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000
FXUS65 KPSR 310034
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
530 PM MST FRI JAN 30 2015

...UPDATED AVIATION DISCUSSION...

.SYNOPSIS...
AREAS OF SHOWERS WILL CONTINUE TO BE LIKELY OVER PARTS OF
SOUTH-CENTRAL ARIZONA TONIGHT...ESPECIALLY HIGHER TERRAIN...AND LESS
LIKELY OVER SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. RAIN CHANCES
WILL CONTINUE SATURDAY BEFORE DIMINISHING SATURDAY NIGHT. SNOW
LEVELS WILL REMAIN HIGH...LOWERING TO AROUND 7000-7500 FEET BY
SATURDAY MORNING. DRY WEATHER AND A SLOW WARMING TREND BEGINS SUNDAY
AND CONTINUES THROUGH NEXT WEEK.

&&

.DISCUSSION...
REST OF TODAY THROUGH SATURDAY...
MAIN BAND OF PRECIP AS OF MID AFTERNOON HAS BEEN OVER PORTIONS OF
GILA...PINAL...AND NORTHEAST MARICOPA COUNTY WHERE A FLOOD ADVISORY
WAS IN EFFECT...INCLUDED FAR EAST PORTIONS OF THE METRO. THIS
APPEARS TO BE ASSOCIATED WITH AN AREA OF UPPER LEVEL DIVERGENCE.
LESSER SHOWERS HAVE CONTINUED OVER THE REST OF THE PHOENIX AREA WITH
LITTLE TO NO ACTIVITY OVER SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA. MODEL CAPE STILL LOOKS QUITE MODEST BUT HELD ON TO
SLIGHT CHANCES FOR THUNDERSTORMS FOR THE REST OF THIS AFTERNOON AND
EARLY EVENING. AS THE SYSTEM SLOWLY SHIFTS EASTWARD...SHOWERS SHOULD
START TO TREND DOWNWARD. HOWEVER...THERE IS ANOTHER VORT MAX OVER
SONORA WHICH MAY BRUSH EASTERN PORTIONS OF THE AREA AND KEEP SOME
SHOWER ACTIVITY GOING. RAP SHOWS A SEPARATE SMALLER VORT MAX MOVING
NORTHEASTWARD FROM NORTHERN BAJA INTO OUR FORECAST AREA FOR A
RESUMPTION OF LIGHT RAIN IN OUR WESTERN AREAS. THUS HELD ON TO POPS
FOR TONIGHT...LOWER NUMBERS WESTERN AREAS. OF NOTE...MOST MODELS
INDICATE THE BRUNT OF THE SONORA VORT MAX TRACKING EAST OF THE
PHOENIX AREA. YET ANOTHER VORT MAX ROUNDS THE BOTTOM OF THE UPPER
TROUGH LATE TONIGHT AND BEGINS AFFECTING SOUTHERN ARIZONA SATURDAY
MORNING. LOOKS LIKE SOUTHEAST ARIZONA WILL SEE MOST OF THE PRECIP
FROM THAT FEATURE BUT DEPICT SOME NOTABLE QPF SPREADING WELL INTO
SOUTH-CENTRAL ARIZONA. THUS WE MAY HAVE ANOTHER ROUND OF WIDESPREAD
SHOWERS BEFORE A DOWNTREND BEGINS IN THE AFTERNOON.
OVERALL...ANTICIPATE LESS DYNAMICAL LIFT TONIGHT AND SATURDAY
COMPARED TO THE PREVIOUS 24 HOURS...DUE AT LEAST IN PART TO LOSS OF
UPPER DIFFLUENCE/DIVERGENCE. ACCORDINGLY...ANTICIPATE LESS PRECIP
TONIGHT AND SATURDAY THAN WE HAD IN THE PRECEDING 24 HOURS.
ANTICIPATE NUISANCE FLOODING TO CONTINUE...MAINLY OVER HIGHER
TERRAIN AND FOOTHILL AREAS...LESS OVER VALLEY FLOORS OF THE CENTRAL
DESERTS. ONE CAVEAT IS THAT WE COULD HAVE A LITTLE BIT MORE
INSTABILITY IF CLOUDS THIN OUT ENOUGH. NAM HAS BEEN DEPICTING THIS
IDEA. THUS HELD ON TO SLIGHT CHANCE OF THUNDERSTORMS FOR SATURDAY
AFTERNOON. THE SYSTEM BEGINS EXITING SOUTHWARD SATURDAY NIGHT AS A
RIDGE BUILDS IN AND THUS POPS DIMINISH OVERNIGHT SATURDAY.

