR 261945 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB










000
FXUS65 KPSR 261945 AAA
AFDPSR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PHOENIX AZ
1245 PM MST TUE AUG 26 2014

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

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
UNFAVORABLE SOUTHWEST TO WEST STEERING FLOW WILL AFFECT THE CENTRAL
DESERTS THIS AFTERNOON AND OVERNIGHT TONIGHT...AND THE STRONGEST
FORCING WILL REMAIN NORTH OF THE PHOENIX AREA...AFFECTING THE
NORTHERN HALF OF THE STATE. STILL...THERE IS PLENTIFUL MOISTURE
LINGERING ACROSS THE CENTRAL DESERTS AND ISOLATED STORMS MAY DEVELOP
LATER THIS AFTERNOON AND PERSIST INTO THE EVENING HOURS. CONFIDENCE
IS TOO LOW TO MENTION THUNDER IN THE TAFS ATTM...WILL SIMPLY CARRY
SCT-BKN CUMULUS DECKS MAINLY FROM 7-10K FEET. SHOULD STORMS FORM
LATER THIS AFTERNOON THAT MAY AFFECT THE TERMINALS...UPDATES WILL BE
MADE TO THE TAFS. ALSO...SHOULD STORMS DEVELOP GUSTY OUTFLOW WINDS
AND BLOWING DUST MAY EVENTUALLY MOVE IN AND AFFECT THE TERMINALS BUT
AGAIN...CONFIDENCE IS TOO LOW TO MENTION THIS IN THE TAFS AT THIS
TIME. OTHERWISE EXPECT CLEARING BY EARLY OR MID EVENING AS A DRIER
MORE STABLE WESTERLY FLOW ALOFT MOVES INTO THE AREA.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION IMPACTS EXPECTED THIS AFTERNOON OR
EVENING...AS THE UPPER LOW TO OUR NORTH SHIFTS OFF TOWARDS THE EAST
AND A DRIER WESTERLY FLOW ALOFT MOVES INTO THE WESTERN DESERTS. BY
EARLY EVENING SKIES WILL BECOME CLEAR OR MOSTLY CLEAR...AND WINDS
WILL DECREASE TO MOSTLY AOB 12KT....FAVORING THE SOUTHWEST OR WEST.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
STRONG HIGH PRESSURE ALOFT WILL CONTINUE ACROSS SOUTHEAST CALIFORNIA
AND SOUTHERN ARIZONA FRIDAY INTO THE WEEKEND...KEEPING A DRY
NORTHWEST FLOW ACROSS THE AREA AND LEADING TO ABOVE NORMAL HIGH
TEMPERATURES. MINIMUM HUMIDITIES WILL BE ON THE LOW SIDE RANGING
MOSTLY FROM 10 TO 15 PERCENT ON FRIDAY AND SATURDAY. FOR SUNDAY INTO
EARLY NEXT WEEK...LOW PRESSURE ALOFT ACROSS THE PACIFIC NORTHWEST
WILL GRADUALLY STRENGTHEN SOUTHWARD LEADING TO INCREASING SOUTHWEST
OR WEST FLOW ALOFT. HIGH TEMPERATURES WILL SLOWLY FALL OFF TO BELOW
NORMAL VALUES BY NEXT TUESDAY. MINIMUM HUMIDITIES WILL STEADILY RISE
SUNDAY THROUGH TUESDAY WITH MANY DESERT LOCALES CLIMBING ABOVE 20
PERCENT. FAIR OVERNIGHT RECOVERIES FRIDAY NIGHT WILL GRADUALLY
INCREASE...BECOMING GOOD OR EXCELLENT BY EARLY NEXT WEEK. STRONG
WINDS ARE NOT EXPECTED DURING THE FIVE DAY PERIOD...HOWEVER LOCALLY
BREEZY CONDITIONS ARE POSSIBLE OVER THE WEEKEND WITH WINDS FAVORING
THE SOUTH TO SOUTHWEST DURING THE AFTERNOON AND EARLY EVENING HOURS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...CB
FIRE WEATHER...CB










000
FXUS65 KFGZ 261728
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1028 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&

.UPDATE...
THE ONLY UPDATE MADE TO THE FORECAST THIS MORNING WAS TO ADD NORTH
CENTRAL AND NORTHEAST ARIZONA TO THE FLASH FLOOD WATCH. WE ARE
ALREADY SEEING STORM DEVELOPMENT IN EAST CENTRAL ARIZONA AND
EXPECT MORE WIDESPREAD ACTIVITY ACROSS THE NORTHEAST BY THIS
AFTERNOON AS THE LARGE SCALE LIFT FROM THE APPROACHING TROUGH ACTS
ON INCREASED MOISTURE (SATELLITE PW ESTIMATES SHOW THREE QUARTERS
OF AN INCH TO AN INCH IN THIS AREA ALREADY). ALL IN ALL...WE STILL
ANTICIPATE A VERY ACTIVE DAY OF CONVECTION ACROSS NORTHERN ARIZONA AIDED
BY SYNOPTIC SCALE LIFT FROM THE UPPER TROUGH. ENHANCED VERTICAL
WIND SHEAR ALSO ADDS A THREAT OF SOME STRONG STORMS. THIS THREAT
IS GREATEST THIS MORNING ACROSS NORTHWESTERN ARIZONA...SHIFTING
INTO NORTHEAST ARIZONA LATE THIS AFTERNOON THROUGH THIS EVENING.

&&

.DISCUSSION...
AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS. IN ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH
SHEAR AND INSTABILITY THAT SOME OF THE STORMS MAY BECOME ORGANIZED
AND STRONG TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.

&&

.AVIATION...
FOR THE 18Z PACKAGE...SCATTERED TO NUMEROUS SHRA/TSRA
ACROSS NORTHERN ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM
ACTIVITY.  SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE
HEAVIER SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR
STRONGER STORMS. STORM COVERAGE DECREASING AFTER 03Z-06Z...AND
MAINLY SHIFTING NE OF KFLG-KSOW LINE OVERNIGHT. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ004>018-037>040.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 261728
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1028 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&

.UPDATE...
THE ONLY UPDATE MADE TO THE FORECAST THIS MORNING WAS TO ADD NORTH
CENTRAL AND NORTHEAST ARIZONA TO THE FLASH FLOOD WATCH. WE ARE
ALREADY SEEING STORM DEVELOPMENT IN EAST CENTRAL ARIZONA AND
EXPECT MORE WIDESPREAD ACTIVITY ACROSS THE NORTHEAST BY THIS
AFTERNOON AS THE LARGE SCALE LIFT FROM THE APPROACHING TROUGH ACTS
ON INCREASED MOISTURE (SATELLITE PW ESTIMATES SHOW THREE QUARTERS
OF AN INCH TO AN INCH IN THIS AREA ALREADY). ALL IN ALL...WE STILL
ANTICIPATE A VERY ACTIVE DAY OF CONVECTION ACROSS NORTHERN ARIZONA AIDED
BY SYNOPTIC SCALE LIFT FROM THE UPPER TROUGH. ENHANCED VERTICAL
WIND SHEAR ALSO ADDS A THREAT OF SOME STRONG STORMS. THIS THREAT
IS GREATEST THIS MORNING ACROSS NORTHWESTERN ARIZONA...SHIFTING
INTO NORTHEAST ARIZONA LATE THIS AFTERNOON THROUGH THIS EVENING.

&&

.DISCUSSION...
AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS. IN ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH
SHEAR AND INSTABILITY THAT SOME OF THE STORMS MAY BECOME ORGANIZED
AND STRONG TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.

&&

.AVIATION...
FOR THE 18Z PACKAGE...SCATTERED TO NUMEROUS SHRA/TSRA
ACROSS NORTHERN ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM
ACTIVITY.  SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE
HEAVIER SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR
STRONGER STORMS. STORM COVERAGE DECREASING AFTER 03Z-06Z...AND
MAINLY SHIFTING NE OF KFLG-KSOW LINE OVERNIGHT. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ004>018-037>040.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 261728
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1028 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&

.UPDATE...
THE ONLY UPDATE MADE TO THE FORECAST THIS MORNING WAS TO ADD NORTH
CENTRAL AND NORTHEAST ARIZONA TO THE FLASH FLOOD WATCH. WE ARE
ALREADY SEEING STORM DEVELOPMENT IN EAST CENTRAL ARIZONA AND
EXPECT MORE WIDESPREAD ACTIVITY ACROSS THE NORTHEAST BY THIS
AFTERNOON AS THE LARGE SCALE LIFT FROM THE APPROACHING TROUGH ACTS
ON INCREASED MOISTURE (SATELLITE PW ESTIMATES SHOW THREE QUARTERS
OF AN INCH TO AN INCH IN THIS AREA ALREADY). ALL IN ALL...WE STILL
ANTICIPATE A VERY ACTIVE DAY OF CONVECTION ACROSS NORTHERN ARIZONA AIDED
BY SYNOPTIC SCALE LIFT FROM THE UPPER TROUGH. ENHANCED VERTICAL
WIND SHEAR ALSO ADDS A THREAT OF SOME STRONG STORMS. THIS THREAT
IS GREATEST THIS MORNING ACROSS NORTHWESTERN ARIZONA...SHIFTING
INTO NORTHEAST ARIZONA LATE THIS AFTERNOON THROUGH THIS EVENING.

&&

.DISCUSSION...
AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS. IN ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH
SHEAR AND INSTABILITY THAT SOME OF THE STORMS MAY BECOME ORGANIZED
AND STRONG TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.

&&

.AVIATION...
FOR THE 18Z PACKAGE...SCATTERED TO NUMEROUS SHRA/TSRA
ACROSS NORTHERN ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM
ACTIVITY.  SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE
HEAVIER SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR
STRONGER STORMS. STORM COVERAGE DECREASING AFTER 03Z-06Z...AND
MAINLY SHIFTING NE OF KFLG-KSOW LINE OVERNIGHT. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ004>018-037>040.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KFGZ 261728
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1028 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&

.UPDATE...
THE ONLY UPDATE MADE TO THE FORECAST THIS MORNING WAS TO ADD NORTH
CENTRAL AND NORTHEAST ARIZONA TO THE FLASH FLOOD WATCH. WE ARE
ALREADY SEEING STORM DEVELOPMENT IN EAST CENTRAL ARIZONA AND
EXPECT MORE WIDESPREAD ACTIVITY ACROSS THE NORTHEAST BY THIS
AFTERNOON AS THE LARGE SCALE LIFT FROM THE APPROACHING TROUGH ACTS
ON INCREASED MOISTURE (SATELLITE PW ESTIMATES SHOW THREE QUARTERS
OF AN INCH TO AN INCH IN THIS AREA ALREADY). ALL IN ALL...WE STILL
ANTICIPATE A VERY ACTIVE DAY OF CONVECTION ACROSS NORTHERN ARIZONA AIDED
BY SYNOPTIC SCALE LIFT FROM THE UPPER TROUGH. ENHANCED VERTICAL
WIND SHEAR ALSO ADDS A THREAT OF SOME STRONG STORMS. THIS THREAT
IS GREATEST THIS MORNING ACROSS NORTHWESTERN ARIZONA...SHIFTING
INTO NORTHEAST ARIZONA LATE THIS AFTERNOON THROUGH THIS EVENING.

&&

.DISCUSSION...
AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS. IN ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH
SHEAR AND INSTABILITY THAT SOME OF THE STORMS MAY BECOME ORGANIZED
AND STRONG TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.

&&

.AVIATION...
FOR THE 18Z PACKAGE...SCATTERED TO NUMEROUS SHRA/TSRA
ACROSS NORTHERN ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM
ACTIVITY.  SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE
HEAVIER SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR
STRONGER STORMS. STORM COVERAGE DECREASING AFTER 03Z-06Z...AND
MAINLY SHIFTING NE OF KFLG-KSOW LINE OVERNIGHT. AVIATION DISCUSSION
NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ004>018-037>040.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF





000
FXUS65 KPSR 261657
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
955 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...MO
FIRE WEATHER...PERCHA/MO







000
FXUS65 KPSR 261657
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
955 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY COMPARED TO YESTERDAY...HOWEVER SOME LOCATIONS MAY MISS OUT ON
RAINFALL ALTOGETHER. STORMS THAT ARE MORE PERSISTENT WILL BE CAPABLE
OF PRODUCING VERY HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM
WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
UPPER LOW CURRENTLY CENTERED OVER NEVADA HAS A VORT LOBE SWINGING
AROUND THE BOTTOM OF THE TROUGH OVER THE MOHAVE DESERT. THIS
FEATURE...AND THE ASSOCIATED JET DYNAMICS...HAS GENERATED SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS OVER JOSHUA TREE NATIONAL PARK
AND PORTIONS OF EASTERN RIVERSIDE COUNTY WITH MOST OF THE ACTIVITY
TO THE NORTH AND NORTHEAST OVER SAN BERNARDINO COUNTY AND MOHAVE
COUNTY. MADE AN UPDATE TO THE FORECAST TO INCREASE POPS OVER EASTERN
RIVERSIDE/JTNP IN RESPONSE TO THE ONGOING SHOWER ACTIVITY AND TO
INCREASE THEM OVER LA PAZ COUNTY AS THE AREA OF FORCING TRANSLATES
EASTWARD. MAIN BRUNT SHOULD STILL BE NORTH OF OUR FORECAST AREA. WE
WILL NEED TO KEEP AN EYE OUT FOR LA PAZ AND NORTHWEST MARICOPA
COUNTY...IN ADDITION TO WHERE WE STILL HAVE THE FLASH FLOOD WATCH.
MAY NEED TO REINSERT THOSE AREAS INTO THE WATCH BUT WILL A BIT
LONGER TO SEE HOW THINGS UNFOLD. LATEST RUC INDICATES A PERSISTENT
BATCH OF FORCING OVER THE PHOENIX AREA THIS AFTERNOON WHICH APPEARS
TO BE ASSOCIATED WITH ANOTHER JET STREAK MOVING ACROSS THE CWA. BUT
12Z NAM AND GFS ARE NOT AS AGGRESSIVE. LOCAL HI RES MODELS FROM 06Z
RUNS KEEP PRECIP OUT OF OUR AREA ALMOST ENTIRELY BUT THEY HAVE NOT
PICKED UP ON THE ACTIVITY IN CALIFORNIA WHICH CALLS THEIR SOLUTIONS
INTO QUESTION. MADE A SUBTLE CHANGE TO PHOENIX AREA FORECAST TO
NUDGE DOWN TO SLIGHT CHANCES FOR THIS MORNING BUT UP TO CHANCE
CATEGORY FOR THIS AFTERNOON. IT IS CONCEIVABLE THAT THE
WATCH...CURRENTLY FOR ZONE 24...MAY NEED TO BE EXTENDED IN TIME. BUT
AGAIN...WILL WAIT A BIT LONGER TO SEE HOW THINGS UNFOLD.

