000
FXUS65 KPSR 202052
AFDPSR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
153 PM MST MON MAY 20 2013

.SYNOPSIS...
STRONGER HIGH PRESSURE WILL SETTLE INTO THE REGION OVER THE NEXT
COUPLE DAYS WITH CONTINUED DRY WEATHER AND ABOVE NORMAL TEMPERATURES
THROUGH MID WEEK. CLEAR SKIES AND SOMEWHAT BREEZY AFTERNOONS ARE
EXPECTED NEARLY EVERY DAY. A DEEP LOW PRESSURE SYSTEM WILL MOVE
SOUTHEAST INTO THE GREAT BASIN BY LATE WEEK ALLOWING A SLIGHT
COOLING TREND. THE DRY CONDITIONS WILL CONTINUE THROUGH THE COMING
WEEKEND WHILE TEMPERATURES FALL BACK TO AROUND SEASONAL NORMALS
STARTING LATE THIS WEEK.

&&

.DISCUSSION...
ELONGATED TROUGH REMAINS POSITIONED ACROSS NORTHEAST ARIZONA THIS
AFTERNOON...WHILE LOW PRESSURE CONTINUES TO STRENGTHEN ACROSS THE
CENTRAL PLAINS WHILE HIGH PRESSURE BUILDS ACROSS THE EASTERN
PACIFIC. ACROSS THE REGION...THIS HAS RESULTED IN BREEZY WINDS AND A
FEW MOUNTAIN CU...ALONG WITH TEMPS IN THE MID 90S.

FORECAST FOR MUCH OF THE WEEK WILL BE QUIET. EASTERN PACIFIC RIDGE
WILL GRADUALLY SLIDE EASTWARD TOMORROW WITH THE RIDGE AXIS
POSITIONING ITSELF OVER ARIZONA LATE TOMORROW AFTERNOON. THERE WILL
BE A BIT OF A LAG IN TERMS OF WARMING...AS WE SHOULD ONLY GAIN ABOUT
1C OF BL WARMING TOMORROW BEFORE REACHING THE PEAK ON WEDNESDAY.
HIGHS ON TUESDAY MAY COME UP JUST SHORT OF THE 100 DEGREE MARK
ACROSS THE DESERTS...BUT SHOULD CERTAINLY HIT 100-103 BY MID WEEK.
INHERITED FORECAST CLOSELY MATCHED BEST PERFORMING GUIDANCE AND ONLY
VERY MINOR CHANGES WERE MADE. SIMILAR TEMPS EXPECTED ON THURSDAY AS
WELL BUT AS THE HIGH GRADUALLY RETREATS EASTWARD...TEMPS WILL FOLLOW
SUIT. HIGHS WILL EVENTUALLY DROP BACK INTO THE UPPER 90S BY THE END
OF THE WEEK.

&&

.PREVIOUS DISCUSSION...
MODELS CONTINUE TO ADVERTISE A DEEP CLOSED LOW MOVING INTO THE
PACIFIC NORTHWEST ON WEDNESDAY AND THEN DRIFTING SOUTHEASTWARD INTO
THE GREAT BASIN FOR LATE THIS WEEK. MODEL CONSENSUS IS FAIRLY HIGH
NOW THAT THE EXPANSIVENESS OF THE UPPER LOW WILL AFFECT THE DESERT
SOUTHWEST AT LEAST PARTIALLY...RESULTING IN SLIGHTLY COOLER
CONDITIONS. HAVE LOWERED TEMPERATURES SEVERAL DEGREES STARTING
THURSDAY AND THROUGH THE WEEKEND WITH THE COOLEST TEMPERATURES
ACROSS WESTERN PORTIONS OF THE CWA. THERE IS STILL SOME QUESTION ON
HOW FAR SOUTH THIS CLOSED UPPER LOW WILL GET...WITH A MORE SOUTHERN
SOLUTION RESULTING IN COOLER TEMPERATURES AND A NORTHERN SOLUTION IN
WARMER TEMPERATURES. EITHER WAY THE REGION WILL REMAIN UNDER A DRY
WESTERLY FLOW WITH LITTLE IN THE WAY OF ANY CLOUDINESS. MOST DAYS
WILL ALSO SEE FAIRLY BREEZY AFTERNOON CONDITIONS...BUT GUSTS SHOULD
GENERALLY REMAIN UNDER 30 MPH. THE LARGE SCALE PATTERN BEYOND THIS
COMING WEEKEND SUGGESTS A TROUGH/RIDGE/TROUGH PATTERN ACROSS THE
CONUS WHICH WILL LIKELY KEEP OUR TEMPERATURES AT OR SLIGHTLY BELOW
NORMAL ACROSS THE DESERT SOUTHWEST INTO EARLY NEXT WEEK.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...KSDL...
THROUGH 03Z TUE...CLEAR SKIES. INCREASING WEST WIND 15 TO 25 KNOTS
BTWN 19Z MON AND 03Z TUE. FROM 03Z TUE TO 12Z TUE...CLEAR SKIES.
WEST WIND 5 TO 10 KNOTS.

SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA...INCLUDING KIPL AND
KBLH...
THROUGH 03Z TUE...CLEAR SKIES. INCREASING NORTH WIND 17 TO 27 KNOTS
FROM 19Z MON TO 03Z TUE. FROM 03Z TUE TO 12Z TUE...CLEAR SKIES.
NORTH WIND 5 TO 10 KNOTS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
A LARGE AND STRONG PACIFIC LOW PRESSURE SYSTEM WILL DEVELOP OVER THE
WESTERN STATES NORTH OF AZ. HOWEVER...GUSTY WEST WINDS WITH LOW
HUMIDITY WILL DEVELOP EVERY AFTERNOON. OVERNIGHT RECOVERY WILL
BECOME GOOD OVER PORTIONS OF SOUTHEAST CALIFORNIA AND FAR SOUTHWEST
ARIZONA...BUT REMAIN POOR ELSEWHERE. AT THIS TIME...CONDITIONS ARE
EXPECTED TO REMAIN BELOW CRITICAL THRESHOLDS.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

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DISCUSSION...LEINS/KUHLMAN
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ/AJ