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