000
FXUS65 KPSR 130350
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
850 PM MST WED JUN 12 2013

.SYNOPSIS...
HIGH PRESSURE OVER THE DESERT SOUTHWEST WILL ALLOW FOR ABOVE NORMAL
TEMPERATURES THROUGH AT LEAST EARLY NEXT WEEK. AFTERNOON
TEMPERATURES WILL RANGE FROM 102-108 ACROSS THE LOWER DESERTS EACH
DAY THROUGH NEXT MONDAY...BUT WILL EVENTUALLY CLIMB BACK ABOVE THE
110 MARK BY THE MIDDLE OF NEXT WEEK. NO PRECIPITATION IS EXPECTED
OVER THE NEXT WEEK.

&&

.DISCUSSION...
STRONG HIGH PRESSURE ALOFT REMAINS SITUATED ACROSS THE SOUTH CENTRAL
CONUS...WITH A HIGH CENTER NEAR 595DM WELL OFF TO OUR EAST. AZ IS ON
THE WESTERN PERIPHERY OF THE STRONG UPPER HIGH AND UNDER A RATHER
DRY SWLY FLOW ALOFT. IR IMAGERY AT 8 PM SHOWED A BAND OF HIGH CLOUDS
ACROSS WESTERN AZ...BETWEEN THE HIGH AND AN UPPER TROF OVER THE PAC
NW. CU OVER THE ERN RIM/FAR CNTRL MOUNTAINS HAVE MOSTLY DISSIPATED
AND HIGH CLOUDS THAT WERE OVER THE CENTRAL DESERTS HAVE MOSTLY
THINNED AND MOVED OFF TO THE NORTHEAST. OTHERWISE...EXPECT THE BAND
OF HIGH CLOUDS OUT WEST TO GRADUALLY THIN AND MOVE EAST ACROSS THE
CWA TONIGHT...FOR PARTLY CLOUDY TO MOSTLY CLEAR SKIES.

GIVEN THE HIGH 500MB HEIGHTS OVER THE AZ DESERTS...AROUND
593-594DM...SURPRISED WE DID NOT GET HOTTER TODAY. HIGHS MOSTLY
STAYED AT OR BELOW 110 OVER THE DESERTS...A COUPLE DEGREES OR SO
BELOW OUR FORECAST AND JUST BELOW EXCESSIVE HEAT WARNING CRITERIA.
HIGH CLOUDS MAY HAVE HELPED KEEP TEMPS DOWN SLIGHTLY. IN ANY CASE
THE HEAT WARNING IS EXPIRED AND WITH HIGH TEMPS FORECAST TO FALL OFF
SLIGHTLY NEXT FEW DAYS...DO NOT SEE ANOTHER WARNING BEING ISSUED IN
THE NEAR FUTURE. FORECAST HAS BEEN UPDATED TO REMOVE WARNING
HEADLINES AND TO TWEAK SKY CONDITIONS SLIGHTLY...AND IS IN FINE
SHAPE ATTM.

.PREVIOUS DISCUSSION...
ANOTHER HOT DAY ACROSS THE LOWER DESERTS...WITH EARLY AFTERNOON
TEMPS ALREADY IN THE 103-109 RANGE AS OF 20Z. VISIBLE SATELLITE
INDICATES A MIXED BAG OF HIGH CLOUD COVER ACROSS THE REGION...A
FAIRLY EXTENSIVE HIGH DECK FROM ABQ TO TUS...WITH A LARGER AREA
STRETCHING FROM UTAH THROUGH NEVADA AND CALIFORNIA. IN
BETWEEN...MOSTLY SUNNY SKIES PREVAIL ACROSS MOST OF THE FORECAST
AREA. STILL HAVE A FEW MORE HOURS OF HEATING TO GO AND THE EXCESSIVE
HEAT WARNING WILL REMAIN INTACT UNTIL 8PM.

HOT TEMPS WILL BE THE RULE OVER THE NEXT WEEK AND A HALF AS HIGH
PRESSURE AND 850MB TEMPS AT OR ABOVE 27C WILL REMAIN OVER THE AREA.
THERE WILL BE SUBTLE COOLING TOMORROW AS A WEAK AREA OF LOW PRESSURE
CURRENTLY OFF THE SOUTHERN CALIFORNIA COAST APPROACHES THE AREA FROM
THE WEST. THIS WILL ALLOW 850MB TEMPS TO RETREAT SLIGHTLY FROM 30C
TODAY TO 28C TOMORROW. AT THE SURFACE THIS SHOULD RESULT IN HIGHS
CLOSER TO 108...WHICH IS STILL ABOVE NORMAL...BUT AN IMPROVEMENT
OVER TODAY.

THIS LOW WILL ALSO PULL SLIGHTLY HIGHER DEWPOINTS NORTHWARD AND
MODEL FORECAST 1000-700MB MIXING RATIOS CLIMB TO AROUND 5 G/KG IN
THE MOUNTAINS EAST OF PHOENIX THURSDAY AND FRIDAY. GIVEN THE
EXPECTED TRACK OF THE LOW ACROSS NORTHWEST ARIZONA...LACK OF ANY
MLCAPE WHATSOEVER...AND CONTINUED RELATIVELY MEAGER MOISTURE
PROFILES...STILL HAVING A HARD TIME IMAGINING MUCH MORE THAN CU EAST
OF PHOENIX. I HELD ONTO THE CLIMO POPS FOR THE MOUNTAINS EAST OF
PHOENIX BUT EVEN SINGLE DIGIT POPS MAY BE TOO MUCH. FOLLOWING THE
DEPARTURE OF THE LOW ON SATURDAY...PRECIP CHANCES DROP OFF
CONSIDERABLY AS MOISTURE PLUMMETS TO AROUND 3 G/KG AND BELOW 2 G/KG
EARLY NEXT WEEK.

SUNDAY AND INTO EARLY NEXT WEEK...BOTH THE GFS AND ECMWF ARE BETTER
AGREEMENT THAT A STRONG RIDGE WILL REMAIN INTACT OVER ARIZONA...NEW
MEXICO AND NORTHERN MEXICO...WITH THE 591-594DM HIGH CENTERED OVER
THE REGION. THIS WOULD ONCE AGAIN RESULT IN VERY HOT TEMPERATURES
BEING INTRODUCED BACK INTO THE FORECAST FOR SOUTH-CENTRAL ARIZONA.
THERE ARE STILL SOME DIFFERENCES IN THE STRENGTH AND POSITION OF THE
RIDGE IN RELATION TO ANOTHER EVOLVING TROUGH IN THE WESTERLIES THAT
COULD DICTATE WHETHER OR NOT THE HOT TEMPS WOULD BE REALIZED. RIGHT
NOW...SIDING WITH A WARMER SOLUTION -- IT IS SUMMER -- AND TAKING
TEMPERATURES BACK UP TO NEAR 110 DEGREES AT MANY LOWER DESERT SITES
MONDAY AND TUESDAY.

&&

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

CU THAT WAS OFF TO THE EAST OF THE GREATER PHX AREA HAS MOSTLY
DISSIPATED...BUT WE MAY SEE A REPEAT TOMORROW AFTN AS IT DEVELOPS
AGAIN OVER HIGHER TERRAIN OF FAR ERN AZ. OTHERWISE EXPECT SOME HIGH
CLOUD DECKS NEXT 24 HOURS...MAINLY AOA 20K FEET AND MOSTLY FEW-SCT.
WINDS WILL FOLLOW NORMAL DIURNAL PATTERNS ACROSS THE CENTRAL AZ
DESERTS...STAYING WEST PAST MIDNIGHT AND RETURNING TO THE
EAST/SOUTHEAST AFTER 09Z OR SO. MAY SEE SOME AFTN GUSTINESS AGAIN
THURSDAY WITH A FEW PEAK SW/W GUSTS TO NEAR 20KT AFTER 20Z. MAY SEE
SOME WESTERLY GUSTS TO 20KT AT KIPL LASTING UNTIL MIDNIGHT...THEN
TAPERING OFF OVERNIGHT. EXPECT WINDS TO SWING TO THE SOUTHEAST BY
LATE MORNING/EARLY AFTERNOON LESS THAN 10KT...RETURNING AGAIN TO THE
WEST BY 5 PM OR SO. WINDS WILL FAVOR THE SOUTH OR SW AT KBLH NEXT 24
HOURS...WITH SUSTAINED SPEEDS IN EXCESS OF 12KT POSSIBLE BY THU
AFTN.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE WITH HIGH PRESSURE
CONTINUING TO BE CENTERED OVER THE PLAINS AND LOW PRESSURE CENTERED
OVER THE PACIFIC NORTHWEST. TEMPERATURES OVER THE WEEKEND WILL BE
SLIGHTLY COOLER BUT STILL A BIT ABOVE NORMAL BEFORE A SLOW INCREASE
NEXT WEEK. HUMIDITIES WILL DECLINE FRIDAY LEADING TO POOR OVERNIGHT
RECOVERY FRIDAY NIGHT WITH LITTLE CHANGE THEREAFTER. NO STRONG WIND
EVENTS ARE ANTICIPATED BUT THERE WILL BE FAMILIAR AFTERNOON AND
EVENING BREEZINESS. BY EARLY NEXT WEEK...TEMPERATURES WILL BEGIN
ANOTHER CLIMB WHERE LOWER DESERT ELEVATIONS MAY OBSERVE 110F PLUS
READINGS AGAIN.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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DISCUSSION...CB
PREVIOUS DISCUSSION...LEINS/MEYERS
AVIATION...CB
FIRE WEATHER...NOLTE/AJ