Heavy Snow in Nevada, November 9 to 10, 2015

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
241 PM PST MON NOV 9 2015

.SYNOPSIS...
A COLD WINTER STORM WILL BRING SNOW SHOWERS THROUGH TUESDAY
MORNING. SNOW SHOWERS WILL CREATE SOME SLICK ROADS IN THE SIERRA
THIS EVENING WITH WIDESPREAD SLICK ROAD CONDITIONS EXPECTED INTO
LOWER WESTERN NEVADA VALLEYS TONIGHT AND TUESDAY MORNING. DRY AND
COLD CONDITIONS WEDNESDAY WILL BE FOLLOWED BY A SLOW WARMING TREND
THE REMAINDER OF THE WEEK.

&&

.SHORT TERM...

WINTER STORM IS STILL ON TRACK TO BRING SNOW TO THE SIERRA AND DOWN
INTO WESTERN NEVADA VALLEYS THIS EVENING THROUGH TUESDAY MORNING.
THE SECOND WAVE OF THE STORM IS CURRENTLY MOVING INTO THE SIERRA
WITH A CONSIDERABLE AMOUNT OF LIGHTNING STRIKES AS THE BAND MOVED
THROUGH CENTRAL CALIFORNIA INDICATING THE CONVECTIVE NATURE OF THE
STORM.

MAIN CHANGES TODAY WERE TO ADD SNOW ADVISORIES TO MINERAL AND
SOUTHERN LYON COUNTIES. WHILE CONFIDENCE IS ONLY MODERATE IN
WHERE THE DEFORMATION BAND WILL SET UP, A FEW INCHES OF
ACCUMULATING SNOW CAN'T BE RULED OUT AS FAR EAST AS HAWTHORNE.
ADVISORIES FOR SOUTHERN LYON, MINERAL, AND MONO COUNTIES ARE IN
EFFECT FROM 6PM TONIGHT THROUGH 10 AM TUESDAY WITH THE HEAVIEST
PRECIPITATION EXPECTED BETWEEN 9PM AND 6 AM.

SNOW ADVISORIES GO INTO EFFECT IN THE TAHOE BASIN AND GREATER
RENO-CARSON CITY AREAS AT 4 PM. THE HEAVIEST PRECIPITATION IN
THESE AREAS IS EXPECTED TO BE BETWEEN 7 PM AND 4 AM. PRECIPITATION
IS CURRENTLY IMPACTING THE SIERRA CREST ALTHOUGH THE ROADS ARE
STILL WET OVER DONNER SUMMIT. EXPECT THIS TO CHANGE TO SNOW
COVERED ROADS SOON AS SNOW LEVEL RADAR ON THE WEST SLOPES RUNNING
AROUND 4000 FEET.

IT'S POSSIBLE THAT AS THE INITIAL STRONG BAND OF PRECIPITATION MOVES
OVER THE SIERRA THAT IT WILL SPILL HEAVIER SNOW OVER THE CREST
AND INTO THE RENO/CARSON CITY AREA AROUND THE EVENING COMMUTE
TONIGHT. ROAD TEMPERATURES ARE EXPECTED TO BE JUST WARM ENOUGH TO
HOLD OFF ROADWAY SNOW ACCUMULATIONS UNTIL AFTER DARK, UNLESS THE
PRECIPITATION BECOMES VERY HEAVY. EITHER WAY ROADS COULD BE SLICK
IN THE RENO/CARSON CITY AREAS THIS EVENING SO SLOW DOWN AND LEAVE
EXTRA TIME TO REACH YOUR DESTINATION.

AS THE COLD CORE OF THE LOW MOVES DIRECTLY OVER THE REGION TONIGHT A
DEFORMATION BAND IS EXPECTED TO FORM IN THE SIERRA AND WESTERN
NEVADA NORTH OF INTERSTATE 80 AND MOVE SOUTH THROUGH MONO COUNTY.
EXACT LOCATION OF DEFORMATION BANDS ARE NOTORIOUSLY DIFFICULT TO
PINPOINT, HOWEVER CONFIDENCE IS HIGH THAT ONE WILL FORM. WHAT THAT
MEANS IS THAT SNOW TOTALS WILL VARY SIGNIFICANTLY FROM ONE AREA TO
ANOTHER AT THE SAME ELEVATION. CONFIDENCE IS STILL RELATIVELY HIGH
THAT RENO AND/OR CARSON CITY WILL SEE ACCUMULATING SNOW TONIGHT,
BUT WHICH AREA WILL RECEIVE THE MOST IS STILL SOMEWHAT LOW
CONFIDENCE AT THIS TIME. TOLBY

WEDNESDAY-THURSDAY SHOULD BE DRY EXCEPT FOR A SLIGHT CHANCE FOR
SHOWERS NEAR THE OREGON BORDER. A FLAT RIDGE THURSDAY-FRIDAY
SHOULD LEAD TO SLIGHT WARMING AT RIDGE LEVEL AND OVERNIGHT
TEMPERATURE INVERSIONS, ESPECIALLY FOR ANY VALLEYS WITH SNOW ON
THE GROUND. AS SUCH, WE EXPECT WORSENING AIR QUALITY IN THE CARSON
AND TRUCKEE RIVER VALLEYS EACH DAY WEDNESDAY THROUGH AT LEAST
FRIDAY. JCM

.LONG TERM...SATURDAY THROUGH MONDAY...