&&

.PREVIOUS DISCUSSION ISSUED 700 AM...
DRY SLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION ISSUED 225 AM...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRY SLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

DISCUSSION...AJ
PREVIOUS DISCUSSION...MO
AVIATION...MO
FIRE WEATHER...PERCHA/MO






000
FXUS65 KTWC 261608
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
908 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

.DISCUSSION...THE COMBINATION OF ELEVATED ATMOSPHERIC
MOISTURE...INSTABILITY...AND AN APPROACHING MID/UPPER TROUGH WILL
LEAD TO AN ACTIVE WEATHER DAY FOR PORTIONS OF SOUTHEAST ARIZONA.
WATER VAPOR IMAGERY IS DEPICTING THE APPROACHING TROUGH NOW
DIGGING EASTWARD ACROSS SOUTHERN CALIFORNIA AND NEVADA. AHEAD OF
THIS TROUGH...SOUTH TO SOUTHWEST FLOW IS FUNNELING AN AIRMASS WITH
NEAR TO ABOVE NORMAL PRECIPITABLE WATER VALUES. A WEAK DISTURBANCE
MOVED AROUND THE BASE OF THE TROUGH AND TRIGGERED SOME
OVERNIGHT/EARLY MORNING CONVECTION OVER THE AREA. THIS FEATURE IS
NOW PROGRESSING TO THE NORTHEAST INTO NEW MEXICO AND MORNING
CONVECTION HAS WANED AREA-WIDE. THE 12Z KTUS SOUNDING INDICATES
THAT A MOIST AND GENERALLY UNSTABLE AIRMASS IS IN PLACE FOR
SOUTHEAST ARIZONA. THE AIRMASS ALSO IS NEARLY SATURATED UP THROUGH
500MB...MEANING STORMS THAT DEVELOP WILL LIKELY BE VERY EFFICIENT
RAIN PRODUCERS. ANOTHER INFLUENTIAL ASPECT OF THE SOUNDING IS
LIGHT WIND FLOW THROUGH THE BOTTOM 6KM OF THE ATMOSPHERIC COLUMN.
THIS COULD MAKE FOR SLOW MOVING STORMS...AT LEAST INITIALLY.

THERE WILL BE A DISTINCT TRANSITION AS THE TROUGH APPROACHES AND
PASSES THROUGH OVER THE NEXT 24 HOURS. CONVECTION WILL LIKELY
TRIGGER OVER AND AROUND TERRAIN INITIALLY...BEFORE INCREASING MID-
LEVEL SOUTHWESTERLY FLOW INCREASES AND BEGINS TO FOCUS CONVECTION
TO THE NORTH. THROUGHOUT THE EVENT TODAY THE BEST DYNAMICS WILL
REMAIN NORTH OF SOUTHEAST ARIZONA...WITH AN EMPHASIS ON NORTHERN
ARIZONA AND SOUTHERN UTAH.

MID/LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AFTER THE TROUGH
PROGRESSES THROUGH OVERNIGHT INTO WEDNESDAY A DRIER AND MORE
STABLE AIRMASS WILL FILTER IN AND REALLY DRY OUT OUR WEATHER
PATTERN THROUGH THE REST OF THE WEEK.


&&

.AVIATION...
A VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT
IN WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING.  EXPECT SCT-BKN 8-12KFT AGL WITH LCL MVFR
CONDS NEAR STRONGEST SHRA/TS.  SFC WINDS VARIABLE AND LESS THEN 10
KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEP MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY.  A DRYING TREND WILL GET STARTED
WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY WARMER
TEMPERATURES.  THURSDAY THROUGH THE WEEKEND...THE DRYING WILL
CONTINUE TO THE POINT THAT CONVECTION IS NOT EXPECTED AND
TEMPERATURES WILL RISE TO OR SLIGHTLY ABOVE NORMAL LEVELS.


&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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






000
FXUS65 KTWC 261608
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
908 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

.DISCUSSION...THE COMBINATION OF ELEVATED ATMOSPHERIC
MOISTURE...INSTABILITY...AND AN APPROACHING MID/UPPER TROUGH WILL
LEAD TO AN ACTIVE WEATHER DAY FOR PORTIONS OF SOUTHEAST ARIZONA.
WATER VAPOR IMAGERY IS DEPICTING THE APPROACHING TROUGH NOW
DIGGING EASTWARD ACROSS SOUTHERN CALIFORNIA AND NEVADA. AHEAD OF
THIS TROUGH...SOUTH TO SOUTHWEST FLOW IS FUNNELING AN AIRMASS WITH
NEAR TO ABOVE NORMAL PRECIPITABLE WATER VALUES. A WEAK DISTURBANCE
MOVED AROUND THE BASE OF THE TROUGH AND TRIGGERED SOME
OVERNIGHT/EARLY MORNING CONVECTION OVER THE AREA. THIS FEATURE IS
NOW PROGRESSING TO THE NORTHEAST INTO NEW MEXICO AND MORNING
CONVECTION HAS WANED AREA-WIDE. THE 12Z KTUS SOUNDING INDICATES
THAT A MOIST AND GENERALLY UNSTABLE AIRMASS IS IN PLACE FOR
SOUTHEAST ARIZONA. THE AIRMASS ALSO IS NEARLY SATURATED UP THROUGH
500MB...MEANING STORMS THAT DEVELOP WILL LIKELY BE VERY EFFICIENT
RAIN PRODUCERS. ANOTHER INFLUENTIAL ASPECT OF THE SOUNDING IS
LIGHT WIND FLOW THROUGH THE BOTTOM 6KM OF THE ATMOSPHERIC COLUMN.
THIS COULD MAKE FOR SLOW MOVING STORMS...AT LEAST INITIALLY.

THERE WILL BE A DISTINCT TRANSITION AS THE TROUGH APPROACHES AND
PASSES THROUGH OVER THE NEXT 24 HOURS. CONVECTION WILL LIKELY
TRIGGER OVER AND AROUND TERRAIN INITIALLY...BEFORE INCREASING MID-
LEVEL SOUTHWESTERLY FLOW INCREASES AND BEGINS TO FOCUS CONVECTION
TO THE NORTH. THROUGHOUT THE EVENT TODAY THE BEST DYNAMICS WILL
REMAIN NORTH OF SOUTHEAST ARIZONA...WITH AN EMPHASIS ON NORTHERN
ARIZONA AND SOUTHERN UTAH.

MID/LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AFTER THE TROUGH
PROGRESSES THROUGH OVERNIGHT INTO WEDNESDAY A DRIER AND MORE
STABLE AIRMASS WILL FILTER IN AND REALLY DRY OUT OUR WEATHER
PATTERN THROUGH THE REST OF THE WEEK.


&&

.AVIATION...
A VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT
IN WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING.  EXPECT SCT-BKN 8-12KFT AGL WITH LCL MVFR
CONDS NEAR STRONGEST SHRA/TS.  SFC WINDS VARIABLE AND LESS THEN 10
KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEP MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY.  A DRYING TREND WILL GET STARTED
WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY WARMER
TEMPERATURES.  THURSDAY THROUGH THE WEEKEND...THE DRYING WILL
CONTINUE TO THE POINT THAT CONVECTION IS NOT EXPECTED AND
TEMPERATURES WILL RISE TO OR SLIGHTLY ABOVE NORMAL LEVELS.


&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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






000
FXUS65 KTWC 261608
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
908 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

.DISCUSSION...THE COMBINATION OF ELEVATED ATMOSPHERIC
MOISTURE...INSTABILITY...AND AN APPROACHING MID/UPPER TROUGH WILL
LEAD TO AN ACTIVE WEATHER DAY FOR PORTIONS OF SOUTHEAST ARIZONA.
WATER VAPOR IMAGERY IS DEPICTING THE APPROACHING TROUGH NOW
DIGGING EASTWARD ACROSS SOUTHERN CALIFORNIA AND NEVADA. AHEAD OF
THIS TROUGH...SOUTH TO SOUTHWEST FLOW IS FUNNELING AN AIRMASS WITH
NEAR TO ABOVE NORMAL PRECIPITABLE WATER VALUES. A WEAK DISTURBANCE
MOVED AROUND THE BASE OF THE TROUGH AND TRIGGERED SOME
OVERNIGHT/EARLY MORNING CONVECTION OVER THE AREA. THIS FEATURE IS
NOW PROGRESSING TO THE NORTHEAST INTO NEW MEXICO AND MORNING
CONVECTION HAS WANED AREA-WIDE. THE 12Z KTUS SOUNDING INDICATES
THAT A MOIST AND GENERALLY UNSTABLE AIRMASS IS IN PLACE FOR
SOUTHEAST ARIZONA. THE AIRMASS ALSO IS NEARLY SATURATED UP THROUGH
500MB...MEANING STORMS THAT DEVELOP WILL LIKELY BE VERY EFFICIENT
RAIN PRODUCERS. ANOTHER INFLUENTIAL ASPECT OF THE SOUNDING IS
LIGHT WIND FLOW THROUGH THE BOTTOM 6KM OF THE ATMOSPHERIC COLUMN.
THIS COULD MAKE FOR SLOW MOVING STORMS...AT LEAST INITIALLY.

THERE WILL BE A DISTINCT TRANSITION AS THE TROUGH APPROACHES AND
PASSES THROUGH OVER THE NEXT 24 HOURS. CONVECTION WILL LIKELY
TRIGGER OVER AND AROUND TERRAIN INITIALLY...BEFORE INCREASING MID-
LEVEL SOUTHWESTERLY FLOW INCREASES AND BEGINS TO FOCUS CONVECTION
TO THE NORTH. THROUGHOUT THE EVENT TODAY THE BEST DYNAMICS WILL
REMAIN NORTH OF SOUTHEAST ARIZONA...WITH AN EMPHASIS ON NORTHERN
ARIZONA AND SOUTHERN UTAH.

MID/LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AFTER THE TROUGH
PROGRESSES THROUGH OVERNIGHT INTO WEDNESDAY A DRIER AND MORE
STABLE AIRMASS WILL FILTER IN AND REALLY DRY OUT OUR WEATHER
PATTERN THROUGH THE REST OF THE WEEK.


&&

.AVIATION...
A VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT
IN WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING.  EXPECT SCT-BKN 8-12KFT AGL WITH LCL MVFR
CONDS NEAR STRONGEST SHRA/TS.  SFC WINDS VARIABLE AND LESS THEN 10
KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEP MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY.  A DRYING TREND WILL GET STARTED
WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY WARMER
TEMPERATURES.  THURSDAY THROUGH THE WEEKEND...THE DRYING WILL
CONTINUE TO THE POINT THAT CONVECTION IS NOT EXPECTED AND
TEMPERATURES WILL RISE TO OR SLIGHTLY ABOVE NORMAL LEVELS.


&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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






000
FXUS65 KTWC 261608
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
908 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

.DISCUSSION...THE COMBINATION OF ELEVATED ATMOSPHERIC
MOISTURE...INSTABILITY...AND AN APPROACHING MID/UPPER TROUGH WILL
LEAD TO AN ACTIVE WEATHER DAY FOR PORTIONS OF SOUTHEAST ARIZONA.
WATER VAPOR IMAGERY IS DEPICTING THE APPROACHING TROUGH NOW
DIGGING EASTWARD ACROSS SOUTHERN CALIFORNIA AND NEVADA. AHEAD OF
THIS TROUGH...SOUTH TO SOUTHWEST FLOW IS FUNNELING AN AIRMASS WITH
NEAR TO ABOVE NORMAL PRECIPITABLE WATER VALUES. A WEAK DISTURBANCE
MOVED AROUND THE BASE OF THE TROUGH AND TRIGGERED SOME
OVERNIGHT/EARLY MORNING CONVECTION OVER THE AREA. THIS FEATURE IS
NOW PROGRESSING TO THE NORTHEAST INTO NEW MEXICO AND MORNING
CONVECTION HAS WANED AREA-WIDE. THE 12Z KTUS SOUNDING INDICATES
THAT A MOIST AND GENERALLY UNSTABLE AIRMASS IS IN PLACE FOR
SOUTHEAST ARIZONA. THE AIRMASS ALSO IS NEARLY SATURATED UP THROUGH
500MB...MEANING STORMS THAT DEVELOP WILL LIKELY BE VERY EFFICIENT
RAIN PRODUCERS. ANOTHER INFLUENTIAL ASPECT OF THE SOUNDING IS
LIGHT WIND FLOW THROUGH THE BOTTOM 6KM OF THE ATMOSPHERIC COLUMN.
THIS COULD MAKE FOR SLOW MOVING STORMS...AT LEAST INITIALLY.

THERE WILL BE A DISTINCT TRANSITION AS THE TROUGH APPROACHES AND
PASSES THROUGH OVER THE NEXT 24 HOURS. CONVECTION WILL LIKELY
TRIGGER OVER AND AROUND TERRAIN INITIALLY...BEFORE INCREASING MID-
LEVEL SOUTHWESTERLY FLOW INCREASES AND BEGINS TO FOCUS CONVECTION
TO THE NORTH. THROUGHOUT THE EVENT TODAY THE BEST DYNAMICS WILL
REMAIN NORTH OF SOUTHEAST ARIZONA...WITH AN EMPHASIS ON NORTHERN
ARIZONA AND SOUTHERN UTAH.

MID/LONG RANGE MODELS ARE IN GOOD AGREEMENT THAT AFTER THE TROUGH
PROGRESSES THROUGH OVERNIGHT INTO WEDNESDAY A DRIER AND MORE
STABLE AIRMASS WILL FILTER IN AND REALLY DRY OUT OUR WEATHER
PATTERN THROUGH THE REST OF THE WEEK.


&&

.AVIATION...
A VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT
IN WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING.  EXPECT SCT-BKN 8-12KFT AGL WITH LCL MVFR
CONDS NEAR STRONGEST SHRA/TS.  SFC WINDS VARIABLE AND LESS THEN 10
KTS...EXCEPT VICINITY TSRA WHERE GUSTS TO 45 MPH ARE POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEP MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY.  A DRYING TREND WILL GET STARTED
WEDNESDAY WITH MUCH LESS CONVECTION EXPECTED AND SLIGHTLY WARMER
TEMPERATURES.  THURSDAY THROUGH THE WEEKEND...THE DRYING WILL
CONTINUE TO THE POINT THAT CONVECTION IS NOT EXPECTED AND
TEMPERATURES WILL RISE TO OR SLIGHTLY ABOVE NORMAL LEVELS.


&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

DISCUSSION...CANTIN
AVIATION/FIRE WEATHER...CERNIGLIA

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






000
FXUS65 KTWC 261508
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
808 AM MST TUE AUG 26 2014

.UPDATE...QUICK UPDATE THIS MORNING TO REDUCE MORNING POPS ACROSS
THE AREA BASED ON SATELLITE AND RADAR TRENDS. REMNANT
MOISTURE...DAYTIME HEATING...AND THE APPROACHING TROUGH WILL LEAD
TO A PERIOD OF CONVECTION AND THUNDERSTORM ACTIVITY LATE MORNING
INTO THE AFTERNOON. FULL DISCUSSION UPDATE COMING AROUND 10 AM
THIS MORNING.


&&

.PREV DISCUSSION... /ISSUED 305 AM MST TUE AUG 26 2014/

SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.


AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

UPDATE...CANTIN

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







000
FXUS65 KTWC 261508
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
808 AM MST TUE AUG 26 2014

.UPDATE...QUICK UPDATE THIS MORNING TO REDUCE MORNING POPS ACROSS
THE AREA BASED ON SATELLITE AND RADAR TRENDS. REMNANT
MOISTURE...DAYTIME HEATING...AND THE APPROACHING TROUGH WILL LEAD
TO A PERIOD OF CONVECTION AND THUNDERSTORM ACTIVITY LATE MORNING
INTO THE AFTERNOON. FULL DISCUSSION UPDATE COMING AROUND 10 AM
THIS MORNING.


&&

.PREV DISCUSSION... /ISSUED 305 AM MST TUE AUG 26 2014/

SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.


AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MST THIS EVENING FOR AZZ502>515.

