A powerful and moist Pacific jet stream brought a period of moderate to heavy snow and blowing snow to the mountains. In the Front Range Mountains, the Joe Wright SNOTEL measured 13 inches of snow, with 12 inches measured at the Loveland Pass SNOTEL.
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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 BOU wrote it up.
A powerful and moist Pacific jet stream brought a period of moderate to heavy snow and blowing snow to the mountains. In the Front Range Mountains, the Joe Wright SNOTEL measured 13 inches of snow, with 12 inches measured at the Loveland Pass SNOTEL. Elsewhere, storm totals ranged from 4 to 7 inches. Above timberline, peak wind gusts ranged from 65 to 75 mph. In the foothills and urban corridor, outflow from a dissipating showers near the foothills of southeast Larimer and eastern Boulder counties pushed an outflow boundary of strong winds across the adjacent plains. Peak wind gusts included: 67 mph, 1 mile northwest of Loveland; 63 mph at the Fort Collins-Loveland Municipal Airport, with 58 mph at Denver International Airport.
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 Denver/Boulder, CO wrote its last area forecast discussion before the first event at Nov 2, 1:49 PM MST, 3 hours 11 minutes earlier.
Area Forecast Discussion National Weather Service Denver/Boulder CO 249 PM MDT Fri Nov 2 2018 .SHORT TERM...(This evening through Saturday) Issued at 249 PM MDT Fri Nov 2 2018 Satellite and radar imagery show our much anticipated short wave dropping southeast across the spine of the northern Rockies this afternoon. The main shot of lift and precipitation was just reaching western Wyoming and southeast Idaho, and probably an hour or two behind original schedule. As a result, we now expect the sharp increase in snowfall to reach the Rabbit Ears Pass to Rocky Mountain National Park area toward 7 PM, and then the I-70 Corridor closer to 10 PM. Snow intensity still expected to increase significantly with snowfall rates around 1 inch per hour later this evening into the early morning hours. Overall, the moisture depth per latest satellite imagery is limited and therefore amounts may be reduced by an inch or so. However, the orographics are very strong (upwards of 40-50 knots at 700 mb for a few hours this evening), lapse rates improve to 7-8 C/km, cold advection occurs, and we have strong lift on the nose of the powerful Pacific jet increasing to 120-130 knots. Those parameters would help make up for the limiting moisture so overall we'll maintain the same forecast snow accumulations at this point. Snowfall rates will be decreasing later tonight through much of Saturday with some drying aloft and gradual decrease of the orographic component. The current Winter Weather Advisory for the mountains above 9000 feet looks good, with a 5 to 12 inch snow forecast and hazardous travel due to blowing snow and snow-packed and icy roads. Road conditions may gradually improve on Saturday especially in valley locations. On the plains, we should see a couple showers spill out of the mountains later this evening with the passage of the mid level cold front and lift from the upper jet. Most of this precipitation would be in the form of rain. Later tonight into Saturday morning, a few snowflakes may mix in but no accumulation is expected given relatively mild temps. Other concern is the wind. For this evening, the cross mountain flow increases to nearly 50 knots, but at the same time the stable layer is lifting so a brute force event is in the works, and not a mountain wave event. Cross mountain gradients are near warning guidance (75 mph gusts), so the gusts to 70 mph in the forecast are good for mountain tops and exposed ridges across the foothills. On the nearby adjacent plains, could see a few gusts around 60 mph before weakening later this evening. Winds on the eastern plains will increase Saturday with good mixing and stronger northerly flow. Using forecast soundings and mixed layer data, most locations east of Greeley to DIA should see speeds of 25-35 mph with gusts up to 50 mph. .LONG TERM...(Saturday night through Friday) Issued at 249 PM MDT Fri Nov 2 2018 Active pattern during the long term period with area under fast northwest flow during the entire extended period. Forecast Saturday night picks up in relative lull of activity behind departing wave as shortwave ridging briefly in charge. Continued northwest flow will keep clouds and wring a few more snowflakes out of residual moisture, and left chc to slight chance pops in the mountains but otherwise fair weather through Sunday morning. POPs increase again Sunday with next approaching 500 mb shortwave trough. Good upward vertical motion over the area with 150 kt jet at 300 mb stretching from Pacific NW into four corners area Sunday night through Monday, putting the forecast area in favorable left front