335  
FXUS65 KVEF 201650  
AFDVEF  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE LAS VEGAS NV  
850 AM PST WED FEB 20 2019  
   
SYNOPSIS
 
A POTENT LOW PRESSURE SYSTEM WILL DIVE DOWN FROM THE  
NORTH THROUGH THURSDAY, BRINING COLD AIR, GUSTY WINDS, SIGNIFICANT  
SNOWS FOR SOME, AND EVEN LOW ELEVATION SNOWS FOR OTHERS.  

 
   
UPDATE
 
MID AND HIGH CLOUDS ARE STREAMING IN ALREADY THIS MORNING  
AHEAD OF OUR INCOMING WINTER STORM SET TO IMPACT THE REGION TONIGHT  
AND TOMORROW. WEBCAMS INDICATE SNOW ALREADY HAS BEGUN FALLING NEAR  
ELY AND ACROSS WHITE PINE COUNTY, AND THIS ACTIVITY WILL SPREAD INTO  
LINCOLN COUNTY BY LATE THIS MORNING.  
 
OVERALL, THE FORECAST REMAINS ON TRACK, ALTHOUGH AFTER A COLD  
MORNING WITH CLOUDS STREAMING IN AFTER SUNRISE, CONCERNED THAT COLD  
AIR WILL BE TRAPPED IN SOME OF THE VALLEYS LIMITING THE HIGH  
TEMPERATURE BY A FEW DEGREES. AS SUCH, I'LL BE SHAVING A COUPLE  
DEGREES FROM THE TEMPERATURE FORECAST FOR THIS AFTERNOON. WILL BE  
SIFTING OVER 12Z MODEL GUIDANCE THIS MORNING, BUT THERE REMAINS A  
WIDE RANGE OF POSSIBILITIES FOR SNOW ACROSS THE LAS VEGAS VALLEY AND  
LOWER DESERTS OF THE MOJAVE. WILL LIKELY MAINTAIN A CONSERVATIVE  
APPROACH, BUT LOCALLY HEAVY VALUES WILL BE POSSIBLE WHERE MORE  
CONCENTRATED SNOW BANDS DEVELOP TONIGHT INTO THURSDAY MORNING.  
 
-OUTLER-  
 

 
   
SHORT TERM
 
THROUGH FRIDAY.  
 
WINTER STORM STILL REMAINS ON TRACK, WITH FEW, RELATIVELY MINOR  
ADJUSTMENTS. THE WEATHER MAKER CURRENTLY ON ITS WAY, DIGGING DOWN  
INTO NORTHERN CALIFORNIA/NEVADA. THE FRONT EDGE OF THE TROUGH WILL  
CONTINUE DIGGING SOUTH AND CLEAR SOUTHERN NEVADA BY THIS EVENING,  
WITH THE REST OF THE TROUGH FOLLOWING SUIT, LEADING TO A CLOSED  
LOW BY THURSDAY MORNING. THE LOW WILL SIT OVERHEAD ALL OF THURSDAY  
INTO FRIDAY BEFORE BEING KICKED OUT OF THE REGION ON FRIDAY.  
PRECIPITATION CHANCES STILL LOOK TO SPREAD FROM NORTH TO SOUTH  
LATER THIS AFTERNOON AND EVENING, WITH PEAK ACTIVITY FROM THURSDAY  
MORNING THROUGH THURSDAY AFTERNOON. THE BEST, HEAVIEST ACTIVITY  
STILL LOOKS TO IMPACT LINCOLN AND MOHAVE COUNTIES, WITH MORE  
SCATTERED SHOWERS OR SMALL SEGMENTS OF SHOWERS FOR THE REST OF THE  
REGION. THIS MAKES THE FORECAST DIFFICULT, AS RESOLVING THESE  
SMALLER FEATURES IS NEARLY IMPOSSIBLE, LET ALONE WHERE THEY WILL  
END UP.  
 
SNOW LEVELS STILL LOOK TO FALL TO 2500'-3000', LEADING TO MOST  
PLACES OUTSIDE OF THE COLORADO RIVER VALLEY AT LEAST SEEING SNOW  
FALL, IF NOT ACCUMULATE. LINCOLN AND MOHAVE COUNTIES AS WELL AS  
THE SPRING MOUNTAINS AND SHEEP RANGE ALL HAVE A SHOT AT SEEING A  
FOOT OR MORE ON THE HIGHER ELEVATIONS, WITH WIDESPREAD 4-8 INCHES  
EVEN AT THE LOWER ELEVATIONS IN THOSE LOCATIONS. JUST ABOUT EVERY  
REGIONAL HIGHWAY WILL BE IMPACTED IN SOME WAY. SNOW LEVELS REMAIN  
LOW ENOUGH FOR PRECIPITATION TO FALL IN THE MORONGO BASIN AS SNOW,  
WITH THE GFS CONTINUING TO INDICATE A BAND ROUGHLY NEAR/ALONG  
SR-62. THIS ADDED ENOUGH CONFIDENCE TO INCLUDE THEM IN THE WINTER  
WEATHER ADVISORY, AS THE AREA IS LIKELY TO HAVE THE OPPORTUNITY TO  
PICK UP A QUICK COUPLE INCHES DURING THIS EVENT.  
 
