CA/NV Snow Storms January 25-27, 2008 Discussion & Analysis

[srainhoutx]

The Northern Sierras/Lake Tahoe Area in for a Huge Storm. Ski areas of Heavenly, Kirkwood, Sierra at Lake Tohoe, Mt Rose are in for a big dump...

FXUS65 KREV 031822 AAA AFDREV AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE RENO NV 1022 AM PST THU JAN 3 2008 .MESOSCALE UPDATE... WE WILL BE UPDATING TO START THE HIGH WIND WARNINGS NOW BASED ON OBSERVATIONS. WINDS GUSTING TO NEAR 40-50 MPH ALREADY NEAR LAKE TAHOE DOWN INTO WIND PRONE AREAS OF WESTERN NEVADA...WITH GUSTS OVER 100 MPH ON THE SIERRA RIDGES. WEBCAMS AROUND LAKE TAHOE SHOW SIGNIFICANT WAVES...ALMOST LOOKS LIKE AN OCEAN SCENE. ALSO SEEING SPOTS OF BLOWING DUST ON THE SOUTH SIDE OF RENO. LATEST GFS IS HINTING A STRENGTHENING INVERSION ~700MB BY 0Z THIS AFTERNOON PLUS DYNAMIC ENHANCEMENT FROM PRECIP ALONG WEST SLOPES OF SIERRA...BOTH OF WHICH COULD INCREASE THREAT FOR DOWNSLOPE WIND EVENT IN LEE OF SIERRA. UPDATED PRODUCTS OUT SHORTLY. CS && .

