A Pacific low pressure system passing by to the north brought a period of downslope winds on the eastern slopes of the Sierra.
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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 VEF wrote it up.
A Pacific low pressure system passing by to the north brought a period of downslope winds on the eastern slopes of the Sierra.
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 Las Vegas, NV wrote its last area forecast discussion before the first event at Jan 4, 1:22 PM PST, 5 hours 38 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 122 PM PST Mon Jan 4 2021 .SYNOPSIS...Numerous systems will pass through the region this week, skirting by our forecast area just to the north that will bring slight chances of precipitation to the Sierra region. Otherwise, periods of breezy northerly winds and high clouds as well as above average temperatures expected through the forecast period for the remainder of the area. && .SHORT TERM...Today through Wednesday. As well-advertised, the next weather system to move through the area will move through today, bringing with it slight chances of precipitation to the Sierra Nevada. Through the week, this forecast has continued to trend drier, with only 1-2 inches of snowfall expected above 6500ft tonight. Chances of spillover into the Owens Valley including Bishop, Independence and Big Pine remain very low, but certainly not out of the question to get brief light rain. Otherwise, the main concern will be enhanced winds. Peak wind gusts may flirt with 50 mph, but will be brief and confined to the mountain crests. Otherwise, there exists the potential for some brief downslope winds reaching the Owens Valley, but chances of this continue to dwindle as well, and may only be a concern for a short period of time. As such, no wind-related headlines have been issued. Through the morning on Tuesday, winds will continue to subside up on the mountains, moving southeastward through our forecast area. Breezy northerly winds expected areawide Tuesday afternoon, especially concentrating down the Colorado River Valley with forecast wind gusts 30-35 mph. Winds will remain below Wind Advisory and even below Lake Wind Advisory criteria. That said, waves on Lake Mohave as well as northern portions of Lake Havasu will be choppy, so be cautious if operating small craft. Enhanced northerly winds will remain along the Colorado River Valley on Wednesday, as winds calm everywhere else. Otherwise, a ridge will set up across the region, resulting in sunny skies with above-average temperatures. .LONG TERM...Thursday through Sunday. Run-to-run consistency remains low. Two systems will pass through the area Wednesday night into Thursday and another on Friday. These systems are not only trending drier, but also further north, resulting in no more than breezy conditions for our area. Details will become less murky as the week progresses, but it looks like our region will continue to be without measurable rainfall for the foreseeable future. && .AVIATION...For McCarran...Light, diurnal winds expected through tonight. North-northeast wind late Tuesday morning and afternoon with sustained wind 6-10 kts. FEW-BKN clouds above 15kft. For the rest of southern Nevada, northwest Arizona and southeast California...Gusty west wind across the Sierra this evening could result in localized downslope winds below canyon openings. Confidence is low-moderate in brief period of westerly winds impacting the KBIH terminal. Also, mechanical turbulence below 16 kft and low level wind shear possible. Elsewhere, FEW-BKN clouds above 15 kft. Westerly wind 10-20 kts increasing across the western Mojave Desert tonight. In the Colorado River, northerly wind increasing at KIFP and KEED after 12z Tuesday. Gusts up to 30 kts possible in the late morning and afternoon hours. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && DISCUSSION...Varian AVIATION...Pierce For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The peak gust was measured 4 miles WSW of Round Valley.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2021Every state in 2021This day in weather historyWarnings in California, January 2021
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: 938749.