&&

$$

UPDATE...CANTIN

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






000
FXUS65 KPSR 261400
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
700 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY ACROSS CENTRAL ARIZONA...HOWEVER SOME LOCATIONS MAY MISS OUT
ON RAINFALL. ANY MORE PERSISTENT STORMS WILL BE CAPABLE OF PRODUCING
HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM WEATHER ARE ANTICIPATED
FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
DRYSLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRYSLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

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







000
FXUS65 KPSR 261400
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
700 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY ACROSS CENTRAL ARIZONA...HOWEVER SOME LOCATIONS MAY MISS OUT
ON RAINFALL. ANY MORE PERSISTENT STORMS WILL BE CAPABLE OF PRODUCING
HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM WEATHER ARE ANTICIPATED
FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
DRYSLOT SUBSIDENCE CONTINUES TO DOMINATE MUCH OF THE FORECAST AREA
THIS MORNING...WITH 2 DISTINCT REGIONS OF ASCENT STRADDLING EITHER
SIDE OF THE CWA. THE MORE PREDOMINANT AREA IS AHEAD OF THE H5 COLD
CORE DESCENDING FROM CNTRL NEVADA...THOUGH THE MOST FAVORABLE AREA
OF LIFT WILL BE FOCUSED IN NORTHERN ARIZONA. A SECONDARY REGION OF
MORE SUBTLE ASCENT WITH A VERY WEAK WAVE OVER SERN ARIZONA MAY FOCUS
LIFT DOWNSTREAM OVER GILA COUNTY. THUS...HAVE CANCELLED THE FLASH
FLOOD WATCH FOR MUCH OF THE AREA...WITH ONLY SOME MODEST EXPECTATION
OF ANY DEVELOPMENT LATER IN THE DAY.

&&

.PREVIOUS DISCUSSION...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRYSLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH UNTIL 2 PM THIS AFTERNOON AZZ024.

CA...NONE.

&&

$$

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

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






000
FXUS65 KFGZ 261044
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&
.DISCUSSION...AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS...ESPECIALLY FROM THE KAIBAB PLATEAU...MOGOLLON
RIM...WHITE MOUNTAINS...YAVAPAI COUNTY AND NORTHERN GILA COUNTY. IN
ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH SHEAR AND INSTABILITY
THAT SOME OF THE STORMS MAY BECOME ORGANIZED AND STRONG TO PRODUCE
LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.
&&

.AVIATION...
FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS TSRA ACROSS NORTHERN
ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM ACTIVITY.
SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE HEAVIER
SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR STRONGER
STORMS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR
AZZ004>008-015>018-037-038.
&&

$$

PUBLIC.........TC
AVIATION.......BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF










000
FXUS65 KFGZ 261044
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
330 AM MST TUE AUG 26 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE HAS MOVED NORTHWARD INTO SOUTHERN SECTIONS OF
THE STATE AND IS FORECAST TO MOVE INTO NORTHERN ARIZONA AHEAD OF AN
ADVANCING LOW PRESSURE TROUGH TODAY AND TONIGHT. THE PASSING TROUGH
WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE.
HEAVY RAIN AND FLOODING WILL BE THE MAIN THREAT...THOUGH SOME STRONG
THUNDERSTORMS WILL ALSO BE POSSIBLE. THURSDAY ONWARD THROUGH EARLY
NEXT WEEK...A DRY WEST TO NORTHWEST FLOW WILL BRING DRY CONDITIONS
AND SLIGHTLY WARMER HIGH TEMPERATURES.

&&
.DISCUSSION...AN UPPER LOW AND TROUGH CONTINUES TO ADVANCE
EAST-SOUTHEAST ACROSS NEVADA EARLY THIS MORNING. AMPLE AMOUNTS OF
SUBTROPICAL MOISTURE HAVE MOVED NORTHWARD INTO THE SOUTHERN HALF OF
THE STATE. THE MOISTURE...INSTABILITY...MODERATE LARGE SCALE
SYNOPTIC LIFT...WEAK TO MODERATE OROGRAPHIC UP SLOPE FLOW WILL ALL
PLAY APART IN PRODUCING NUMEROUS SHOWERS AND THUNDERSTORMS TODAY
WITH THE THREAT OF HEAVY RAIN AND FLASH FLOODING FROM SOME OF THE
STRONGER STORMS...ESPECIALLY FROM THE KAIBAB PLATEAU...MOGOLLON
RIM...WHITE MOUNTAINS...YAVAPAI COUNTY AND NORTHERN GILA COUNTY. IN
ADDITION TO THE HEAVY RAIN...THERE IS ENOUGH SHEAR AND INSTABILITY
THAT SOME OF THE STORMS MAY BECOME ORGANIZED AND STRONG TO PRODUCE
LARGE HAIL AND DAMAGING WINDS.

THE COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOVE
RAPIDLY EASTWARD ACROSS THE AREA EARLY WEDNESDAY MORNING AND INTO
NEW MEXICO BY LATE MORNING. THE COLD FRONT WILL PUSH THE DEEPER
MOISTURE INTO NEW MEXICO BRINGING AND END TO THE THREAT OF FLASH
FLOODING. THERE WILL STILL BE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS OVER NORTHERN ARIZONA WEDNESDAY AFTERNOON AND EARLY
EVENING. HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA WEDNESDAY
AFTERNOON AND BECOME ESTABLISHED OVER THE REGION LATE WEDNESDAY
NIGHT. A DRY NORTHWEST FLOW AND A MORE STABLE ATMOSPHERE WILL BRING
AND END TO THE SHOWERS AND THUNDERSTORMS OVERNIGHT WEDNESDAY INTO
EARLY THURSDAY MORNING.

THURSDAY INTO EARLY NEXT WEEK...DRY CONDITIONS AND SLIGHTLY WARMER
DAYTIME HIGHS ARE FORECAST THROUGH THIS PERIOD. A TROUGH OF LOW
PRESSURE WILL PASS BY TO THE NORTH OF ARIZONA SUNDAY INTO MONDAY
BRINGING A DRY BREEZY WESTERLY FLOW.
&&

.AVIATION...
FOR THE 12Z PACKAGE...SCATTERED TO NUMEROUS TSRA ACROSS NORTHERN
ARIZONA TODAY AS A STRONG TROUGH ENHANCES STORM ACTIVITY.
SCATTERED MVFR/WIDELY SCATTERED IFR CONDITIONS IN THE HEAVIER
SHOWERS. EXPECT STRONG ERRATIC GUSTY WINDS AND HAIL NEAR STRONGER
STORMS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.
&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR
AZZ004>008-015>018-037-038.
&&

$$

PUBLIC.........TC
AVIATION.......BOHLIN

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF











000
FXUS65 KTWC 261005
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
305 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.

&&

.AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...FLASH WATCH THRU THIS EVENING FOR
     AZZ502>515.

$$

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






000
FXUS65 KTWC 261005
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
305 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.

&&

.AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...FLASH WATCH THRU THIS EVENING FOR
     AZZ502>515.

$$

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






000
FXUS65 KTWC 261005
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
305 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.

&&

.AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...FLASH WATCH THRU THIS EVENING FOR
     AZZ502>515.

$$

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






000
FXUS65 KTWC 261005
AFDTWC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
305 AM MST TUE AUG 26 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGHOUT TODAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...A FLASH FLOOD WATCH REMAINS IN EFFECT AS ADDITIONAL
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TO DEVELOP THROUGHOUT THE
DAY. SEVERAL LOCATIONS RECEIVED HEAVY RAINFALL LAST EVENING MAINLY
WEST OF TUCSON ON THE TOHONO O`ODHAM NATION. RUNOFF FROM THIS RAIN
HAD RESULTED IN HIGH FLOWS IN THE VAMORI WASH OVERNIGHT.
OTHERWISE...MOST OF THE POPULATED AREAS IN SOUTHEAST ARIZONA HAD
DODGED THE HEAVY RAINFALL...ESPECIALLY AROUND TUCSON...EVEN THOUGH A
FLASH FLOOD WATCH REMAINED IN EFFECT. THAT SAID...THE BIG DILEMMA
FOR THE MORNING FORECAST PACKAGE WILL BE WHETHER OR NOT THIS HIT AND
MISS HEAVY RAINFALL WILL BE ENOUGH TO JUSTIFY KEEPING THE WATCH
POSTED AND EVEN EXTENDING IT IN TIME FOR TODAY. LATEST MODELS DO NOT
APPEAR TO BE MUCH HELP AS BIG DIFFERENCES IN THE FINER DETAILS WERE
SHOWING UP IN THE LOCATION AND TIMING OF THE HIGHER QPF AMOUNTS.
RECENT RADAR AND SATELLITE IMAGERY WERE SHOWING SOMEWHAT OF A LULL
IN THE SHOWER AND THUNDERSTORM ACTIVITY EARLY THIS MORNING. IN
ADDITION TO THIS LULL...SKIES WERE CLEARING NICELY ACROSS CENTRAL
AND WESTERN PIMA COUNTY JUST WEST OF TUCSON. THIS CLEARING SHOULD
TRANSLATE A LITTLE FARTHER EAST BY DAYBREAK TODAY. BASED ON THIS
CLEARING AND THE FACT THAT THE TAIL END OF THE SYSTEM PASSING
THROUGH NEVADA WAS STILL APPROACHING...WOULD EXPECT MORE SURFACE
HEATING AND UPPER LEVEL SUPPORT FOR STRONG THUNDERSTORMS TODAY
COMPARED TO YESTERDAY. THUS...WILL KEEP THE FLASH FLOOD WATCH POSTED
AND EXTENDED IT THROUGH EARLY THIS EVENING.

ANOTHER DAY OF COOLER TEMPERATURES CAN BE ANTICIPATED TODAY. BY
WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD START THE DRYING
TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL TRANSLATE TO A
WARMING TREND AS WELL...WITH PROJECTED HIGH TEMPERATURES REBOUNDING
TO SLIGHTLY ABOVE NORMAL READINGS THIS WEEKEND.

&&

.AVIATION...VALID THRU 27/12Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS MOST OF SOUTHEAST ARIZONA
THROUGH THIS EVENING. EXPECT SCTD 8-12KFT AGL WITH LCL MVFR CONDS
NEAR STRONGEST SHRA/TS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS...SOME
WITH VERY HEAVY RAINFALL TODAY. IMPROVING WEATHER CAN THEN BE
EXPECTED LATE TONIGHT INTO WEDNESDAY...WITH DAYTIME TEMPERATURES
REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...FLASH WATCH THRU THIS EVENING FOR
     AZZ502>515.

$$

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






000
FXUS65 KPSR 260928
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
225 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY ACROSS CENTRAL ARIZONA...HOWEVER SOME LOCATIONS MAY MISS OUT
ON RAINFALL. ANY MORE PERSISTENT STORMS WILL BE CAPABLE OF PRODUCING
HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM WEATHER ARE ANTICIPATED
FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRYSLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH THROUGH THIS AFTERNOON AZZ022>024-027-028.

CA...NONE.

&&

$$

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

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







000
FXUS65 KPSR 260928
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
225 AM MST TUE AUG 26 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL PASS NORTH OF THE AREA TODAY HELPING PULL
MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES FOR
THUNDERSTORMS. SOMEWHAT MORE WIDESPREAD RAINFALL COVERAGE IS LIKELY
TODAY ACROSS CENTRAL ARIZONA...HOWEVER SOME LOCATIONS MAY MISS OUT
ON RAINFALL. ANY MORE PERSISTENT STORMS WILL BE CAPABLE OF PRODUCING
HEAVY RAINFALL. MUCH DRIER AND TRANQUIL WARM WEATHER ARE ANTICIPATED
FOR THE LATTER HALF OF THE WEEK.

&&

.DISCUSSION...
A VERY COMPLEX AND CHAOTIC ATMOSPHERIC STRUCTURE EARLY THIS MORNING
IS RESULTING IN A LOW CONFIDENCE FORECAST DESPITE NUMEROUS
INGREDIENTS PRESENT THAT WOULD SUGGEST AN OTHERWISE ACTIVE
CONVECTIVE PERIOD. FIRST...A WELL DEFINED POSITIVELY TILTED WAVE HAS
DESCENDED INTO CNTRL NEVADA WITH STRONGER JET ENERGY TRANSLATING
INTO THE EASTERN DOWNSTREAM SIDE OF THE WAVE ACROSS NORTHERN
ARIZONA. MEANWHILE...HURRICANE MARIE CONTINUES TO CHURN WELL
SOUTHWEST OF THE BAJA PENINSULA WITH OUTER FEEDER BANDS LOOPING INTO
THE SOUTHERN GULF OF CALIFORNIA. IN BETWEEN THESE TWO FEATURES...A
COL REGION HAS FORMED ALLOWING STRETCHING AND SHEARING OF ANY
SMALLER EASTERLY WAVES PROPAGATING THROUGH NORTHERN MEXICO. THIS COL
REGION IS ALSO NOTABLE FOR ITS STRONGER SUBSIDENCE...AND CURRENT
SATELLITE LOOPS CLEARLY SHOW THIS SUBSIDENT AREA AND DRYSLOT BEING
ADVECTED NORTHEAST INTO CNTRL ARIZONA BEHIND A SHORTWAVE BECOMING
ABSORBED INTO THE NORTHERN ARIZONA JET AXIS.

DESPITE THESE INHIBITING FEATURES...THERE ARE STILL SEVERAL OUTFLOW
BOUNDARIES...GRAVITY WAVES...AND SUBTLE EASTERLY WAVES THAT COULD
INVIGORATE RENEWED CONVECTION LATER THIS MORNING. ONE SUCH FEATURE
OVER SERN ARIZONA WAS ALLOWING PERSISTENT STORMS TO PERCOLATE OVER
GRAHAM COUNTY WITH SOME BACK BUILDING NOTED TOWARDS PIMA COUNTY.
SEVERAL BANDS OF ACCAS ALSO APPEAR EVIDENT THROUGH PARTS OF
PIMA...PINAL...AND MARICOPA COUNTIES...AND SHOULD SUFFICIENT LIFT
PRESENT ITSELF...A MARGINALLY UNSTABLE ENVIRONMENT (MUCAPES UP TO
1000 J/KG) AND JUICY ATMOSPHERE (PWATS NEAR 1.50 INCHES AND LOW
LEVEL MIXING RATIOS APPROACHING 15 G/KG) WOULD SUPPORT STORMS
PRODUCING HEAVY RAIN. HOWEVER...OPERATIONAL AND EXPERIMENTAL HIGH
RESOLUTION MODELS OFFER COMPLETELY MIXED SIGNALS AS TO THE EVOLUTION
OF FEATURES THIS MORNING RANGING FROM A COMPLETE DEARTH OF RAINFALL
TO NUMEROUS STORMS DEVELOPING OVER THE EASTERN CWA AROUND SUNRISE.
HAVE HEDGED THE POP FORECAST TOWARDS SREF MEANS...THOUGH BASED ON
RECENT SATELLITE AND RADAR TRENDS...PROSPECTS DO NOT APPEAR ALL THAT
FAVORABLE.