PREVIOUS DISCUSSION... /ISSUED 330 AM PST THU JAN 3 2008/

SHORT TERM... STRONG PACIFIC STORM IS STILL ON TRACK TO PUSH INTO THE WEST COAST TONIGHT AND FRIDAY AND SPREAD WIND AND HEAVY PRECIPITATION ACROSS THE REGION. SYSTEM AND ASSOCIATED 200KT JET WERE PASSING SOUTH OF THE ALEUTIANS THIS MORNING AND WILL HELP INTENSIFY GULF OF ALASKA LOW AS IT WORKS SOUTHEASTWARD TOWARD THE WEST COAST. BOTH THE GFS AND ECMWF SHOW COLD UPPER LOW DROPPING TO SLIGHTLY ABOVE 500DAM WITH PLENTY OF COLD AIR EXPECTED TO GRADUALLY WORK INTO THE SIERRA AND NORTHERN AREAS FRIDAY AND THEN ACCELERATE INTO THE LOWER ELEVATIONS OF THE EASTERN SIERRA AND WESTERN NEVADA FRIDAY NIGHT. STRONG WINDS AND HEAVY SNOW WILL MAKE FOR A VERY DANGEROUS SITUATION IN THE SIERRA AND MOUNTAINS OF NORTHEAST CALIFORNIA. SEE BLIZZARD WARNINGS FOR DETAIL. SHORTWAVES PRECEDING MAIN JET WILL ACT AS PRIMERS AS THEY PUSH INTO THE PACNW/NORTHERN CALIFORNIA AND BRING INCREASING MOISTURE TODAY AND A ROUND OF SHOWERS TO THE SIERRA TONIGHT. MOST OF THE SHOWERS WILL OCCUR AFTER MIDNIGHT TONIGHT WITH SEVERAL INCHES OF SNOW MAINLY ABOVE LAKE LEVEL. SNOW MAY BRIEFLY FALL DOWN TO LAKE LEVEL ALTHOUGH MIXING OVERNIGHT INTO TODAY SHOULD PRECLUDE VALLEY INVERSIONS TONIGHT ESPECIALLY GIVEN THE INCREASING SURFACE GRADIENTS AND THICK CLOUD COVER. AS THE MAIN STORM APPROACHES LATE TONIGHT...THE SURFACE GRADIENT AND RIDGE LEVEL WINDS INCREASE DRAMATICALLY WITH 55MB OF PRESSURE DIFFERENCE BETWEEN SURFACE LOW OFF THE PACNW COAST AND SOUTHERN NEVADA. A LOCAL HIGH RESOLUTION CROSS SECTION OF THE GFS (8KM WRF) SHOWS INTENSE MOUNTAIN WAVE OVER THE SIERRA NEVADA MIDDAY FRIDAY WITH 70-80KT BREAKING DOWN THE LEE SIDE FOR SEVERAL HOURS. HIGH WINDS WILL BE THE BIG PROBLEM FRIDAY AS WIDESPREAD GUSTS TO 50KT ARE LIKELY JUST DUE TO THE SURFACE GRADIENT ALONE. THEN THERE IS THE POTENTIAL DAMAGING WINDS EXCEEDING 70KT TO THE IMMEDIATE LEE OF THE SIERRA WHERE MOUNTAIN WAVES ARE ABLE TO BREAK TO THE SURFACE. THESE STRONG WINDS WILL ALSO BE A PROBLEM IN THE HIGH ELEVATIONS WHERE HEAVY PRECIPITATION WILL BE ONGOING FRIDAY. THE WIND AND SNOW WILL CREATE BLIZZARD CONDITIONS ABOVE 7000 FEET FOR THE FIRST HALF OF THE DAY. AS SNOW LEVELS LOWER...THESE BLIZZARD CONDITIONS WILL LOWER TO MANY OF THE LOWER ELEVATIONS OF THE SIERRA AND NORTHEAST CALIFORNIA. SNOW LEVELS WILL BE TRICKY FOR LOWER ELEVATIONS AS THE COLD FRONT WILL LIKELY BE SHARP AND WELL DEFINED. MUCH OF THE PRECIPITATION IN WESTERN NEVADA WILL OCCUR ALONG THIS FRONTAL ZONE LATE FRIDAY INTO EARLY SATURDAY MORNING. PRECIPITATION DROPS OFF QUICKLY AS SNOW LEVELS APPROACH THE VALLEY FLOORS. MUCH OF THE PRECIPITATION ON VALLEY FLOORS WILL FALL AS RAIN WITH PERHAPS A COUPLE OF INCHES ACCUMULATION AS THE SNOW ENDS. VERY DEEP MOIST AND UNSTABLE WEST FLOW HOWEVER WILL KEEP SNOW GOING LONGER IN THE FOOTHILLS JUST EAST OF THE SIERRA. THESE AREAS ABOVE 5000 FEET MAY SEE AS MUCH AS 8 INCHES BASED ON CURRENT PROJECTIONS. A WATCH WILL BE MAINTAINED UNTIL LATER TODAY WHEN FORECASTERS CAN ASSESS ONE MORE SET OF DATA WITH REGARD TO SNOW LEVELS/SNOW AMOUNTS AND THEIR IMPACT AT LOWER ELEVATIONS FRIDAY NIGHT. MODEL QPF CONTINUES TO TRANSLATE INTO 3 TO 5 FEET AT AND JUST WEST OF THE SIERRA CREST WITH THE MAIN SYSTEM FRIDAY THROUGH EARLY SATURDAY. SO LITTLE CHANGE WAS MADE TO SNOWFALL PROJECTIONS. THE GFS CONTINUES TO SHOW TWO MORE DISTINCT WAVES SATURDAY NIGHT AND SUNDAY NIGHT WHICH MAY BRING ANOTHER 1 TO 2 FEET OF SNOW TO THE HIGH SIERRA AND SEVERAL INCHES TO LOWER VALLEY FLOORS. THESE BANDS OF SNOW ARE GOING TO BE MORE MESOSCALE IN NATURE BEYOND THE OROGRAPHICS OF THE SIERRA AND THUS VERY DIFFICULT TO PINPOINT OVER WESTERN NEVADA. THE DETERMINISTIC RUNS OF THE GFS (BOTH 00Z/06Z) SPREAD A BAND OF MODERATE SNOW FROM NORTHWEST NEVADA SOUTHWARD TO BETWEEN I-80 AND HIGHWAY 50 SATURDAY NIGHT/SUNDAY MORNING AND AGAIN SUNDAY NIGHT. THESE SYSTEMS COULD ACTUALLY BE MORE PROBLEMATIC FOR THE VALLEYS AS TEMPERATURES WILL BE VERY COLD AND ROAD SURFACES WILL BE MORE PRONE TO FREEZING. MORE ON THIS LATER. LONG TERM...SUNDAY THROUGH WEDNESDAY... ACTIVE PATTERN WILL CONTINUE IN THE EXTENDED. ON SUNDAY THE BROAD UPPER TROUGH THAT SHOULD BE SITUATED OVER THE WRN CONUS IS PROGGED TO TAKE ON A SLIGHT NEGATIVE TILT AS A VORT MAX DIGS SOUTHEAST TOWARD NRN CALIFORNIA. THE JET MAX ASSOCIATED WITH THIS VORT MAX SHOULD BE ENOUGH TO PULL THE UPPER TROUGH TO THE EAST ON MONDAY. THE STRONG PROGRESSIVE FLOW SHOULD PULL THE TROUGH TO THE ROCKIES BY 00Z TUESDAY. IN ITS WAKE RIDGING WILL BUILD INTO THE WEST COAST. BY MONDAY NIGHT THE NEXT IN A SERIES OF SHORTWAVES SHOULD MOVE INTO THE PACIFIC NW BUT THE MAIN DYNAMICS WILL STAY NORTH OF THE WRN GREAT BASIN. AS A RESULT HAVE KEPT PRECIP ONLY IN THE WRN ZONES FOR MONDAY NIGHT. BY TUESDAY THE WEST COAST RIDGE SHOULD FLATTEN AS THE PACIFIC NW SYSTEM MOVES EAST. ALTHOUGH NOT AS DEEP AS THE PREVIOUS UPPER LOW...THIS LATEST SYSTEM WILL PULL A COLD FRONT ONTO THE OREGON AND NRN CALIFORNIA COAST BY 18Z TUESDAY. THE UPPER FLOW SHOULD REMAIN WLY SINCE THE E PACIFIC RIDGE IS NOT PROGGED TO WEAKEN VERY MUCH. WITH THE FLOW MORE PERPENDICULAR TO THE SIERRA WE SHOULD SEE MAINLY OROGRAPHIC PRECIP ON WEDNESDAY. HAVE KEPT THE GREATEST CHANCE OF PRECIP ALONG THE SIERRA WITH A SLIGHT CHC OF PRECIP IN WRN NEVADA. O`HARA

http://www.wrh.noaa.gov/rev/prodreq.php ... d&pvnum=11

[CrazyC83]

Not just that, but wind gusts equivalent to that of a Category 4 hurricane at the summits...

[Stratosphere747]

Wind wise that is nothing new for the Tahoe area, especially the peaks. Now the possible snowfall projections are an eye catcher. One thing to keep in mind is that this is a series of events and not just one storm. If all three or so fall in line, than historic type levels may be seen. Will be fun to see how it plays out up that way. One of our favorite vacation spots!

I've been out there for a few biggies. Nothing like sitting in a jacuzzi about 20ft away from your room and being stuck for a spell during a whiteout.

[srainhoutx]

Just talked to friends in from Magalia, CA. Flying out to do a little skiing next weekend. Should be Awesome.

[Stratosphere747]

Could be a good one - NWS Reno

TOTAL SNOW ACCUMULATIONS THROUGH SATURDAY MORNING WILL BE 3 TO
5 FEET ABOVE 7000 FEET WITH HIGHER AMOUNTS ALONG THE SIERRA
CREST...AND 1 TO 3 FEET BELOW 7000 FEET...INCLUDING THE LAKE
TAHOE BASIN. LARGE AND DEEP SNOW DRIFTS WILL OCCUR DUE TO STRONG
WINDS PRODUCING BLOWING AND DRIFTING SNOW.

