000 
FXUS65 KVEF 291645
AFDLAS

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
944 AM PDT SAT JUN 29 2002

.SYNOPSIS...UPPER LEVEL HIGH PRESSURE WILL BUILD OVER THE SOUTHERN 
GREAT BASIN AND THE MOJAVE DESERT THROUGH THE WEEKEND. THIS WILL 
RESULT IN CONTINUED DRY WEATHER WITH TEMPERATURES RISING TO ABOVE 
NORMAL LEVELS.

.DISCUSSION...RIDGE BEGINNING TO BUILD OVER THE SW AS ADVERTISED 
LAST FEW DAYS. 12Z HIGH CENTER WAS NEAR FMN AT 400-500MB AND DRA 
SOUNDING SHOWED SUBSTANTIAL 24-HR WARMING IN THAT LAYER. ETA AND AVN 
BOTH CONSISTENT IN KEEPING AREA HOT AND DRY WITH LIGHT WIND THROUGH 
MONDAY MORNING AS RIDGE EXPANDS BUT AVN DEPICTS SEVERAL SPURIOUS 
VORTICITY CENTERS ROTATING AROUND THE BOTTOM OF THE RIDGE AND 
LIFTING NW OUT OF OLD MEXICO IN THE MONDAY-WEDNESDAY TIME FRAME. THE 
FIRST OF THE SERIES APPEARS OVER SW AZ MONDAY AFTERNOON AND IS 
FORECAST TO INTENSIFY AS IT TRACKS INTO SRN CA MONDAY EVENING. THE 
SOURCE OF THIS IMPULSE IS UNCERTAIN. IT DOES NOT APPEAR TO BE 
RELATED TO THE PV ANOMALY OVER S TX NOR DOES IT LOOK LIKE IT IS 
EJECTING FROM THE CLOSED LOW OFF BAJA. WIND AND TEMP FIELDS DO NOT 
SUGGEST A VORTICITY SPIN-UP FROM JETSTREAK-O-GENESIS EITHER. WILL 
LOOK AT THIS MORE CLOSELY FOR THE AFTERNOON FORECAST PACKAGE BUT AT 
THIS POINT IM LEANING TOWARD DOUBTING THE STRENGTH...TIMING...AND 
PERHAPS EVEN EXISTENCE OF THESE FEATURES. WE ARE CLEARLY DEVELOPING 
A FLOW PATTERN THAT WOULD FAVOR IMPORTING SOME MOISTURE INTO THE 
FORECAST AREA WITH TIME...BUT THERE ARE TOO MANY UNCERTAINTIES TO 
INTRODUCE A CHANCE FOR TSTMS BASED ON SUCH DUBIOUS GUIDANCE. NO 
UPDATES PLANNED.    

RUNK

.LAS...NONE.