High Wind in Arizona, February 17, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
650 PM PST WED FEB 17 2016

.SYNOPSIS...A QUICK HITTING PACIFIC STORM SYSTEM WILL IMPACT THE
REGION THROUGH THURSDAY MORNING WITH INCREASED CLOUDS...GUSTY
WINDS...AND PRECIPITATION CHANCES. IMPACTS WILL BE GREATEST ACROSS
THE SIERRA WHERE SIGNIFICANT SNOWFALL IS LIKELY ALONG WITH STRONG
WINDS. LIGHT PRECIPITATION CHANCES WILL SPREAD ACROSS ALL AREAS
NORTH OF I-40 BY THURSDAY MORNING BEFORE ENDING THURSDAY AFTERNOON.
DRY WEATHER AND GRADUAL WARMING WILL RETURN FOR THE WEEKEND INTO
EARLY NEXT WEEK.
&&

.UPDATE...AS EXPECTED IT IS AN ACTIVE EVENING WITH RAIN SPREADING
ACROSS MUCH OF THE WESTERN MOJAVE DESERT AND GUSTY WINDS CONTINUING
FOR MANY AREAS AT THIS HOUR. LATEST SATELLITE IMAGERY CONTINUES TO
DEPICT A WELL DEVELOPED FRONTAL BAND WITH A MOISTURE TAP EXTENDING
INTO THE SUBTROPICS. RADAR TRENDS FURTHER HIGHLIGHT WIDESPREAD RAIN
STRETCHING FROM THE SOUTHERN GREAT BASIN ACROSS THE WESTERN MOJAVE
DESERT AND INTO THE LOS ANGELES BASIN. DEPTH OF THE MOISTURE IS
ALLOWING MINIMAL RAINSHADOWING TO OCCUR IN THESE AREAS AND RAIN IS
CURRENTLY BEING REPORTED IN BARSTOW...BICYCLE LAKE...DESERT ROCK
NV...AND INDIAN SPRINGS. AS THE MOISTURE BAND PUSHES EASTWARD...RAIN
WILL DEVELOP ACROSS MOST OF SOUTHERN NEVADA AND EASTERN CALIFORNIA
BEFORE SPREADING INTO NORTHWEST ARIZONA TONIGHT.

FOR THE ABOVE OUTLINED REASONS...IVE RAISED POPS CONSIDERABLY
TONIGHT FOR MOST OF THE DESERTS. THE LOW LEVEL AIRMASS REMAINS QUITE
DRY SO CONSIDERABLE EVAPORATION WILL LIMIT RAINFALL TOTALS...BUT
STILL THINK MEASURABLE RAIN IS A GOOD BET FOR MOST AREAS NORTH OF
INTERSTATE 40 TONIGHT.  WILL CONTINUE TO MONITOR TRENDS AND MAKE ANY
ADDITIONAL UPDATES AS NECESSARY.

-OUTLER-

.AVIATION...FOR MCCARRAN...GUSTY SOUTHWEST WINDS REMAIN POSSIBLE
THIS EVENING WITH SPEEDS OF 10-15 KTS WITH GUSTS 20-25 KTS. WINDS OF
15-25 KTS AND GUSTS TO 25-35 KTS ARE EXPECTED DURING MUCH OF THE
MORNING...THEN DECREASING DURING THE AFTERNOON. CIGS CURRENTLY NEAR
10K FEET WILL FALL TO AROUND 6K AFTER 5Z AS MOISTURE BAND MOVES
THROUGH.  LIGHT RAIN LIKELY OVERNIGHT AFTER 5Z. AREAS OF MECHANICAL
TURBULENCE SHOULD BE EXPECTED TO THE NORTH AND EAST OF THE SPRING
MOUNTAINS NOW THROUGH THURSDAY.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GUSTY SOUTH TO SOUTHWEST WINDS CONTINUE TO DEVELOP
ACROSS THE REGION THIS AFTERNOON...WITH SPEEDS OF 15-25 KTS AND
GUSTS 25-35 KTS COMMON...STRONGER TO THE NORTH AND WEST OF LAS
VEGAS. WINDS WILL REMAIN ELEVATED OVERNIGHT AND THROUGH MUCH OF
THURSDAY AS A STRONG SYSTEM MOVES THROUGH THE AREA. BKN-OVC CIGS
WILL LOWER ACROSS THE REGION THIS EVENING...DOWN TO 4-6 K FEET AS A
BAND OF LIGHT RAIN PUSHES ACROSS THE AREA. AREAS OF MECHANICAL
TURBULENCE SHOULD BE EXPECTED TO THE NORTH AND EAST OF MOUNTAIN
RANGES NOW THROUGH THURSDAY.

&&

.SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT.

THE ADVERTISED PACIFIC STORM SYSTEM IS ON ITS WAY. THE CORE OF THE
SYSTEM REMAINS WELL OFF THE PACIFIC NW COAST MOVING EASTWARD WITH A
TRAILING COLD FRONT EXTENDED DOWN ALONG THE WEST COAST. IR SATELLITE
IMAGERY SHOWS THE SYSTEM HAS DEVELOPED A NICE TROPICAL TAP AND IS
FEEDING MOISTURE INTO CENTRAL AND SOUTHERN CALIFORNIA. OVERALL,
FORECAST DETAILS HAVE CHANGED LITTLE AS WINDS ACROSS THE AREA HAVE
BEGUN TO RESPOND TO THE INCOMING SYSTEM. WINDS ARE NEAR ADVISORY
LEVEL IN NYE AND PORTIONS OF INYO COUNTY WHERE WIND ADVISORIES ARE
IN EFFECT AND ARE ALSO INCREASING IN THE SPRING MOUNTAINS WHERE A
HIGH WIND WARNING IS IN EFFECT. ELSEWHERE, WINDS ARE GENERALLY
GUSTING BETWEEN 20 AND 30 MPH AT THIS TIME.