STRONG WINDS WILL CONTINUE THROUGH FRIDAY NIGHT...WITH THE MOST
DANGEROUS WINDS FROM EARLY FRIDAY MORNING THROUGH FRIDAY EVENING.
WIND GUSTS UP TO 70 MPH WILL BE COMMON WITH GUSTS NEAR 145 MPH
OVER THE SIERRA RIDGES.

[CrazyC83]

The west coast is going to be isolated from the rest of North America for a few days...pretty much all the mountain passes are going to be closed...

[RL3AO]

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RENO NV
410 AM PST FRI JAN 4 2008

DO NOT ATTEMPT TO TRAVEL ACROSS THE SIERRA PASSES. ATTEMPTING TO
TRAVEL IN THE SIERRA WILL PUT YOUR LIFE AT RISK! EXTREMELY HIGH
SNOWFALL RATES WILL MAKE IT IMPOSSIBLE FOR ROAD CREWS AND
EMERGENCY PERSONNEL TO KEEP ROADS PASSABLE AND TO ASSIST STRANDED
VEHICLES. IF YOU DO ATTEMPT TRAVEL IN THE SIERRA YOUR CHANCES OF
BEING STRANDED FOR MORE THAN A FEW HOURS IS VERY HIGH. REMAIN
INDOORS DURING THIS BLIZZARD...EVEN A SHORT WALK OUTDOORS COULD BE
DEADLY AS YOU WILL BECOME DISORIENTED IN THE WHITEOUT CONDITIONS
WITH ZERO VISIBILITY.

[srainhoutx]

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE RENO NV
759 AM PST FRI JAN 4 2008

CAZ070>073-NVZ001>005-050000-
SURPRISE VALLEY CALIFORNIA-LASSEN-EASTERN PLUMAS-
EASTERN SIERRA COUNTIES-GREATER LAKE TAHOE AREA-MONO-
MINERAL AND SOUTHERN LYON COUNTIES-GREATER RENO-CARSON CITY-
MINDEN AREA-WESTERN NEVADA BASIN AND RANGE INCLUDING PYRAMID LAKE-
NORTHERN WASHOE COUNTY-
INCLUDING THE CITIES OF...CEDARVILLE...EAGLEVILLE..
FORT BIDWELL...PORTOLA...SUSANVILLE...WESTWOOD...SIERRAVILLE..
SOUTH LAKE TAHOE...TAHOE CITY...TRUCKEE...MARKLEEVILLE..
BRIDGEPORT...COLEVILLE...LEE VINING...MAMMOTH LAKES...HAWTHORNE..
YERINGTON...SMITH VALLEY...MINA...SCHURZ...GLENBROOK..
INCLINE VILLAGE...SPARKS...VERDI...GARDNERVILLE...FERNLEY..
FALLON...LOVELOCK...SILVER SPRINGS...NIXON...IMLAY...EMPIRE..
GERLACH
759 AM PST FRI JAN 4 2008


MAJOR WINTER STORM MOVING INTO THE SIERRA

THE FOLLOWING IS A LIST OF IMPACTS FROM THIS STORM


...CURRENT WATCHES AND WARNINGS..

* BLIZZARD WARNING UNTIL 4 AM SATURDAY FOR THE SIERRA NORTH OF
INTERSTATE 80.

* BLIZZARD WARNING UNTIL 10 AM SATURDAY FOR THE SIERRA SOUTH OF
INTERSTATE 80 INCLUDING THE LAKE TAHOE BASIN AND MONO COUNTY.

* HIGH WIND WARNING UNTIL NOON TODAY FOR NORTHERN WASHOE COUNTY
AND THE SURPRISE VALLEY.

* HIGH WIND WARNING UNTIL 3 PM TODAY FOR THE RENO-CARSON CITY-
MINDEN AREA.

* HIGH WIND WARNING UNTIL 6 PM TODAY FOR LYON...MINERAL..
CHURCHILL AND PERSHING COUNTIES.

* WINTER STORM WARNING FROM NOON TODAY TO 4 AM SATURDAY FOR
NORTHERN WASHOE COUNTY AND THE SURPRISE VALLEY.

* WINTER STORM WARNING FROM 3 PM TODAY T0 10 AM SATURDAY FOR THE
RENO-CARSON CITY AREA SOUTH TO MINDEN AND GARDNERVILLE.

* WINTER STORM WARNING FROM 6 PM TODAY TO 10 AM SATURDAY FOR
WESTERN NEVADA SOUTH OF INTERSTATE 80 AND EAST OF HIGHWAY 95.


...STORM INFORMATION..

A MAJOR WINTER STORM IS MOVING INTO NORTHERN CALIFORNIA AND WILL
IMPACT THE SIERRA AND WESTERN NEVADA TONIGHT THROUGH SATURDAY
MORNING. COLD AIR FROM A LOW PRESSURE SYSTEM IN THE GULF OF
ALASKA WILL COMBINE WITH A PLUME OF SUBTROPICAL MOISTURE TO
PRODUCE VERY LARGE SNOW ACCUMULATIONS BETWEEN THIS MORNING AND
SATURDAY MORNING IN THE SIERRA.

HEAVY SNOW IS ALSO LIKELY FOR THE VALLEY FLOORS OF NORTHEAST
CALIFORNIA AND WESTERN NEVADA BETWEEN THIS AFTERNOON AND SATURDAY
MORNING...THIS INCLUDES THE RENO-CARSON CITY AREA.

THIS STORM WILL PRODUCE STRONG AND DAMAGING WINDS GUSTS THROUGH
THIS AFTERNOON. THESE WINDS ARE FORECAST TO COMBINE WITH HEAVY
SNOW TO PRODUCE DANGEROUS BLIZZARD CONDITIONS IN THE SIERRA.

STATE AND LOCAL EMERGENCY MANAGERS ARE WORKING WITH THE NATIONAL
WEATHER SERVICE AND ARE IN THE PROCESS OF PREPARING FOR EMERGENCY
RESPONSE...SHOULD IT BECOME NECESSARY. CITIZENS CAN ASSIST IN THIS
EFFORT BY STAYING INFORMED ON THE LATEST FORECASTS FROM THE NATIONAL
WEATHER SERVICE AT WEATHER.GOV/RENO.


