000 
FXUS65 KPSR 210923
AFDPSR
AZZ020>028-CAZ030>033-211745-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
220 AM MST TUE MAY 21 2002

.SYNOPSIS...
A COLD FRONT WILL BRING NOTICEABLY COOLER DAYTIME HIGHS TO SOUTHWEST 
ARIZONA TODAY...WITH A BIT COOLER TEMPERATURES OVER FAR SOUTHEAST 
CALIFORNIA. IT WILL BE BREEZY TODAY...BUT WINDS WILL NOT BE AS 
STRONG AS WHAT OCCURRED ON MONDAY. AFTER A RATHER COOL MORNING ON 
WEDNESDAY...A SLOW WARMING TREND WILL OCCUR THROUGH SATURDAY...WITH 
A RETURN TO NEAR NORMAL DAYTIME HIGHS OVER THE MEMORIAL DAY 
WEEKEND.  

.DISCUSSION...
RATHER STRONG COLD FRONT SWEEPING ACROSS THE AREA THIS MORNING.
..SO IDEA OF NOTICEABLY COOLER DAYTIME HIGHS OVER SOUTHWEST AND 
SOUTH CENTRAL AZ TODAY LOOKS GOOD. AS OF 2 AM...TEMPS RANGED FROM 
THE LOWER 70S AT PHOENIX TO THE LOW 60S AT BLYTHE/YUMA/IMPERIAL... 
AND 24 HR CHANGES WERE ON THE ORDER OF -7 TO -12 DEGREES. SFC DEW 
POINTS ALSO LOWER BY 5 TO 10 DEGREES. HIGH TEMPS MOST AREAS TODAY 
WILL BE 10-12 DEGREES BELOW NORMAL. 

AS OF 2 AM...WINDS HAD DROPPED BELOW ADVISORY LEVELS OVER FAR 
SOUTHEAST CALIFORNIA AND ALONG THE LOWER COLORADO RIVER...SO WIND 
ADVISORY FOR THAT AREA WAS CANCELLED AT 1 AM. STILL BREEZY AS UPPER 
JET STREAK AND ASSOCIATED CIRRIFORM CLOUD STREAK PROPAGATES ACROSS 
WESTERN AZ...BUT GRADIENTS FORECAST TO WEAKEN DURING THE DAY AS 
FRONT PUSHES EAST AND WEAKENS...SO BREEZY WORDING SHOULD SUFFICE FOR 
MOST AREAS. WITH MOSTLY CLEAR SKIES...DRY CONDITIONS...AND LIGHT 
WINDS... OVERNIGHT LOWS TUESDAY NIGHT/WEDNESDAY MORNING WILL BE THE 
COOLEST MOST OF THE FORECAST AREA HAS SEEN SINCE THE FIRST WEEK OF 
MAY...MAINLY IN THE 50S OVER THE LOWER DESERT. SLOW DAY-TO-DAY 
WARMUP COMMENCES WEDNESDAY AND CONTINUES THROUGH UPCOMING WEEKEND 
...WITH RATE OF WARMUP MITIGATED BY FACT THAT THE FORECAST AREA WILL 
REMAIN UNDER CYCLONIC FLOW/TROUGHING AND BELOW NORMAL 500 MB HEIGHTS 
NEXT FEW DAYS. 500 MB HEIGHTS FORECAST TO REBOUND TO NEAR CLIMO BY 
SATURDAY BY ALL EXTENDED MODELS...BUT LONG WAVE PATTERN STILL 
DOMINATED BY EAST U.S. RIDGE AND EPAC TROF...WHICH SUPPORTS IDEA OF 
TEMPS REBOUNDING TO ONLY NEAR OR SLIGHTLY ABOVE NORMAL LEVELS THIS 
WEEKEND AND EARLY NEXT WEEK. WILL LIKELY SEE SOME HIGH CLOUDS FROM 
TIME TO TIME WITH THIS REGIME IN PLACE...SO MOSTLY CLEAR WORDING 
APPEARS TO BE A GOOD WAY TO GO FOR MOST OF THE UPCOMING 7 DAYS. NO 
PRECIP EXPECTED THE NEXT 7 DAYS...WHICH IS TYPICAL FOR THIS TIME OF 
YEAR...AND LOW LEVEL MOISTURE/SURFACE RELATIVE HUMIDITY WILL 
CONTINUE TO BE A BIT BELOW NORMAL. DG

.PSR...NONE.