Winter Weather in California, March 29 to 31, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
327 AM PDT SAT MAR 29 2014

.SYNOPSIS...
A LATE SEASON WINTER STORM WILL BRING HEAVY SNOW IN THE SIERRA AND
RAIN FOR LOWER ELEVATIONS THROUGH TONIGHT. A COLDER STORM SYSTEM WILL
IMPACT THE REGION NEXT MONDAY AND TUESDAY WITH LIGHT SNOW POSSIBLE
IN LOWER ELEVATIONS. BELOW NORMAL TEMPERATURES ARE EXPECTED
THROUGH MUCH OF THE UPCOMING WEEK, WITH LIGHT RAIN AND SNOW
SHOWERS POSSIBLE AGAIN LATE NEXT WEEK.

&&

.SHORT TERM...
PRECIPITATION CONTINUES ITS SLOW PROGRESSION ACROSS NORTHERN
CALIFORNIA MAINLY NORTH OF I-80. AREA WEBCAMS SHOWING SNOW BEGINNING
TO MIX WITH RAIN AT BOGARD IN WESTERN LASSEN COUNTY WITH SURFACE
TEMPERATURES A FEW DEGREES ABOVE FREEZING. THIS PRECIP WILL CONTINUE
TO WORK ITS WAY SOUTH ACROSS THE SIERRA TODAY WITH PERIODS OF
HEAVY SNOWFALL EXPECTED THIS AFTERNOON ACROSS THE SIERRA IN THE
TAHOE BASIN AND THIS EVENING IN MONO COUNTY.

GUSTY WINDS HAVE DEVELOPED AHEAD OF THE PRECIPITATION WITH SOME OF THE
WIND PRONE AREAS ALREADY GUSTING INTO THE 60-70 MPH RANGE. OUTSIDE
OF THE WIND PRONE REGIONS WIND GUSTS HAVE BEEN GENERALLY IN THE
20-30 MPH RANGE. 700MB FLOW WILL PEAK THIS MORNING WITH THE
SURFACE GRADIENT INCREASING AS THE SURFACE LOW DEEPENS. AS SUCH,
WILL ISSUE A WIND ADVISORY COVERING AREAS IN THE LEE OF THE SIERRA
WHICH WILL INCLUDE THE RENO/CARSON/GARDNERVILLE REGION ALONG WITH
MONO COUNTY. WIND GUSTS OF 50 MPH ARE POSSIBLE ACROSS VALLEY AREAS
WITH WIND PRONE AREAS CONTINUING IN THE 60-70 MPH RANGE. HAZARDOUS
BOATING CONDITIONS ARE ALSO EXPECTED ACROSS AREAS LAKES. WINDS
WILL DIMINISH THIS AFTERNOON WITH THE ARRIVAL OF THE PRECIPITATION
AND FRONT.

HEAVY SNOWFALL WILL IMPACT AREAS ABOVE 7000 FEET THIS MORNING BEFORE
SNOW LEVELS STEADILY DROP THROUGH THE DAY AS COLDER AIR ALOFT
FILTERS INTO THE REGION. THIS SYSTEM WILL FEATURE DYNAMIC SUPPORT
VIA A COUPLED JET AND FRONTOGENETICAL FORCING WHICH WILL PROVIDE
PERIODS OF HEAVY SNOWFALL ABOVE 7000 FEET ALLOWING FOR SNOWFALL
RATES HEAVY ENOUGH TO ACCUMULATE ON ROADWAYS RESULTING IN TRAVEL
IMPACTS ACROSS PASSES. SNOW LEVELS LOOK TO FALL TO LAKE LEVEL
DURING THE AFTERNOON SOMEWHERE BETWEEN 3-6PM. PERIODS OF
CHANGEOVER TO SNOW ARE POSSIBLE EARLIER WITHIN HEAVIER BANDS OF
PRECIP. ALL TOLD SNOWFALL TOTALS THROUGH SUNDAY MORNING COULD SEE
UPWARDS OF 2 FEET ACROSS THE CREST WITH GENERALLY ABOUT 6-12"
POSSIBLE BELOW 7000 FEET, HIGHEST ALONG THE WESTERN SIDE OF THE
BASIN. SPILLOVER IS LIKELY INTO WESTERN NEVADA LATE SATURDAY
AFTERNOON INTO EARLY EVENING WITH THE PRESENCE OF DYNAMIC FORCING.
A QUARTER TO A THIRD OF AN INCH OF RAINFALL IS POSSIBLE WITH THE
FRONT WITH SNOWFALL POSSIBLE IN THE FOOTHILLS AS SNOW LEVELS
QUICKLY FALL TO NEAR 5000 FEET WITH THE FRONT. TIMING ACROSS MONO
COUNTY FOR THE HEAVIEST PRECIPITATION STILL LOOKS TO BE THIS
EVENING AND TONIGHT AS THE COUPLED JET SYSTEM TRACKS SOUTH.
SNOWFALL ACCUMULATIONS OF 1.5-2 FEET STILL POSSIBLE ACROSS THE
CREST IN MONO COUNTY WITH HIGHER AMOUNTS ACROSS THE NORTHERN HALF
OF THE COUNTY.