...SNOW ACCUMULATIONS..

FOR THE SIERRA...FROM THIS MORNING THROUGH SATURDAY MORNING

* 3 TO 5 FEET ABOVE 7000 FEET WITH HIGHER AMOUNTS ALONG THE SIERRA
CREST.

* 1 TO 3 FEET BETWEEN 5000 AND 7000 FEET INCLUDING THE LAKE TAHOE
BASIN.

FOR WESTERN NEVADA AND NORTHEAST CALIFORNIA...FROM FRIDAY EVENING
THROUGH SATURDAY MORNING

* 4 TO 10 INCHES ARE POSSIBLE WITH AMOUNTS UP TO 16 INCHES IN THE
FOOTHILLS.


...WINDS..

STRONG AND DAMAGING WIND GUSTS ARE FORECAST.

FOR THE SIERRA RIDGES...WINDS OF 60 TO 80 MPH WITH GUSTS TO 120
MPH WILL INCREASE TO 80 TO 110 MPH WITH GUSTS OVER 150 MPH AFTER
NOON AND CONTINUE THROUGH THIS EVENING.

FOR THE EASTERN SIERRA SLOPES AND WESTERN NEVADA...WINDS OF 20 TO
35 MPH WITH GUSTS TO 60 MPH WILL INCREASE TO 30 TO 45 MPH WITH
GUSTS TO 65 MPH EARLY THIS MORNING AND CONTINUE THROUGH THIS AFTERNOON.
GUSTS IN WIND PRONE AREAS ALONG HIGHWAYS 95 AND 395 MAY EXCEED 80
MPH TODAY.

WINDS WILL ALSO CREATE AREAS OF BLOWING DUST WHICH MAY LOWER
VISIBILITIES BELOW 1 MILE AT TIMES.

WINDS OF THIS MAGNITUDE MAY DOWN TREES...UTILITY POLES...AND
DAMAGE FENCES AND ROOFS. HIGH PROFILE VEHICLES MAY OVER TURN IF
ATTEMPTING TO TRAVEL IN AREAS OF STRONG CROSS WINDS.


...TRAVEL IMPACTS FOR THE SIERRA..

* DO NOT ATTEMPT TO TRAVEL IN THE SIERRA TODAY AND SATURDAY.

* ATTEMPTING TO TRAVEL IN THE SIERRA WILL PUT YOUR LIFE AT RISK!

MOST SIERRA ROADS WILL BE CLOSED FOR A PERIOD OF TIME DURING THIS
STORM DUE TO THE DANGEROUS BLIZZARD CONDITIONS. HEAVY SNOW AND
STRONG WINDS WILL GENERATE WHITEOUT CONDITIONS WITH ZERO
VISIBILITY WHICH WILL MAKE TRAVEL IMPOSSIBLE.

SNOWFALL RATES OF 2 TO 4 INCHES PER HOUR WILL OCCUR FROM THIS
MORNING THROUGH SATURDAY MORNING. DURING THE STRONGEST PORTION OF
THE STORM THIS AFTERNOON AND EVENING...SNOWFALL RATES OVER THE
MOUNTAIN PASSES WILL BE NEAR 6 INCHES PER HOUR.

THESE VERY HIGH SNOWFALL RATES WILL MAKE IT IMPOSSIBLE FOR ROAD
CREWS AND EMERGENCY PERSONNEL TO KEEP ROADS PASSABLE AND TO ASSIST
STRANDED VEHICLES. IF YOU DO ATTEMPT TRAVEL IN THE SIERRA YOUR
CHANCES OF BEING STRANDED FOR MORE THAN A FEW HOURS IS VERY HIGH.

DELAY ALL TRAVEL PLANS IN THE SIERRA UNTIL AFTER THE STORM PASSES
AND ROAD CONDITIONS IMPROVE LATE THIS WEEKEND OR EARLY NEXT WEEK.
ALTERNATE ROUTES WILL NOT BE AVAILABLE...AS DANGEROUS BLIZZARD
CONDITIONS WILL AFFECT ALL ROADS CROSSING THE SIERRA FROM LASSEN
COUNTY SOUTHWARD TO MONO COUNTY.


...TRAVEL IMPACTS FOR AREAS BELOW 5000 FEET..

* HIGHWAY 395 CURRENTLY HAS RESTRICTIONS TO CAMPERS...TRAILERS AND
PERMIT LOADS.

TRAVEL CONDITIONS ACROSS WESTERN NEVADA AND EASTERN CALIFORNIA WILL
BE IMPACTED BY STRONG WINDS THROUGH THIS AFTERNOON.

RAIN WILL REACH THE LOWER VALLEYS THIS MORNING AND WILL CHANGE TO
SNOW THIS AFTERNOON OR EVENING AS A COLD FRONT MOVES THROUGH THE
REGION. SEVERAL INCHES OF SNOW WILL CREATE HAZARDOUS DRIVING
CONDITIONS TONIGHT AND SATURDAY MORNING.


...RIVERS AND STREAMS..

AS THE STORM MOVES INTO THE AREA THERE IS THE POSSIBILITY FOR A
FEW HOURS OF MODERATE TO HEAVY RAIN BELOW 6500 FEET. THIS MAY
CAUSE RISES ON SMALL CREEKS AND STREAMS WITH SOME RUNOFF ON
RECENTLY BURNED SLOPES SUCH AS THE HAWKEN FIRE SITE NEAR RENO AND
THE LARSON FIRE NEAR COLEVILLE.

