High Wind in California, April 25, 2016

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
950 AM PDT MON APR 25 2016

.SYNOPSIS...SHOWERS AND ISOLATED THUNDERSTORMS ARE LIKELY TODAY
MAINLY NORTH OF INTERSTATE 40 AS A WEATHER SYSTEM MOVES THROUGH THE
REGION. STRONG WINDS AND PATCHY BLOWING DUST CAN ALSO BE EXPECTED
ESPECIALLY ACROSS THE MOJAVE DESERT AND THE SOUTHERN GREAT BASIN.
IMPROVING CONDITIONS EXPECTED TUESDAY BEFORE ANOTHER WEATHER SYSTEM
MOVES IN MIDWEEK WITH ADDITIONAL SHOWER CHANCES AND ANOTHER ROUND OF
SPRING WINDS.
&&

.UPDATE...UPPER LOW CURRENT PUSHING SOUTHEAST THROUGH CENTRAL NEVADA
WILL CONTINUE TO MOVE INTO UTAH THIS AFTERNOON. SCATTERED LIGHT
SHOWERS HAVE BEEN OCCURRING OVER PORTIONS OF CLARK...LINCOLN AND
WESTERN MOHAVE COUNTIES AND THESE WILL CONTINUE TO MOVE EAST THROUGH
THE DAY. THERE HAVE BEEN A COUPLE OF LIGHTNING STRIKES IN LINCOLN
COUNTY SINCE 9AM WHICH IS CLOSE TO THE LOW CENTER SO ISOLATED
THUNDERSTORMS FOR LINCOLN AND NORTHERN MOHAVE WILL STILL REMAIN A
THREAT THROUGH THE DAY. HOWEVER...AREAS SUCH AS SOUTHERN CLARK AND
SOUTHERN MOHAVE COUNTIES WHICH HAVE BEEN SUN FOR MUCH OF THE MORNING
WILL ALSO SEE A THUNDERSTORM THREAT THIS AFTERNOON.

THE OTHER CONCERN FOR TODAY WILL BE GUSTY WINDS ACROSS THE REGION.
WIND ADVISORIES ARE CURRENTLY IN PLACE FOR PARTS OF SAN
BERNARINO...ESMERALDA...CENTRAL NYE...AND SOUTHERN MOHAVE COUNTIES.
THESE STILL LOOK GOOD AND NO CHANGES WILL BE NEEDED. WINDS COULD
BECOME STRONG ENOUGH OVER WESTERN SAN BERNARDINO COUNTY THIS
AFTERNOON TO PUSH HIGH WIND WARNING CRITERIA...BUT FOR NOW WILL TAKE
A WAIT AND SEE APPROACH. AT THIS TIME FEEL ITS BORDERLINE FOR THAT
TO OCCUR. NEED TO MAKE A FEW CHANGES TO INCREASE POPS OVER SOUTHERN
MOHAVE AND CLARK COUNTIES.
&&

PREV DISCUSSION
250 AM PDT MON APR 25 2016

.SHORT TERM...THROUGH TUESDAY NIGHT.

