A fast-moving storm brought widespread strong winds to northeast and eastern California on November 20. The storm also produced a modest snowfall from around Lake Tahoe northward.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS REV wrote it up.
A fast-moving storm brought widespread strong winds to northeast and eastern California on November 20. The storm also produced a modest snowfall from around Lake Tahoe northward.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Reno, NV wrote its last area forecast discussion before the first event at Nov 20, 4:44 AM PST, 3 hours 16 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE RENO NV
444 AM PST FRI NOV 20 2009
.SHORT TERM...
ALL WARNINGS ISSUED REMAIN IN EFFECT FOR TODAY...WITH WIND TO REMAIN
THE MAIN IMPACT UNTIL THE COLD FRONT MOVES INTO THE REGION THIS
AFTERNOON. WINDS HAVE ALREADY BEGUN TO PICK UP OVER PARTS OF ERN CA
AND FAR WRN NV WITH GUSTS OVER 40 MPH. RIDGE LEVEL GUSTS HAVE
REACHED 70-90 MPH AT TIMES OVERNIGHT. RIDGE WINDS WILL CONTINUE TO
INCREASE DURING THE NEXT FEW HOURS...AND WILL EFFICIENTLY MIX DOWN
TO THE VALLEYS BY MID OR LATE MORNING. PEAK GUSTS OVER MOST AREAS
WILL OCCUR IN A 2-4 HOUR TIME FRAME AHEAD OF THE COLD FRONT. THIS
FRONT IS EXPECTED TO PASS THRU NERN CA-NWRN NV BTWN 18-21Z...THEN
REACH THE RENO-TAHOE AREAS BTWN 21-00Z. THE SOUTHERN END OF THE
FRONT SHOULD CLEAR SRN MINERAL-MONO COUNTIES BY 06Z THIS EVENING.
THE PASSAGE OF THE COLD FRONT WILL TRANSITION THE MAIN IMPACTS
FROM WIND TO PRECIPITATION AND POOR VISIBILITY...ESPECIALLY IN
THE SIERRA. WINDS WILL BEGIN TO DIMINISH AS SNOW INCREASES...BUT
REMAIN GUSTY. TOTAL SNOW AMOUNTS WILL BE HARD TO MEASURE WITH THE
PRESENCE OF THE WIND AND MAY FALL SHORT OF WARNING CRITERIA. THE
PERIOD OF POTENTIAL WHITEOUT CONDITIONS DURING A TYPICALLY BUSY
TRAVEL PERIOD WILL PRODUCE SIGNIFICANT IMPACTS OVER THE PASSES FOR A
FEW HOURS THIS AFTERNOON AND INTO THE EVENING. FOR THE RENO-CARSON
AREAS...RAIN WILL CHANGE TO SNOW AROUND DUSK BUT LITTLE
ACCUMULATION...MAYBE UP TO AN INCH ABOVE 5000 FT MAINLY ON UNPAVED
SURFACES SINCE TEMPS ARE NOT EXPECTED TO FALL BELOW FREEZING UNTIL
AFTER THE PRECIP ENDS. THE MAIN TRAVEL HAZARD MAY BE ICY PATCHES
LATER TONIGHT ON UNTREATED ROAD SURFACES THAT ARE NOT ABLE TO DRY
OUT AS THE COLD AIR POURS IN.
THE PASSAGE OF THE UPPER LEVEL TROF WILL PRODUCE SOME ENHANCED
LIFT OVER NRN LASSEN COUNTY...SURPRISE VALLEY AND FAR NWRN NV LATER
THIS EVENING. THIS COULD YIELD AN INCH OR TWO OF ACCUMULATION AFTER
SNOW HAS LARGELY TAPERED OFF ACROSS THE REMAINDER OF ERN CA AND WRN
NV. THE FAST MOVEMENT OF THIS FEATURE WILL PROBABLY KEEP SNOW
AMOUNTS BELOW ADVISORY CRITERIA...AND ALSO LEAD TO A RAPID DROP IN
WINDS OVERNIGHT.