NO WIDESPREAD FLOODING IS FORECAST WITH THIS STORM.


$$

HOON

HTTP://WEATHER.GOV/RENO

http://www.wrh.noaa.gov/warnings.php?wf ... +Statement


The skiing should be great next weekend. We're thinking Kirkwood, Sierra At Tahoe, or Mt Shasta. Can't wait

[Stratosphere747]

Mammoth Lakes says "Meh" - http://www.wrh.noaa.gov/rev/

Today: Periods of snow. The snow could be heavy at times. High near 23. Strong and damaging winds, with a south wind 75 to 80 mph decreasing to between 55 and 60 mph. Winds could gust as high as 125 mph. Chance of precipitation is 100%. Total daytime snow accumulation of 55 to 61 inches possible.

Tonight: Periods of snow. The snow could be heavy at times. Low around 16. Very windy, with a southwest wind 50 to 55 mph decreasing to between 40 and 45 mph. Winds could gust as high as 85 mph. Chance of precipitation is 100%. New snow accumulation of 53 to 59 inches possible.

http://mammothmountain.com/cams/index.cfm?cam=village

http://mammothmountain.com/cams/index.cfm?cam=main - Blizzard!

http://www.mammoth-snowman.com/mammoth- ... b-cam.html

http://www.sierravisionsstock.com/cams.html

[Stratosphere747]

Can't stand Kirkwood or Heavenly anymore.

Northstar has become our home away from home when in Tahoe.

http://www.northstarattahoe.com/

[tomboudreau]

Interesting forecast discussion from NWS Reno...

AREA FORECAST DISCUSSION

FXUS65 KREV 041040
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
240 AM PST FRI JAN 4 2008

.NEAR TERM...UNTIL 6 AM SATURDAY
AN EXTREMELY POWERFUL PACIFIC STORM IS JUST ON THE DOORSTEP AT THIS
TIME. SEE ALL THE SUPPLEMENTAL STATEMENTS...WATCHES...AND WARNINGS
THAT ARE OUT. ALSO SEE THE LINKS FROM THE TOP OF OUR HOMEPAGE FOR
ADDITIONAL INFORMATION...WINTER SAFETY TIPS...AND LATEST STORM
REPORTS.

SATELLITE IMAGERY SHOWS AN IMPRESSIVE LOW PRESSURE AREA NEARING
130W RIDING A STRONG JET STREAM. SATELLITE DERIVED JET LEVEL WINDS
ARE AS HIGH AS 235 KTS!!!! WV/IR SAT IMAGERY SHOWS AN IMPRESSIVE
BAROCLINIC LEAF NOW INSIDE 130W AT AROUND 35N. THIS FEATURE IS
POINTED DIRECTLY AT THE SIERRA AND WESTERN NEVADA WITH CURRENT RAINFALL
RATES ESTIMATED CLOSE TO 1 INCH PER HOUR.

WIND HAVE BACKED OFF TEMPORARILY ACROSS THE AREA...BUT
EXPECT THEM TO INCREASE AGAIN AS MAIN PRECIP SHIELD MOVES INTO THE
SIERRA. AS FAR AS WIND POTENTIAL...LOOKS TO BE VERY GOOD FOR
STRONG DOWNSLOPE WINDS IN THE LEE OF THE SIERRA FOR AN HOUR OR TWO
BETWEEN 15 AND 18Z. GUSTS OVER 100 MPH POSSIBLE IN THE FOOTHILLS
AND 75 MPH IN THE VALLEYS NEAR RENO...GERLACH...HAWTHORNE. THEN
PRECIP SHIELD WILL MOVE INTO THE SIERRA. GIVEN THE THERMODYNAMIC
PROFILES...AREA WILL BE ONLY WEAKLY STABLE WHICH WILL PROMOTE
IMMEDIATE SPILLOVER INTO WESTERN NEVADA NORTH OF GARDNERVILLE AND
WEST OF FERNLEY. DYNAMICS ARE NOT STRONG ENOUGH TO PUSH THE PRECIP
TOWARDS FERNLEY FALLON AT THIS TIME SO THE STRONGEST WINDS THERE
ARE LIKELY BETWEEN 18 AND 00Z...AS WELL AS THE HAWTHORNE/YERINGTON
AREAS. THEN PRECIP IS EXPECTED TO MOVE INTO ALL AREAS.

AS FAR AS THE SIERRA...WIDESPREAD BLIZZARD CONDITIONS EXPECTED BY
LATE MORNING. WHILE SNOW LEVELS WILL BRIEFLY RISE THIS MORNING TO
NEAR 6500 TO 7000 FEET...THE HEAVY PRECIPITATION RATES WILL
QUICKLY BRING SNOW LEVELS DOWN STARTING AROUND NOON. EXTREMELY
HEAVY SNOWFALL WITH WIND GUSTS UP TO 60 MPH OR MORE WILL MAKE ANY
TRAVEL NEARLY IMPOSSIBLE AND LIFE THREATENING. IN ADDITION...RIDGE
GUSTS OF UP TO 200 MPH WILL OCCUR. AS DAY SHIFT MENTIONED...
SNOWFALL RATES OF 6 INCHES PER HOUR ARE LIKELY FOR A FEW
HOURS...AND MAY EVEN BE HEAVIER AT TIMES. TOTAL SNOW IN THE SIERRA
WILL BE SEVERAL FEET...AND WILL BE INCREASING ACCUMULATION AROUND
LAKE TAHOE AS SNOW LEVELS WILL NOT RISE AS HIGH AS EARLIER THOUGHT
DUE TO THE EXTREME PRECIP RATES. EXPECT THE PRECIP TO LET UP AFTER
MIDNIGHT MANY AREAS...BUT IT WILL STILL BE HEAVY AT TIMES...JUST
NOT EXTREME. WINDS WILL ALSO LET UP SOME...BUT GUSTS TO 45 MPH ARE
STILL LIKELY AFTER MIDNIGHT.