ITS BEEN AN ACTIVE EVENING AND OVERNIGHT PERIOD TODAY AS A FAIRLY
POTENT TROUGH PIVOTS INTO THE REGION. THIS HAS SPARKED SHOWERS AND
ISOLATED THUNDERSTORMS THROUGH THE NIGHT MAINLY ACROSS INYO COUNTY
AND THE SOUTHERN GREAT BASIN. THUNDERSTORMS NEAR DEATH VALLEY WERE
FAIRLY POTENT FOR A FEW HOURS AFTER SUNSET AS THEY WERE SPARKED BY
SURFACE CONVERGENCE ALONG A SOUTHWARD MOVING COLD FRONT AND AIDED BY
STRONG LIFT IN THE LEFT EXIT REGION OF AN INCOMING JET. THUNDERSTORM
ACTIVITY HAS SINCE WANED WITH NO NEW STRIKES DETECTED IN THE PAST
HOUR...HOWEVER WE REMAIN IN THE FAVORABLY DIFFLUENT LEFT EXIT REGION
OF A 80KT JET AT 300MB....WHICH WILL AID IN ADDITIONAL SHOWER
DEVELOPMENT ACROSS OUR REGION THROUGH THE MORNING HOURS.  HIGH RES
GUIDANCE INCLUDING THE HRRR BREAK OUT ADDITIONAL SHOWERS IN SOUTHERN
INYO COUNTY EARLY THIS MORNING AND DRIFT THEM EASTWARD TOWARDS THE
LAS VEGAS VALLEY AROUND SUNRISE. STRONG FORCING AND MARGINAL
INSTABILITY COULD RESULT IN A FEW RUMBLES OF THUNDER AS WELL. GIVEN
THE MODEL AGREEMENT IN THIS PARTICULAR PART OF THE FORECAST
AREA...IVE BOOSTED POPS INTO THE LIKELY CATEGORY FOR THE LAS VEGAS
AREA FOR THE MORNING HOURS. BEWARE OF WET AND SLICK
ROADWAYS...THOUGH IM NOT ANTICIPATING MUCH MORE THAN A FEW
HUNDREDTHS FOR MOST AREAS.  OUTSIDE OF FAR SOUTHERN
NEVADA...WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS CAN BE
EXPECTED TODAY NORTH OF INTERSTATE 40...PARTICULARLY ACROSS THE
SOUTHERN GREAT BASIN WHERE SOME AREAS MAY PICK UP OVER A QUARTER OF
AN INCH OF PRECIPITATION...AND PERHAPS SOME SLUSHY ACCUMULATIONS OF
SNOW ABOVE 6000 FEET.

ASIDE FROM THE PRECIPITATION...THE OTHER BIG CONCERN IS WIND.
HIGHEST IMPACT AREA FROM WIND WILL BE ACROSS THE WESTERN MOJAVE
DESERT PARTICULARLY NEAR DAGGETT AND BICYCLE LAKE. IVE MAINTAINED
THE WIND ADVISORY FOR THESE AREAS IN FAVOR OF THE WIND SPEEDS
ADVERTISED BY OUR HIGH RES MODELS. HOWEVER...MOS GUIDANCE
PARTICULARLY THE MAV HAS BEEN VERY BULLISH WITH HIGH WINDS IN THE
MID AFTERNOON FOR DAGGETT. SO WE WILL NEED TO KEEP AN EYE ON
IT...BUT I HAVE DISCOUNTED IT FOR NOW SINCE IT HAS RUN TOO HIGH IN
RECENT PAST EVENTS. ANTICIPATE PEAK GUSTS IN THE 50 TO 55 MPH RANGE
FOR MOST AREAS IN THE WESTERN MOJAVE DESERT....THOUGH A COUPLE
ISOLATED LOCATIONS MAY EXCEED THAT.  GUSTY NORTHWEST WINDS WILL ALSO
MATERIALIZE IN THE SOUTHERN GREAT BASIN BEHIND THE COLD FRONT.

IMPROVING CONDITIONS ARE EXPECTED TUESDAY AS A SHORTWAVE RIDGE
BUILDS IN AND TEMPERATURES WARM CLOSER TO SEASONAL NORMALS.

.LONG TERM...WEDNESDAY THROUGH SATURDAY.

THE PROGRESSIVE PATTERN CONTINUES WITH YET ANOTHER PACIFIC TROUGH
FORECAST TO DIVE ACROSS NORTHERN CALIFORNIA WEDNESDAY AND SPIN INTO
A CLOSED UPPER LOW OVER THE DESERT SOUTHWEST WEDNESDAY NIGHT AND
THURSDAY. THE MEDIUM RANGE MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
THE TRACK AND TIMING OF THIS SYSTEM THROUGH THURSDAY AND CONFIDENCE
IS HIGH THAT COOL AND SHOWERY WEATHER WILL OCCUR AGAIN ACROSS THE
FORECAST AREA WEDNESDAY AFTERNOON THROUGH THURSDAY. THE SYSTEM WILL
HAVE LIMITED MOISTURE DUE TO THE INLAND TRACK AND PRECIPITATION
AMOUNTS DO NOT LOOK IMPRESSIVE. THE PROBABILITY OF ANY PARTICULAR
POINT SEEING MEASURABLE PRECIPITATION IS 30-40 PERCENT IN THE
VALLEYS/DESERTS AND 50-60 PERCENT IN THE MOUNTAINS. SNOW LEVELS WILL
GENERALLY BE AROUND 7000 FEET THOUGH MAY DIP TO AROUND 6000 FEET IN
THE SOUTHERN SIERRA WEDNESDAY NIGHT.