RADAR IMAGERY SHOWS SHOWER ACTIVITY CONTINUING OVER THE SIERRA WITH
THE DEEPER MOISTURE BAND FORECAST TO ENHANCE SNOWFALL OVERNIGHT. THE
LATEST MODEL DATA FORECAST UPWARDS OF 20 INCHES IN THE SIERRA AT THE
PEAKS WITH 12-18 INCHES ABOVE 8000 FEET. THIS LINES UP WELL WITH THE
ONGOING WINTER STORM WARNING ALREADY IN EFFECT. LESSER AMOUNTS ARE
FORECAST IN THE WHITE MOUNTAINS WHERE A WINTER WEATHER ADVISORY IS
IN EFFECT. ELSEWHERE, IF SNOW LEVELS DROP BEFORE THE MOISTURE IS
PUSHED EAST, 1-3 INCHES WILL BE POSSIBLE ACROSS THE HIGHER
ELEVATIONS OF THE SOUTHERN GREAT BASIN MOUNTAINS TONIGHT AND IN THE
SPRING MOUNTAINS THURSDAY MORNING.

EXPECTED PRECIPITATION AMOUNTS UNCHANGED FROM THE PREVIOUS FORECAST
PACKAGE AND ARE LISTED BELOW...

* TRACE TO 0.20 INCHES IN VALLEY LOCATIONS NORTH OF I-40
* 0.20-0.40 INCHES IN THE HIGHER TERRAIN NORTH OF I-15
* 0.40-0.60 INCHES IN THE HIGHER TERRAIN OF LINCOLN COUNTY
* 0.33-0.75 INCHES IN THE WHITE MOUNTAINS
* 0.33-1.00 INCHES IN THE SIERRA (UP TO 1.5 INCHES NEAR THE CREST)

SNOW WILL TAPER OFF IN THE SIERRA AND WHITE MOUNTAINS THURSDAY
MORNING AS THE SYSTEM MOVES EAST WITH SKIES BEGINNING TO CLEAR.
THE BEST CHANCE OF RAIN AND HIGH ELEVATION SNOW SHIFTS TO THE
SOUTHERN GREAT BASIN THURSDAY MORNING.

WINDS WILL BE THE PRIMARY CONCERN THURSDAY AS THE SYSTEM CROSSES THE
FORECAST AREA. MODELS CONTINUE TO SHOW WINDY CONDITIONS THURSDAY
MORNING THROUGH MID AFTERNOON ACROSS PORTIONS OF SOUTHERN NEVADA AND
NORTHWEST ARIZONA THEN RAPIDLY DECREASING BY LATE THURSDAY
AFTERNOON. TEMPERATURES WILL BE COOLER THURSDAY...GENERALLY 10-15
DEGREES COOLER THAN WEDNESDAY. CLEARING CONDITIONS ARE STILL
EXPECTED THURSDAY NIGHT WITH A DRY...WARMER PERIOD BEGINNING FRIDAY.

THE ONLY OTHER ITEM TO NOTE IS A PACIFIC SHORTWAVE MOVING INTO
NORTHERN CALIFORNIA FRIDAY BRINGING AN INCREASE IN WINDS TO THE
SIERRA CREST.

.LONG TERM...SATURDAY THROUGH TUESDAY.

THE PERSISTENT FEBRUARY RIDGE WILL RETURN IN FULL FORCE OVER THE
WEEKEND AND EARLY NEXT WEEK PROVIDING DRY WEATHER AND WELL ABOVE
NORMAL TEMPERATURES...SIMILAR TO WHAT WE HAVE BEEN EXPERIENCING THE
PAST 10 DAYS. A MINOR DELAY TO THIS PATTERN WILL BE A PACIFIC
NORTHWEST TROUGH WHICH WILL LIFT INLAND FRIDAY AND BRUSH NORTHERN
CALIFORNIA AND NORTHWEST NEVADA. IT WILL HAVE MINIMAL EFFECT ON OUR
REA BUT SHOULD PRODUCE GUSTY WINDS OVER THE SOUTHERN SIERRA RIDGE
TOPS AND SOUTH-SOUTHWEST WINDS OF 10-20 MPH IN THE AFTERNOON ACROSS
MUCH OF THE FORECAST AREA.

THE RIDGE WILL THEN BEGIN TO BUILD OVER THE WESTERN STATES SATURDAY
AND SUNDAY AND CONTINUE AMPLIFYING THROUGH TUESDAY. ASIDE FROM A
WARMING TREND...THIS WILL LEAD TO GUSTY NORTH WINDS DOWN THE
COLORADO RIVER VALLEY...ESPECIALLY NEAR LAUGHLIN AND BULLHEAD CITY
SATURDAY THROUGH TUESDAY. ANOTHER PACIFIC TROUGH IS FORECAST TO
BRUSH NORTHERN CALIFORNIA WEDNESDAY BUT THE ECMWF AND GFS INDICATE
THIS FEATURE WILL HAVE VERY LITTLE IMPACT ON THE FORECAST
AREA...SIMILAR TO WHAT IS EXPECTED THIS FRIDAY. THE RIDGE THEN
QUICKLY REBUILDS BEHIND IT AND HOLDS THROUGH THE END OF THE MONTH.
&&

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

SHORT TERM...SALMEN
AVIATION...WOLCOTT
LONG TERM...ADAIR

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