189 FXUS65 KSLC 052113 AFDSLC UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SALT LAKE CITY UT 315 PM MDT SAT OCT 5 2002 .SYNOPSIS...A COOL AND FAIRLY DRY NORTHWEST FLOW ALOFT WILL BE OVER THE AREA THROUGH THE WEEKEND. BROAD SPLITTING TROUGH PATTERN OVER THE INTERMOUNTAIN WEST THIS AFTERNOON WITH A WEAK SHORTWAVE CURRENTLY MOVING THROUGH NORTHEAST SECTIONS. MOSTLY MID TO HIGH CLOUDS ASSOCIATED WITH IT AND POSSIBLY SOME HIGHER ELEVATION SPRINKLES. MODELS CONTINUE TO MOVE THIS SHORTWAVE EAST THIS EVENING TO LEAVE MOST OF THE AREA IN FAIRLY DRY NORTHWEST FLOW ALOFT. MEANWHILE...ENERGY AT THE BASE OF THE TROUGH SPLITS OFF TONIGHT AND CLOSES OFF OVER SOUTHERN ARIZONA. LOWER SURFACE PRESSURE ASSOCIATED WITH THIS SYSTEM WILL PRODUCE A FAVORABLE GRADIENT FOR SOME LOCAL NORTHEAST WINDS OVER SOUTHWEST ZONES TONIGHT AND SUNDAY. SUNDAY WILL BE SUNNIER ACROSS THE NORTH...THOUGH THE COOL NORTHWEST FLOW WILL ONLY ALLOW HIGHS TO BE A FEW DEGREES WARMER THAN TODAY. LATEST MODELS SHOW A SLIGHT WEAKNESS IN THE NORTHWEST FLOW BRUSHING THE NORTH SUNDAY NIGHT. HIGH CLOUDS...CURRENTLY PILING DOWN THROUGH BC ON THE FRONT SIDE OF THE STRONG EPAC RIDGE...WILL LIKELY MOVE INTO THE NORTH LATE SUNDAY AND SUNDAY NIGHT AS A RESULT. FLOW GRADUALLY TURNS MORE ZONAL AFTER MONDAY WITH ANOTHER VERY WEAK SYSTEM BRUSHING THE NORTH ON TUESDAY AS IT DOES. HAVE LOWERED TUESDAYS MAX TEMPS A COUPLE OF DEGREES FROM MONDAY. MAYBE SOME ISOLATED SHOWERS IN THE EXTREME NORTHEAST LATE MONDAY OR EARLY TUESDAY. FOR THE LATTER HALF OF THE WEEK...FLOW TURNS MORE SOUTHWESTERLY WITH A DEVELOPING TROUGH JUST OFF THE WEST COAST. THIS WILL HELP MODERATE TEMPERATURES SLIGHTLY WED-THU AND PICK UP SOUTHWESTERLY WINDS AS WELL...MOSTLY OVER WESTERN SECTIONS. MODELS ARE CONVERGING TOWARDS SPLITTING THIS SYSTEM AS IT MOVES EAST INTO SATURDAY. LATEST EC IS THE OUTLIER WITH A STRONG CLOSED LOW OVER SW OREGON FRIDAY 12Z. THE END OF THE 12Z AVN HINTS AT THE BEGINNING OF A SPLIT...AND MORE SPLIT THAN THE 00Z RUN. THE AVN EXTENSION CONTINUES WITH THIS IDEA...PUTTING THE FORECAST AREA BETWEEN THE SOUTHERN ENERGY OF THE TROUGH AND THE FASTER NORTHERN BRANCH. HEIGHTS AND 700 TEMPS WILL DIP DOWN AS IT MOVES THROUGH SAT SO HAVE TRENDED TEMPERATURES DOWN FRIDAY AND A LITTLE MORE SATURDAY TO REFLECT THE TROUGH PASSAGE. AT THIS TIME SYSTEM LOOKS TO BE MOSTLY DRY AS IT MOVES THROUGH. SLC 1000 CDC 0000 JACKSON .SLC...NONE.