954 FPUS65 KTUS 060414 AFDTUS SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 930 PM MST TUE MAY 5 1998 SYNOPSIS...SOUTHEAST ARIZONA WILL REMAIN BETWEEN A LOW PRESSURE SYSTEM OFF THE CENTRAL CALIFORNIA COAST AND HIGH PRESSURE TO THE EAST FOR THE NEXT COUPLE OF DAYS. THIS WILL RESULT IN A DRY SOUTHWEST FLOW ALOFT EXCEPT FOR A SLIGHT CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE WHITE MOUNTAINS. TEMPERATURES WILL REMAIN A LITTLE BELOW NORMAL. THIS LOW PRESSURE SYSTEM WILL MOVE ACROSS ARIZONA ON FRIDAY FOR SOME COOLING BUT CONTINUED DRY. HIGH PRESSURE WILL REBUILD OVER THE WEEKEND WITH TEMPERATURES CLIMBING ABOVE NORMAL BY SUNDAY. DISCUSSION...NO SURPRISES IN THE EVENING COMPUTER MODEL GUIDANCE AS AN UPPER LEVEL LOW PRESSURE SYSTEM CONTINUES TO SPIN OFF THE CENTRAL CALIFORNIA COAST. VORTICITY LOBES EJECTING FROM THE PARENT UPPER LOW WILL MOVE THROUGH MAINLY NORTHWEST ARIZONA THROUGH THURSDAY. THE WHITE MOUNTAINS MAY BE CLOSE ENOUGH TO THE UPPER LEVEL DYNAMICS AND MOISTURE FOR ISOLATED AFTERNOON THUNDERSTORMS. THE REST OF SOUTHEAST ARIZONA WILL REMAIN DRY THROUGH THURSDAY. 500 MB HEIGHTS AND THICKNESSES CHANGE LITTLE DURING THE NEXT 48 HOURS IN THE SOUTHWEST FLOW ALOFT. TEMPERATURES WILL STAY ABOUT 2 TO 4 DEGREES BELOW THE CLIMATOLOGICAL AVERAGE FOR THIS TIME OF YEAR. THE EXISTING FORECAST PACKAGE IS ON TRACK. NO UPDATES. TUS 0000. OKULSKI TUS...NONE.