SHOWERS TAPER OFF SUNDAY MORNING WITH A BREAK BETWEEN SYSTEMS
THROUGH EARLY MONDAY AS A COLDER SYSTEM IS POISED TO PROVIDE
ANOTHER ROUND OF SNOWFALL TO THE SIERRA WITH SNOW LEVELS LOW
ENOUGH TO EVEN PROVIDE SNOW TO THE VALLEY AREAS ACROSS WESTERN
NEVADA BY MONDAY NIGHT. THOUGH THE BEST JET DYNAMICS LOOK TO
REMAIN SOUTH OF THE REGION, THE COLDER AIRMASS SHOULD PROVIDE FOR
HIGHER RATIO SNOWFALLS WITH AN ADDITIONAL FOOT OF SNOWFALL
POSSIBLE ACROSS THE SIERRA AND LIGHT ACCUMULATIONS POSSIBLE DOWN
AT THE VALLEY FLOORS IN WESTERN NEVADA. FUENTES

.LONG TERM...TUESDAY THROUGH FRIDAY...
MADE FEW CHANGES TO THE LONG TERM FORECAST, BUT UNCERTAINTY IS A BIT
HIGHER THIS MORNING THAN 24 HOURS AGO. MODELS ARE STRUGGLING A BIT
MORE WITH THE SPLITTING OF THE UPPER LOW TUESDAY AS IT COMES IN AS
WELL AS THE NEXT SYSTEM FOR LATE IN THE WEEK.

THE UPPER LOW IS NOW FORECAST BY THE MODELS TO DROP WEST OF THE AREA
WITH MORE OF A SPLIT ON TUESDAY. DESPITE THIS OCCURRING, THERE WILL
STILL BE PLENTY OF COLD AIR ALOFT FOR SOME SHOWERS TUESDAY ALL
ACROSS THE SIERRA AND WESTERN NEVADA. THERE COULD ALSO BE A
THUNDERSTORM OR TWO, BUT WILL LEAVE THAT OUT FOR NOW AS IT STILL
LOOKS MARGINAL.

SLOW DRYING TUESDAY NIGHT AS THE LOW PULLS AWAY. WEDNESDAY LOOKS
MOSTLY DRY RIGHT NOW, BUT THE EC AND A COUPLE GFS ENSEMBLE MEMBERS
SHOW ENOUGH COLD AIR AND MOISTURE ALOFT REMAIN FOR A COUPLE SHOWERS.
WILL HAVE TO KEEP AN EYE ON THAT. FOR THE NEXT SYSTEM LATE IN THE
WEEK, THE MODELS SHOW WIDELY VARYING SOLUTIONS. THE EC BRINGS IN
ANOTHER UPPER LOW SLOWLY WHILE THE GFS KEEPS AN OPEN WAVE WITH THE
JET STREAM REMAINING NORTH INTO OREGON. HAVE NOT CHANGED ANYTHING
YET AS IT STILL LOOKS TO BE SOMEWHAT WET AND SLIGHT CHC TO CHC POPS
LOOK GOOD FOR NOW.

WITH THE UPPER LOW AND SYSTEMS MOVING THROUGH, EXPECT TEMPS TO
REMAIN A BIT BELOW AVERAGE FOR THE WEEK WITH TUESDAY BEING THE
COLDEST DAY. OVERNIGHT LOWS WILL BE CLOSER TO NORMAL DUE TO THE
MOISTURE AND CLOUD COVER. WALLMANN

.AVIATION...
BAND OF MODERATE/HEAVY RAIN AND SNOW IS NOW MOVING INTO THE SIERRA
NORTH OF LAKE TAHOE. THIS BAND WILL SLOWLY SHIFT SOUTH DURING THE
DAY AND PUSH THROUGH MONO COUNTY BY THIS TIME TOMORROW.

FOR THE SIERRA TERMINALS: EXPECT MOSTLY RAIN THROUGH MID-AFTERNOON
WITH SNOW LEVELS NEAR 7000 FEET AT KTRK/KTVL. CIGS/VIS TO REMAIN
MVFR TO OCNL IFR THRU 22Z AND THERE COULD BE SOME ICING ISSUES
ALOFT. TRANSITION TO SNOW BETWEEN 22-00Z WITH 70% CONFIDENCE WITH
HEAVY SNOW THEREAFTER THROUGH 06Z BLO KTRK/KTVL MINIMUMS. RUNWAY
ACCUM AROUND 6 INCHES. IMPROVING CONDS THEREAFTER.

FOR KMMH, SOME GUSTY WINDS TO 40 KTS THROUGH 22Z WITH SIGNIFICANT
TURBULENCE BEFORE -RA BEGINS AFTER 00Z. CHANGES TO SNOW 03-06Z WITH
IFR CONDS AND 2-4 INCHES RUNWAY ACCUMULATION WITH CONFIDENCE 60-70%.

KRNO/KCXP: GUSTY WINDS TO 35 KTS THIS MORNING WITH MTN WAVE
TURBULENCE AND LIMITED LLWS THROUGH 18Z. AS BAND SHIFTS SOUTH, MORE
FAVORABLE FOR SPILLOVER SO EXPECT WINDS TO DIMINISH TO LESS THAN 20
KTS. WITH MVFR CIGS/VIS IN RA 20-03Z AND 70% CONFIDENCE. -RA WILL
CHANGE TO -SN AS IT ENDS AROUND 03Z, BUT NO RUNWAY ACCUMULATION.
EXPECT VFR CONDS THEREAFTER WITH AN OCCASIONAL STRAY -SHSN
OVERNIGHT. WALLMANN

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY NVZ002.

     WIND ADVISORY UNTIL 11 AM PDT THIS MORNING NVZ003.

     LAKE WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR PYRAMID
     LAKE IN NVZ004.

CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT SUNDAY ABOVE 5500 FEET
     FOR CAZ071.

     WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON CAZ073.

     WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM PDT SUNDAY
     CAZ073.

     WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ072.

&&

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)