307 
FXUS65 KPSR 151145
AFDPSR
AZZ020>028-CAZ030>033-151745-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
330 AM MST TUE APR 15 2003

.SYNOPSIS...
A LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WITH SHOWERS AND 
GUSTY WINDS WILL MOVE RAPIDLY EAST OF ARIZONA FOLLOWED BY PARTLY TO 
MOSTLY SUNNY SKIES...DECREASING WIND...AND MUCH COOLER WEATHER TODAY.
IT IS EXPECTED TO BE MOSTLY CLEAR TONIGHT...THEN SUNNY AND MUCH 
WARMER WEDNESDAY AS HIGH PRESSURE ALOFT EAST ACROSS THE SOUTHWESTERN 
UNITED STATES. ANOTHER PACIFIC LOW PRESSURE SYSTEM AND ASSOCIATED 
COLD FRONT WILL BRING A SLIGHT CHANCE OF SHOWERS BY LATE THURSDAY 
INTO FRIDAY. HIGH PRESSURE ALOFT FROM THE PACIFIC IS EXPECTED TO 
BRING DRY AND WARMER WEATHER BACK TO THE AREA SATURDAY WITH MUCH 
WARMER WEATHER SUNDAY.

.DISCUSSION...
A COLD FRONT WITH SCATTERED SHOWERS AND GUSTY WINDS WAS MOVING EAST 
ACROSS SOUTH-CENTRAL ARIZONA EARLY THIS MORNING AND IS EXPECTED TO 
BE EAST OF THE AREA BY MID MORNING. SOME INSTABILITY SHOWERS BEHIND 
THIS FRONT ARE POSSIBLE THIS MORNING...OTHERWISE CLEARING SKIES WILL 
TAKE PLACE AS THE ASSOCIATED LOW PRESSURE SYSTEM ALOFT MOVES RAPIDLY 
EAST OF ARIZONA TODAY. A DECREASE IN THE PRESSURE GRADIENT BEHIND 
THE COLD FRONT MEANS DECREASING WIND TODAY. A MUCH COOLER AIRMASS 
BEHIND THE COLD FRONT MEANS MUCH COOLER WEATHER TODAY COMPARED WITH 
YESTERDAY. HIGH PRESSURE ALOFT WILL MOVE EAST AND BRING MOSTLY CLEAR 
SKIES TONIGHT...AND SUNNY AND MUCH WARMER WEATHER WEDNESDAY. TIMING 
IS SOMEWHAT QUESTIONABLE...BUT THE BEST ESTIMATE IS THAT YET ANOTHER 
PACIFIC LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL BRING A 
SLIGHT CHANCE OF SHOWERS BY LATE THURSDAY INTO FRIDAY. HIGH PRESSURE 
ALOFT FROM THE PACIFIC IS EXPECTED TO BRING DRY AND WARMER WEATHER 
BACK TO THE AREA SATURDAY WITH MUCH WARMER WEATHER SUNDAY.

.PSR...NONE.

ELLIS

$$