THIS WEEKEND WILL BE CHILLY WITH MAX TEMPS MAINLY IN THE 40S EACH
DAY FOR MOST VALLEYS. ANOTHER WEAK SHORTWAVE WILL BRUSH ACROSS THE
NWRN US BY LATE SAT NIGHT AND SUNDAY AND BRING SOME INCREASED
WINDS MAINLY TO THE HIGHER ELEVATIONS...BUT PRECIP PROSPECTS ARE
LOOKING LESS PROMISING AS THE BEST MOISTURE AND DYNAMICS ARE
LIKELY TO REMAIN NORTH OF THE OREGON BORDER. AS A RESULT...PRECIP
CHANCES HAVE BEEN REDUCED TO SLGT CHC OVER THE TAHOE BASIN AND
MOST OF NERN CA-NWRN NV. MJD
.LONG TERM...MONDAY THROUGH THURSDAY...
MODELS IN GOOD AGREEMENT WITH RIDGE BUILDING OVER THE WEST
MONDAY...AND THE AXIS SLOWLY PUSHING EAST THROUGH THURSDAY. THIS
WILL BRING DRY CONDITIONS WITH A MINIMAL WARMING TREND TO THE LOWER
VALLEYS THROUGH WEDNESDAY DUE TO SUBSIDENCE INVERSION AND LIGHT
FLOW. SIERRA WILL WARM FASTER DUE TO INCREASING TEMPERATURES ABOVE
THE INVERSION.
WITH THE RIDGE OVER THE WEST/GREAT BASIN...ENERGY FROM THE PACIFIC
SHOULD BE DEFLECTED NORTH OF THE AREA. TEMPERATURES IN THE NEVADA
VALLEYS SHOULD WARM BY LATE IN THE WEEK...IF THE RIDGE AXIS MOVES
EAST OF THE AREA ALLOWING THE WESTERLIES TO INCREASE AND MIX OUT
THE INVERSION. BRONG
&&
.AVIATION...
TROUGH MOVING INTO NORTHERN CALIFORNIA WILL BRING STRONG WINDS TO
THE AREA TODAY AHEAD OF A COLD FRONT. SURFACE WINDS AT THE SIERRA
TERMINALS GUSTING 30-40 KTS...WITH RIDGE WINDS 50-70 KTS. THESE
WINDS WILL CONTINUE TO INCREASE THROUGH 21Z WHEN THE FRONT REACHES
THE AREA. PEAK WINDS AT THE SIERRA TERMINALS SHOULD REACH 45-50 KTS
WITH SIERRA RIDGE WINDS 70-80 KTS GUSTING TO 100-110 KTS. WIND OF
THIS MAGNITUDE WILL GENERATE MOUNTAIN WAVES AND MODERATE TO STRONG
TURBULENCE...ESPECIALLY DURING AN HOUR OR TWO BEFORE THE FRONT
HITS THE AREA AS THE FLOW TURNS PERPENDICULAR TO THE SIERRA.
OTHER CONCERN FOR THE SIERRA IS DECREASING CEILINGS AND VISIBILITY
DUE TO MODERATE TO HEAVY SNOW. SNOW SHOULD REACH THE SIERRA BY
21Z...WITH PERIODS OF IFR CONDITIONS LIKELY THRU 06Z THIS EVE. LIGHT
SNOW SHOWERS ARE POSSIBLE THROUGH 12Z SATURDAY AS CONDITIONS
SLOWLY IMPROVE ONCE THE FRONT PASSES.