FOR SPILLOVER INTO WESTERN NEVADA...THIS WILL BE A VERY IMPRESSIVE
EVENT. ALL THE INGREDIENTS ARE THERE...WEAKLY STABLE TO UNSTABLE
THERMODYNAMIC PROFILES...STRONG CROSS BARRIER MID-LEVEL
WINDS...EXIT REGION OF A CYCLONICALLY CURVED JET STREAK AND STRONG
LOW-LEVEL FRONTOGENESIS. EXPECT HEAVY AMOUNTS INTO RENO WITH 1.5-2
INCHES WATER EQUIVALENT AT THE AIRPORT WITH UP TO 4 INCHES IN THE
FOOTHILLS. CARSON CITY/MINDEN WILL SEE SIMILAR AMOUNTS. FURTHER
INTO WESTERN NEVADA AMOUNTS WILL BE LIGHTER BUT WILL STILL
REPRESENT OVER 100% OF THE MONTHLY NORMAL. 3/4 TO 1 INCH IS LIKELY
IN THESE AREAS FROM GERLACH SOUTHEAST TO HAWTHORNE. THE PRECIP
WILL BEGIN AS RAIN BUT WILL CHANGE TO SNOW AS THE FRONT MOVES
THROUGH AND PRECIP BECOMES INTENSE. WITH THE IMPRESSIVE PRECIP
RATES HELPING TO LOWER SNOW LEVELS FURTHER WILL INCREASE SNOWFALL
AMOUNTS IN THE RENO AREA. WILL ALSO UPGRADE THE WATCHES TO
WARNINGS IN ZONES 1 AND 4 FOCUSED ON AREAS ABOVE 5000 FEET. HAVE
ALSO HAD WIND WARNINGS EXPIRE EARLIER AND WINTER WARNINGS BEGIN
EARLIER FOR WESTERN NEVADA DUE TO THE ALMOST INSTANT SPILLOVER
WHICH HELPS TO REDUCE THE WINDS. KEEP IN MIND THAT ALTHOUGH THE
WINDS WILL NOT BE EXTREME GUSTS OF 40-50 MPH ARE LIKELY IN MANY
AREAS WITH PRECIP AS 700 MB WINDS REACH 100 KTS. SNOW WILL BE
THE HEAVY WET STUFF ACROSS WESTERN NEVADA SO DO NOT EXPECT THAT
MUCH BLOWING SNOW. THEREFORE BLIZZARD WARNINGS FOR THE IMMEDIATE
LEE OF THE SIERRA SHOULD NOT BE NECESSARY ALTHOUGH LATER SHIFTS
WILL NEED TO CONTINUOUSLY RE-EVALUATE THE SITUATION. TRAVEL IS
DISCOURAGED EVEN IN WESTERN NEVADA THIS EVENING...ESPECIALLY THE
SIERRA FRONT. AS FAR AS POSSIBLE RAINFALL CONCERNS AND MINOR
FLOODING BEFORE THE CHANGEOVER...SEE HYDRO DISCUSSION BELOW.
WALLMANN

.SHORT TERM...SATURDAY THROUGH SUNDAY NIGHT...
COLD POOL ALOFT KEEPS VERY UNSTABLE AIRMASS OVER THE REGION
SATURDAY TRIGGERING SHOWERS THROUGHOUT THE DAY. WHILE THE
WIDESPREAD HEAVY SNOW WILL HAVE DIMINISHED...THE SHOWERS WILL BE
RATHER PERSISTENT WITH SO MUCH INSTABILITY AND ANY BREAK IN THE
ACCUMULATING SNOWFALL SHOULD BE SHORT-LIVED. THE BEST INSTABILITY
REMAINS OVER THE NRN ZONES AND THE BEST JET DYNAMICS CONTINUES TO
BE OVER THE SIERRA EXTENDING INTO THE IMMEDIATE LEESIDE...SO THE
BEST CHANCE FOR A LONGER BREAK IN THE SNOW SHOWERS WOULD BE OVER
THE GREAT BASIN ZONES.

THE JET DYNAMICS AND WAA BEGIN TO INCREASE BY SATURDAY EVENING AS
THE NEXT UPPER SHORTWAVE APPROACHES THE WEST COAST. THE PRECIP BAND
WILL FIRST INTENSIFY OVER THE NRN AND CENTRAL SIERRA SATURDAY NIGHT
AND SPREAD TO THE SRN SIERRA BY SUNDAY MORNING. WHILE STILL IN THE
COLD SECTOR...SNOW LEVELS WILL BE QUITE LOW AND PRECIP SHOULD HAVE
NO PROBLEM SPILLING OVER THE SIERRA. THIS MEANS WIDESPREAD
ACCUMULATING SNOWFALL ONCE AGAIN FOR THE LEESIDE VALLEYS IN ADDITION
TO THE SIERRA. SNOW ACCUMULATIONS FROM SATURDAY NIGHT THROUGH SUNDAY
EVENING LOOK TO BE ANOTHER 12 TO 18 INCHES IN THE SIERRA WITH AROUND
6 INCHES IN THE LEESIDE VALLEYS. AMOUNTS MAY BE A LITTLE HIGHER ON
THE SIERRA FOOTHILLS AS WELL AS IN THE SURPRISE VALLEY WHICH SHOULD
GET THE BEST SPILLOVER FROM THE WARNERS...HOWEVER THE GREAT BASIN
ZONES SOUTH OF INTERSTATE 80 MAY ONLY SEE A FEW INCHES.

STILL NOT SURE WHAT STATEMENTS TO ISSUE TO COVER THIS PERIOD AND
CREATE THE LEAST AMOUNT OF PUBLIC CONFUSION. WINDS IN THE SIERRA
WILL STILL BE IMPRESSIVE BUT NOT NEARLY AS STRONG AS TODAYS
SYSTEM...SO NOT SURE IF THE BLIZZARD WARNING SHOULD BE CONTINUED OR
IF A WINTER STORM WARNING SHOULD BE ISSUED. MOST LIKELY SCENARIO FOR
THE LEESIDE VALLEYS WILL BE TO CONTINUE THE WINTER STORM WARNINGS
THROUGH THE ENTIRE PERIOD AS BREAKS IN THE SNOWFALL WILL BE BRIEF
AND BLOWING AND DRIFTING SNOW WILL CONTINUE.

NWLY UPPER JET MOVES IN SUNDAY NIGHT BEHIND THE COLD FRONT USHERING
IN A MUCH COLDER AIRMASS. H7 TEMPS DROP TO AROUND -14C WHICH WILL
COMBINE WITH NEW SNOW ON THE GROUND TO POSSIBLY MAKE FOR A VERY COLD
NIGHT IF SKIES CLEAR FAST ENOUGH. JORDAN

.LONG TERM...MONDAY THROUGH THURSDAY...
UNSETTLED WEATHER WILL CONTINUE THROUGH THE EXTENDED. ON MONDAY A
DEEP UPPER TROUGH SHOULD BE MOVING INTO THE ROCKIES AS THE NEXT
SYSTEM MOVES INTO WASHINGTON STATE. THE MODELS HAVE BEEN CONSISTENT
IN SHOWING THIS SCENARIO THE LAST FEW MODEL RUNS. WITH THE ZONAL
PATTERN AND STRONG JET STREAM IN PLACE THERE WILL NOT BE MUCH CHANCE
FOR THE SYNOPTIC PATTERN TO AMPLIFY. AS A RESULT ONE SHORTWAVE
AFTER ANOTHER WILL AFFECT THE ERN SIERRA AND WRN NEVADA MONDAY
THROUGH THURSDAY.

ON MONDAY THE COLD AIR MASS IN PLACE WILL HELP TO KEEP SNOW LEVELS
RELATIVELY LOW. THE GFS SHOWS 700 MB TEMPERATURES AT AROUND -14 DEG
CELSIUS OVER THE CNTRL SIERRA. THIS TRANSLATES TO A SNOW LEVEL
EASILY TO THE VALLEY FLOORS IN WRN NEVADA. PRECIPITATION ON MONDAY
WILL BE ALL SNOW. ON TUESDAY WARM AIR ADVECTION AHEAD OF THE NEXT
SYSTEM WILL BRING SNOW LEVELS UP WHICH WILL CHANGE SNOW INTO RAIN IN
THE VALLEYS OF WRN NEVADA. THE 1000-500 MB THICKNESS VALUES RISE TO
548 DAM OVER WRN NEVADA BY 00Z WEDNESDAY. THIS WILL BE SHORTLIVED
HOWEVER AS THE NEXT SYSTEM MOVES THROUGH THE SIERRA. MTN SNOW AND
VALLEY RAIN CAN BE EXPECTED ON WEDNESDAY. BY THURSDAY COLDER AIR
FILTERING BEHIND THE SYSTEM WILL BRING ALL SNOW AGAIN TO THE
REGION. LATE THURSDAY HOWEVER THE UPPER TROUGH SHOULD QUICKLY MOVE
TO THE CNTRL ROCKIES AS RIDGING BUILDS INTO THE WEST COAST. THIS
WILL BRING A DRIER FLOW SO HAVE DECIDED TO DECREASE COVERAGE OF
PRECIP AFTER 18Z THURSDAY. O`HARA

&&

.AVIATION...
WINDS HAVE DECREASED SOME ACROSS THE SIERRA AS PRECIP MOVES IN.
HOWEVER THE STRONG JET WILL CONTINUE TO AFFECT WIND SPEEDS AT THE
SFC. WINDS WILL START TO INCREASE AGAIN BY 12Z WITH GUSTS TO 50 KT
POSSIBLE THROUGH THE DAY. NGM MOS GUIDANCE HAS SUSTAINED WINDS OF
31 KT AT KRNO BY 21Z THIS AFTN. WINDS ARE PROGGED TO BE EVEN
STRONGER AT KTVL AND KTRK.

SNOW HAS MOVED INTO THE CNTRL SIERRA AT 09Z WITH VISIBILITY AT KTVL
DROPPING TO LESS THAN 3SM. PRECIP COVERAGE IS NOT CONTINUOUS SO
EXPECT VSBYS AND CEILINGS TO FLUCTUATE THROUGH 15Z BEFORE THE
HEAVIER PRECIP MOVES INTO THE REGION. WHITEOUT CONDITIONS ARE
POSSSIBLE IN THE HEAVIER SHSN...MAINLY BETWEEN 18Z AND 00Z TODAY
WHICH WILL GREATLY AFFECT FLIGHT PLANNING. O`HARA

&&

.HYDROLOGY...
SOME HEAVY RAIN AT TIMES IS EXPECTED IN THE RENO-CARSON AREAS
BEFORE THE CHANGEOVER. THIS COULD IMPACT THE HAWKEN BURN AREA AS
WELL AS THE LARSON BURN IN NORTHERN MONO COUNTY. WHILE RAINFALL
RATES WILL BE HEAVY FOR 2-3 HOURS...GUIDANCE FROM AREA EMERGENCY
MANAGERS SUGGEST WE WILL FALL JUST BELOW CRITERIA. STILL...DAY
SHIFT WILL BE MONITORING THE SITUATION AS THE BAROCLINIC LEAF
MOVES INTO THE REGION.

OTHERWISE...SOME LOCALIZED MINOR STREET FLOODING IS EXPECTED IN
RENO-CARSON AND SUSANVILLE. GIVEN THE LOCALIZED NATURE
EXPECTED...WILL NOT ISSUE AN ADIVSORY AS THINGS MAY BE CONFUSING
ENOUGH AS IT IS. ALSO...THE IMPACTS WILL BE MINOR COMPARED TO THE
WINDS AND SNOW. WALLMANN

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...HIGH WIND WARNING UNTIL NOON PST TODAY FOR NVZ005.

WINTER STORM WARNING FROM NOON TODAY TO 4 AM PST SATURDAY FOR
NVZ005.

BLIZZARD WARNING UNTIL 10 AM PST SATURDAY FOR NVZ002.

HIGH WIND WARNING UNTIL 6 PM PST THIS AFTERNOON FOR NVZ001-004.

WINTER STORM WARNING FROM 6 PM THIS EVENING TO 10 AM PST
SATURDAY FOR NVZ001-004.

