National Weather Service Raw Text Product

541 
FXUS65 KVEF 241905
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1105 AM PST SUN NOV 24 2013

.SYNOPSIS...A SLOW MOVING LOW PRESSURE WILL FINALLY PULL AWAY FROM 
THE AREA TODAY RESULTING IN DRIER CONDITIONS. FURTHER WARMING IS 
EXPECTED ACROSS THE AREA MONDAY THROUGH WEDNESDAY. ANOTHER AREA OF 
LOW PRESSURE DROPPING SOUTH NEAR THE CALIFORNIA COAST MAY BRING A 
FEW SHOWERS MAINLY TO WESTERN PORTIONS OF THE AREA FOR THANKSGIVING 
DAY AND FRIDAY.
&&

.UPDATE...UPPER LOW EXITING THE REGION TODAY WITH A FEW SHOWERS 
STILL POSSIBLE IN MOHAVE COUNTY AND FAR EASTERN LINCOLN COUNTY. 
CLOUDS HAD CLEARED OUT A BIT MORE THAN PREVIOUSLY FORECAST AND THE 
SKY COVER GRID WAS ADJUSTED TO REDUCE SKY COVER OVER A GOOD PORTION 
OF THE FORECAST AREA. NO OTHER UPDATES NEEDED.
&&

.AVIATION...FOR MCCARRAN...SOME DRYING OF THE LOWER LEVELS OF THE 
ATMOSPHERE IS TAKING PLACE...AND THE LOWEST CLOUD BASES HAVE 
SCATTERED OUT LEAVING CIGS GENERALLY AROUND 10K FEET. CLEARING 
BEGINS TONIGHT WITH MAINLY CLEAR SKIES EXPECTED MONDAY. WINDS WILL 
FAVOR MORE TYPICAL DIURNAL TRENDS THROUGH TONIGHT AT SPEEDS MAINLY 
LESS THAN 6 KTS.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST 
CALIFORNIA...SHOWERS SHOULD BE CONFINED TO EASTERN MOHAVE COUNTY 
THROUGH AROUND 21Z. CIGS BTWN 5K-8K FEET IN THIS AREA OTHERWISE 
SCT-BKN AROUND 10K FEET. WINDS OVERALL SHOULD FAVOR TYPICAL DIURNAL 
TRENDS AT 10 KTS OR LESS. MAINLY CLEAR CONDITIONS MONDAY EXPECT FOR 
PATCHY FG/BR POSSIBLE EARLY IN THE MORNING.
&&

.PREV DISCUSSION...
254 AM PST SUN NOV 24 2013

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.

WELL AFTER 3 DAYS OF CLOUDS AND RAIN WE ARE FINALLY IN FOR A CHANGE 
TODAY IN VEGAS WITH THE POTENTIAL OF SEEING SOME SUNSHINE AS A SLOW 
MOVING UPPER LEVEL LOW FINALLY HEADS OUT OF THE AREA. THE LATEST 
WATER VAPOR IMAGERY SHOWS THE CENTER OF THE LOW NEAR PARKER, ARIZONA 
AS OF EARLY THIS MORNING WITH MOISTURE STILL WRAPPING AROUND THE 
BACK SIDE OF THE LOW. THE MAIN ISSUE FOR TODAY, ESPECIALLY FOR THIS 
MORNING, WILL BE HOW QUICKLY WE ARE ABLE TO DRY THINGS OUT ACROSS 
THE AREA WHICH WILL DETERMINE WHEN SHOWERS COME TO AN END AND HOW 
QUICKLY ANY LOW AND MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED.
THE LATEST RADAR IMAGES FROM KESX SHOW MAINLY LIGHT RETURNS ACROSS 
THE EASTERN PORTIONS OF THE AREA AND IT IS LIKELY THE RADAR IS 
OVERSHOOTING SOME OF THE PRECIPITATION. BASED ON THE HRRR AND THE 
00Z REGIONAL WRF, THE BEST POTENTIAL FOR ANY SHOWERS THIS MORNING 
WILL BE ACROSS NORTHERN AND CENTRAL MOHAVE COUNTY, LINCOLN COUNTY 
AND THE MOUNTAINS OF CLARK COUNTY AND I HAVE KEPT IN 20-30 POPS WITH 
SOME NEAR 40 POP VALUES (IN THE HIGHEST TERRAIN) OVER THESE AREAS. 
AS THE LOW LEVELS START TO DRY OUT, WE SHOULD SEE THE LOWER AND 
MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED IN COVERAGE BY EARLY 
THIS AFTERNOON ESPECIALLY FROM LINCOLN AND CLARK COUNTIES ON EAST. 
THERE COULD BE A LITTLE FOG AROUND, MAINLY ALONG THE INTERFACES OF 
THE HIGHER TERRAIN WHERE THEY HIT THE CLOUD BASES. OUTSIDE OF THE 
COLORADO CITY AREA WHERE FOG WAS REPORTED EARLIER THIS MORNING, NO 
OTHER FOG WILL BE PLACED IN THE GRIDS AS THE COVERAGE LOOKS TOO 
SMALL. WITH THE COLD POOL DEPARTING THE AREA ASSOCIATED WITH THE 
LOW, A LOT OF WARMING ALOFT WILL TAKE PLACE TODAY. THIS COMBINED 
WITH SOME SUN WILL MAKE FOR A BIG BOOST IN TEMPS, HOWEVER, HIGHS 
SHOULD STILL BE ABOUT 10 DEGREES BELOW NORMAL ACROSS THE AREA AND I 
DID CHOP A FEW DEGREES OFF THE PREVIOUS FORECAST BASED ON THE LATEST 
GUIDANCE.

