Area Forecast Discussion
Issued by NWS Phoenix, AZ

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000
FXUS65 KPSR 030333
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
835 PM MST SUN AUG 2 2015

&&

.SYNOPSIS...
MUCH DRIER WEATHER IS IN STORE THROUGH AT LEAST THE MIDDLE PART OF
THE COMING WEEK WITH STORM CHANCES CONFINED TO THE HIGHER TERRAIN
EAST OF PHOENIX. SLIGHTLY WARMER THAN NORMAL CONDITIONS ARE EXPECTED
THROUGH WEDNESDAY WITH HIGHS NEAR 110 DEGREES ACROSS THE SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA DESERTS. MODEST MONSOONAL MOISTURE
MAY RETURN TO THE EASTERN HALF OF ARIZONA LATE IN THE WEEK ALLOWING
FOR A RETURN TO SHOWER AND THUNDERSTORM CHANCES ACROSS THE SOUTH-
CENTRAL ARIZONA DESERTS.

&&

.DISCUSSION... THUNDERSTORM ACTIVITY ACROSS OUR CWA THIS
AFTERNOON/EVENING HAS BEEN BASICALLY NONEXISTENT AS WESTERLY FLOW
ALOFT CONTINUES TO BRING DRIER AIR INTO THE REGION...WITH THE 00Z
PSR SOUNDING NOW SHOWING A RATHER DRY 1.02 INCH PWAT VALUE. TO OUR
NORTH...A WEAK SHORTWAVE MOVING EASTWARD ACROSS SOUTHERN UTAH HELPED
TO TRIGGER WIDESPREAD CONVECTIVE ACTIVITY ACROSS THE FLAGSTAFF CWA
FOR A TIME THIS AFTERNOON...BEFORE RAPIDLY DIMINISHING THIS EVENING.
THE LATEST (18Z) GFS AND 00Z NAM CONTINUE TO FORECAST FURTHER DRYING
THROUGH MONDAY AS WESTERLY FLOW CONTINUES OVER THE REGION...WITH
MOISTURE/CHANCES FOR THUNDERSTORM TO NOT RETURN UNTIL AT LEAST
THURSDAY. FOR THE VERY SHORT-TERM...OTHER THAN REDUCING POPS FURTHER
THROUGH THE REMAINDER OF THIS EVENING AND SOME MINOR ADJUSTMENTS TO
THE HOURLY GRIDS...INHERITED FORECASTS ARE HOLDING UP WELL.

&&

.PREVIOUS DISCUSSION... DRY AIR CONTINUES TO WORK INTO THE
REGION...BUT ENOUGH MOISTURE REMAINS IN THE LOW LEVELS TO SPARK OFF
SOME HIGH TERRAIN SHOWERS AND THUNDERSTORMS THIS AFTERNOON MAINLY TO
THE NORTH AND EAST OF PHOENIX. THE 12Z PHOENIX RAOB SHOWS PWATS DOWN
TO 1.36 INCHES AND THIS WILL LOWER TO 0.75-1.00 INCHES FOR MONDAY
THROUGH WEDNESDAY ENDING ANY RAIN CHANCES OVER THE DESERTS. THIS ALL
HAPPENS AS THE RIDGE OF HIGH PRESSURE CURRENTLY JUST OFF THE
SOUTHWEST U.S. COAST SLOWLY DRIFTS EASTWARD BECOMING CENTERED OVER
ARIZONA BY WEDNESDAY. THIS WILL BRING WEAK SOUTHWESTERLY FLOW ALOFT
THROUGH MOST OF THE UPCOMING WEEK.

THE DRYING PATTERN WILL ALLOW TEMPERATURES TO GRADUALLY RISE TO
SLIGHTLY ABOVE SEASONAL NORMALS...THOUGH AT THIS TIME NONE OF THE
GUIDANCE BRINGS TEMPERATURES TO THE 110 DEGREE MARK FOR PHOENIX.
A BIT WARMER CONDITIONS WILL BE FOUND ACROSS THE SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA DESERTS WITH HIGHS AROUND 110
DEGREES IN MANY LOCATIONS THROUGH THE MIDDLE OF THE WEEK. STORM
CHANCES OVER THE NEXT 5-6 DAYS ARE SUBSTANTIALLY LESS THAN THE
PREVIOUS DAYS ACROSS THE LOWER DESERTS. LOW END SLIGHT CHANCES AT
MOST WILL BE KEPT FOR HIGHER ELEVATIONS NORTH AND EAST OF PHOENIX DUE
TO THE NATURE OF MOUNTAIN ACTIVITY. THE NEXT FLOW REVERSAL APPEARS TO
SHAPE UP BY LATE WEEK INTO NEXT WEEKEND AS MOISTURE MAKES A RETURN
APPEARANCE AND WIND FLOW RETURNS TO A SOUTH- SOUTHEASTERLY DIRECTION.

&&

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

DRY WESTERLY FLOW ALOFT TO KEEP SKIES MAINLY CLEAR AT ALL OF THE TAF
SITES THROUGH MONDAY.  WINDS WILL CONTINUE TO FOLLOW TYPICAL DIURNAL
PATTERNS...WITH SLIGHTLY ENHANCED WESTERLY AFTN AND EVENING FLOW FOR
KIPL AND THE PHX AREA TERMINALS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...

WEDNESDAY THROUGH SUNDAY...DRY AND STABLE FLOW ALOFT WEDNESDAY WILL
TRANSITION INTO A WEAK MONSOON PATTERN WHERE MOISTURE FROM MEXICO
WILL RETURN MAINLY TO CENTRAL AND EASTERN ARIZONA. A SLIGHT CHANCE
OF AFTERNOON AND EARLY EVENING SHOWERS AND THUNDERSTORMS WILL RETURN
TO SOUTHERN GILA COUNTY THURSDAY THROUGH SUNDAY. MINIMUM RELATIVE
HUMIDITIES WILL INCREASE GENERALLY INTO THE 15 TO 20 PERCENT
RANGE...EXCEPT NEAR 30 PERCENT IN THE MOUNTAINS OF SOUTHERN GILA
COUNTY. TYPICAL DIURNAL SOUTHWEST WINDS 10 TO 15 MPH WILL DEVELOP
DURING THE AFTERNOONS. FAIR OVERNIGHT RECOVERY.

&&

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

&&

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

$$

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

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



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