Area Forecast Discussion
Issued by NWS Phoenix, AZ

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000
FXUS65 KPSR 302157
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
255 PM MST TUE JUN 30 2015

.SYNOPSIS...
OCCASIONAL SHOWERS AND THUNDERSTORMS WILL BE COMMON ACROSS THE
MOUNTAINS OF SOUTHERN AND EASTERN ARIZONA THROUGH MUCH OF THE WEEK.
THERE WILL BE SOME OPPORTUNITY FOR SHOWERS TO AFFECT LOWER ELEVATION
DESERT COMMUNITIES DURING THE MIDDLE OF THE WEEK. AFTERNOON
TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THIS WEEK BEFORE
MODERATING BACK DOWN TOWARDS NORMAL BY THE WEEKEND.

&&

.DISCUSSION...
THE FORECAST AREA IS CAUGHT BETWEEN TWO MCVS...WITH DEBRIS CLOUDS
AND LINGERING THUNDERSHOWER ACTIVITY HOLDING OVER SOUTHEAST CA...
RAPIDLY COOLING CONVECTIVE CLOUD TOPS OVER THE RIM AND FAIRLY CLEAR
SKIES OVER THE LOWER AZ DESERT ELEVATIONS. AM CLOUD COVER AND
INCREASED MOISTURE POOL HAS ALLOWED DAYTIME TEMPERATURES TO BE ON
THE SLIGHTLY COOLER SIDE...WITH AREA TEMPERATURES 3 TO 5 DEGREES
COOLER THAN MONDAY AFTERNOON. WILL LOOK FOR RADAR COVERAGE TO
RAPIDLY FILL IN OVER THE RIM THE NEXT FEW HOURS AND DROP OUTFLOWS
AND RESULTING STORM BUILD-UPS INTO THE LOWER DESERT ELEVATIONS WHILE
STORM ACTIVITY SLOWLY CLEARS TO THE WEST ACROSS SOUTHEAST CA.

AIRCRAFT SOUNDINGS...SATELLITE OBSERVED WINDS AND A SPECIAL 18Z
SOUNDING FROM KTWC TODAY ALL INDICATE STILL FAVORABLE SPEED SHEAR
AND ENHANCED STEERING FLOW AFTN/EVENING PROFILE AVAILABLE ACROSS
SOUTHEAST AZ AND INTO EASTERN AZ. MODEL FCSTS CONTINUE FAVORABLE ML
SHEAR...BALLPARK 30 TO 40 KTS ACROSS SE/SOUTH-CENTRAL AZ...THIS
EVENING AND INTO THE OVERNIGHT HOURS. BLENDED TPW PWATS AND GPS IPW
INDICATE 1.5 TO 1.7 INCH VALUES THROUGHOUT MUCH OF AZ AHEAD OF THE
COMPACT MCV JUST OVER THE NM BOOTHEEL. FCST SOUNDINGS ACROSS THE
REGION STILL PAINT FAIRLY HEALTH ML AND MU CAPES AMOUNTS ANYWHERE
FROM 1000-1500 J/KG DURING THE AFTERNOON AND EVENING. ALL THIS
COMING TOGETHER TO SAY POTENTIAL IS HIGH...AND CONCERN AS WELL...FOR
STRONG STORMS THIS EVENING FIRST OVER THE HIGHER TERRAIN AND THEN
DEVELOPING DOWN IN THE AZ DESERT ELEVATIONS. SIMILAR TO LAST EVENING
OVER THE PHOENIX METRO....STRONG STORMS ON THE PERIPHERY MAY SEND
SEVERAL STRONG OUTFLOWS INTO THE REGION TO HELP INITIAL ACTIVITY
DURING THE EVENING. EVEN THOUGH STORM MOTION MAY BE FASTER THAN WHAT
WE TYPICALLY SEE DURING THE MONSOON...CANNOT RULE OUT HEAVY RAINFALL
POTENTIAL AS WELL GIVEN THE NEAR-RECORD AMOUNTS OF MOISTURE IN THE
AREA FOR THIS LATE IN JUNE. STRONG DOWNBURST/MICROBURST WINDS...LONG-
LIVED OUTFLOWS...ACCOMPANYING BLOWING DUST AND EVEN HAIL IN THE
SOME OF THE STRONGER UPDRAFT STORMS ARE POSSIBLE WITH DEVELOPMENT
TONIGHT.