SUNDAY THROUGH FRIDAY...
SUNDAY LOOKS TO BE A DRY AND WARMER DAY. PATCHY MORNING FOG IS A
POSSIBILITY BUT THERE MAY BE ENOUGH LINGERING CLOUDS TO HINDER THE
RADIATIONAL COOLING NECESSARY. PARED BACK ON THE AREAL COVERAGE TO
REMOVE SOUTHEAST CALIFORNIA AND THE LOWER COLORADO RIVER VALLEY AS
SOME DRY ADVECTION MOVES IN THERE. THE RIDGE SLOWLY BUILDS INTO THE
WEST MONDAY THROUGH THURSDAY FOR A GRADUAL WARMING TREND...AND WE
CAN EXPECT DESERT HIGHS TO REACH BACK INTO THE LOW TO MID 70S BY
NEXT WEDNESDAY...WITH THE WARMER WESTERN DESERTS RISING TO NEAR 80
BY NEXT THURSDAY...LITTLE CHANGE FRIDAY.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
SHORT TERM: RAINFALL HAS MOVED EAST OF TERMINALS THOUGH LOWER END
MVFR CIGS ARE PERSISTING AS OF 00Z. MODERATE TO GOOD CONFIDENCE THAT
SHOWERS HAVE LARGELY ENDED FOR THE EVENING...AND CIGS WILL IMPROVE
TO UPPER MVFR OR LOWER END VFR CATEGORY IN THE 02Z-03Z TIME FRAME
(MOST LIKELY TOWARDS THE WESTERN PARTS OF THE PHOENIX METRO...AND
MAYBE MORE DELAYED TO THE EAST). VISIBILITIES WILL BE VERY
GOOD...THOUGH MOUNTAIN OBSCURATION WILL STILL BE A PROBLEM
(ESPECIALLY EAST).

TONIGHT-SAT MORNING: LOWER CONFIDENCE THAT RESIDUAL MOISTURE WILL
ALLOW MVFR BR/HZ TO FORM OVERNIGHT AND INTO SAT MORNING...AND TAF
FORECAST TIMING IS MERELY TRYING TO SET A TREND TOWARDS THIS IDEA.
SETUP FOR BR/HZ IS FAVORABLE...BUT COVERAGE MAY BE MORE SPOTTY
AND/OR ISOLATED. BETTER CONFIDENCE THAT THE NEXT ROUND OF SHOWERS
WILL IMPACT TERMINALS IN THE 12Z-18Z TIME FRAME...WITH ASSOCIATED
MVFR VSBY/CIGS LIKELY.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SHOWERS SHOULD STAY SOUTH AND WEST OF CALIFORNIA TERMINALS THROUGH
12Z SAT...THOUGH RESIDUAL MOISTURE COULD FORM LOCAL MVFR BR/HZ
(ESPECIALLY AT THE MORE FAVORED KIPL SITE). SCT SHRA AND POTENTIALLY
BRIEF PERIODS OF MVFR CIGS/VSBY MAY BE POSSIBLE LATER SATURDAY
MORNING...THOUGH CONFIDENCE IS ONLY LOW TO MODERATE.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
DRIER AND SIGNIFICANTLY WARMER WEATHER IS EXPECTED...AS HIGH
PRESSURE BEGINS BUILDING BACK INTO THE REGION. HIGH TEMPERATURES IN
THE LOWER DESERTS WILL START OUT IN THE UPPER 60S ON SUNDAY AND
GRADUALLY CLIMB INTO THE UPPER 70S BY THURSDAY. WINDS ARE EXPECTED
TO BE LIGHT AND VARIABLE FOR MOST OF THE FORECAST PERIOD.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

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