Area Forecast Discussion
Issued by NWS Las Vegas, NV

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858
FXUS65 KVEF 101609
AFDVEF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
810 AM PST WED FEB 10 2016

.SYNOPSIS...SPRING LIKE WEATHER WILL CONTINUE ACROSS THE REGION
THROUGH THE REST OF THE WEEK WITH DRY AND UNSEASONABLY WARM WEATHER
EXPECTED. SCATTERED HIGH CLOUDS WILL PASS THROUGH THE AREA AT TIMES
AND LOCALLY BREEZY CONDITIONS WILL REMAIN ALONG THE COLORADO RIVER
NEAR LAUGHLIN AND BULLHEAD CITY.
&&

.UPDATE...THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. ANOTHER
MILD AND SPIRNG-LIKE FEBRUARY DAY IS IN STORE. THIS MORNINGS
SOUNDING FROM LAS VEGAS INDICATED A FAIRLY SIMILAR PROFILE TO
YESTERDAY WITH EVER SO SUBTLE WARMING IN THE LOW LEVELS. THE RECORD
HIGH THIS AFTERNOON IN LAS VEGAS IS 74F DEGREES SET IN 2014...AND
THIS AFTERNOON IS LIKELY TO TIE THAT IF NOT BREAK IT.

-OUTLER-

&&

.SHORT TERM...THROUGH FRIDAY.

HIGH PRESSURE WILL CONTINUE TO DOMINATE OVER THE WESTERN CONUS
THROUGH THE SHORT TERM BUT THE RIDGE AXIS WILL SHIFT EVER-SO-SLOWLY
EAST THROUGH FRIDAY MORNING. THIS WILL RESULT IN SCATTERED HIGH
CLOUDS CROSSING THE AREA AT TIMES WITH CONTINUED DRY CONDITIONS AND
WELL ABOVE NORMAL TEMPERATURES. AS NOTED BY THE PREVIOUS FORECASTER,
HIGH TEMPERATURE RECORDS COULD BE IN JEOPARDY THIS AFTERNOON FOR LAS
VEGAS AND DEATH VALLEY WHERE HIGHS OF 74 AND 84 DEGREES RESPECTIVELY
ARE FORECAST. TEMPERATURE RECORDS FOR BOTH AREAS SHIFT SEVERAL
DEGREES HIGHER AFTER TODAY AND RECORDS WILL LIKELY BE SAFE.

BY FRIDAY, THE LARGE AREA OF LOW PRESSURE THAT HAS BEEN ANCHORED
OVER THE GULF OF ALASKA THAT PAST SEVERAL DAYS FINALLY ERODES AND A
STRONGER PACIFIC SHORTWAVE IS ABLE TO APPROACH THE WEST COAST AT A
SLIGHTLY DIFFERENT ORIENTATION NUDGE THE RIDGE TO THE CENTER OF THE
COUNTRY AND FLATTEN THE UPPER LEVEL FLOW OVER THE WEST. OVERALL, IT
WILL HAVE LITTLE EFFECT ON SENSIBLE WEATHER IN OUR AREA AS HIGH
TEMPERATURES FRIDAY AND SATURDAY ARE EXPECTED TO REMAIN 10-12
DEGREES ABOVE NORMAL.

PROBABLY THE BIGGEST CHANGE OVER THE NEXT SEVERAL DAYS WILL BE FOR
THE FOLKS ALONG THE COLORADO RIVER VALLEY WHERE STRONG NORTH WINDS
OF THE PAST SEVERAL DAYS WILL FINALLY BEGIN TO SUBSIDE. HOWEVER,
LOCALLY GUSTY CONDITIONS WILL CONTINUE IN THE LAUGHLIN/BULLHEAD CITY
AREA BUT EVEN THERE, GUSTS WILL BE LESS INTENSE AND RELIEF WILL
ARRIVE BY FRIDAY.

.LONG TERM...SATURDAY THROUGH TUESDAY.

LONG-DURATION AMPLIFIED RIDGE IN THE WEST WEAKENS THIS WEEKEND WITH
AN ONSLAUGHT OF VORTICITY MAXIMA PROGRESSING INTO THE PACIFIC
NORTHWEST. MODELS ARE TRENDING FASTER AND WEAKER WITH THE SHORTWAVE
TROUGH REACHING THE COAST 00Z-12Z SATURDAY WITH THE GFS A BIT SLOWER
THAN THE ECMWF. THE FASTER PROGRESSION OF THE TROUGH CORRESPONDS TO
A SOMEWHAT WEAKER DEPICTION OF THE HIGH-AMPLITUDE RIDGE, UNDOUBTEDLY
OWING TO A RATHER POTENT PREDECESSOR NEGATIVELY TILTED TROUGH
PROGRESSING THROUGH THE RIDGE LATE THIS WEEK WELL NORTH OF OUR AREA.
MAIN EFFECT THIS HAS ON THE WEEKEND FORECAST IS THE DEGREE OF
COOLING EXPECTED AS THE SOUTHERN STREAM PORTION OF THE VORT MAX
MOVES THROUGH THE AREA. GENERAL IMPRESSION IS THAT THE SHORTWAVE
TROUGH LOOKS A TAD WEAKER TODAY THAN YESTERDAY, AND WITH THE
SLIGHTLY WEAKER LOOKING RIDGE ON SATURDAY COMPARED TO HOW IT WAS
DEPICTED 24 HOURS AGO...THINKING THAT THERE WILL BE SOMEWHAT LESS
COOLING FROM SATURDAY TO SUNDAY THAN WHAT WAS FORECAST 24 HOURS AGO.
NEVERTHELESS, THESE CHANGES ARE QUITE MINOR (A MATTER OF A DEGREE OR
TWO COOLER ON SATURDAY AND A DEGREE OR TWO WARMER ON SUNDAY). TROUGH
PASSAGE IS EXPECTED TO BE DRY REGIONWIDE WITH BREEZY NORTH WINDS
AFTER TROUGH PASSAGE ON SUNDAY AND MONDAY, PARTICULARLY FOR THE
COLORADO RIVER VALLEY. LONGWAVE RIDGING RECOMMENCES EARLY NEXT WEEK.

