000
FXUS65 KVEF 032343 CCA
AFDVEF
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE LAS VEGAS NV
341 PM PST WED DEC 3 2008
.SYNOPSIS...AN UPPER LOW OFF THE COAST OF CALIFORNIA WILL BRUSH THE
AREA WITH SOME HIGH CLOUDS TONIGHT AND TOMORROW. THIS SYSTEM IS
EXPECTED TO REMAIN OFFSHORE THROUGH THE WEEKEND AND BRING SCATTERED
HIGH CLOUDS TO THE AREA AT TIMES. OTHERWISE A DRY NORTHERLY FLOW
WILL PREVAIL WITH GENERALLY LITTLE SIGNIFICANT CHANGE IN
TEMPERATURES THROUGH THE NEXT SEVEN DAYS.
&&
.SHORT TERM...A DRY NORTHWEST FLOW HAS RESULTED IN PLENTY OF
SUNSHINE ACROSS THE AREA TODAY WITH TEMPERATURE TRENDS THIS
AFTERNOON ALL OVER THE PLACE. OBSERVED SOUNDINGS FROM AROUND THE
AREA STILL INDICATE A SHALLOW INVERSION IS PLACE...HOWEVER IT IS NOT
AS STEEP AS YESTERDAY AND IS ACCOMPANIED BY SEVERAL DEGREES OF
COOLING ALOFT. THIS HAS RESULTED IN MOUNTAIN LOCALS RUNNING SEVERAL
DEGREES BELOW YESTERDAY AND ALSO RUNNING BELOW VALLEY LOCATIONS THIS
AFTERNOON. WATER VAPOR IMAGERY PRESENTLY SHOWS AN UPPER LOW OFF THE
COAST OF NORCAL WITH A PLUME OF HIGH LEVEL MOISTURE PUSHING
SOUTHEAST IN ADVANCE OF THIS FEATURE INTO NEVADA. THIS MOISTURE WILL
RESULT IN AN INCREASE IN HIGH CLOUDS ACROSS THE AREA LATER TONIGHT.
MODEL SOUNDINGS SHOW A SHALLOW INVERSION TONIGHT AND WITH LIGHT
WINDS THIS SHOULD ALLOW TEMPS IN THE VALLEYS TO DROP TONIGHT WITH
NORTHERN LOCATIONS LIKE BISHOP AND CALIENTE POSSIBLY SEEING THEIR
COLDEST NIGHT OF THE SEASON SO FAR. IF HIGH CLOUDS DO ARRIVE SOONER
THAN EXPECTED IT COULD KEEP UP TEMPS A BIT TONIGHT.
THE AFOREMENTIONED UPPER LOW WILL DROP SOUTHWARD JUST OFF THE
CALIFORNIA COAST TOMORROW INTO FRIDAY BECOMING CUT OFF FROM THE
UPPER FLOW. SOME HIGH CLOUDS WILL BRUSH THE AREA TOMORROW AS AN
UPPER TROUGH/PIECE OF ENERGY MOVES ACROSS THE GREAT BASIN BUT SHOULD
CLEAR OUT BY TOMORROW NIGHT AS IT HEADS EAST. OTHERWISE LITTLE
CHANGE IN TEMPS IS EXPECTED AS A SHALLOW INVERSION REMAINS IN PLACE
KEEPING LOW-LEVEL COLD AIR IN PLACE IN THE VALLEYS AS LOW-LEVEL
WINDS REMAIN LIGHT. SATURDAY MORNING LOOKS TO BE THE COLDEST MORNING
OF THE SEASON SO FAR ACROSS MOST VALLEYS...WITH FREEZING TEMPS
POSSIBLE AT KINGMAN AND 30S LIKELY IN OUTLYING PARTS OF THE LAS
VEGAS VALLEY ESPECIALLY IN LOWER SPOTS LIKE NELLIS AFB.
.LONG TERM...CONFIDENCE HAS INCREASED IN THE IDEA THAT A CUTOFF LOW
WILL REMAIN WELL OFF THE SOUTHERN CALIFORNIA COAST SATURDAY THROUGH
THE MIDDLE OF NEXT WEEK. THE 12Z ECMWF SOLUTION NOW SHOWS THIS
PATTERN ALONG WITH THE OPERATIONAL GFS AND MOST OF ITS ENSEMBLE
MEMBERS. THE SYSTEM WILL REMAIN TRAPPED UNDER A MEAN EASTERN PACIFIC
RIDGE WHICH WILL KEEP DRY NORTHWEST FLOW OVER THE FORECAST AREA
THROUGH THE PERIOD. A SHORTWAVE TROUGH RIDING OVER THE RIDGE IS
FORECAST TO BRUSH THE INTERMOUNTAIN REGION AS IT DIVES INTO THE
CENTRAL STATES MONDAY AND TUESDAY. THIS MAY PROVIDE SOME NORTH
SURFACE WINDS TO THE REGION BUT THE ECMWF TRACKS THIS FEATURE EVEN
FARTHER EAST THAN THE GFS...SO ITS IMPACT COULD BE MINIMAL.
TEMPERATURES SHOULD HOLD ABOVE NORMALS THROUGH THE PERIOD. EVEN
THOUGH IT NOW APPEARS TO BE OUT OF THE PICTURE FOR A WHILE...THE
CUTOFF LOW CANNOT BE COMPLETELY FORGOTTEN AND BEARS WATCHING.
&&
.AVIATION...FOR MCCARRAN...GENERALLY LIGHT AND VARIABLE SURFACE
WINDS LESS THAN 5 KNOTS CAN BE EXPECTED THROUGH THURSDAY NIGHT.
DENSE CIRRUS AOA 20K FEET WILL SPREAD ACROSS THE AREA LATE TONIGHT
THROUGH THURSDAY AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...VARIABLE SURFACE WINDS GENERALLY LESS THAN 10 KNOTS
WILL BE OBSERVED AREA WIDE THROUGH THURSDAY AFTERNOON. INCREASE
NORTH WINDS OF 10 TO 20 KNOTS WILL DEVELOP THURSDAY NIGHT. DENSE
CIRRUS AOA 20K FEET WILL SPREAD ACROSS THE REGION FROM NORTH TO
SOUTH THIS EVENING THROUGH THURSDAY AFTERNOON.
&&
.CLIMATE...THE LOW TEMPERATURE AT MCCARRAN INTERNATIONAL AIRPORT
ONLY DROPPED TO 46 DEGREES THIS MORNING WHICH SET A NEW RECORD FOR
CONSECUTIVE DAYS WITH A MINIMUM TEMPERATURE OF 40 DEGREES OR BETTER.
TODAY WAS THE 291 DAY WITH A LOW TEMPERATURE IN LAS VEGAS OF 40
DEGREES OR BETTER...BREAKING THE OLD STRETCH OF 290 DAYS SET FROM
FEBRUARY 10TH 2005 AND RUNNING THROUGH NOVEMBER 26TH 2005.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
STACHELSKI/ADAIR
HTTP://WEATHER.GOV/LASVEGAS