THE AFOREMENTIONED NEVADA LOW PRESSURE SYSTEM WILL PROPAGATE INTO
WRN UTAH THIS EVENING...WITH STRONGER FORCED JET ASCENT FOCUSED OVER
NORTHERN ARIZONA. TAKING INTO ACCOUNT ALL THE SYNOPTIC FEATURES AND
POTENTIAL MESOSCALE INFLUENCES...MUCH OF THE FORECAST AREA MAY STILL
REMAIN IN AN UNFAVORABLE SUBSIDENT REGION SOUTH OF THE JET AXIS IN
DEEPER SWLY FLOW. THE VAST PREPONDERANCE OF PROBABILISTIC ENSEMBLE
OUTPUT ALONG WITH DETERMINISTIC MODELS PAINT A RATHER DISMAL PICTURE
FOR PRECIPITATION CHANCES OUTSIDE OF HIGHER TERRAIN AREAS OF GILA
COUNTY. CANNOT COMPLETELY DISCOUNT THE ABYSMAL NUMERICAL GUIDANCE
POPS EITHER...AND HAVE ATTEMPTED TO REALLY TRIM POPS FOR LOWER
ELEVATION LOCATIONS THIS AFTERNOON. WILL KEEP THE FLASH FLOOD WATCH
VALID FOR THE TIME BEING GIVEN THE ATMOSPHERIC MOISTURE
PROFILES...THOUGH IF STORMS CANNOT BE GENERATED LOCALLY IT MAY BE
CANCELLED LATER THIS MORNING.

WITH THE PASSAGE OF THE TROUGH AXIS WEDNESDAY MORNING...STRONG
SYNOPTIC SUBSIDENCE AND DRYING OF THE ENTIRE COLUMN WILL SURGE
SOUTHEAST THROUGHOUT THE ENTIRE FORECAST AREA. THOUGH SOME RESIDUAL
MOISTURE MAY LINGER IN THE EASTERN CWA WITH SFC-H7 MIXING RATIOS
HOLDING NEAR 11 G/KG...NOTABLE WARMING ALOFT WILL SEVERELY LIMIT
INSTABILITY AND HAVE RELEGATED SOME MODEST SLIGHT CHANCE POPS TO
HIGHER TERRAIN LOCATIONS. OTHERWISE...SEASONABLY STRONG RIDGING WILL
TAKE HOLD OVER THE LOS ANGELES BASIN WITH H5 HEIGHTS AROUND
594DM...AND DOWNSTREAM NWLY FLOW COMPLETELY SCOURING MOISTURE FAR
AWAY FROM THE LOCAL REGION. ONLY ADDING INSULT TO INJURY...A STRONG
WLY JET CORE WILL DESCEND INTO THE GREAT BASIN BY THE END OF THE
WEEKEND...FURTHER REINFORCING THE WESTERLY FLOW LOCALLY (THE
ANTITHESIS OF THE NORTH AMERICAN MONSOON SEASON FLOW) AND KEEPING
MOISTURE WELL REMOVED FROM THE AREA. GIVEN THE EXCELLENT MODEL
AGREEMENT OF THIS PATTERN MORE REMINISCENT OF LATE
SEPTEMBER...FORECAST CONFIDENCE IS VERY HIGH FOR THURSDAY AND BEYOND
OF COMPLETELY DRY WEATHER AND HIGH TEMPERATURES NEAR TO SLIGHTLY
ABOVE AVERAGE.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL
VERY LOW CONFIDENCE FORECAST AS THE CURRENT ENVIRONMENT IS
UNFAVORABLE FOR STORM DEVELOPMENT...YET THE AIRMASS IS VERY MOIST
AND MARGINALLY UNSTABLE. HAVE REMOVED VCTS MENTION FOR THE TIME
BEING BASED ON CURRENT TRENDS...THOUGH NOT OUT OF THE QUESTION TO
SEE ISOLD/SCT TSRA AROUND THE TERMINAL SITES LATER THIS MORNING.
WINDS DIRECTIONS MAY ALSO BECOME QUITE VARIABLE THROUGH THE MORNING
HOURS...THOUGH SHOULD GENERALLY FAVOR A SE COMPONENT BEFORE BECOMING
MORE SWLY IN THE AFTERNOON.

SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
ONLY PERIODIC HIGH CLOUDS EXPECTED THROUGH WEDNESDAY MORNING WITH
ANY STORMINESS LIKELY REMAINING NORTH OF THE AREA. SFC WINDS SHOULD
RETAIN A SLY COMPONENT AT KBLH...WITH MORE VARIABILITY AT KIPL.
OVERALL...NO AVIATION IMPACTS EXPECTED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT AND WESTERLY FLOW IS WILL KEEP MONSOON
MOISTURE WELL REMOVED FROM THE DISTRICT...WITH MOSTLY CLEAR SKIES
THROUGH THE ENTIRE PERIOD. TEMPERATURES WILL REMAIN AT OR SLIGHTLY
ABOVE SEASONAL NORMALS WITH MAINLY LIGHT WINDS...THOUGH SOME
AFTERNOON GUSTS CAN BE EXPECTED NEAR UPSLOPE REGIONS. AFTERNOON
HUMIDITIES WILL FALL INTO THE SINGLE DIGITS AND TEENS ACROSS THE
LOWER DESERTS...WITH SOMEWHAT MORE MOIST CONDITIONS ACROSS THE
HIGHER TERRAIN OF GILA COUNTY. OVERNIGHT RECOVERY WILL GENERALLY BE
GOOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH THROUGH THIS AFTERNOON AZZ022>024-027-028.

CA...NONE.

&&

$$

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

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






000
FXUS65 KTWC 260457
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
957 PM MST MON AUG 25 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...THE UPPER PATTERN IS DEFINED BY A TROUGH OF LOW
PRESSURE OVER THE GREAT BASIN...A CATEGORY 3 HURRICANE /MARIE/
LOCATED AT 19.2N/116.7W MOVING NW@13MPH...AND A WEAK MID-LEVEL
FEATURE POSITIONED NE OF THE BAJA SPUR IN THE SOUTHWEST FLOW ALOFT.

IT HAS BEEN AN ACTIVE AND WET NIGHT ACROSS THE WESTERN HALF OF
FORECAST AREA THIS EVENING. THE MAJORITY OF THE STORMS DEVELOPED
ALONG A MID-LEVEL BOUNDARY THAT TRACKED SLOWLY WEST. ALTHOUGH
INDIVIDUAL STORMS WERE MOVING NORTHEAST...STORMS PROPAGATED WEST ALL
EVENING...WITH STORMS DOWNSTREAM OF THE CIRRUS BLOWOFF STRUGGLING TO
SUSTAIN THEMSELVES. STORMS HAVE BEGUN TO QUIET DOWN LATE THIS
EVENING. HOWEVER...KEMX RADAR IMAGERY INDICATED AN MCV POSITIONED
ACROSS WESTERN PIMA AND SOUTHERN MARICOPA COUNTIES. LOOK FOR THIS
FEATURE TO MOVE NE IN THE UPPER FLOW...INITIATING CONVECTION ACROSS
THE NORTHERN CWA OVERNIGHT. IN ADDITION...A WEAK MID-LEVEL FEATURE
NE OF THE BAJA SPUR WILL MOVE TOWARD NE TONIGHT...HELPING TO TRIGGER
OFF SOME STORMS OVERNIGHT ACROSS THOSE AREAS THAT DIDNT SEE MUCH
RAINFALL TONIGHT...TUCSON EAST. ANOTHER FEATURE IS EXPECTED TO MOVE
NORTH AND INTERACT WITH THE UPPER TROUGH TRACKING THRU TO THE NORTH.
THIS WILL HELP ENHANCE THUNDERSTORM COVERAGE TOMORROW. THERE ARE
STILL SOME DIFFERENCES IN THE 00Z MODELS. THE NAM WANTS TO FINISH
THINGS UP BY LATE TUESDAY EVENING...WITH THE GFS HAVING A MUCH MORE
PRONOUNCED EFFECT FROM THE UPPER TROUGH TRACKING THRU...KEEPING POPS
UP WELL INTO WEDNESDAY MORNING. GIVEN THE MOIST AIRMASS IN PLACE
ACROSS THE REGION...WILL LEAVE FLASH FLOOD WATCH ALONE AS ADDITIONAL
MODERATE TO HEAVY RAINFALL IS POSSIBLE.

&&

.PREV DISCUSSION...CONVECTION...HEAVY RAIN AND SOME FLASH FLOODING
ONGOING ACROSS SOUTHEAST ARIZONA. THE PRIMARY THREAT FOR THE NEXT 24
TO 48 HOURS IS HEAVY RAIN BUT A STRONGER STORM MAY KICK OUT SOME
INTENSE WINDS.

THE GOOD FOLKS AT NESDIS POINTED OUT TODAY THAT THE MOIST AIR IN
PLACE CURRENTLY OVER SE ARIZONA IS LIKELY FROM THE REMNANTS OF
HURRICANE LOWELL AND NOT HURRICANE MARIE WHO IS SITTING OFF THE BAJA
PENINSULA SEVERAL HUNDRED MILES TO THE SOUTH OF AZ. REGARDLESS OF
THE SOURCE...THE AIR IN PLACE RIGHT NOW WILL ONLY BECOME MORE
SATURATED WHEN THE DEEPER MOISTURE FROM MARIE FINALLY WORKS INTO SE
ARIZONA TONIGHT AND TUESDAY. THE BOTTOM LINE...THE FLASH FLOOD
THREAT IS LIKELY TO EXTEND WELL INTO TUESDAY...BUT WE DECIDED TO SET
AN END TIME ON THE FLASH FLOOD WATCH TO 18Z TO AVOID ISSUING A TWO
DAY WATCH.

THINKING THE MAIN THREAT AREA TUESDAY WILL SHIFT TOWARD THE NORTHERN
ZONES...GRAHAM AND GREENLEE COUNTIES...WHERE THEIR WILL BE BETTER
UPPER SUPPORT FROM THE TAIL END OF AN UPPER TROUGH. I AM ALSO
CONCERNED THAT THE SEVERE THREAT MAY INCREASE TOMORROW DUE TO THE
COOLER AIR ALOFT AND STRONGER UPPER JET PUSHING ACROSS THE NORTHERN
ZONES. THE LIMITING FACTOR WILL BE THE ABUNDANT CLOUD COVER AND
LIMITED HEATING.

MODELS THEN SHOW RAPID DRYING STARTING WEDNESDAY WITH CONTINUED
DRYING THURSDAY. POP TRENDS ADEQUATELY SHOW THIS DOWNTURN IN PRECIP
CHANCES. IN ADDITION...THE WARM AIR WILL RETURN WITH THE DRYING SO
TEMPS WILL RISE BACK TO NORMAL OR EVEN SLIGHTLY WARMER THAN NORMAL
BY LATE IN THE WEEK.

&&

.AVIATION...VALID THRU 27/06Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS THE MAJORITY OF THE AREA THRU
TUESDAY EARLY AFTERNOON. CONDITIONS WILL IMPROVE THRU THE DAY
TOMORROW FROM WEST TO EAST...WITH SHOWERS TRACKING OUT OF THE AREA
TUESDAY NIGHT. EXPECT P6SM VCSH SCT8-10KFT BKN12-14KFT MSL THRU THE
MAJORITY OF THE PERIOD...WITH 5SM -SHRA BKN6KFT MSL WITH THE
STRONGER STORMS. ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT STILL CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS...SOME WITH VERY
HEAVY RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN THEN BE
EXPECTED WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO
SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

$$

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


















000
FXUS65 KTWC 260457
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
957 PM MST MON AUG 25 2014

.SYNOPSIS...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA WILL
RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN THEN BE EXPECTED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...THE UPPER PATTERN IS DEFINED BY A TROUGH OF LOW
PRESSURE OVER THE GREAT BASIN...A CATEGORY 3 HURRICANE /MARIE/
LOCATED AT 19.2N/116.7W MOVING NW@13MPH...AND A WEAK MID-LEVEL
FEATURE POSITIONED NE OF THE BAJA SPUR IN THE SOUTHWEST FLOW ALOFT.

IT HAS BEEN AN ACTIVE AND WET NIGHT ACROSS THE WESTERN HALF OF
FORECAST AREA THIS EVENING. THE MAJORITY OF THE STORMS DEVELOPED
ALONG A MID-LEVEL BOUNDARY THAT TRACKED SLOWLY WEST. ALTHOUGH
INDIVIDUAL STORMS WERE MOVING NORTHEAST...STORMS PROPAGATED WEST ALL
EVENING...WITH STORMS DOWNSTREAM OF THE CIRRUS BLOWOFF STRUGGLING TO
SUSTAIN THEMSELVES. STORMS HAVE BEGUN TO QUIET DOWN LATE THIS
EVENING. HOWEVER...KEMX RADAR IMAGERY INDICATED AN MCV POSITIONED
ACROSS WESTERN PIMA AND SOUTHERN MARICOPA COUNTIES. LOOK FOR THIS
FEATURE TO MOVE NE IN THE UPPER FLOW...INITIATING CONVECTION ACROSS
THE NORTHERN CWA OVERNIGHT. IN ADDITION...A WEAK MID-LEVEL FEATURE
NE OF THE BAJA SPUR WILL MOVE TOWARD NE TONIGHT...HELPING TO TRIGGER
OFF SOME STORMS OVERNIGHT ACROSS THOSE AREAS THAT DIDNT SEE MUCH
RAINFALL TONIGHT...TUCSON EAST. ANOTHER FEATURE IS EXPECTED TO MOVE
NORTH AND INTERACT WITH THE UPPER TROUGH TRACKING THRU TO THE NORTH.
THIS WILL HELP ENHANCE THUNDERSTORM COVERAGE TOMORROW. THERE ARE
STILL SOME DIFFERENCES IN THE 00Z MODELS. THE NAM WANTS TO FINISH
THINGS UP BY LATE TUESDAY EVENING...WITH THE GFS HAVING A MUCH MORE
PRONOUNCED EFFECT FROM THE UPPER TROUGH TRACKING THRU...KEEPING POPS
UP WELL INTO WEDNESDAY MORNING. GIVEN THE MOIST AIRMASS IN PLACE
ACROSS THE REGION...WILL LEAVE FLASH FLOOD WATCH ALONE AS ADDITIONAL
MODERATE TO HEAVY RAINFALL IS POSSIBLE.

&&

.PREV DISCUSSION...CONVECTION...HEAVY RAIN AND SOME FLASH FLOODING
ONGOING ACROSS SOUTHEAST ARIZONA. THE PRIMARY THREAT FOR THE NEXT 24
TO 48 HOURS IS HEAVY RAIN BUT A STRONGER STORM MAY KICK OUT SOME
INTENSE WINDS.

THE GOOD FOLKS AT NESDIS POINTED OUT TODAY THAT THE MOIST AIR IN
PLACE CURRENTLY OVER SE ARIZONA IS LIKELY FROM THE REMNANTS OF
HURRICANE LOWELL AND NOT HURRICANE MARIE WHO IS SITTING OFF THE BAJA
PENINSULA SEVERAL HUNDRED MILES TO THE SOUTH OF AZ. REGARDLESS OF
THE SOURCE...THE AIR IN PLACE RIGHT NOW WILL ONLY BECOME MORE
SATURATED WHEN THE DEEPER MOISTURE FROM MARIE FINALLY WORKS INTO SE
ARIZONA TONIGHT AND TUESDAY. THE BOTTOM LINE...THE FLASH FLOOD
THREAT IS LIKELY TO EXTEND WELL INTO TUESDAY...BUT WE DECIDED TO SET
AN END TIME ON THE FLASH FLOOD WATCH TO 18Z TO AVOID ISSUING A TWO
DAY WATCH.

THINKING THE MAIN THREAT AREA TUESDAY WILL SHIFT TOWARD THE NORTHERN
ZONES...GRAHAM AND GREENLEE COUNTIES...WHERE THEIR WILL BE BETTER
UPPER SUPPORT FROM THE TAIL END OF AN UPPER TROUGH. I AM ALSO
CONCERNED THAT THE SEVERE THREAT MAY INCREASE TOMORROW DUE TO THE
COOLER AIR ALOFT AND STRONGER UPPER JET PUSHING ACROSS THE NORTHERN
ZONES. THE LIMITING FACTOR WILL BE THE ABUNDANT CLOUD COVER AND
LIMITED HEATING.

