813 
FXUS65 KPSR 210934
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
234 AM MST FRI MAR 21 2014

.SYNOPSIS...
DRY WEATHER WITH ONLY PERIODIC HIGH CLOUD COVER WILL CONTINUE 
THROUGH EARLY NEXT WEEK. ABOVE NORMAL TEMPERATURES WILL ALSO PREVAIL 
WITH DAILY HIGHS GENERALLY FROM THE UPPER 70S TO UPPER 80S ACROSS 
LOWER DESERT COMMUNITIES. 

&&

.DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY REVEALS QUASI ZONAL FLOW ACROSS 
THE REGION ALONG WITH A WEAK CIRCULATION NOTED OVER CENTRAL 
CALIFORNIA. ABUNDANT SUBTROPICAL MOISTURE REMAINS IN PLACE FROM BAJA 
CALIFORNIA THROUGH TEXAS AND INTO KANSAS AND OKLAHOMA...BUT THE 
ASSOCIATED CLOUD COVER HAS THINNED OUT SUBSTANTIALLY ACROSS THE 
FORECAST AREA THIS MORNING. MOST SITES ACROSS THE FORECAST AREA HAVE 
CLEARED OUT COMPLETELY AND AS SUCH...TEMPS HAVE DROPPED QUICKLY. 
DESERT TEMPS WERE GENERALLY IN THE MID 50S AS OF 09Z.

THE FORECAST FOR THE VAST MAJORITY OF THE UPCOMING WEEK WILL BE 
QUIET WITH VARYING AMOUNTS OF HIGH CLOUDS ALONG WITH ABOVE NORMAL 
TEMPERATURES. IN THE VERY SHORT TERM...SKIES SHOULD CONTINUE TO 
CLEAR TODAY ALTHOUGH THERE COULD BE SOME HIGH CLOUDS THAT 
SNEAK INTO SOUTHEAST CALIFORNIA ON THE LEADING EDGE OF THE 
AFOREMENTIONED WEAK CIRCULATION. ALL OPERATIONAL MODELS SHOW THIS 
WEAK TROUGH WASHING OUT LATER THIS AFTERNOON AS IT MOVES THROUGH 
ARIZONA AND IT SHOULD BE A NON-FACTOR IN OUR WEATHER. IN THE WAKE OF 
THIS TROUGH...EXPECT MOSTLY SUNNY SKIES SATURDAY AND SUNDAY. A VERY 
WEAK TROUGH IS EXPECTED TO MOVE THROUGH PARTS OF NORTHERN ARIZONA 
LATE THIS WEEKEND BUT MOISTURE WILL BE LACKING AND BEST FORCING 
ASSOCIATED WITH THIS TROUGH WILL BE DISPLACED WELL TO THE NORTH OF 
OUR FORECAST AREA. POPS WERE ALREADY AT ZERO ACROSS THE DESERTS AND 
ASIDE FROM SOME LOW-END SINGLE DIGITS AROUND 
GLOBE/MIAMI/HILLTOP...THIS SHOULD ALSO BE A NON-EVENT. AS FOR 
TEMPS...A BLENDED CONSENSUS APPROACH TO TEMPERATURES YIELDS 
AFTERNOON HIGHS IN THE LOW/MID 80S ALONG WITH LOWS IN THE MID 50S. 
NO REASON TO ARGUE AGAINST THESE NUMBERS.