THE LOW CENTER IS FORECAST TO LIFT ACROSS THE FOUR CORNERS REGION
FRIDAY THOUGH SOME LINGERING MOISTURE AND INSTABILITY ON THE BACK
SIDE OF THE TROUGH MAY KEEP A CHANCE OF SHOWERS GOING OVER THE
MOUNTAINS AND ZONES NORTH AND EAST OF LAS VEGAS FRIDAY AND TO A
LESSER EXTENT SATURDAY. THE OPERATIONAL MEDIUM RANGE MODELS INDICATE
ANOTHER SHORTWAVE TROUGH WILL DROP OVER EASTERN WA/OR AND IDAHO
SATURDAY THEN SLIDE DOWN THE NEVADA/UTAH BORDER SATURDAY NIGHT AND
SUNDAY. THIS WOULD PRIMARILY LEAD TO GUSTY NORTH WINDS AND COOLER
TEMPERATURES SUNDAY AND ALSO THE POSSIBILITY OF SHOWERS OVER LINCOLN
AND MOHAVE COUNTIES. CONFIDENCE IN ANY DETAILS BUT WILL TREND TEMPS
AND WINDS TOWARD THIS SCENARIO.

&&

.AVIATION...FOR MCCARRAN...CLOUDS WILL RAPIDLY INCREASE PRIOR TO
SUNRISE WITH SHOWERS DEVELOPING IN THE VICINITY OF THE AIRFIELD
BETWEEN 12-15Z. A PERIOD OF LIGHT RAIN IS PROBABLE THROUGH THE
MORNING HOURS WITH CIGS IN THE 4-6K RANGE AND MOUNTAIN OBSCURATIONS
LIKELY. WINDS WILL CONTINUE TO FAVOR A SOUTH OR SOUTHWEST DIRECTION
GENERALLY IN THE 9-12 KNOT RANGE...THOUGH OCCASIONAL STRONGER PULSES
CAN BE EXPECTED ESPECIALLY PRIOR TO THE ARRIVAL OF SHOWER ACTIVITY.
PERIODIC GUSTS TO 25 KNOTS POSSIBLE DURING THOSE PERIODS. IMPROVING
CONDITIONS EXPECTED IN THE AFTERNOON WITH CIGS RISING CLOSER TO 10K
WHILE CLOUDS BECOME MORE SCATTERED BUT ISOLATED SHOWERS REMAIN
POSSIBLE. BREEZY SOUTHWEST WINDS WILL CONTINUE INTO THE AFTERNOON AS
WELL IN THE 12-18KT RANGE WITH GUSTS TO 25KTS.

FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS EXPECTED
TODAY MAINLY NORTH OF INTERSTATE 40. EXPECT REDUCED CIGS ESPECIALLY
IN THE MORNING HOURS AND MOUNTAIN OBSCURATIONS...WITH POCKETS OF
TURBULENCE. STRONG WINDS EXPECTED ALONG A BELT FROM THE WESTERN
MOJAVE DESERT EASTWARD TOWARDS THE COLORADO RIVER. SITES SUCH AS
KNXP AND KDAG CAN ANTICIPATE WESTERLY WIND GUSTS OVER 45KTS ALONG
WITH AREAS OF BLOWING AND SUSPENDED DUST.

&&

.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT
ANTICIPATED THIS WEEKEND. HOWEVER, SPOTTERS SHOULD REPORT ANY
SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES.
&&

UPDATE...GORELOW
SHORT TERM/AVIATION...OUTLER
LONG TERM...ADAIR

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

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