FOR TONIGHT, SOME LOW AND MID-LEVEL CLOUDS MAY LINGER EARLY ON, 
OTHERWISE EXPECT A CLEAR SKY. TEMPS SHOULD BE A LITTLE COLDER WITH 
LESS CLOUD COVER. ONE CONCERN WILL BE IN THE WESTERN PORTIONS OF THE 
MOJAVE DESERT, MAINLY ACROSS NW SAN BERNARDINO COUNTY AND FAR SW 
INYO COUNTY, WHERE PATCHY FOG MAY BE POSSIBLE. STATISTICAL GUIDANCE 
SHOWS NEARLY SATURATED OR SATURATED SFC CONDITIONS TONIGHT 
(ESPECIALLY THE COLDER MET GUIDANCE) AND BUFKIT SOUNDINGS FROM THE 
NAM SHOW THE VERY LOW-LEVELS MOISTENING AROUND OR JUST AFTER 
SUNRISE. I WILL GO AHEAD AND ADD PATCHY FOG IN HERE GIVEN THE WET 
GROUND FROM THE RECENT RAINS, LIGHT WINDS AND CLEAR SKY EXPECTED 
INITIALLY TONIGHT, HOWEVER CONFIDENCE IS NOT THE BEST WITH THIS.

RIDGING ALOFT IS FORECAST TO SLIDE EAST ACROSS THE AREA FROM MONDAY 
INTO TUESDAY. THIS WILL RESULT IN FURTHER WARMING WITH HIGHS ABOUT 
4-6 DEGREES BELOW NORMAL. AS THE RIDGE AXIS SLIDES EAST ON TUESDAY 
AND A TROUGH OFFSHORE STARTS TO APPROACH HIGH LEVEL MOISTURE SHOULD 
START TO SPILL IN FROM THE WEST AND COULD BRING A DECENT AMOUNT OF 
CIRRUS TO THE AREA FOR TUESDAY NIGHT.

.LONG TERM...WEDNESDAY THROUGH SATURDAY...THE PACIFIC SYSTEM THAT IS 
FORECAST TO APPROACH THE WEST COAST BY LATE WEDNESDAY DOES NOT 
APPEAR TO HAVE THE MAKINGS OF A SIGNIFICANT STORM FOR OUR FORECAST 
AREA. THE LATEST MEDIUM RANGE MODELS ARE NOW IN BETTER AGREEMENT 
WITH THE TRACK OF THE SYSTEM....BRINGING THE CENTER OF THE CLOSED 
LOW ALONG THE CENTRAL CALIFORNIA COAST THANKSGIVING DAY THEN 
INDICATING IT WILL TRANSFORM INTO A WEAKER AND ELONGATED POSITIVE 
TILT TROUGH AS IT SAGS OFF THE SOUTHERN CALIFORNIA COAST FRIDAY AND 
CONTINUES WORKING TOWARD NORTHERN BAJA SATURDAY. THE BEST CHANCE FOR 
PRECIPITATION WILL BE ACROSS THE SOUTHERN SIERRA AND THE INYO COUNTY 
MOUNTAINS THANKSGIVING DAY INTO THURSDAY NIGHT AS A SHORTWAVE EJECTS 
OUT OF THE COASTAL LOW ACROSS SOUTHEAST CALIFORNIA AND SOUTHERN 
NEVADA. SNOW WILL BE LIKELY IN THE HIGH SIERRA WITH LESSER CHANCES 
FOR LIGHT SNOW SHOWERS ACROSS THE REST OF THE INYO COUNTY MOUNTAINS 
AND THE MOUNTAINS OF SOUTHERN NEVADA. PRECIPITATION CHANCES THEN 
DIMINISH CONSIDERABLY FRIDAY INTO SATURDAY. CONSIDERING THE SEED FOR 
THIS SYSTEM IS CURRENTLY A BARELY NOTICEABLE PACIFIC SHORTWAVE NEAR 
40N AND THE DATELINE...THERE ARE SURE TO BE SOME CHANGES DURING ITS 
EVOLUTION. IT BEARS WATCHING BUT DOES NOT LOOK THAT IMPRESSIVE FOR 
NOW.
&&

.CLIMATE...WE HAVE HAD OUR FILL OF CLOUDS IN THE SKY HERE IN VEGAS 
THE LAST FEW DAYS BUT WHEN IS THE LAST TIME WE HAD 3 DAYS WITH THIS 
MUCH CLOUD COVER AROUND? BASED ON SUNRISE TO SUNSET CLOUD COVER, THE 
LAST TIME WE HAD BACK-TO-BACK DAYS WITH A 10 (WHICH MEANS AS CLOUDY 
AS IT GETS) WAS ON DECEMBER 20TH AND 21ST OF 2010. THOSE AROUND THEN 
HERE WILL REMEMBER THAT AS A PERIOD WHEN A BARRAGE OF STORMS CAME IN 
FROM THE PACIFIC. THIS WAS ALSO THE ONLY SUCH PERIOD LOOKING BACK 
THROUGH SKY COVER RECORDS FOR THE LAST 5 YEARS TO NOVEMBER 2008.
&&


.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE. 
AZ...NONE. 
CA...NONE.
&&

$$

UPDATE...HARRISON
AVIATION...SALMEN
PREV DISCUSSION...STACHELSKI/ADAIR

FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:

HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER