Breezy conditions developed across western Colorado as a shortwave trough approached the region from the Pacific Northwest. Some wind gusts met High Wind Warning criteria across northwest Colorado.
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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 GJT wrote it up.
Breezy conditions developed across western Colorado as a shortwave trough approached the region from the Pacific Northwest. Some wind gusts met High Wind Warning criteria across northwest Colorado.
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 Grand Junction, CO wrote its last area forecast discussion before the first event at Nov 18, 11:09 AM MST, 2 hours 44 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 1109 AM MST Wed Nov 18 2020 .SHORT TERM...(Today through Thursday) Issued at 200 AM MST Wed Nov 18 2020 Modest southwest flow has become established across the area in between the midlevel ridge over the plains and a Pacific Northwest trough. Warm advection, increasing cirrus and breezy conditions in the higher elevations have kept temperatures from dropping much this morning. With the onset of daytime heating strong winds will begin to mix down into the lower valleys. Temperatures today will be the warmest of the week with some areas possibly approaching record values. Density of the cirrus cloud cover will determine whether records fall. The Pacific Northwest trough begins to break down today with most of the energy tracking over the northern Rockies. Lows tonight are expected to be warmer than this morning by several degrees mainly due to the warm advection pattern and clouds. The northern trough sends cooler air southward tomorrow so record highs seem less likely, but it will still be unseasonably warm. The pressure gradient will also relax therefore conditions will not be as breezy. A weak front associated with the trough looks to clip portions of northern Colorado bringing Pacific moisture into the region. This may result in snow showers to the Elkheads and Park range with minor accumulations in the highest elevations. .LONG TERM...(Thursday night through Tuesday) Issued at 200 AM MST Wed Nov 18 2020 The models are still showing that a positively tilted shortwave will reach the forecast area on Friday night and Saturday. The dynamics are not overly impressive, but the persist flow looks to usher in Pacific moisture ahead of the wave. The jet may also provide some lift and support showers mainly in the higher elevations. Valleys might not see much with the warm and dry low levels. The models are indicating instability especially over the southeastern half of the forecast area on Saturday, so there may be some banding. Warm temperatures in the profile and potential convection may result in lowered snow to liquid ratios. The precipitation looks to dissipate Saturday evening as the lift moves east of the Divide. The model consensus QPF has actually come down a bit and so have the snow amounts. There are really no indications that this wave will be stronger than what is currently forecasted. This system will cool temperatures back to near normal by Sunday as a midlevel ridge quickly moves over the region. Under this ridge conditions will be mostly dry ahead of another approaching wave. This introduces chances for precipitation centered around Tuesday, but there is a fair amount of disagreement. In the extended the GFS is still quasi-zonal while the Canadian and EC show a more amplified pattern across the west. && .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1106 AM MST Wed Nov 18 2020 VFR conditions will prevail for the next 24 hours with scattered to broken cloud cover. LLWS will continue across many TAF sites due to strong southwest flow aloft and lighter valley winds. These winds will mix to the surface this afternoon with gusts in the 25 to 35 mph range at times. Winds will decouple after sunset with generally light, terrain driven winds in the valleys with LLWS still present. Higher elevation TAF sites may still remain occasionally breezy. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...KJS LONG TERM...KJS AVIATION...MDA
Hazardous Weather Outlook National Weather Service Grand Junction CO 348 AM MST Wed Nov 18 2020 COZ001>014-017>023-UTZ022>025-027>029-191100- Lower Yampa River Basin-Central Yampa River Basin- Roan and Tavaputs Plateaus-Elkhead and Park Mountains- Upper Yampa River Basin-Grand Valley-Debeque to Silt Corridor- Central Colorado River Basin-Grand and Battlement Mesas- Gore and Elk Mountains/Central Mountain Valleys- Central Gunnison and Uncompahgre River Basin- West Elk and Sawatch Mountains-Flat Tops- Upper Gunnison River Valley-Uncompahgre Plateau and Dallas Divide- Northwest San Juan Mountains-Southwest San Juan Mountains- Paradox Valley/Lower Dolores River- Four Corners/Upper Dolores River-Animas River Basin- San Juan River Basin-Southeast Utah-Eastern Uinta Mountains- Eastern Uinta Basin-Tavaputs Plateau-Arches/Grand Flat- La Sal and Abajo Mountains-Canyonlands/Natural Bridges- 348 AM MST Wed Nov 18 2020 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday A system could bring precipitation to the area beginning on Thursday with chances continuing through Saturday. Accumulating snow is possible in high mountain elevations which will be more widespread on Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
A peak gust of 58 MPH was recorded by the automated sensor at the Craig-Moffat County Airport.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Colorado in 2020Every state in 2020This day in weather historyWarnings in Colorado, November 2020
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: 921527.