744 
FXUS65 KVEF 172116
AFDLAS

MOJAVE DESERT/SOUTHERN GREAT BASIN AREA FORECAST DISCUSSION 
NATIONAL WEATHER SERVICE LAS VEGAS NV
215 PM PDT WED OCT 17 2001

SYNOPSIS...AN AREA OF HIGH PRESSURE ALOFT WILL START TO REBUILD OVER 
THE SOUTHWEST STATES THURSDAY. THE RIDGE WILL REMAIN OVER THE REGION 
THROUGH SATURDAY PROVIDING THE AREA WITH SEVERAL MORE DAYS OF ABOVE 
NORMAL TEMPERATURES AND LIGHT WINDS.

DISCUSSION...ANOTHER GREAT DAY IN PROGRESS ACROSS THE FORECAST AREA 
WITH PLENTY OF SUNSHINE AND TEMPERATURES A FEW DEGREES ABOVE NORMAL. 
FOR THE IMMEDIATE SHORT TERM...I.E. THROUGH SATURDAY DO NOT EXPECT 
MUCH CHANGE.

WATER VAPOR IMAGERY SHOWS WEST COAST TROUGH SPLITTING WITH SHORTWAVE 
OVER THE NORTHERN ROCKIES CONTINUING EAST TONIGHT/THURSDAY INTO 
LONGWAVE TROUGH OVER THE CENTRAL STATES. MEANTIME...SHORTWAVE NEAR 
35 DEG. N/136 DEG. W PROGGED TO DEVELOP INTO A CUTOFF LOW NEAR 30 
DEG. N/140 DEG. W BY LATE THURSDAY AFTERNOON. ON FRIDAY...CUTOFF LOW 
STAYS WELL OFFSHORE OF CALIFORNIA WITH UPPER RIDGE REBUILDING OVER 
THE WESTERN STATES. PRESENTLY...AREA VOID OF HIGH CLOUDS...BUT 
SATELLITE SHOWS NEXT PLUME INCREASING TOWARD THE CENTRAL/SOUTHERN 
CALIFORNIA COAST. ALL MODEL TIME HEIGHT SECTIONS SIMILAR INCREASING 
THE HIGH CLOUDS TONIGHT AND LINGERING THEM THROUGH TOMORROW. SKIES 
WILL BE MOSTLY CLEAR THURSDAY NIGHT/FRIDAY UNDER INFLUENCE OF RIDGE. 
AVN SUGGESTS A PIECE OF ENERGY BREAKING OFF CUTOFF LOW OVER THE 
EASTERN PACIFIC FRIDAY NIGHT/SATURDAY FLATTENING THE RIDGE AND 
SPREADING ANOTHER PLUME OF HIGH LEVEL MOISTURE OVER THE GREAT 
BASIN.   

WEAK FRONTAL BOUNDARY PRESENTLY ACROSS NORTHWEST NEVADA MAY SAG 
FURTHER SOUTH INTO SOUTH CENTRAL NEVADA TONIGHT AND THURSDAY BUT 
OVERALL SURFACE GRADIENTS/WINDS ALOFT REMAIN LIGHT FOR NO 
SIGNIFICANT WINDS. AVN MORE AGGRESSIVE THAN ETA WITH COLD AIR 
ADVECTION INTO SOUTHERN NEVADA TONIGHT. SINCE TROUGH IS SPLITTING 
BELIEVE COLD AIR ADVECTION SHOWN BY MODELS IS OVERDONE AND NOT 
ANTICIPATING MUCH IN THE WAY OF TEMPERATURE CHANGES THROUGH 
SATURDAY. 

FOR SUNDAY THROUGH WEDNESDAY MEDIUM RANGE MODELS IN GENERAL 
CONSENSUS WITH THE DEVELOPMENT OF FAST NORTHWEST FLOW ACROSS PACIFIC 
NORTHWEST WITH MEAN LONGWAVE TROUGH REMAINING OVER THE CENTRAL 
STATES. NORTHWEST FLOW TYPICALLY DRY FOR OUR AREA...BUT WITH 
LOWERING HEIGHTS AND INCREASED WINDS ALOFT WILL CALL FOR OCCASIONAL 
BREEZES AND COOLER TEMPERATURES. PIERCE        

.LAS...NONE.