MODELS THEN SHOW RAPID DRYING STARTING WEDNESDAY WITH CONTINUED
DRYING THURSDAY. POP TRENDS ADEQUATELY SHOW THIS DOWNTURN IN PRECIP
CHANCES. IN ADDITION...THE WARM AIR WILL RETURN WITH THE DRYING SO
TEMPS WILL RISE BACK TO NORMAL OR EVEN SLIGHTLY WARMER THAN NORMAL
BY LATE IN THE WEEK.

&&

.AVIATION...VALID THRU 27/06Z.
VERY MOIST AIRMASS IN PLACE ACROSS SOUTHEAST ARIZONA WILL RESULT IN
WIDESPREAD SHRA/ISOLATED -TSRA ACROSS THE MAJORITY OF THE AREA THRU
TUESDAY EARLY AFTERNOON. CONDITIONS WILL IMPROVE THRU THE DAY
TOMORROW FROM WEST TO EAST...WITH SHOWERS TRACKING OUT OF THE AREA
TUESDAY NIGHT. EXPECT P6SM VCSH SCT8-10KFT BKN12-14KFT MSL THRU THE
MAJORITY OF THE PERIOD...WITH 5SM -SHRA BKN6KFT MSL WITH THE
STRONGER STORMS. ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT STILL CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE IN PLACE ACROSS SOUTHEAST ARIZONA
WILL RESULT IN WIDESPREAD SHOWERS AND THUNDERSTORMS...SOME WITH VERY
HEAVY RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN THEN BE
EXPECTED WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO
SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

$$

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



















000
FXUS65 KFGZ 260446
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
944 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&
.DISCUSSION...ISOLATED THUNDERSTORMS HAVE BEEN MOVING FROM SOUTHWEST
TO NORTHEAST IN SOUTHERN YAVAPAI AND APACHE COUNTIES THIS EVENING.
ONE STORM DROPPED OVER TWO INCHES OF RAIN ALONG THE SOUTHERN BORDER
OF YAVAPAI COUNTY AND MARICOPA COUNTY NEAR HIGHWAY 93. MORE SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN COCONINO AND
SOUTHERN YAVAPAI COUNTY TONIGHT AS THE TROUGH OF LOW PRESSURE OVER
CALIFORNIA AND NEVADA GETS CLOSER TO ARIZONA AND PROVIDES MORE
LIFT. CURRENT FORECAST SHOWS THIS INCREASE OVERNIGHT. MAY UPDATE
FORECAST LATER THIS EVENING TO ADJUST TIMING OF PRECIPITATION.
OTHERWISE...NO CHANGES EXPECTED.

&&

.PREV DISCUSSION /344 PM MST/...AN INCREASE IN MOISTURE IS EVIDENCED
THIS AFTERNOON MAINLY SOUTH OF I-40 WHERE A COUPLE OF AREAS OF
SCATTERED STORMS HAVE DEVELOPED. THE STRONGER STORMS SO FAR HAVE
DEVELOPED IN WESTERN YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY
ARE HIGHEST. WEAKER STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS.
A CHANCE FOR SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN
ARIZONA BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER
TONIGHT OR EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD TSRA SOUTH OF A KPRC-KSJN LINE THROUGH
10Z. SHRA/TSRA COVERAGE INCREASING FROM SOUTH TO NORTH AFTER 10Z AND
CONTINUING THROUGH TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR
CONDITIONS IN THE HEAVIER RAIN AREAS. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MAS/MCS
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF







000
FXUS65 KFGZ 260446
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
944 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&
.DISCUSSION...ISOLATED THUNDERSTORMS HAVE BEEN MOVING FROM SOUTHWEST
TO NORTHEAST IN SOUTHERN YAVAPAI AND APACHE COUNTIES THIS EVENING.
ONE STORM DROPPED OVER TWO INCHES OF RAIN ALONG THE SOUTHERN BORDER
OF YAVAPAI COUNTY AND MARICOPA COUNTY NEAR HIGHWAY 93. MORE SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER WESTERN COCONINO AND
SOUTHERN YAVAPAI COUNTY TONIGHT AS THE TROUGH OF LOW PRESSURE OVER
CALIFORNIA AND NEVADA GETS CLOSER TO ARIZONA AND PROVIDES MORE
LIFT. CURRENT FORECAST SHOWS THIS INCREASE OVERNIGHT. MAY UPDATE
FORECAST LATER THIS EVENING TO ADJUST TIMING OF PRECIPITATION.
OTHERWISE...NO CHANGES EXPECTED.

&&

.PREV DISCUSSION /344 PM MST/...AN INCREASE IN MOISTURE IS EVIDENCED
THIS AFTERNOON MAINLY SOUTH OF I-40 WHERE A COUPLE OF AREAS OF
SCATTERED STORMS HAVE DEVELOPED. THE STRONGER STORMS SO FAR HAVE
DEVELOPED IN WESTERN YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY
ARE HIGHEST. WEAKER STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS.
A CHANCE FOR SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN
ARIZONA BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER
TONIGHT OR EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 06Z PACKAGE...ISOLD TSRA SOUTH OF A KPRC-KSJN LINE THROUGH
10Z. SHRA/TSRA COVERAGE INCREASING FROM SOUTH TO NORTH AFTER 10Z AND
CONTINUING THROUGH TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR
CONDITIONS IN THE HEAVIER RAIN AREAS. AVIATION DISCUSSION NOT
UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MAS/MCS
AVIATION.......MAS

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF








000
FXUS65 KPSR 260338
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.UPDATE...FLASH FLOOD WATCH TO START AT AN EARLIER TIME.

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...THROUGH PM
TUESDAY.

CA...NONE.

&&

$$

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

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



















000
FXUS65 KPSR 260338
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.UPDATE...FLASH FLOOD WATCH TO START AT AN EARLIER TIME.

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...THROUGH PM
TUESDAY.

CA...NONE.

&&

$$

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

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



















000
FXUS65 KPSR 260338
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.UPDATE...FLASH FLOOD WATCH TO START AT AN EARLIER TIME.

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...THROUGH PM
TUESDAY.

CA...NONE.

&&

$$

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

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



















000
FXUS65 KPSR 260338
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.UPDATE...FLASH FLOOD WATCH TO START AT AN EARLIER TIME.

&&

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...THROUGH PM
TUESDAY.

CA...NONE.

&&

$$

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

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



















000
FXUS65 KPSR 260259
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...2 AM UNTIL 2 PM
     TUESDAY.

CA...NONE.

&&

$$

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

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















000
FXUS65 KPSR 260259
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM MST MON AUG 25 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
WEATHER BALLOON DATA ACROSS THE WESTERN STATES CONTINUED TO SHOW AN
EARLY SEASON COOL TROF FROM WESTERN CANADA DEVELOPING SOUTH OVER
WEST CENTRAL NEVADA THIS EVENING. AHEAD OF THIS SYSTEM...
UNSEASONABLY STRONG SOUTHWESTERLY JET STREAM WINDS OVER AZ...WITH A
BRIEF MOISTURE SURGE FROM MEXICO...GENERATED LARGE AREAS OF THUNDER
STORMS IN WEST CENTRAL AZ...AND IN SOUTHEAST AZ. FLOOD OR FLASH
FLOODING WAS REPORTED 75 MILES NORTHWEST OF PHOENIX...AND 80 MILES
SOUTH TO SOUTHEAST OF PHOENIX MONDAY AFTERNOON. IN OTHER WORDS...
PHOENIX WAS IN A MOSTLY CLEAR SLOT BETWEEN THE STORM AREAS.

AS THE NEVADA LOW CENTER BECOMES BETTER ORGANIZED TONIGHT...
UNSEASONABLY STRONG JET STREAM WINDS...REPLETE WITH A SMALL
DISTURBANCE FROM OFF THE NORTHERN BAJA COAST WILL CONTINUE THE
THREAT OF SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. A FLASH
FLOOD WATCH WILL REMAIN IN EFFECT ACROSS A LARGE SWATH OF SOUTH
CENTRAL AZ FROM JUST AFTER MIDNIGHT TO TUESDAY AFTERNOON.  WE ARE
NOT EXPECTING A WIDESPREAD HEAVY RAIN EVENT LIKE LAST TUESDAY WHERE
3 TO 5 INCH RAINS FELL OVER THE MOUNTAINS/DESERTS NEAR PHOENIX.
ONE TO ONE AND ONE HALF INCH RAINS ARE POSSIBLE WITH STORMS...WITH
THE THREAT OF FLOODING IN THOSE AREAS WHERE SOIL MOISTURE IS STILL
HIGH...AND THOSE WASHES THAT ARE STILL RUNNING OR TRICKLING.

CURRENT FORECASTS LOOK OK FOR NOW. NO UDPATES PLANNED.


.PREVIOUS DISCUSSION...210 PM MST...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO GENERATE A
CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT THROUGH TUESDAY. MAIN
TIME FRAME FOR ANY STORMS IN THE PHOENIX VALLEY IS BETWEEN 09Z TUE
AND 16Z MON. CIGS IN RAIN COULD DROP AS LOW AS 6 THSD AGL WITH
VARIABLE WIND GUSTS TO 25 KNOTS.

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

THROUGH 19Z TUE...SCT TO BKN CLDS AOA 16 THSD AGL. SOUTHWEST WIND
UNDER 9 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...2 AM UNTIL 2 PM
     TUESDAY.

CA...NONE.

&&

$$

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

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
















000
FXUS65 KFGZ 252244
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
344 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&

.DISCUSSION...
AN INCREASE IN MOISTURE IS EVIDENCED THIS AFTERNOON MAINLY SOUTH
OF I-40 WHERE A COUPLE OF AREAS OF SCATTERED STORMS HAVE
DEVELOPED. THE STRONGER STORMS SO FAR HAVE DEVELOPED IN WESTERN
YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY ARE HIGHEST. WEAKER
STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS. A CHANCE FOR
SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN ARIZONA
BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER TONIGHT OR
EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCATTERED TSRA WEST OF KGCN-KPRC
LINE THROUGH 02-04Z WITH ISOLD SHOWERS ELSEWHERE. SHRA/TSRA COVERAGE
INCREASING FROM SOUTH TO NORTH AFTER 08-12Z AND CONTINUING THROUGH
TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR CONDITIONS IN THE HEAVIER
RAIN AREAS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 252244
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
344 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&

.DISCUSSION...
AN INCREASE IN MOISTURE IS EVIDENCED THIS AFTERNOON MAINLY SOUTH
OF I-40 WHERE A COUPLE OF AREAS OF SCATTERED STORMS HAVE
DEVELOPED. THE STRONGER STORMS SO FAR HAVE DEVELOPED IN WESTERN
YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY ARE HIGHEST. WEAKER
STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS. A CHANCE FOR
SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN ARIZONA
BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER TONIGHT OR
EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCATTERED TSRA WEST OF KGCN-KPRC
LINE THROUGH 02-04Z WITH ISOLD SHOWERS ELSEWHERE. SHRA/TSRA COVERAGE
INCREASING FROM SOUTH TO NORTH AFTER 08-12Z AND CONTINUING THROUGH
TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR CONDITIONS IN THE HEAVIER
RAIN AREAS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 252244
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
344 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&

.DISCUSSION...
AN INCREASE IN MOISTURE IS EVIDENCED THIS AFTERNOON MAINLY SOUTH
OF I-40 WHERE A COUPLE OF AREAS OF SCATTERED STORMS HAVE
DEVELOPED. THE STRONGER STORMS SO FAR HAVE DEVELOPED IN WESTERN
YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY ARE HIGHEST. WEAKER
STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS. A CHANCE FOR
SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN ARIZONA
BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER TONIGHT OR
EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCATTERED TSRA WEST OF KGCN-KPRC
LINE THROUGH 02-04Z WITH ISOLD SHOWERS ELSEWHERE. SHRA/TSRA COVERAGE
INCREASING FROM SOUTH TO NORTH AFTER 08-12Z AND CONTINUING THROUGH
TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR CONDITIONS IN THE HEAVIER
RAIN AREAS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KFGZ 252244
AFDFGZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
344 PM MST MON AUG 25 2014

.SYNOPSIS...
SUBTROPICAL MOISTURE WILL MOVE NORTHWARD OVER NORTHERN
ARIZONA TONIGHT AHEAD OF AN ADVANCING LOW PRESSURE TROUGH WITH
INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. THE PASSING
TROUGH WILL BRING NUMEROUS SHOWERS AND THUNDERSTORMS TO THE STATE
ON TUESDAY. HEAVY RAIN AND FLOODING WILL BE THE MAIN
THREATS...THOUGH SOME STRONG THUNDERSTORMS WILL ALSO BE
POSSIBLE. THURSDAY ONWARD...A DRYING NORTHWEST FLOW WILL DECREASE
THUNDERSTORM CHANCES.

&&

.DISCUSSION...
AN INCREASE IN MOISTURE IS EVIDENCED THIS AFTERNOON MAINLY SOUTH
OF I-40 WHERE A COUPLE OF AREAS OF SCATTERED STORMS HAVE
DEVELOPED. THE STRONGER STORMS SO FAR HAVE DEVELOPED IN WESTERN
YAVAPAI COUNTY WHERE MOISTURE AND INSTABILITY ARE HIGHEST. WEAKER
STORMS HAVE DEVELOPED OVER THE WHITE MOUNTAINS. A CHANCE FOR
SHOWERS WILL CONTINUE THIS EVENING FOR MOST OF NORTHERN ARIZONA
BUT DON`T EXPECT WIDESPREAD ACTIVITY UNTIL MUCH LATER TONIGHT OR
EARLY TUESDAY MORNING.

THE APPROACHING LOW PRESSURE SYSTEM HAS MOVED INTO NORTHERN
NEVADA AND WILL CONTINUE PUSHING SOUTH OVER THE NEXT 24 HRS. WE
ARE STILL ANTICIPATING A WIDESPREAD PRECIPITATION EVENT TO UNFOLD
AS BROAD SYNOPTIC SCALE LIFT FROM THE TROUGH INTERACTS WITH PLENTY
OF MONSOON MOISTURE STREAMING NORTH ACROSS THE FORECAST AREA.
THERE APPEAR TO BE TWO FEATURES AT PLAY HERE...THE APPROACHING
TROUGH FROM THE NORTHWEST PROVIDING SYNOPTIC SCALE LIFT...AND A
WEAKER DISTURBANCE ROTATING NORTH INTO THE WHITE MOUNTAINS FROM
SOUTHERN ARIZONA. BELIEVE THE BEST THREAT FOR HEAVY RAIN AND
FLOODING WILL BE WHERE THESE FEATURES INTERACT WITH THE DEEPEST
MOISTURE CONTENT...ROUGHLY OVER WESTERN AND SOUTHERN PORTIONS OF
OUR FORECAST AREA WHERE A FLASH FLOOD WATCH IS IN EFFECT THROUGH
TUESDAY EVENING. A GENERAL 1-2 INCHES OF RAINFALL ARE ANTICIPATED
WITH LOCALLY HIGHER AMOUNTS...ESPECIALLY IN UP-SLOPE FAVORED AREAS
AND UNDER THE STRONGEST STORM CELLS.