THE OPERATIONAL GFS HAS BEEN THE LOWEST MEMBER IN ITS OWN  
ENSEMBLE QPF, ESPECIALLY FOR LAS VEGAS. THE PAST NUMBER OF 00Z  
RUNS DISPLAY THIS TREND, WITH THE ENSEMBLE MEAN ABOUT DOUBLE THE  
OPERATIONAL VALUE. GIVEN THE LAST EVENT EXCEEDED THE OPERATIONAL  
RUN, SUSPECT OUR QPF GRIDS MIGHT BE A BIT UNDERDONE AGAIN, BUT  
THIS LIKELY GOES BACK TO THE CONVECTIVE MODE OF THE PRECIPITATION  
AND DIFFICULTY WITH PINPOINT WHERE SHOWERS AND BANDS MAY SET UP.  
THE CONVECTION WITH THIS SYSTEM LOOKS TO BE STRONGER THAN THAT OF  
THE PREVIOUS SYSTEM, WITH THE COLDER AIR AND ADDITIONAL MOISTURE  
LEADING TO MORE INSTABILITY, COMPARATIVELY. THE STRONGER  
CONVECTION MAY HAVE THE ADDED BENEFIT OF KEEPING SNOW LEVELS FROM  
RISING MUCH DURING THE DAY ON THURSDAY.  
 
BY FRIDAY, THE SYSTEM EXITS THE REGION TO THE EAST, WITH RISING  
HEIGHTS AND TEMPS IN ITS WAKE FOR THE WEEKEND.  
   
LONG TERM
 
SATURDAY THROUGH TUESDAY.  
 
THE MEDIUM RANGE MODELS INDICATE THE WEATHER PATTERN REMAINS  
PROGRESSIVE THROUGH THE WEEKEND AND EARLY NEXT WEEK WITH AT LEAST AN  
ADDITIONAL COLD TROUGH DROPPING OVER THE GREAT BASIN AND BRUSHING  
SOUTHERN NEVADA AND NORTHWEST ARIZONA. IMPACTS DO NOT LOOK TO BE  
SIGNIFICANT WITH MAINLY GUSTY NORTHWEST WINDS AND SOME SCATTERED  
SNOW SHOWERS OVER THE SOUTHERN GREAT BASIN ZONES. HIGH TEMPERATURES  
SHOULD MANAGE TO CLIMB BACK INTO THE 50S IN LAS VEGAS BUT WILL  
STILL BE 5-8 DEGREES BELOW NORMAL EARLY NEXT WEEK.  

 
   
AVIATION...FOR MCCARRAN
 
AFTER A QUIET MORNING, CEILINGS AROUND  
8000 FEET WILL ARRIVE ABOUT NOON, ALONG WITH SOUTH WINDS GUSTING TO  
20 KNOTS. CLOUDS WILL LOWER FURTHER BY LATE AFTERNOON, WITH CHANCES  
FOR RAIN AND SNOW BEGINNING AROUND SUNSET. LOWER CEILINGS AND  
CHANCES FOR PRECIPITATION WILL PERSIST THROUGH THURSDAY NIGHT BEFORE  
NORTHWEST WINDS BRING IN DRIER AIR FRIDAY.  
 
FOR THE REST OF SOUTHERN NEVADA, NORTHWEST ARIZONA AND SOUTHEAST  
CALIFORNIA...A COLD STORM SYSTEM WILL BRING CHANCES FOR SNOW, WITH  
RAIN LIMITED TO THE LOWEST ELEVATIONS, BEGINNING IN THE SIERRA AND  
SOUTHERN GREAT BASIN THIS MORNING AND SPREADING ACROSS THE MOJAVE  
DESERT THIS AFTERNOON AND TONIGHT. WIDESPREAD LOW CEILINGS AND  
TERRAIN OBSCURATION CAN BE EXPECTED, WITH POOR CONDITIONS PERSISTING  
THROUGH THURSDAY NIGHT. STRONG WESTERLY WINDS WILL ALSO BE A CONCERN  
TODAY IN THE BARSTOW AND MORONGO BASIN AREAS.  

 
 
   
SPOTTER INFORMATION STATEMENT
 
ANOTHER COLD WINTER STORM WILL  
IMPACT THE REGION THROUGH THURSDAY. SPOTTERS ARE ENCOURAGED TO  
REPORT SNOW AMOUNTS AND IMPACTS TO ROADS ACCORDING TO STANDARD  
OPERATING PROCEDURES.  

 
 

 
 
SHORT TERM...STEELE  
AVIATION.....MORGAN  
LONG TERM....ADAIR  
 
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:  
 
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab NV Page
The Nexlab AZ Page
The Nexlab CA Page Main Text Page