Areal Flood Advisory 21, NWS Phoenix, AZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
145 PM MST MON JUL 15 2013

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

&&

.SYNOPSIS...
AN UPPER LEVEL LOW TRACKING WESTWARD INTO THE REGION WILL PROVIDE
DEEPENING MONSOON MOISTURE LEVELS AND FAVORABLE DYNAMICS TO SUPPORT
INCREASED STORM CHANCES BEGINNING TUESDAY.

&&

.DISCUSSION...
STARTING TO SEE SOME CONVECTION DEVELOP ACROSS NORTHERN AND SOUTHERN
ARIZONA AS OF 19Z. LITTLE TO NOTHING IN THE FORECAST AREA SO
FAR...BUT 12Z HI-RES MODELS INDICATE ACTIVITY SHOULD INCREASE IN
COVERAGE LATER THIS AFTERNOON. SOME GUIDANCE SUGGESTING STORMS WILL
STAY ON THE RIM...OTHER MODELS SHOW MORE VIGOROUS ACTIVITY ACROSS
THE LOWER DESERTS COURTESY OF COLLIDING OUTFLOW BOUNDARIES. I
INCREASED POPS ACROSS THE MOUNTAINS EAST OF PHOENIX FOR THE REST OF
THE AFTERNOON/EVENING HOURS AND HELD ONTO THE 20-30 PERCENT CHANCE
ACROSS THE METRO AREA. ANOTHER TOUGH CALL IF WE WILL GET STORMS HERE
TODAY.

OTHERWISE THE FORECAST REMAINS ON TRACK. PRECIP CHANCES SHOULD
INCREASE TUESDAY AND WEDNESDAY AS LOW PRESSURE CONTINUES ITS ODD
TRACK WESTWARD THROUGH OK/TX/NM/AZ. TIMING AT THIS POINT LOOKS TO BE
MAINLY TUESDAY AFTERNOON INTO TUESDAY NIGHT AND POPS WERE ALREADY
FAIRLY HIGH DURING THIS TIME FRAME. INCREASED THEM A FEW PERCENT
ACROSS THE BOARD THROUGH WEDNESDAY MORNING. ONLY NOTEWORTHY CHANGE
WAS TO SPREAD PRECIP ALL THE WAY TO THE CO RIVER ON WEDNESDAY.
GFS/EURO NOW TRYING TO INDICATE PRECIP WORKING INTO YUMA AT SOME
POINT EITHER EARLY WEDNESDAY OR WEDNESDAY AFTERNOON.

VARIETY OF FORECAST INDICATORS ARE COMING TOGETHER IN OUR FAVOR FOR
AN UPTICK IN MONSOON ACTIVITY BEGINNING TUESDAY AND POTENTIALLY FOR
THE REST OF THE WEEK. AS THE UPPER LOW CONTINUES TO PROGRESS
SOUTHWESTWARD THE EASTERN PORTION OF THE FORECAST AREA...INCLUDING
THE PHOENIX METRO...FALLS UNDER THE LARGE AREA OF UPPER LEVEL
DIVERGENCE. ALSO...MOVEMENT OF THE LOW THROUGH THIS PERIOD WILL HELP
REINFORCE MONSOON MOISTURE LEVELS INTO THE REGION...WITH MIXING
RATIOS BEGINNING A STEADY CLIMB THAT IS FORECAST TO CONTINUE THROUGH
MUCH OF THE WEEK. TUESDAY IS STILL EXPECTED TO SERVE AS A
TRANSITIONAL DAY...WITH THE CHANCE FOR WELL ORGANIZED AND SUSTAINED
STORM ACTIVITY ACROSS THE SOUTH CENTRAL DESERTS THAT MAY PERSIST WELL
INTO THE OVERNIGHT HOURS. UPPER LEVEL DIVERGENCE AND SHEAR
TRANSITIONS FURTHER WEST BY WEDNESDAY...WHICH COULD SERVE TO GENERATE
CONVECTIVE ACTIVITY ACROSS SOUTHEAST CALIFORNIA AND THE COLORADO
RIVER VALLEY.

ADDITIONAL SPECIFICS OF THE FORECAST ESPECIALLY TEMPERATURES...SKY
COVER AND EXTENDED PRECIPITATION CHANCES...HANG ON THE POTENTIAL /OR
FAILURE TO MATERIALIZE/ CONVECTIVE ACTIVITY FOR THE MIDWEEK PERIOD.
WITH THE INCREASING MOISTURE AND PLACEMENT OF THE UPPER LEVEL LOW TO
OUR SOUTHEAST ACROSS THE INTERNATIONAL BORDER WITH NEW AND OLD
MEXICO...DYNAMICS...STEERING FLOW AND A FAVORABLE MONSOON MOISTURE
FETCH WILL REMAIN OVER THE REGION. CONSIDERABLE COOLING TREND SHOULD
COMMENCE EITHER DUE TO RAIN COOLED AIR OR PERSISTENT CLOUDINESS
WORKING TO KEEP DAYTIME READINGS BELOW NORMAL. MODELS ARE TRENDING
TOWARDS THE UPPER LOW TRANSITIONING TO MORE OF AN OPEN WAVE WHILE
CONTINUING TO TRACK ACROSS NORTHERN MEXICO AND REACHING THE BAJA
PENINSULA BY THE WEEKEND. PRECIPITATION CHANCES FOR THE END OF THE
WEEK AND EARLY WEEKEND REMAIN SLIGHTLY ABOVE CLIMO...GIVEN THE
CYCLONIC FLOW AND CONTINUED ELEVATED MONSOON MOISTURE LEVELS OVER
THE REGION.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL... SCT TO BKN
CLOUDS ABV FL050 THROUGH 06Z THIS AFTN AND EVENING. WINDS WESTERLY
10 TO 15 KTS THROUGH 03Z WITH EXCEPTION OF ANY OUTFLOW BOUNDARIES
THAT MAY BE GENERATED BTWN 00Z AND 03Z AND COULD SHIFT WINDS FROM SE.

SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH... MOSTLY
CLEAR WITH LIGHT SOUTHERLY WINDS 5 TO 10 KTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH SUNDAY...
THERE WILL BE AN INCREASED LIKELIHOOD OF SHOWERS AND THUNDERSTORMS
THROUGH THE ENTIRE PERIOD. MOST LOCATIONS IN ARIZONA WILL EXPERIENCE
A GOOD CHANCE FOR WETTING RAIN...WITH SOMEWHAT LESSER CHANCES OVER
SOUTHEAST CALIFORNIA. MINIMUM HUMIDITIES WILL RANGE FROM 15 PCT IN
SOUTHEAST CA UP TO 35 PCT ACROSS HIGHER TERRAIN IN CENTRAL AZ...WITH
EXCELLENT OVERNIGHT RECOVERY. WINDS WILL OBTAIN MORE OF A PERSISTENT
EASTERLY TO SOUTHEASTERLY DIRECTION THROUGH MUCH OF THE
PERIOD...WITH OCCASIONAL LOCALLY HIGHER GUSTS IN ASSOCIATION WITH
THUNDERSTORM OUTFLOW BOUNDARIES.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

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

DISCUSSION...LEINS/NOLTE
AVIATION....VASQUEZ
FIRE WEATHER...WATERS/VASQUEZ/MCLANE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
500 AM MST MON JUL 15 2013

AZZ022-023-027-028-161400-
NORTHWEST MARICOPA COUNTY-GREATER PHOENIX AREA-
SOUTHWEST MARICOPA COUNTY-NORTHWEST AND NORTH CENTRAL PINAL COUNTY-
500 AM MST MON JUL 15 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH-CENTRAL ARIZONA.

.DAY ONE...TODAY AND TONIGHT.

A FEW ISOLATED THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON AND
EVENING ACROSS THE HIGHER TERRAIN AROUND THE PERIPHERY OF THE PHOENIX
METRO AREA. A STRAY STORM MAY WORK DOWN INTO THE LOWER DESERT
ELEVATIONS...HOWEVER THE PRIMARY THREATS WILL BE GUSTY WINDS AND
BLOWING DUST.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORM CHANCES INCREASE AND REMAIN ELEVATED THROUGH AT LEAST
THE END OF THE WEEK. STORMS DURING THIS PERIOD WILL HAVE THE POTENTIAL
FOR GUSTY WINDS...BLOWING DUST...HEAVY RAINFALL...LOCALIZED FLASH
FLOODING AND DANGEROUS LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

AZZ024-161400-
SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS-
500 AM MST MON JUL 15 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST-CENTRAL ARIZONA.

.DAY ONE...TODAY AND TONIGHT.

THERE IS A CONTINUED THREAT OF ISOLATED THUNDERSTORMS AGAIN
TODAY...WITH THE PRIMARY THREATS BEING DANGEROUS LIGHTNING...GUSTY
WINDS...AND LOCALLY HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORMS CHANCES INCREASE FOR TUESDAY AND LAST THROUGH THE END
OF THE WEEK. THE PRIMARY THREATS WILL BE GUSTY WINDS...HEAVY
RAINFALL...LOCALIZED FLASH FLOODING AND DANGEROUS LIGHTNING

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

AZZ020-021-025-026-161400-
LOWER COLORADO RIVER VALLEY AZ-WEST CENTRAL DESERTS-
YUMA/MARTINEZ LAKE AND VICINITY-SOUTHWEST DESERTS-
500 AM MST MON JUL 15 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHWEST
ARIZONA...EXTREME WEST-CENTRAL ARIZONA...SOUTHWEST ARIZONA AND WEST-
CENTRAL ARIZONA.

.DAY ONE...TODAY AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

INCREASING CHANCES FOR THUNDERSTORMS WILL RETURN TUESDAY AND REMAIN
THROUGH THE REST OF THE WEEK. THE PRIMARY THREATS WILL BE GUSTY
WINDS...BLOWING DUST...HEAVY RAINFALL...LOCALIZED FLASH FLOODING AND
DANGEROUS LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

CAZ030>033-161400-
JOSHUA TREE NATIONAL PARK-LOWER COLORADO RIVER VALLEY CA-
RIVERSIDE COUNTY/EASTERN DESERTS-IMPERIAL COUNTY-
500 AM PDT MON JUL 15 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EXTREME SOUTHEAST CALIFORNIA
AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORM CHANCES WILL EXPAND WESTWARD FROM ARIZONA AND INTO THE
SOUTHEAST CALIFORNIA DESERTS BY MIDWEEK...POTENTIALLY LAST THROUGH
THE WEEKEND. THE PRIMARY THREATS WILL BE GUSTY WINDS...BLOWING
DUST...HEAVY RAINFALL...LOCALIZED FLASH FLOODING AND DANGEROUS
LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.

NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT

WEATHER.GOV/PHOENIX