IN ADDITION...INCREASED SHEAR AND INSTABILITY ASSOCIATED WITH THE
TROUGH WILL BRING A THREAT FOR STRONG OR ORGANIZED STORMS THAT
COULD PRODUCE HAIL AND HIGH WINDS.

ACTIVITY WILL BEGIN TO DECREASE BY WEDNESDAY MORNING AS THE TROUGH
MOVES INTO COLORADO. SCATTERED STORMS WILLS TILL BE POSSIBLE
WEDNESDAY WITH COOL AIR ALOFT AND AVAILABLE MOISTURE...BUT A QUICK
DRYING TREND MOVES IN BY THURSDAY WITH VERY LITTLE CHANCE FOR ANY
PRECIPITATION THURSDAY INTO NEXT WEEKEND.

&&

.AVIATION...
FOR THE 00Z PACKAGE...SCATTERED TSRA WEST OF KGCN-KPRC
LINE THROUGH 02-04Z WITH ISOLD SHOWERS ELSEWHERE. SHRA/TSRA COVERAGE
INCREASING FROM SOUTH TO NORTH AFTER 08-12Z AND CONTINUING THROUGH
TUESDAY AFTERNOON. AREAS MVFR/LOCAL IFR CONDITIONS IN THE HEAVIER
RAIN AREAS. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING
FOR AZZ004>008-015>018-037-038.

&&

$$

PUBLIC.........MCS
AVIATION.......JJ

FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT
WEATHER.GOV/FLAGSTAFF






000
FXUS65 KTWC 252143
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
243 PM MST MON AUG 25 2014

.SYNOPSIS...A SIGNIFICANT CHANGE IN THE WEATHER PATTERN WILL TAKE
PLACE THROUGH TUESDAY AS DEEPER MOISTURE MOVES BACK INTO ARIZONA.
THIS WILL RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN BE ANTICIPATED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...CONVECTION...HEAVY RAIN AND SOME FLASH FLOODING
ONGOING ACROSS SOUTHEAST ARIZONA. THE RAIN RATES IN THESE STORMS ARE
IMPRESSIVE...WITH SOME RAIN GAUGES REPORTING UP TO ONE INCH RAIN
TOTALS IN 15 TO 30 MINUTES. STORM TOPS SO FAR HAVE BEEN RELATIVELY
LOW...WITH THE STRONGEST STORM CORES BELOW 20 KFT. SO THE PRIMARY
THREAT FOR THE NEXT 24 TO 48 HOURS IS HEAVY RAIN BUT A STRONGER
STORM MAY KICK OUT SOME INTENSE WINDS.

THE GOOD FOLKS AT NESDIS POINTED OUT TODAY THAT THE MOIST AIR IN
PLACE CURRENTLY OVER SE ARIZONA IS LIKELY FROM THE REMNANTS OF
HURRICANE LOWELL AND NOT HURRICANE MARIE WHO IS SITTING OFF THE BAJA
PENINSULA SEVERAL HUNDRED MILES TO THE SOUTH OF AZ. REGARDLESS OF
THE SOURCE...THE AIR IN PLACE RIGHT NOW WILL ONLY BECOME MORE
SATURATED WHEN THE DEEPER MOISTURE FROM MARIE FINALLY WORKS INTO SE
ARIZONA TONIGHT AND TUESDAY. THE BOTTOM LINE...THE FLASH FLOOD
THREAT IS LIKELY TO EXTEND WELL INTO TUESDAY...BUT WE DECIDED TO SET
AN END TIME ON THE FLASH FLOOD WATCH TO 18Z TO AVOID ISSUING A TWO
DAY WATCH.

THINKING THE MAIN THREAT AREA TUESDAY WILL SHIFT TOWARD THE NORTHERN
ZONES...GRAHAM AND GREENLEE COUNTIES...WHERE THEIR WILL BE BETTER
UPPER SUPPORT FROM THE TAIL END OF AN UPPER TROUGH. I AM ALSO
CONCERNED THAT THE SEVERE THREAT MAY INCREASE TOMORROW DUE TO THE
COOLER AIR ALOFT AND STRONGER UPPER JET PUSHING ACROSS THE NORTHERN
ZONES. THE LIMITING FACTOR WILL BE THE ABUNDANT CLOUD COVER AND
LIMITED HEATING.

MODELS THEN SHOW RAPID DRYING STARTING WEDNESDAY WITH CONTINUED
DRYING THURSDAY. POP TRENDS ADEQUATELY SHOW THIS DOWNTURN IN PRECIP
CHANCES. IN ADDITION...THE WARM AIR WILL RETURN WITH THE DRYING SO
TEMPS WILL RISE BACK TO NORMAL OR EVEN SLIGHTLY WARMER THAN NORMAL
BY LATE IN THE WEEK.

JJB

&&

.AVIATION...VALID THRU 26/18Z.
AREA SPLIT BETWEEN HURRICANE MARIE TO THE SOUTH AND A DIGGING UPPER
TROUGH TO THE NORTH. THE LATER WILL KEEP PUMPING CIRRUS LEVEL CLOUDS
INTO THE AREA...WHILE THE FORMER WILL PUMP IN LOW/MID LEVEL MOISTURE
IN. ENOUGH MOISTURE IN PLACE FOR SCT -SHRA THIS AFTERNOON. POINT
SOUNDINGS SHOW LOWEST 5-8 KFT REMAINING DRY THOUGH WHICH SUPPORTS
SOME GUSTY OUTFLOW WINDS EVEN THOUGH FLOW ALOFT REMAINS WEAK. THE
GENERAL LACK OF STORM MOTION WILL HELP SATURATE THE COLUMN EARLY SO
THIS THREAT WILL LESSEN LATER IN THE PERIOD. ALSO...EXPECT DEEPER
MOISTURE TO SLOW WORK INTO THE AREA WHICH WILL CONTRIBUTE AS WELL.
THE SLOW STORM MOTION AND FAIRLY TROPICAL NATURE OF THE AIRMASS WILL
SUPPORT MVFR-IFR CONDITIONS NEAR THE STRONGER SHOWERS. HAVE REMOVED
THE TS MENTION FROM ALL TERMINALS AS TIMING AND CONFIDENCE IS TOO
LOW TO SUPPORT GIVEN THE LACK OF ELEVATED INSTABILITY.
NEVERTHELESS...ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE WILL CONTINUE TO SETTLE IN ACROSS
AREA TODAY AS MOISTURE FROM HURRICANE MARIE SURGES NORTHWARD. THIS
AFTERNOON THERE WILL BE SOME POTENTIAL FOR GUSTY OUTFLOW WINDS AS
LOW LEVEL WILL REMAIN RELATIVELY DRY...THOUGH THIS WILL DIMINISH
LATER IN THE EVENING AS COLUMN BECOMES SATURATED. LIGHTNING ACTIVITY
CONTINUES TO LOOK FAIRLY LIMITED. STORM MOTION WILL BE FAIRLY SLOW
SO GIVEN THIS AND THE DEEP MOISTURE EXPECTED THIS LOOKS TO BE A GOOD
CHANCE FOR WETTING RAINS ACROSS THE AREA. CONFIDENCE IN WHEN THE
MOISTURE/SHOWERS WILL ERODE REMAINS LOW...BUT SHOULD SEE DRY
CONDITIONS AGAIN LATE WEDNESDAY AS THE UPPER TROUGH DIGGING ACROSS
THE WRN CONUS SLIDES THROUGH THE REGION. THIS WILL ALLOW TEMPS TO
CLIMB BACK TO NEAR NORMAL BY THE END OF THE MONTH.


&&

$$

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















000
FXUS65 KTWC 252143
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
243 PM MST MON AUG 25 2014

.SYNOPSIS...A SIGNIFICANT CHANGE IN THE WEATHER PATTERN WILL TAKE
PLACE THROUGH TUESDAY AS DEEPER MOISTURE MOVES BACK INTO ARIZONA.
THIS WILL RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...THROUGH TUESDAY. IMPROVING WEATHER CAN BE ANTICIPATED
WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE
NORMAL READINGS BY THE WEEKEND.

&&

.DISCUSSION...CONVECTION...HEAVY RAIN AND SOME FLASH FLOODING
ONGOING ACROSS SOUTHEAST ARIZONA. THE RAIN RATES IN THESE STORMS ARE
IMPRESSIVE...WITH SOME RAIN GAUGES REPORTING UP TO ONE INCH RAIN
TOTALS IN 15 TO 30 MINUTES. STORM TOPS SO FAR HAVE BEEN RELATIVELY
LOW...WITH THE STRONGEST STORM CORES BELOW 20 KFT. SO THE PRIMARY
THREAT FOR THE NEXT 24 TO 48 HOURS IS HEAVY RAIN BUT A STRONGER
STORM MAY KICK OUT SOME INTENSE WINDS.

THE GOOD FOLKS AT NESDIS POINTED OUT TODAY THAT THE MOIST AIR IN
PLACE CURRENTLY OVER SE ARIZONA IS LIKELY FROM THE REMNANTS OF
HURRICANE LOWELL AND NOT HURRICANE MARIE WHO IS SITTING OFF THE BAJA
PENINSULA SEVERAL HUNDRED MILES TO THE SOUTH OF AZ. REGARDLESS OF
THE SOURCE...THE AIR IN PLACE RIGHT NOW WILL ONLY BECOME MORE
SATURATED WHEN THE DEEPER MOISTURE FROM MARIE FINALLY WORKS INTO SE
ARIZONA TONIGHT AND TUESDAY. THE BOTTOM LINE...THE FLASH FLOOD
THREAT IS LIKELY TO EXTEND WELL INTO TUESDAY...BUT WE DECIDED TO SET
AN END TIME ON THE FLASH FLOOD WATCH TO 18Z TO AVOID ISSUING A TWO
DAY WATCH.

THINKING THE MAIN THREAT AREA TUESDAY WILL SHIFT TOWARD THE NORTHERN
ZONES...GRAHAM AND GREENLEE COUNTIES...WHERE THEIR WILL BE BETTER
UPPER SUPPORT FROM THE TAIL END OF AN UPPER TROUGH. I AM ALSO
CONCERNED THAT THE SEVERE THREAT MAY INCREASE TOMORROW DUE TO THE
COOLER AIR ALOFT AND STRONGER UPPER JET PUSHING ACROSS THE NORTHERN
ZONES. THE LIMITING FACTOR WILL BE THE ABUNDANT CLOUD COVER AND
LIMITED HEATING.

MODELS THEN SHOW RAPID DRYING STARTING WEDNESDAY WITH CONTINUED
DRYING THURSDAY. POP TRENDS ADEQUATELY SHOW THIS DOWNTURN IN PRECIP
CHANCES. IN ADDITION...THE WARM AIR WILL RETURN WITH THE DRYING SO
TEMPS WILL RISE BACK TO NORMAL OR EVEN SLIGHTLY WARMER THAN NORMAL
BY LATE IN THE WEEK.

JJB

&&

.AVIATION...VALID THRU 26/18Z.
AREA SPLIT BETWEEN HURRICANE MARIE TO THE SOUTH AND A DIGGING UPPER
TROUGH TO THE NORTH. THE LATER WILL KEEP PUMPING CIRRUS LEVEL CLOUDS
INTO THE AREA...WHILE THE FORMER WILL PUMP IN LOW/MID LEVEL MOISTURE
IN. ENOUGH MOISTURE IN PLACE FOR SCT -SHRA THIS AFTERNOON. POINT
SOUNDINGS SHOW LOWEST 5-8 KFT REMAINING DRY THOUGH WHICH SUPPORTS
SOME GUSTY OUTFLOW WINDS EVEN THOUGH FLOW ALOFT REMAINS WEAK. THE
GENERAL LACK OF STORM MOTION WILL HELP SATURATE THE COLUMN EARLY SO
THIS THREAT WILL LESSEN LATER IN THE PERIOD. ALSO...EXPECT DEEPER
MOISTURE TO SLOW WORK INTO THE AREA WHICH WILL CONTRIBUTE AS WELL.
THE SLOW STORM MOTION AND FAIRLY TROPICAL NATURE OF THE AIRMASS WILL
SUPPORT MVFR-IFR CONDITIONS NEAR THE STRONGER SHOWERS. HAVE REMOVED
THE TS MENTION FROM ALL TERMINALS AS TIMING AND CONFIDENCE IS TOO
LOW TO SUPPORT GIVEN THE LACK OF ELEVATED INSTABILITY.
NEVERTHELESS...ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE WILL CONTINUE TO SETTLE IN ACROSS
AREA TODAY AS MOISTURE FROM HURRICANE MARIE SURGES NORTHWARD. THIS
AFTERNOON THERE WILL BE SOME POTENTIAL FOR GUSTY OUTFLOW WINDS AS
LOW LEVEL WILL REMAIN RELATIVELY DRY...THOUGH THIS WILL DIMINISH
LATER IN THE EVENING AS COLUMN BECOMES SATURATED. LIGHTNING ACTIVITY
CONTINUES TO LOOK FAIRLY LIMITED. STORM MOTION WILL BE FAIRLY SLOW
SO GIVEN THIS AND THE DEEP MOISTURE EXPECTED THIS LOOKS TO BE A GOOD
CHANCE FOR WETTING RAINS ACROSS THE AREA. CONFIDENCE IN WHEN THE
MOISTURE/SHOWERS WILL ERODE REMAINS LOW...BUT SHOULD SEE DRY
CONDITIONS AGAIN LATE WEDNESDAY AS THE UPPER TROUGH DIGGING ACROSS
THE WRN CONUS SLIDES THROUGH THE REGION. THIS WILL ALLOW TEMPS TO
CLIMB BACK TO NEAR NORMAL BY THE END OF THE MONTH.


&&

$$

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
















000
FXUS65 KPSR 252110
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
210 PM MST MON AUG 25 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO ALLOW CONVECTIVE
ACTIVITY TO DEVELOP ACROSS SE AZ THIS AFTERNOON...WITH A SLIGHT
CHANCE THAT STORMS WILL MOVE INTO THE PHX AREA THIS EVENING...WITH
KIWA SEEING THE BEST CHANCE FOR STORMS. THERE IS A BETTER CHANCE
THAT OUTFLOWS...AND EVEN SOME BLOWING DUST WILL AFFECT THE PHX AREA
TERMINALS THIS EVENING...WHICH IS CURRENTLY REFLECTED BY A WIND
SHIFT TO A SE-LY DIRECTION IN THE TAFS. THERE IS A MUCH BETTER
CHANCE FOR SHOWERS...OR THUNDERSTORMS LATE TONIGHT...AND DURING THE
DAY ON TUESDAY. THESE STORMS COULD PRODUCE GUSTY WINDS AND BRIEF
HEAVY DOWNPOURS...WITH PERHAPS EVEN A PERIOD OF STEADIER RAIN ON
TUESDAY MORNING...WHICH COULD PUSH CIGS DOWN TO AROUND 6K FT...OR
EVEN LOWER IN THE HEAVIER SHOWERS.

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

LOW PRESSURE THAT WILL BE TRACKING OVER NORTHERN AND CENTRAL NV
TONIGHT AND TUESDAY WILL KEEP WINDS AT KIPL MAINLY FROM A SE-LY
DIRECTION FROM THIS EVENING INTO TUESDAY...AND S-LY WINDS GOING AT
KBLH THROUGH THE ENTIRE TAF PERIOD. THIS UPPER LOW CENTER WILL
LIKELY ALSO BRING PERIODS OF MID TO HIGH CIGS TO THE TERMINALS AS
WELL...WITH CIGS MAINLY AOA 10K FT. THERE IS A VERY SLIGHT CHANCE
THAT SHOWERS/THUNDERSTORMS COULD AFFECT KBLH ON TUESDAY...BUT
CONFIDENCE IS FAR TOO LOW TO INCLUDE THEM IN THE TAF AT THIS TIME.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...2 AM UNTIL 2 PM
     TUESDAY.