FOR RENO...MAIN CONCERN IS THE WINDS. INITIALLY THE SOUTH-SOUTHEAST
DIRECTION WILL LIMIT STRENGTH OF MOUNTAIN WAVE AND ANY ROTORS NEAR
THE TERMINAL. WINDS SHOULD INCREASE QUICKLY BETWEEN 14-18Z...WITH
STRONGEST WINDS (GUSTS 35-45 KTS) BETWEEN 18Z-23Z. FRONT SHOULD HIT
THE TERMINAL NEAR 21Z (GIVE OR TAKE AN HOUR)...SHIFTING THE WINDS TO
THE WEST PRIOR TO THE FRONTAL PASSAGE. THIS WILL BRING THE BEST
PERIOD FOR LLWS...ERRATIC SURFACE WINDS AND ROTORS NEAR THE
TERMINAL. RAIN/SNOW SHOWERS AND MVFR CEILINGS SHOULD AFFECT THE
TERMINAL BEHIND THE FRONT 23Z-03Z...BUT NOT LOOKING FOR MUCH IN THE
WAY OF ACCUMULATION ON RUNWAYS. BRONG
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...HIGH WIND WARNING UNTIL 1 PM PST THIS AFTERNOON FOR NVZ002.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS
EVENING FOR NVZ002.
HIGH WIND WARNING FROM 7 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR NVZ003-005.
HIGH WIND WARNING FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING FOR NVZ001.
BLOWING DUST ADVISORY FROM 10 AM THIS MORNING TO 10 PM PST THIS
EVENING FOR NVZ004.
CA...HIGH WIND WARNING UNTIL 1 PM PST THIS AFTERNOON FOR CAZ071-072.
WINTER STORM WARNING FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS
EVENING FOR CAZ071-072.
HIGH WIND WARNING FROM 7 AM THIS MORNING TO 4 PM PST THIS
AFTERNOON FOR CAZ070.
HIGH WIND WARNING FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING FOR CAZ073.
&&
HTTP://WEATHER.GOV/RENOPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
654 AM PST FRI NOV 20 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0503 AM NON-TSTM WND GST 4 NE MOUNT ROSE SKI ARE 39.38N 119.83W
11/20/2009 M61.00 MPH WASHOE NV MESONET
MEASURED AT GALENA CREEK RAWS AT THE BASE OF THE MOUNT
ROSE HIGHWAY.
0641 AM NON-TSTM WND GST 5 WSW GARDNERVILLE 38.91N 119.83W
11/20/2009 M80.00 MPH DOUGLAS NV TRAINED SPOTTER
&&
BRONGThe national radar mosaic for the moment the first event began.
4 high wind, 2 winter weather. Local standard time, as filed.
Winds were sustained between 40-50 mph on Lake Tahoe. Truckee AWOS recorded a gust to 64 mph at 1255PST.
Walker RAWS recorded a 78 mph wind gust at 1400PST. Other high wind gust observations include: Bridgeport AWOS with 60 mph at 1500PST and the Mammoth Airport AWOS with 68 mph at 2110PST.
A spotter two miles west of Loyalton reported winds sustained at 55 mph with gusts to 65 mph at 1133PST. Additional high wind gusts include: 67 mph at Bull Flat RAWS at 1059PST and 69 mph at Doyle RAWS at 1211PST.
Overall, most of the area received 3 inches or less of snowfall on November 20. However, isolated areas of Plumas and Sierra Counties received heavier amounts including 4 inches in Portola, 3.8 inches 3 miles SSW of Susanville, and approximately 6 inches 12 miles NW of Portola (on a ridge at 6900 feet).
Power outage, blowing dust, and 4-inch tree limbs down reported with high winds in Cedarville at 1120PST.
An intense but brief period of snow dropped modest snowfall amounts. Here are some of the snowfall totals: 6-10 inches near the Sierra crest west of Lake Tahoe, Tahoe City with 5-8 inches, 5 inches for Truckee and South Lake Tahoe, and an estimated 3-6 inches from SNOTEL observations south and east of Lake Tahoe.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2009Every state in 2009This day in weather historyWarnings in California, November 2009
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 200255, 200256, 200254, 200177, 200253, 200176.