MODELS CONTINUE TO DEPICT A LOW CUTTING OFF IN THE SUBTROPICAL
EASTERN PACIFIC AS THE WEEKEND SYSTEM PROGRESSES THROUGH THE WEST.
WHAT EXACTLY HAPPENS TO THIS LOW IS ANYONE`S GUESS, AS MODELS ARE
STRUGGLING MIGHTILY WITH HOW THIS LOW INTERACTS WITH AN UPSTREAM
LARGE-SCALE TROUGH PROGRESSING THROUGH THE EAST PACIFIC INTO THE
WEST COAST NEXT WEEK. 00Z ECMWF SHOWS REASONABLE
PHASING/AMPLIFICATION WITH THE TROUGH AS IT MOVES THROUGH THE WEST
MID-TO-LATE NEXT WEEK, BUT ALSO SHOWS A RATHER DRY DEPICTION OF THE
SOUTHERN PORTION OF THE TROUGH. MEANWHILE...00Z GFS LOOKS WETTER BUT
ACTUALLY CLOSES OFF A SECONDARY LOW OFF THE CALIFORNIA COAST THAT
PROGRESSES THROUGH OUR REGION LATE NEXT WEEK, CREATING A SECOND
PERIOD OF WIDESPREAD PRECIP FOR THE SOUTHWEST. 00Z CMC LOOKS AT
LEAST REASONABLY SIMILAR TO THE 00Z ECMWF, AND THE 06Z DGEX LOOKS
REMINISCENT OF THE 00Z GFS. 18Z DGEX HAD THE EAST PACIFIC LOW MOVING
NORTHEAST INTO THE SOUTHWEST BRINGING WIDESPREAD PRECIPITATION
THROUGHOUT THE REGION ON WEDNESDAY (SOMETHING HINTED AT BY THE MODEL
24 HOURS BEFORE) BUT HAS ESSENTIALLY ZERO SUPPORT FROM ANY OTHER
DETERMINISTIC MODEL SOLUTION. VERY BRIEF LOOK AT 06Z GFS SHOWS A
MUCH DIFFERENT DEPICTION OF THE PACIFIC TROUGH`S PASSAGE THROUGH THE
WEST THE MIDDLE OF NEXT WEEK (MUCH SLOWER AND FARTHER NORTH) WITH A
SUBSEQUENT CUTOFF LOW DEVELOPING MUCH FARTHER NORTHWEST THAN ITS 00Z
COUNTERPART SUGGESTS. HOWEVER, IT DOES PROGRESS THIS CUTOFF INTO THE
SOUTHWEST THE FOLLOWING WEEKEND.

SUCH LARGE SPREAD FROM MODEL TO MODEL AND SUCH LARGE CHANGES IN
CONTINUITY FROM MODEL RUN TO MODEL RUN, QUITE COMMON WITH CUTOFF
LOWS PROGRESSING INTO LONGWAVE RIDGES, LEAD TO HIGH UNCERTAINTY IN
THE FORECAST NEXT WEEK. THROUGH TUESDAY, IT APPEARS WARM AND DRY
WEATHER WILL HOLD (FAIRLY HIGH CONFIDENCE), BUT AFTER THAT IS NOT AT
ALL CLEAR. PLENTY OF TIME TO FIGURE THINGS OUT, THOUGH.
&&

.AVIATION...FOR MCCARRAN...TRANQUIL WEATHER WILL CONTINUE TODAY WITH
THIN CIRRUS AND VARIABLE WINDS GENERALLY LESS THAN 6 KNOTS. NO
SIGNIFICANT WEATHER IS EXPECTED THROUGH FRIDAY.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...TRANQUIL WEATHER CAN BE EXPECTED ACROSS MOST OF THE
REGION WITH GENERALLY LIGHT WINDS AND ONLY SOME THIN CIRRUS TODAY.
THE EXCEPTION WILL BE LINGERING NORTH BREEZES GUSTING AROUND 20-25
KNOTS ALONG THE COLORADO RIVER VALLEY NEAR KIFP TODAY AND THURSDAY.
&&

.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED.
PLEASE REPORT ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&

$$

SHORT TERM/AVIATION...SALMEN
LONG TERM...SHAFER

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

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



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