CA...NONE.

&&

$$

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

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












000
FXUS65 KPSR 252110
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
210 PM MST MON AUG 25 2014

.SYNOPSIS...
A WEATHER DISTURBANCE WILL APPROACH THE REGION TONIGHT AND TUESDAY
PULLING MONSOON MOISTURE NORTHWARD AND SUPPORTING INCREASED CHANCES
FOR THUNDERSTORMS. STORMS MAY STRUGGLE TO REACH INTO LOWER DESERT
LOCATIONS THIS EVENING...BUT MORE WIDESPREAD RAINFALL COVERAGE IS
LIKELY ACROSS CENTRAL ARIZONA LATER TONIGHT AND TUESDAY. MUCH DRIER
AND TRANQUIL WARM WEATHER ARE ANTICIPATED FOR THE LATTER HALF OF THE
WEEK.

&&

.DISCUSSION...
TWO PRIMARY FEATURES OF NOTE EARLY THIS AFTERNOON...THE FIRST BEING
A SHARP UPPER TROF DIGGING SOUTHEASTWARD OUT OF THE PAC NW INTO THE
GREAT BASIN WHICH WILL BE IMPORTING SIGNIFICANT MONSOON MOISTURE
INTO THE STATE...AND THEN MOVING NORTHWARD ACROSS THE STATE TUESDAY
INTO WEDNESDAY LEADING TO WIDESPREAD SHOWERS/STORMS ACROSS
ARIZONA...SOME WITH HEAVY RAIN. THE SECOND FEATURE BEING HURRICANE
MARIE MOVING TO THE NORTHWEST WELL OFF THE SRN TIP OF BAJA CA. MAIN
IMPACT OF MARIE WILL BE ADDING TROPICAL MOISTURE TO THE MIX AS THE
APPROACHING UPPER TROF TAPS MID/UPPER LEVEL MOISTURE BEING SHED FROM
MARIES OUTER BANDS. MOISTURE HAS ALREADY INCREASED QUITE A BIT
ACROSS THE STATE...AT 1 PM SURFACE DEWPOINTS ACROSS THE CENTRAL AZ
DESERTS WERE IN THE MID 60S...UP NEARLY 10 DEGREES FROM 24 HOURS
AGO. DEWPOINTS OUT WEST RANGED FROM THE MID 5OS TO LOW 70S AND WERE
UP 20-30 DEGREES FROM A DAY AGO. PWAT VALUES WERE UP OVER 1.5 INCHES
AT TUS AND YUM AS SEEN IN THE MORNING RAOBS. SCATTERED STORMS WERE
ALREADY FIRING OVER SERN AZ...BUT SWLY STEERING FLOW WILL LIKELY
KEEP MOST OF THEM FROM BODILY ADVECTING INTO THE CENTRAL DESERT.
LATEST SPC MESOANALYSIS GRAPHIC SHOWED MLCAPE VALUES RANGING FROM
1000 TO 3000 J/KG OVER THE WESTERN DESERTS THIS AFTERNOON...HOWEVER
RECENT VIS IMAGERY SHOWED JUST A CU FIELD DEVELOPING IN THE AREA. WE
WILL CARRY A SLIGHT CHANCE FOR THUNDERSTORMS OVER SWRN AZ FOR THIS
AFTERNOON AND EVENING IN CASE THE CU BREAK THRU THE CAP AND REALLY
TAKE OFF. OTHERWISE FOR THIS EVENING...WE SHOULD SEE AN INCREASING
CHANCE FOR THUNDERSTORMS ACROSS SOUTH CENTRAL AZ AS MOISTURE
CONTINUES TO SPREAD INTO THE AREA...AND OUTFLOWS FROM SERN AZ
CONVECTION MOVE INTO THE DESERTS AND POSSIBLY CAUSE NEW STORMS TO
FORM. BLOWING DUST MAY ALSO BE AN ISSUE THIS EVENING AS CONVECTIVE
OUTFLOWS MOVE INTO THE LOWER DESERTS THIS EVENING.

IT APPEARS THAT THE BEST THREAT FOR THUNDERSTORMS...HEAVY RAIN AND
POTENTIAL FLASH FLOODING WILL OCCUR BEGIN AFTER MIDNIGHT TONIGHT
AND LASTING INTO THE LATE MORNING OR EARLY AFTERNOON ON TUESDAY.
THIS WILL BE WHEN THE BEST DYNAMICS AND MOISTURE COME TOGETHER AS
THE UPPER TROF MOVING THRU THE GREAT BASIN DRAWS CLOSER...AND AN
INVERTED TROF MOVING OUT OF NWRN MEXICO MOVES NORTH AND INTO EASTERN
ARIZONA. PWAT VALUES CLIMB TO NEARLY 2 INCHES ACROSS SOUTH CENTRAL
AZ...LIFTED INDICES FALL BELOW MINUS 4 AND WIND FIELDS ALOFT REALLY
STRENGTHEN. HIGHEST POPS WILL BE IN THE WINDOW FROM 06Z TONIGHT THRU
18Z TUESDAY WITH VALUES IN THE LIKELY CATEGORY FROM PHOENIX
EASTWARD. WE FEEL THAT THE MODEL POP FORECASTS FOR THIS EVENT ARE
VERY UNDERDONE...AND OUR POPS WILL BE DOUBLE OR TRIPLE THE CURRENT
MOS NUMBERS. THIS EVENT WILL LIKELY PLAY OUT SIMILAR TO THE EVENT
FROM AROUND A WEEK AGO THAT BROUGHT FLOODING TO AREAS NORTH AND EAST
OF PHOENIX...SUCH AS NEW RIVER AND BLACK CANYON CITY.

HAVE ISSUED A FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ...MARICOPA
COUNTY EASTWARD...STARTING 2 AM TUESDAY AND RUNNING THROUGH 2 PM.
THIS SHOULD BE THE BEST WINDOW FOR HEAVY RAIN...AND WILL PUT US INTO
GOOD AGREEMENT WITH OUR SURROUNDING OFFICES.

BY AFTERNOON THE INVERTED TROF WILL HAVE EXITED TO THE EAST AND QG
FORCING WILL START TO DECREASE. SOME OF THE DEEPER MOISTURE WILL
START TO PUSH OFF TOWARDS THE NORTHEAST AND THUS OUR POPS AND
CHANCES FOR HEAVY RAINS WILL START TO DIMINISH AS THE AFTERNOON
PROGRESSES. STILL...WE WILL HAVE A PRETTY GOOD CHANCE FOR AFTERNOON
AND EVENING CONVECTION CONSIDERING THAT THE UPPER LOW WILL BE
TRANSLATING EASTWARD TO OUR NORTH...AND THERE WILL BE CONSIDERABLE
LINGERING LOW LEVEL MOISTURE ACROSS THE LOWER DESERTS...WITH 850MB
DEWPOINTS IN EXCESS OF 12C. WE HAVE RAISED OUR POPS FOR TUESDAY
AFTERNOON AND OVERNIGHT TUESDAY NIGHT TO REFLECT THIS CHANCE FOR
LINGERING CONVECTION. ON THE TEMPERATURE FRONT...HIGHS ACROSS THE
CENTRAL DESERTS TUESDAY WILL BE DOWN SHARPLY AND MANY LOCALES MAY
STRUGGLE TO REACH THE MID 90S. OUT OF 40 SOME GUIDANCE
PACKAGES...COOLEST HIGH FORECAST FOR PHOENIX ON TUESDAY IS JUST
93...BUT DEPENDING ON THE AMOUNT OF SHOWERS/CONVECTION EARLIER IN
THE DAY WE MAY BE LUCKY TO REACH 90. WILL GO WITH 96 DUE TO
PREPONDERANCE OF THE GUIDANCE BUT THIS MAY BE TOO WARM.

BOTH THE ECMWF AND GFS TAKE THE LOW EAST AND INTO EASTERN UT/WESTERN
CO BY WEDNESDAY AFTERNOON...AND THEY OVERSPREAD A
DRYING...SUBSIDENCE AND WESTERLY FLOW ALOFT ACROSS MOST OF THE
REGION. HOWEVER...DESPITE THE DRYING TENDENCIES OF THE WESTERLY
FLOW...LOW LEVEL MOISTURE IS HARD TO SCOUR OUT AND PWAT VALUES
REMAIN AT NEARLY 1.5 INCHES INTO THE AFTERNOON ON WEDNESDAY...AND
850MB DEWPOINTS REMAIN NEAR 12C. CAPE IS STILL PRESENT...WITH VALUES
IN EXCESS OF 500 J/KG. AS SUCH WE WILL RAISE POPS A BIT AND INTO THE
SLIGHT CHANCE CATEGORY ACROSS MOST OF SOUTH CENTRAL ARIZONA.
CONTINUED DRYING WILL TAKE PLACE WED EVENING INTO THURSDAY AND BY
THURSDAY WE SHOULD SEE MOSTLY SUNNY SKIES ACROSS THE LOWER DESERTS
AND JUST THE SLIMMEST OF CHANCES FOR STORMS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX.

BUILDING RIDGING OVER THE LOS ANGELES BASIN AND PREDOMINANT NWLY
FLOW DOWNSTREAM OVER ARIZONA WILL BE THE MAIN THEME FOR THE
REMAINDER OF THIS WEEK AND INTO EARLY NEXT WEEK. THERE IS EXCELLENT
MODEL AGREEMENT THAT MOISTURE WILL BE COMPLETELY SCOURED WELL SOUTH
AND EAST OF THE AREA WITH THE FLOW PATTERN RESEMBLING MORE THE END
OF SEPTEMBER VERSUS THE END OF AUGUST. HAVE VIRTUALLY STRIPPED ALL
POPS FROM THE FORECAST GIVEN PATTERN RECOGNITION WITH STRONG SUPPORT
FROM NUMERICAL GUIDANCE. H5 HEIGHTS AOA 590DM SHOULD RESULT IN
AFTERNOON HIGHS NEAR AND SLIGHTLY ABOVE AVERAGE...THOUGH THE DRY
AIRMASS AND LONGER NIGHTS SHOULD LEAD TO A WIDE DIURNAL SPREAD AND
OVERNIGHT LOWS AT OR SLIGHTLY BELOW AVERAGE.

&&

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

A WEATHER DISTURBANCE PASSING TO THE NORTH...ALONG WITH INCREASING
MONSOONAL MOISTURE OVER THE REGION...IS EXPECTED TO ALLOW CONVECTIVE
ACTIVITY TO DEVELOP ACROSS SE AZ THIS AFTERNOON...WITH A SLIGHT
CHANCE THAT STORMS WILL MOVE INTO THE PHX AREA THIS EVENING...WITH
KIWA SEEING THE BEST CHANCE FOR STORMS. THERE IS A BETTER CHANCE
THAT OUTFLOWS...AND EVEN SOME BLOWING DUST WILL AFFECT THE PHX AREA
TERMINALS THIS EVENING...WHICH IS CURRENTLY REFLECTED BY A WIND
SHIFT TO A SE-LY DIRECTION IN THE TAFS. THERE IS A MUCH BETTER
CHANCE FOR SHOWERS...OR THUNDERSTORMS LATE TONIGHT...AND DURING THE
DAY ON TUESDAY. THESE STORMS COULD PRODUCE GUSTY WINDS AND BRIEF
HEAVY DOWNPOURS...WITH PERHAPS EVEN A PERIOD OF STEADIER RAIN ON
TUESDAY MORNING...WHICH COULD PUSH CIGS DOWN TO AROUND 6K FT...OR
EVEN LOWER IN THE HEAVIER SHOWERS.

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

LOW PRESSURE THAT WILL BE TRACKING OVER NORTHERN AND CENTRAL NV
TONIGHT AND TUESDAY WILL KEEP WINDS AT KIPL MAINLY FROM A SE-LY
DIRECTION FROM THIS EVENING INTO TUESDAY...AND S-LY WINDS GOING AT
KBLH THROUGH THE ENTIRE TAF PERIOD. THIS UPPER LOW CENTER WILL
LIKELY ALSO BRING PERIODS OF MID TO HIGH CIGS TO THE TERMINALS AS
WELL...WITH CIGS MAINLY AOA 10K FT. THERE IS A VERY SLIGHT CHANCE
THAT SHOWERS/THUNDERSTORMS COULD AFFECT KBLH ON TUESDAY...BUT
CONFIDENCE IS FAR TOO LOW TO INCLUDE THEM IN THE TAF AT THIS TIME.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
STRONG HIGH PRESSURE ALOFT IS EXPECTED TO KEEP MONSOON MOISTURE WELL
AWAY FROM THE REGION...WITH MOSTLY CLEAR SKIES EXPECTED THROUGH THE
FORECAST PERIOD. TEMPERATURES TO REMAIN NEAR SEASONAL NORMALS...WITH
MAINLY LIGHT DIURNALLY-DRIVEN WINDS. HUMIDITIES ARE EXPECTED TO FALL
MAINLY INTO THE TEENS EACH DAY ACROSS THE LOWER DESERTS...WITH FAIR
TO GOOD OVERNIGHT RECOVERIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...FLASH FLOOD WATCH AZZ022>024...AZZ027>028...2 AM UNTIL 2 PM
     TUESDAY.

CA...NONE.

&&

$$

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

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













000
FXUS65 KTWC 251734
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
904 AM MST MON AUG 25 2014

.SYNOPSIS...A SIGNIFICANT CHANGE IN THE WEATHER PATTERN WILL TAKE
PLACE TODAY AND TUESDAY AS DEEPER MOISTURE MOVES BACK INTO ARIZONA.
THIS WILL RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...LATER TODAY AND TUESDAY. IMPROVING WEATHER CAN BE
ANTICIPATED WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO
SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.UPDATED...SEE AVIATION AND FIRE WX DISCUSSIONS BELOW.

&&

.DISCUSSION...ALTO CUMULUS FIELD OVER THE CATALINA MOUNTAINS THIS
MORNING IS A SIGN OF THINGS TO COME LATER TODAY. AS ADVERTISED...THE
MOIST AIR STREAMING UP FROM THE SOUTH IS NOW INVADING SE ARIZONA.
DEW POINTS IN YUMA ARE IN THE MID 70S...WITH MID 60S IN TUCSON. 12Z
MORNING SOUNDING IN TUCSON AND YUMA SHOWED PRECIP WATER VALUES OVER
1.5 INCHES...BUT RECENT SOUNDER SATELLITE IMAGERY SUGGESTS THE 1.8
INCH AND ABOVE AIR IS NOW IN THE NORTHERN EDGE OF THE GULF OF
CALIFORNIA. LOCAL HI RES WRF MODEL RUNS...ALONG WITH THE U OF A WRF
RUNS SHOWS THE ELEVATED PRECIP WATER VALUES SPREADING ACROSS SANTA
CRUZ...PIMA AND PINAL COUNTIES STARTING AROUND 20Z...CONTINUING
THROUGH TUESDAY. SO...JUST LIKE THE MIDNIGHT SHIFT...I AM STILL
CONFIDENT IN A HEAVY RAIN EVENT IMPACTING SE ARIZONA...AND FURTHER
NORTH FOR THAT MATTER. HOWEVER...TIMING IS STILL THE KEY AND WHERE
THE GREATEST UNCERTAINTY LIES. CURRENTLY THINKING TODAY AND TONIGHT
WILL PROVIDE THE BEST SHOT FOR HEAVY RAIN FROM SAY TUCSON
SOUTH...BUT WE SHOULD SEE THAT HEAVIER PRECIP SHIELD SHIFT NORTH
TOWARD GRAHAM AND GREENLEE COUNTIES ON TUESDAY. WE ARE CONSIDERING A
FLASH FLOOD WATCH FOR TODAY AND WILL FURTHER CONSULT THE HIGHER
RESOLUTION DATA TO DETERMINE IF WE CAN FINE TUNE THE BEST TIME AND
LOCATION FOR THE WATCH.