LOOKING AHEAD TO NEXT WEEK...RIDGING TAKES SHAPE MONDAY THROUGH 
WEDNESDAY AND AS SUCH TEMPERATURES WILL TAKE A RUN UPWARD INTO THE 
UPPER 80S. GOING TO HOLD OFF FORECASTING 90 AS CONSENSUS NUMBERS 
ONLY YIELD 85-87 AT PHOENIX...BUT 90S AROUND YUMA AND EL CENTRO ARE 
CERTAINLY A POSSIBILITY. BOTH THE GFS AND THE EUROPEAN...AND TO A 
LESSER EXTENT THEIR RESPECTIVE ENSEMBLES FORECAST A TRANSITION 
TOWARD NORTHWESTERLY FLOW THURSDAY AND FRIDAY WITH A TROUGH MOVING 
THROUGH ARIZONA LATE NEXT WEEK. MOISTURE TRANSPORT FROM THE GFS IS A 
BIT MORE IMPRESSIVE THAN THE EUROPEAN BUT STILL NOT ENOUGH TO 
PRODUCE WIDESPREAD RAINFALL. ON THAT SUBJECT...PWATS ONLY EXPECTED 
TO INCREASE TO AROUND 0.5 INCHES COINCIDENT WITH THE PASSAGE OF THE 
TROUGH. SINCE BOTH MODELS INDICATE SOME DEGREE OF ISENTROPIC ASCENT 
WITH THIS TROUGH /MAINLY IN THE MOUNTAINS EAST OF PHOENIX/...I 
MAINTAINED THE IDEA OF SINGLE-DIGIT CLIMO-LIKE POPS EAST OF PHOENIX 
FOR THURSDAY. STILL DOESN\T LOOK LIKE A VERY IMPRESSIVE EVENT 
WHATSOEVER GIVEN THE TRAJECTORY OF THE TROUGH BUT FELT SOME SORT OF 
NON-ZERO POPS WERE WARRANTED GIVEN THE INCREASE IN MOISTURE. IF 
NOTHING ELSE IT WILL KNOCK TEMPERATURES BACK INTO THE LOWER 80S TO 
CLOSE OUT THE WEEK.   

&&

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

CURRENT SCT TO BKN CIRRUS LAYERS OVER THE PHX AREA TO GRADUALLY 
CLEAR LATER TONIGHT AND EARLY FRIDAY AS THE WEAK WEATHER DISTURBANCE 
THAT PUSHED THESE CLOUDS INTO THE REGION TODAY MOVES OFF TO THE 
EAST. THE SOUTHEAST CA TERMINALS WILL SEE FEW-SCT CIRRUS LAYERS 
THROUGH THE ENTIRE TAF PERIOD. WEAK SFC PRESSURE GRADIENTS TO KEEP 
WINDS ON THE LIGHT SIDE...MAINLY AOB 10 KTS THROUGH FRIDAY AT ALL 
THE TAF SITES...WITH THE USUAL DIURNAL TRENDS IN DIRECTION AND SPEED.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. 

&&

.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
HIGH PRESSURE AND DRY WESTERLY FLOW ALOFT WILL AFFECT THE REGION 
THIS WEEKEND AND INTO EARLY NEXT WEEK...LEADING TO CONTINUED 
ABOVE NORMAL HIGH TEMPERATURES AND NO CHANCE FOR ANY PRECIPITATION. 
WEAK DISTURBANCES EMBEDDED IN THE FLOW MAY PRODUCE OCCASIONAL HIGH 
CLOUDINESS FOR MOSTLY CLEAR SKIES. MINIMUM HUMIDITIES WILL TYPICALLY 
RANGE FROM 10 TO 15 PERCENT THIS WEEKEND...AND THEN LOWER INTO THE 
SINGLE DIGITS MONDAY INTO TUESDAY AS A DRY LOWER LEVEL NORTH FLOW 
SETS IN. OVERNIGHT RECOVERIES WILL BE ON THE GOOD SIDE UNTIL 
TUESDAY...WHEN THEY WILL FALL INTO THE FAIR OR POOR RANGE... 
ESPECIALLY OVER THE DRIER WESTERN DESERTS. EXCEPT FOR SOME LOCAL 
AFTERNOON GUSTINESS WINDS WILL BE ON THE LIGHT SIDE EACH DAY FROM 
SATURDAY INTO NEXT MONDAY...HOWEVER A DRY WEATHER SYSTEM APPROACHING 
FROM THE WEST WILL LEAD TO INCREASED BREEZINESS DURING THE AFTERNOON 
HOURS TUESDAY INTO WEDNESDAY.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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

DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...CB