WITH THE ADDITIONAL BOOST OF ENERGY AND POTENTIAL FROM THE LONG-
TRAVELING TX MCV...STORMS HAVE THE POTENTIAL TO PERSIST TOWARDS THE
CO RIVER VALLEY AND INTO SOUTHEAST CA LATER OVERNIGHT AND INTO
WEDNESDAY. PLENTY OF DEBRIS CLOUDS WILL GREAT THE AREA BY THE
AM...KEEPING THE OVERNIGHT TEMPS ON THE WARMSIDE BUT ALSO
INTRODUCING THE POTENTIAL FOR A SLIGHTLY COOLER WEDNESDAY AND OPEN
TO JULY WITH AT LEAST NORMAL TEMPERATURES FOR THE AREA.

500MB HIGH BEGINS TO REPOSITION BACK TOWARDS THE FOUR CORNERS AREA
TODAY AND THURSDAY...ALLOWING FOR AN ADDITIONAL WAVE OR TWO TO
ROTATE AROUND THE SOUTHERN PERIPHERY OF THE HIGH. THE UPPER LEVEL
HIGH REMAINS IN A NW-SE ORIENTED FASHION THROUGH FRIDAY. THIS
CONFIGURATION WILL CONTINUE TO PROMOTE A LOW GRADE MONSOON PATTERN
AND DAILY CONVECTION DEPENDENT ON HOW INSTABILITY MODIFIES OVER
TIME. PRECIPITATION CHANCES DWINDLE A BIT THURSDAY AND FRIDAY AS THE
LOW LEVEL FLOW IS REALLY NOT CONDUCIVE TO IMPORTING RICHER MOISTURE
INTO THE REGION. SO...THE BEST PRECIP CHANCES WILL BE LIMITED TO
HIGHER TERRAIN LOCATIONS DURING THIS TIME FRAME AS MOISTURE MAY
BEGIN TO MIX OUT AT LOWER ELEVATIONS.

HOWEVER...BY SATURDAY-SUNDAY...THE HIGH BEGINS TO SHIFT AND THE AXIS
ONCE AGAIN ALIGNING NORTH TO SOUTH OVER THE INTERMOUNTAIN WEST...
THE HIGH 500-300MB CENTERS STACKING/CO-LOCATING NEAR THE FOUR
CORNERS AREA. THIS IS A VERY FAVORABLE POSITION OF THE HIGH FOR
SOUTHEAST FLOW AND GOOD MOISTURE ADVECTION.

&&

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

ACTIVE NIGHT IS EXPECTED CONVECTIVELY SPEAKING...AS AN UNSEASONABLY
STRONG MID LEVEL EASTERLY WIND FIELD WILL ADVECT STORMS ACROSS THE
HIGHER TERRAIN FROM EAST TO WEST THIS EVENING. DUE TO HIGH AMOUNTS
OF MOISTURE AND INSTABILITY AS WELL AS STRONGER THEN NORMAL WINDS
ALOFT...STORMS WILL LIKELY BECOME WELL ORGANIZED AND PERSIST THROUGH
THE EVENING AND INTO THE MORNING HOURS...AFFECTING ALL OF THE TAF
SITES. AT THE MOMENT...DUE TO LOWER CONFIDENCE WITH TIMING...WILL
SIMPLY MENTION VCTS IN THE TAFS AFTER ABOUT 03Z AND KEEP THIS IN
PAST MIDNIGHT. WINDS WILL ALSO BE DOWNPLAYED BUT COULD BECOME STRONG
AND GUSTY AT ANY TERMINAL OVERNIGHT. SHORT TERM UPDATES WILL BE
NEEDED FOR THE TAFS TO ADDRESS GUSTY VARIABLE WINDS AS WELL AS TSRA
AT THE AIRPORTS. CIGS LIKELY TO STAY AOA 8K FEET OVERNIGHT UNLESS
VERY HEAVY RAIN PERSISTS AT THE TERMINAL. BROKEN MID DECKS ARE ALSO
EXPECTED TO CONTINUE INTO THE MORNING HOURS WEDNESDAY...WITH MOST
BASES ABOVE 9K FEET.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...

