999 
FXUS65 KPSR 020413
AFDPSR

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
910 PM MST MON MAR 1 1999

.SYNOPSIS...
HIGH PRESSURE ALOFT OVER THE REGION WILL CONTINUE TO MOVE TO THE EAST
WHILE BEING WEAKENED BY WEATHER DISTURBANCES MOVING THROUGH THE GREAT
BASIN AND THE PACIFIC NORTHWEST STATES. THIS WILL RESULT IN GRADUALLY
LOWERING PRESSURE ALOFT OVER THE REGION...BRINGING GRADUAL DAY-TO-DAY
COOLING BEGINNING TUESDAY. HOWEVER...TEMPERATURES SHOULD STILL REMAIN
ABOVE NORMAL INTO THE WEEKEND. MOREOVER...WEAK UPPER-AIR DISTURBANCES
MOVING ACROSS THE REGION FROM TIME TO TIME WILL BRING LOCAL AFTERNOON
BREEZINESS THURSDAY AND FRIDAY. THE WIND IS EXPECTED TO INCREASE OVER
THE WEEKEND AS LOWER PRESSURE APPROACHING THE STATE INTENSIFIES.

.DISCUSSION...
FAST-MOVING VORTICITY MAX ANALYZED OVER NRN AZ AT 00Z WITH NGM HAVING
PRIMARY CENTER NEAR WILLIAMS. CIFM CLDS AT OR ABOVE 20K FT ALREADY
SPREADING ACROSS NM.  WATER VAPOR IMAGERY INDICATED STRONG DRYING
THROUGHOUT UPPER LEVELS...AND ONLY SIGNIFICANT MSTR REMAINING SOUTH
OF A  YUMA-TUCSON LINE AT 03Z.  SHORT TERM FCSTS IN GOOD SHAPE SO
UPDATES NOT NECESSARY.  MAX TEMPS MORE LIKE MID APRIL IN PHX.

MODELS NOT DIFFERING TOO MUCH ON MAJOR FEATURES THIS EVE.  NGM AND
ETA VERY CLOSE ON 500MB PATTERN BUT DIFFERENCES REALLY APPARENT AFT
TUESDAY PM.  IN FACT ETA BRINGS THE PACIFIC LOW ONSHORE FARTHER SOUTH
THAN NGM AND RESULTING 700MB HEIGHTS LOWER ACROSS AZ.  IN ANY CASE
WILL EXPECT MAX TEMPS TO PEAK ON TUESDAY WITH A RETURN TO MORE
SEASONABLE READINGS BY SAT.
SIPPLE