000
FXUS65 KVEF 031743
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
942 AM PST WED DEC 3 2008
.SYNOPSIS...GENERALLY COOLER TEMPERATURES WILL BE SEEN TODAY AND
INTO THE END OF THE WEEK AS A DRY WEATHER PATTERN REMAINS OVER THE
AREA. A LOW PRESSURE SYSTEM OFF THE SOUTHERN CALIFORNIA COAST MAY
MOVE INLAND LATE IN THE WEEKEND WHICH COULD BRING ISOLATED SHOWERS
TO SOUTHERN NEVADA.
&&
.UPDATE...THE 12Z SOUNDING OUT OF DESERT ROCK STILL INDICATED AN
INVERSION AROUND THOUGH NOWHERE AS STEEP AS YESTERDAY. TEMPS ALOFT
HAVE COOLED SIGNIFICANTLY AS WELL WHEN COMPARED TO 24 HOURS AGO WITH
AS MUCH AS 8 DEGREES C OF COOLING AROUND 750 MB/8400 FEET. THUS DO
NOT EXPECT TO SEE TEMPS IN HIGHER ELEVATIONS EQUAL THOSE IN THE
VALLEYS AS WAS THE CASE YESTERDAY. THE TEMPERATURE AT MCCARRAN
INTERNATIONAL AIRPORT THIS MORNING DROPPED TO 46 DEGREES WHICH NOW
PUTS THE STREAK OF LOW TEMPS AT OR ABOVE 40 DEGREES IN LAS VEGAS AT
291 DAYS WHICH IS A NEW RECORD...THE OLD RECORD WAS 290 DAYS SET IN
2005. THIS STREAK OF WARMTH FOR LOWS MAY BE CHALLENGED IN THE NEXT
FEW NIGHTS AS WE MAY GET CLOSE TO GOING BELOW THE 40 DEGREE MARK AT
SOME POINT. OVERALL THE CURRENT FORECAST LOOKS IN GOOD SHAPE AND SO
NO CHANGES ARE PLANNED.
&&
.SHORT TERM...DRY NORTHERLY FLOW ACROSS THE CWA TODAY AS NEXT SHORT
WAVE/CUT-OFF LOW DROPS SOUTH ALONG THE CALIFORNIA COAST. LOW TO BE
WEST OF SAN FRANCISCO BY 12Z THURSDAY AND THEN SHIFT WELL OFF THE
SOUTHERN CALIFORNIA COAST BY 12Z FRIDAY...TO NEAR 28N/127W. ALTHOUGH
MINOR POSITION DIFFERENCES...NAM/GFS/EURO ALL IN GOOD AGREEMENT IN
THIS SCENARIO. ON FRIDAY...WEAK RIPPLE TO SHIFT ACROSS THE CWA IN
THE NORTHERLY FLOW AND ALTHOUGH SOME CLOUDS WILL LIKELY BE SEEN
THURSDAY AND FRIDAY...OVERALL PATTERN WILL KEEP THE CWA DRY.
WEAK COLD FRONT ASSOCIATE WITH TUESDAY SHORT WAVE WILL BRING COOLER
TEMPS TO MUCH OF THE AREA TODAY AND THEN CONTINUE THESE COOLER
CONDITIONS THROUGH THE END OF THE WEEK. HOWEVER EVEN WITH THE
COOLING...TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL. LOCAL GUSTY
WINDS ON TUESDAY TO BE LIGHTER TODAY AS SURFACE PRESSURE GRADIENTS
RELAX/FLOW ALOFT DECREASES.
.LONG TERM...ALTHOUGH EXTENDED MODELS ARE STILL SHOWING A CLOSED
UPPER LOW OFF THE COAST NEXT WEEKEND ITS STILL NOT APPARENT WHERE
THE FINAL TRACK WILL BE. THE MOST CONSISTENT MODEL IS STILL THE
ECMWF...BUT 00Z RUN NOW BRINGS THE LOW ONSHORE A LITTLE FURTHER
SOUTH NEAR NORTHERN BAJA. THIS WOULD KEEP MOST OF THE PRECIPITATION
SOUTH OF THE AREA WITH ONLY A SLIGHT CHANCE OF SHOWERS ACROSS THE
SOUTHERN CWA. THE GFS HAS THE LOW APPROACH THE COAST BY SUNDAY...BUT
INSTEAD OF TAKING IT ONSHORE IT CONTINUES TO DIVE SOUTH ALONG THE
BAJA COAST...KEEPING ALL QPF OUT OF THE AREA. WILL CONTINUE TO LEAN
WITH THE ECMWF AND KEEP SOME QPF IN THE FORECASTED GRIDS...BUT WILL
LOWER POPS JUST A BIT...ESPECIALLY OVER THE NORTHERN AND CENTRAL
CWA. ECMWF BRINGS WEAK RIDGING OVER THE AREA TUESDAY FOLLOWED BY A
NORTHWEST FLOW ON WEDNESDAY.
&&
.AVIATION...FOR MCCARRAN...GENERALLY LIGHT AND VARIABLE SURFACE
WINDS TODAY WITH OCCASIONAL NORTHEAST WINDS UP TO 6KTS THROUGH 20Z.
SKIES WILL REMAIN MOSTLY CLEAR.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GENERALLY LIGHT AND VARIABLE SURFACE WINDS WITH A FEW
AREAS SEEING NORTHEAST WINDS UP TO 8KTS THROUGH 20Z. SKIES WILL
REMAIN MOSTLY CLEAR.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
UPDATE...STACHELSKI
AVIATION...GORELOW/ADAIR
PREVIOUS SHORT RANGE/LONG RANGE...JENSEN/GORELOW
HTTP://WEATHER.GOV/LASVEGAS