VERY LITTLE IS EXPECTED IN TERMS OF CLOUDS OR WEATHER AT THE
TERMINALS THIS AFTERNOON AND EVENING...BUT THERE IS A GOOD CHANCE
FOR SHOWERS/STORMS TO MOVE OUT OF THE CENTRAL AZ DESERTS AND INTO
THE AREA LATER TONIGHT AND PERSIST INTO THE MORNING HOURS ON
WEDNESDAY. FOR NOW WILL SIMPLY MENTION VCSH AT KBLH AND KIPL AFTER
09Z...BUT IT IS POSSIBLE THAT THUNDER MAY AFFECT THE TERMINALS. FOR
THE MOST PART CIGS OVERNIGHT SHOULD STAY ABOVE 8K FEET UNLESS HEAVY
RAIN DEVELOPS AT AN UNFAVORABLE TIME OF DAY...AND PERSISTS AT THE
TERMINALS. WINDS SHOULD FAVOR THE SOUTH AT KBLH NEXT 24 HOURS...AND
MAY GET GUSTY OVERNIGHT AND INTO WED MORNING WITH SPEEDS ABOVE 15KT.
WINDS TO FAVOR THE SOUTH TO SOUTHEAST AT KIPL MOSTLY LESS THAN 12KTS.

WINDS TO FAVOR THE SOUTH MOST OF THE NEXT 24 HOURS AT KBLH...AND
FAVOR THE SOUTHEAST AT KIPL WITH SPEEDS MOSTLY AOB 12KT.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A LOW GRADE MONSOON PATTERN WILL BE IN PLACE THROUGH THE WEEK...
CHARACTERIZED BY NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES...AND
WIDELY SCATTERED AFTERNOON AND EVENING SHOWERS/THUNDERSTORMS THAT
MOVE FROM EAST TO WEST OFF THE MOUNTAINS AND INTO THE LOWER DESERTS
EACH DAY. FOR THURSDAY INTO SATURDAY THE STORMS WILL PRIMARILY FOCUS
OVER THE HIGHER TERRAIN WITH RATHER LOW CHANCES OF SURVIVING INTO
THE LOWER DESERTS. SUNDAY INTO EARLY NEXT WEEK...AS HUMIDITIES RISE
THERE WILL BE A BETTER CHANCE OF THUNDERSTORMS AND SHOWERS MOVING
INTO THE CENTRAL DESERTS DURING THE OVERNIGHT HOURS. DAYTIME
HUMIDITY VALUES GENERALLY WILL BE IN THE UPPER TEENS TO MID 20
PERCENT RANGE THROUGH SATURDAY WITH HUMIDITIES RISING SEVERAL
PERCENT BY MONDAY. VERY GOOD OVERNIGHT RECOVERY IS EXPECTED EACH
NIGHT. WINDS EACH DAY WILL BE LIGHT AND FAVOR SOUTHWESTERLY
DIRECTIONS THROUGH FRIDAY...BECOMING SOUTHERLY BY THE WEEKEND.

&&

.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER 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...NOLTE/MEYERS
AVIATION...CB
FIRE WEATHER...CB


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