000 FXUS65 KVEF 262227 AFDLAS MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 330 PM PDT FRI APR 26 2002 SYNOPSIS...AN UPPER LEVEL LOW PRESSURE SWINGING ACROSS THE MOJAVE DESERT EARLY THIS EVENING WILL PRODUCE SCATTERED SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS SOUTH CENTRAL NEVADA TONIGHT AND SATURDAY...AS WELL AS BREEZY AND COOLER CONDITIONS. ANOTHER STORM SYSTEM WILL DEVELOP OFF THE WEST COAST THIS WEEKEND RESULTING IN A THREAT OF SHOWERS LATE SUNDAY AND MONDAY OVER THE SIERRA AND CENTRAL NEVADA. DISCUSSION...COLD CORE LOW KICKING ACROSS MOJAVE DESERT LATE THIS AFTERNOON AS EXPECTED...WITH SCATTERED THUNDERSTORMS ACROSS OUR NORTHERN ZONES AND MORE ISOLATED CENTRAL AND SOUTHERN ZONES. A WEAK SHORT WAVE MOVING WEST ACROSS THE SIERRA RIGHT NOW IS ALMOST BLENDING IN WITH THE LEAD SYSTEMS DEFORMATION ZONE AND APPEARS TO BE ASSISTING ADDITIONAL DEVELOPMENT TO OUR NORTHWEST...THAT WILL BE DRIFTING THROUGH AS WELL THIS EVENING AND MAY HELP ENHANCE ACTIVITY OVERNIGHT OVER OUR CENTRAL AND EASTERN ZONES. BASICALLY MAINTAINED MINIMAL POPS ACROSS SOUTHERN ZONES WITH SCATTERED ACROSS NORTH... ALTHOUGH LIKELY CHANCES WERE ADDED TO NORTH CENTRAL ZONES TO ACCOUNT FOR CURRENT TRENDS AND TO MATCH CLOSER THE MESO ETA PRECIPITATION FORECAST FOR TONIGHT ACROSS THAT AREA. FOLLOWING CURRENT LOW...FLOW IS EXPECTED TO BACK TO THE SOUTHWEST AS ANOTHER LOW DIGS SOUTHWEST OFF THE WEST COAST. JET PROGGED TO BE ACROSS CENTRAL NEVADA SATURDAY BEFORE LIFTING NORTH A BIT SUNDAY... ENOUGH TO CONTINUE MENTION OF SHOWERS CENTRAL ZONES ON SATURDAY. CONSENSUS SEEMS TO FAVOR THAT A SIGNIFICANT PORTION OF ENERGY WILL EJECT FROM THE LOW POSITION OFF THE WEST COAST SUNDAY...AND ACROSS THE DESERT BY TUESDAY. IN ADVANCE OF THAT DEVELOPMENT...AVN SHOWS A GOODLY SLUG OF MOISTURE BECOMING ENTRAINED FROM THE PACIFIC THAT MOVES IN THE SIERRA SUNDAY NIGHT AND MONDAY. BASICALLY HAVE INCREASED PRECIPITATION CHANCES/COVERAGE FOR ALL NORTHERN ZONES MONDAY THROUGH WEDNESDAY...THEN DECREASING THURSDAY/FRIDAY. LOTS OF UNKNOWNS IN THIS PATTERN SO WILL NOT GET CARRIED AWAY WITH TOO MANY DETAILS YET ALTHOUGH IT APPEARS THE SIERRA MAY BE LUCKY ENOUGH TO BE THREATENED BY A LATE SEASON SNOWFALL SUNDAY NIGHT-EARLY TUESDAY. WELL SEE. MCQUEEN .LAS...NONE.