quadrant. Overall this system will resemble tonight's, with most precip in the mountains and little on the plains. Blustery NW wind again Sunday in the mountains, then spreading out onto the plains with a cold frontal passage Monday morning in northeast CO. Broad upper level cyclonic flow aloft over the central US, with weak surface high pressure over the forecast area through the first part of the week. Our next shortwave trough in northwest flow moves across southwest Colorado Wednesday night, and east to northeast upslope flow on the plains will give better chances on the plains than the mountains for precip this time around. Have high chance pops for now. Cold enough for snow Wednesday night, although too soon for forecast amounts. Temps...no real airmass change during the extended period, and with NW flow over the region temps will keep a few degrees below normal. Lower heights during the week and temps will be a few degrees cooler in the last half of the forecast period. && .AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon) Issued at 249 PM MDT Fri Nov 2 2018 West/northwest winds of 20G30-32kts should continue through 01Z, with crosswind limits possibly exceeded for north/south runway ops at KDEN. KBJC will see potential gusts around 40 knots. The winds should slowly subside 01Z-03Z this evening. However, as some high based showers move off the higher terrain decent mixing could lead to sporadic gusty west to southwest winds 04Z-08Z. As far as ceilings they may drop down to 8000-10000 feet tonight as higher based showers move across. On Saturday, gusty north winds will develop with speeds at KDEN increasing to 20-25 knots with gusts around 35 knots. KBJC and KAPA should see somewhat lighter winds. && .BOU WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 6 PM this evening to 6 PM MDT Saturday for COZ031-033-034. && SHORT TERM...Barjenbruch LONG TERM...Hanson AVIATION...Barjenbruch
Hazardous Weather Outlook National Weather Service Denver/Boulder CO 1111 AM MDT Fri Nov 2 2018 COZ030>051-031715- Jackson County Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- Grand and Summit Counties Below 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- Central and Southeast Park County- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 1111 AM MDT Fri Nov 2 2018 This hazardous weather outlook is for northeast and north central Colorado. .DAY ONE...Today and Tonight Areas of light snow, drizzle, and light freezing drizzle over the high mountain passes today will give way to more widespread and heavier snow tonight. The heaviest is expected to develop in the Rabbit Ears Pass and Rocky Mountain National Park area toward 6 PM,and then shift southward into the I-70 Mountain Corridor from Vail Pass to Georgetown between 8 and 10 PM. Accumulations of 3 to 6 inches with locally up to 8 inches will be possible by late tonight. Winds will gradually increase today and tonight over the mountains and foothills with gusts from to 50 to 70 mph at times especially this afternoon and evening. Areas of blowing snow will occur over the higher passes reducing visibility over the higher mountain passes especially tonight with poor travel conditions expected as the heavier snow begins this evening. Across northeast Colorado there will be a chance of rain showers tonight as a weather disturbance moves across. Meanwhile gusty west to northwest winds are expected this afternoon with gusts up to 40 mph near the foothills and along the Wyoming border. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Mountain snow will taper off Saturday morning, although gusty winds will continue for much of the day, producing blowing and drifing snow. The next round of wintry weather will be Sunday night into Monday morning, when additional snow will create a slippery morning commute, mainly in the mountains. Strong winds over the foothills and mountains may gust as high as 60 mph as well. If you are traveling into the Colorado high country this weekend be prepared for hazardous winter travel conditions including snowpacked roads and reduced visibility in snow and blowing snow. The plains will see mainly dry conditions, seasonal temperatures, and gusty winds at times. Expect strong northwest winds on the plains Saturday afternoon with gusts up to 50 mph possible. A few rain and snow showers will be possible on Saturday, and again Sunday night through Monday. The Sunday night into Monday disturbance may bring some snow accumulation to portions of the plains. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed today or tonight.
The national radar mosaic for the moment the first event began.
3 winter weather, 2 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2018Every state in 2018This day in weather historyWarnings in Colorado, November 2018
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: 792720, 792722, 792723, 794365, 794366.