HIGH WIND WARNING UNTIL 3 PM PST THIS AFTERNOON FOR NVZ003.

WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 10 AM PST
SATURDAY FOR NVZ003.

CA...HIGH WIND WARNING UNTIL 4 AM PST EARLY THIS MORNING FOR
CAZ071>073.

BLIZZARD WARNING UNTIL 4 AM PST SATURDAY FOR CAZ071.

HIGH WIND WARNING UNTIL NOON PST TODAY FOR CAZ070.

WINTER STORM WARNING FROM NOON TODAY TO 4 AM PST SATURDAY FOR
CAZ070.

BLIZZARD WARNING UNTIL 10 AM PST SATURDAY FOR CAZ072-073.

&&

$$

HTTP://WEATHER.GOV/RENO

[Lowpressure]

Could we maybe see the wind speed record currently held at Mount Washington finally come down?

[srainhoutx]

Can't stand Kirkwood or Heavenly anymore.

Northstar has become our home away from home when in Tahoe.

http://www.northstarattahoe.com/

Gave up on Heavenly in the late 90's. Kirkwood can be fun and much less traveled. Mammoth Lakes looks interesting. Our fiends suggested Mt Shasta due to the fact it is a bit less crowded. They are life time residents out there. Still should be Awesome.

[Stratosphere747]

Could we maybe see the wind speed record currently held at Mount Washington finally come down?

Can't see that happening, though it's not everyday you see the mentioning of 200mph gusts.

[Stratosphere747]

Can't stand Kirkwood or Heavenly anymore.

Northstar has become our home away from home when in Tahoe.

http://www.northstarattahoe.com/

Gave up on Heavenly in the late 90's. Kirkwood can be fun and much less traveled. Mammoth Lakes looks interesting. Our fiends suggested Mt Shasta due to the fact it is a bit less crowded. They are life time residents out there. Still should be Awesome.

We have heard great things about Shasta as well. Just can't break the Tahoe ritual..

[srainhoutx]

What a storm via Radar. WOW...

http://radar.weather.gov/Conus/pacnorth ... e_loop.php

[Coredesat]

This system is an absolute monster on satellite.

[srainhoutx]

MESOSCALE DISCUSSION 0006
NWS STORM PREDICTION CENTER NORMAN OK
1237 PM CST FRI JAN 04 2008

AREAS AFFECTED...CA SIERRA MOUNTAINS

CONCERNING...BLIZZARD

VALID 041837Z - 042300Z

HEAVY SNOW WILL INCREASE ACROSS THE CENTRAL/SOUTHERN SIERRA THIS
AFTERNOON...WITH RATES OF 2-5 IN/HR AND VERY STRONG WINDS/WHITE-OUT
CONDITIONS.

WATER VAPOR IMAGERY FEATURES POWERFUL/COLD UPPER TROUGH CENTERED OFF
THE PACIFIC NORTHWEST COAST AROUND 45N/130W...WITH ASSOCIATED
COLD/OCCLUDED FRONTAL BOUNDARY AND EXTENSIVE MOISTURE PLUME ARCING
ACROSS THE PACIFIC NORTHWEST AND NORTHERN CA INTO THE EASTERN
PACIFIC. SIMILAR TO OBSERVATIONAL TRENDS...SHORT TERM MODEL GUIDANCE
SUGGESTS THE PRONOUNCED MID/UPPER LEVEL JET WILL GRADUALLY SHIFT
SOUTHWARD ACROSS THE CENTRAL/SOUTHERN SIERRA THIS AFTERNOON. WITHIN
THIS PLUME...SPECIAL 17Z RAOB FROM OAKLAND AND LATEST GPS-IPW DATA
IMPLY THAT 1.0-1.2 INCH PRECIPITABLE WATER VALUES EXTEND WELL INLAND
ACROSS NORTHERN CA. THIS AMPLE MOISTURE...ALONG WITH SIGNIFICANT
OROGRAPHIC/LARGE SCALE LIFT...ESPECIALLY FOR WEST-FACING
SLOPES...WILL SUPPORT FALLING SNOW LEVELS LATER THIS AFTERNOON WITH
A SOUTHWARD DEVELOPMENT OF VERY HEAVY SNOW ACROSS THE
CENTRAL/SOUTHERN SIERRA. WHILE LIGHTNING HAS DIMINISHED ALONG/OFF
THE NORTHERN CA COAST OVER THE PAST FEW HOURS...MAINLY SLANTWISE
INSTABILITY/STEEPENING LAPSE RATES WITH EMBEDDED CONVECTIVE ELEMENTS
WILL SUPPORT SNOW RATES ON THE ORDER OF 2-5 IN/HR IN THE HIGHER
ELEVATIONS OF THE SIERRA THROUGH LATE AFTERNOON/EARLY
EVENING...ESPECIALLY ABOVE 7000 FT. IN ADDITION...AS HAS BEEN
SAMPLED THIS MORNING VIA NUMEROUS SURFACE NETWORK OBSERVATION SITES
ACROSS NORTHERN CA...VERY STRONG WINDS WILL CONTRIBUTE TO
BLIZZARD/WHITE-OUT CONDITIONS.

..GUYER.. 01/04/2008


http://www.spc.noaa.gov/products/md/md0006.html

Amazing Storm

[RL3AO]

Category 5 wind gust.

Code: Select all

Hourly data from Ward Mountain near Lake Tahoe (Elevation 8637 Ft)
Collected by the National Weather Service - Reno NV

 MN DY    Hour       Temp       |       Wind        |
                  av   mx   mn  | Dir   Speed   Gst |
  1 4     1200    27   27   26    230     56    118
  1 4     1100    27   28   26    229     86    163
  1 4     1000    26   27   26    224     79    127
  1 4     0900    26   27   26    222     71    113
  1 4     0800    27   27   27    210     79    124
  1 4     0700    27   28   27    206     86    129
  1 4     0600    27   28   27    206     73    112


[JonathanBelles]

WOW! that really is a monster.