WEAK RIDGING BEGINS TO BREAK DOWN LATE NEXT WEEK AS FLOW BECOMES
INCREASINGLY AMPLIFIED AHEAD OF AN APPROACHING LOW. MID-RANGE MODELS
HAVE BEEN FAIRLY CONSISTENT SHOWING THIS FEATURE APPROACHING, BUT
HAVE BEGUN TO TREND SLOWER WITH THE SYSTEM'S MOVEMENT INTO THE
SIERRA. PAST RUNS WERE SHOWING AN EARLY SUNDAY APPROACH INTO
CALIFORNIA. CURRENTLY, MODEL DEPICTIONS ARE ABOUT 12 HOURS LATER
WITH MORE IMPACTS OF THE SYSTEM SUNDAY NIGHT INTO MONDAY. EXPECT
THE TIMING OF THIS SYSTEM TO FLUCTUATE OVER THE NEXT COUPLE OF
DAYS AS MODELS HONE IN ON THE DETAILS.

NO MAJOR ADJUSTMENTS WERE MADE TO THE PARTICULARS OF THE FORECAST.
HOLDING WITH SLIGHT CHANCES OF SHOWERS BEGINNING SUNDAY AND CARRYING
INTO MONDAY; HIGHER CHANCES FOR THE SIERRA NORTHWARD THROUGH LASSEN
COUNTY. PRECIPITATION CHANCES WILL INCREASE ONCE THE TIMING BECOMES
CLEARER. SNOW LEVELS WILL START WARMER THAN RECENT STORMS, BUT
SHOULD FALL BELOW 6000 FEET THROUGH THE EVENT.

TEMPERATURES HOLD IN THE MID 50S FOR WESTERN NEVADA AND WILL COOL
WHEN THE SYSTEM MOVES INLAND EARLY NEXT WEEK. SIMILARLY, HIGHS IN
SIERRA VALLEYS WILL BE IN THE MID/LOW 40S BEFORE COOLING. OVERNIGHT
LOWS REMAIN BRISK, GENERALLY IN THE LOW/MID 30S FOR WESTERN NEVADA
AND LOW/MID 20S IN THE SIERRA. CLOUD COVER MAY TEMPER OVERNIGHT
LOWS, BUT MODELS ARE UNCERTAIN ON MOISTURE THIS FAR OUT. BOYD

&&

.AVIATION...

SHOWERS ARE BEGINNING TO FILL IN ACROSS THE SIERRA AND WESTERN
NEVADA EARLY THIS AFTERNOON. EXPECT COVERAGE TO INCREASE INTO THIS
EVENING. BANDS OF SNOW SHOWERS WILL INCREASE IN INTENSITY EARLY THIS
EVENING AND CONTINUE OVERNIGHT WITH HIGHEST CONFIDENCE FROM THE
TAHOE BASIN AND EASTERN SIERRA OF ALPINE AND MONO COUNTIES EASTWARD
TO THE SIERRA FRONT AROUND KCXP/KMEV. THIS SNOW WILL RESULT IN THE
MOST SIGNIFICANT AVIATION IMPACTS FOR THIS STORM AS THE AIR MASS
WILL BE COLD ENOUGH FOR SNOW ACCUMULATIONS AFTER 02Z FOR
KRNO/KCXP/KMEV WITH SIERRA TERMINALS STARTING TO ACCUMULATE 23-00Z.
KMMH WILL ALSO BE RIPE FOR ACCUMULATIONS ONCE PRECIPITATION RAMPS
UP. LATEST PROJECTIONS FOR SNOW ACCUMULATIONS RANGE BETWEEN 4 AND 8
INCHES AT SIERRA TERMINALS, 2 TO 4 INCHES AT KRNO/KCXP (POSSIBLY
3 TO 6 INCHES FOR KCXP/KMEV), AND 4 TO 7 INCHES AT KMMH.

FREQUENT PERIODS OF IFR OR WORSE CIGS/VSBY WILL ACCOMPANY SNOWFALL.
THE SNOWFALL WILL TAPER BETWEEN 13Z-16Z TUE AS THE UPPER LOW SHIFTS
EAST. HOHMANN/BOYD

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 8 AM PST TUESDAY NVZ002.

     WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 10 AM PST
     TUESDAY NVZ001.

     WINTER WEATHER ADVISORY UNTIL 8 AM PST TUESDAY NVZ003.

CA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 10 AM PST
     TUESDAY CAZ073.

     WINTER WEATHER ADVISORY UNTIL 8 AM PST TUESDAY CAZ072.

&&

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