EITHER WAY...BE AWARE THAT HEAVY RAIN AND FLASH FLOODING ARE A
CONCERN FOR THE NEXT 24 TO 48 HOURS.

JJB

&&

.AVIATION...VALID THRU 26/18Z.
AREA SPLIT BETWEEN HURRICANE MARIE TO THE SOUTH AND A DIGGING UPPER
TROUGH TO THE NORTH. THE LATER WILL KEEP PUMPING CIRRUS LEVEL CLOUDS
INTO THE AREA...WHILE THE FORMER WILL PUMP IN LOW/MID LEVEL MOISTURE
IN. ENOUGH MOISTURE IN PLACE FOR SCT -SHRA THIS AFTERNOON. POINT
SOUNDINGS SHOW LOWEST 5-8 KFT REMAINING DRY THOUGH WHICH SUPPORTS
SOME GUSTY OUTFLOW WINDS EVEN THOUGH FLOW ALOFT REMAINS WEAK. THE
GENERAL LACK OF STORM MOTION WILL HELP SATURATE THE COLUMN EARLY SO
THIS THREAT WILL LESSEN LATER IN THE PERIOD. ALSO...EXPECT DEEPER
MOISTURE TO SLOW WORK INTO THE AREA WHICH WILL CONTRIBUTE AS WELL.
THE SLOW STORM MOTION AND FAIRLY TROPICAL NATURE OF THE AIRMASS WILL
SUPPORT MVFR-IFR CONDITIONS NEAR THE STRONGER SHOWERS. HAVE REMOVED
THE TS MENTION FROM ALL TERMINALS AS TIMING AND CONFIDENCE IS TOO
LOW TO SUPPORT GIVEN THE LACK OF ELEVATED INSTABILITY.
NEVERTHELESS...ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE WILL CONTINUE TO SETTLE IN ACROSS
AREA TODAY AS MOISTURE FROM HURRICANE MARIE SURGES NORTHWARD. THIS
AFTERNOON THERE WILL BE SOME POTENTIAL FOR GUSTY OUTFLOW WINDS AS
LOW LEVEL WILL REMAIN RELATIVELY DRY...THOUGH THIS WILL DIMINISH
LATER IN THE EVENING AS COLUMN BECOMES SATURATED. LIGHTNING ACTIVITY
CONTINUES TO LOOK FAIRLY LIMITED. STORM MOTION WILL BE FAIRLY SLOW
SO GIVEN THIS AND THE DEEP MOISTURE EXPECTED THIS LOOKS TO BE A GOOD
CHANCE FOR WETTING RAINS ACROSS THE AREA. CONFIDENCE IN WHEN THE
MOISTURE/SHOWERS WILL ERODE REMAINS LOW...BUT SHOULD SEE DRY
CONDITIONS AGAIN LATE WEDNESDAY AS THE UPPER TROUGH DIGGING ACROSS
THE WRN CONUS SLIDES THROUGH THE REGION. THIS WILL ALLOW TEMPS TO
CLIMB BACK TO NEAR NORMAL BY THE END OF THE MONTH.


&&

.PREV DISCUSSION...A BIG CHANGE IN THE WEATHER PATTERN WAS SHAPING
UP FOR THE NEXT COUPLE OF DAYS AS DEEPER MOISTURE RETURNS TO THE
REGION. LATEST MODELS CONTINUED TO SHOW 2 LARGE SCALE WEATHER
FEATURES THAT WILL BECOME A FACTOR IN BRINGING WIDESPREAD RAIN TO
SOUTHEAST ARIZONA LATER TODAY AND TUESDAY. HURRICANE MARIE
POSITIONED WELL OFF THE SOUTHERN TIP OF BAJA THIS MORNING WILL
CONTRIBUTE TO THE NORTHWARD PUSH OF MOISTURE POOLED SOUTH OF THE
INTERNATIONAL BORDER TODAY AND TUESDAY. RECENT SURFACE OBSERVATIONS
SUGGESTED THAT THIS MOISTURE INCREASE WAS ALREADY MATERIALIZING AS
DEWPOINTS HAVE CLIMBED INTO THE LOW TO MID 70S IN YUMA ALONG WITH
READINGS IN THE MID 60S BEING REPORTED IN TUCSON EARLY THIS MORNING.
THIS DEEPER MOISTURE WILL INTERACT WITH THE TAIL END OF A LOW
PRESSURE SYSTEM MOVING THROUGH NEVADA AND UTAH TONIGHT INTO EARLY
WEDNESDAY. THERE WAS A HIGH DEGREE OF CONFIDENCE THAT THE
INGREDIENTS FOR HEAVY RAINFALL AND SUBSEQUENT FLASH FLOODING WILL
COME TOGETHER DURING THE NEXT 12 TO 36 HOURS ACROSS SOUTHEAST
ARIZONA. CONFIDENCE REMAINED RATHER LOW...HOWEVER...ON THE TIMING OF
THE HEAVIEST RAINFALL AS MODEL SOLUTIONS DIFFER. SOME POINT TO
TONIGHT AND OTHERS SUGGEST TUESDAY AFTERNOON AND EVENING WILL BE THE
HEAVIEST. THAT SAID...NOT CONFIDENT ENOUGH ON THE TIMING TO JUSTIFY
POSTING A FLASH FLOOD WATCH ON THE MORNING FORECAST PACKAGE. FOR
NOW...WILL BANK ON TUESDAY AFTERNOON AND EARLY EVENING FOR BEING THE
BEST TIME FRAME FOR THE BULK OF THE HEAVY RAINFALL AREAWIDE. ALONG
WITH THE CLOUDINESS AND RAIN...COOLER DAYTIME TEMPERATURES CAN BE
ANTICIPATED. BY WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD
START THE DRYING TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL
TRANSLATE TO A WARMING TREND AS WELL...WITH PROJECTED HIGH
TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS THIS
WEEKEND.

&&

$$

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000
FXUS65 KTWC 251734
AFDTWC

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TUCSON AZ
904 AM MST MON AUG 25 2014

.SYNOPSIS...A SIGNIFICANT CHANGE IN THE WEATHER PATTERN WILL TAKE
PLACE TODAY AND TUESDAY AS DEEPER MOISTURE MOVES BACK INTO ARIZONA.
THIS WILL RESULT IN SHOWERS AND THUNDERSTORMS...SOME WITH VERY HEAVY
RAINFALL...LATER TODAY AND TUESDAY. IMPROVING WEATHER CAN BE
ANTICIPATED WEDNESDAY...WITH DAYTIME TEMPERATURES REBOUNDING TO
SLIGHTLY ABOVE NORMAL READINGS BY THE WEEKEND.

&&

.UPDATED...SEE AVIATION AND FIRE WX DISCUSSIONS BELOW.

&&

.DISCUSSION...ALTO CUMULUS FIELD OVER THE CATALINA MOUNTAINS THIS
MORNING IS A SIGN OF THINGS TO COME LATER TODAY. AS ADVERTISED...THE
MOIST AIR STREAMING UP FROM THE SOUTH IS NOW INVADING SE ARIZONA.
DEW POINTS IN YUMA ARE IN THE MID 70S...WITH MID 60S IN TUCSON. 12Z
MORNING SOUNDING IN TUCSON AND YUMA SHOWED PRECIP WATER VALUES OVER
1.5 INCHES...BUT RECENT SOUNDER SATELLITE IMAGERY SUGGESTS THE 1.8
INCH AND ABOVE AIR IS NOW IN THE NORTHERN EDGE OF THE GULF OF
CALIFORNIA. LOCAL HI RES WRF MODEL RUNS...ALONG WITH THE U OF A WRF
RUNS SHOWS THE ELEVATED PRECIP WATER VALUES SPREADING ACROSS SANTA
CRUZ...PIMA AND PINAL COUNTIES STARTING AROUND 20Z...CONTINUING
THROUGH TUESDAY. SO...JUST LIKE THE MIDNIGHT SHIFT...I AM STILL
CONFIDENT IN A HEAVY RAIN EVENT IMPACTING SE ARIZONA...AND FURTHER
NORTH FOR THAT MATTER. HOWEVER...TIMING IS STILL THE KEY AND WHERE
THE GREATEST UNCERTAINTY LIES. CURRENTLY THINKING TODAY AND TONIGHT
WILL PROVIDE THE BEST SHOT FOR HEAVY RAIN FROM SAY TUCSON
SOUTH...BUT WE SHOULD SEE THAT HEAVIER PRECIP SHIELD SHIFT NORTH
TOWARD GRAHAM AND GREENLEE COUNTIES ON TUESDAY. WE ARE CONSIDERING A
FLASH FLOOD WATCH FOR TODAY AND WILL FURTHER CONSULT THE HIGHER
RESOLUTION DATA TO DETERMINE IF WE CAN FINE TUNE THE BEST TIME AND
LOCATION FOR THE WATCH.

EITHER WAY...BE AWARE THAT HEAVY RAIN AND FLASH FLOODING ARE A
CONCERN FOR THE NEXT 24 TO 48 HOURS.

JJB

&&

.AVIATION...VALID THRU 26/18Z.
AREA SPLIT BETWEEN HURRICANE MARIE TO THE SOUTH AND A DIGGING UPPER
TROUGH TO THE NORTH. THE LATER WILL KEEP PUMPING CIRRUS LEVEL CLOUDS
INTO THE AREA...WHILE THE FORMER WILL PUMP IN LOW/MID LEVEL MOISTURE
IN. ENOUGH MOISTURE IN PLACE FOR SCT -SHRA THIS AFTERNOON. POINT
SOUNDINGS SHOW LOWEST 5-8 KFT REMAINING DRY THOUGH WHICH SUPPORTS
SOME GUSTY OUTFLOW WINDS EVEN THOUGH FLOW ALOFT REMAINS WEAK. THE
GENERAL LACK OF STORM MOTION WILL HELP SATURATE THE COLUMN EARLY SO
THIS THREAT WILL LESSEN LATER IN THE PERIOD. ALSO...EXPECT DEEPER
MOISTURE TO SLOW WORK INTO THE AREA WHICH WILL CONTRIBUTE AS WELL.
THE SLOW STORM MOTION AND FAIRLY TROPICAL NATURE OF THE AIRMASS WILL
SUPPORT MVFR-IFR CONDITIONS NEAR THE STRONGER SHOWERS. HAVE REMOVED
THE TS MENTION FROM ALL TERMINALS AS TIMING AND CONFIDENCE IS TOO
LOW TO SUPPORT GIVEN THE LACK OF ELEVATED INSTABILITY.
NEVERTHELESS...ISOLATED TS DEVELOPMENT WILL BE POSSIBLE ACROSS THE
AREA BUT CAN`T PIN POINT DEVELOPMENT NEAR THE TERMINALS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...DEEPER MOISTURE WILL CONTINUE TO SETTLE IN ACROSS
AREA TODAY AS MOISTURE FROM HURRICANE MARIE SURGES NORTHWARD. THIS
AFTERNOON THERE WILL BE SOME POTENTIAL FOR GUSTY OUTFLOW WINDS AS
LOW LEVEL WILL REMAIN RELATIVELY DRY...THOUGH THIS WILL DIMINISH
LATER IN THE EVENING AS COLUMN BECOMES SATURATED. LIGHTNING ACTIVITY
CONTINUES TO LOOK FAIRLY LIMITED. STORM MOTION WILL BE FAIRLY SLOW
SO GIVEN THIS AND THE DEEP MOISTURE EXPECTED THIS LOOKS TO BE A GOOD
CHANCE FOR WETTING RAINS ACROSS THE AREA. CONFIDENCE IN WHEN THE
MOISTURE/SHOWERS WILL ERODE REMAINS LOW...BUT SHOULD SEE DRY
CONDITIONS AGAIN LATE WEDNESDAY AS THE UPPER TROUGH DIGGING ACROSS
THE WRN CONUS SLIDES THROUGH THE REGION. THIS WILL ALLOW TEMPS TO
CLIMB BACK TO NEAR NORMAL BY THE END OF THE MONTH.


&&

.PREV DISCUSSION...A BIG CHANGE IN THE WEATHER PATTERN WAS SHAPING
UP FOR THE NEXT COUPLE OF DAYS AS DEEPER MOISTURE RETURNS TO THE
REGION. LATEST MODELS CONTINUED TO SHOW 2 LARGE SCALE WEATHER
FEATURES THAT WILL BECOME A FACTOR IN BRINGING WIDESPREAD RAIN TO
SOUTHEAST ARIZONA LATER TODAY AND TUESDAY. HURRICANE MARIE
POSITIONED WELL OFF THE SOUTHERN TIP OF BAJA THIS MORNING WILL
CONTRIBUTE TO THE NORTHWARD PUSH OF MOISTURE POOLED SOUTH OF THE
INTERNATIONAL BORDER TODAY AND TUESDAY. RECENT SURFACE OBSERVATIONS
SUGGESTED THAT THIS MOISTURE INCREASE WAS ALREADY MATERIALIZING AS
DEWPOINTS HAVE CLIMBED INTO THE LOW TO MID 70S IN YUMA ALONG WITH
READINGS IN THE MID 60S BEING REPORTED IN TUCSON EARLY THIS MORNING.
THIS DEEPER MOISTURE WILL INTERACT WITH THE TAIL END OF A LOW
PRESSURE SYSTEM MOVING THROUGH NEVADA AND UTAH TONIGHT INTO EARLY
WEDNESDAY. THERE WAS A HIGH DEGREE OF CONFIDENCE THAT THE
INGREDIENTS FOR HEAVY RAINFALL AND SUBSEQUENT FLASH FLOODING WILL
COME TOGETHER DURING THE NEXT 12 TO 36 HOURS ACROSS SOUTHEAST
ARIZONA. CONFIDENCE REMAINED RATHER LOW...HOWEVER...ON THE TIMING OF
THE HEAVIEST RAINFALL AS MODEL SOLUTIONS DIFFER. SOME POINT TO
TONIGHT AND OTHERS SUGGEST TUESDAY AFTERNOON AND EVENING WILL BE THE
HEAVIEST. THAT SAID...NOT CONFIDENT ENOUGH ON THE TIMING TO JUSTIFY
POSTING A FLASH FLOOD WATCH ON THE MORNING FORECAST PACKAGE. FOR
NOW...WILL BANK ON TUESDAY AFTERNOON AND EARLY EVENING FOR BEING THE
BEST TIME FRAME FOR THE BULK OF THE HEAVY RAINFALL AREAWIDE. ALONG
WITH THE CLOUDINESS AND RAIN...COOLER DAYTIME TEMPERATURES CAN BE
ANTICIPATED. BY WEDNESDAY...THE RAPID DECREASE IN MOISTURE SHOULD
START THE DRYING TREND THROUGH THE WEEKEND. THIS DRYING TREND WILL
TRANSLATE TO A WARMING TREND AS WELL...WITH PROJECTED HIGH
TEMPERATURES REBOUNDING TO SLIGHTLY ABOVE NORMAL READINGS THIS
WEEKEND.

&&

$$

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













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