A wildfire began from unknown causes 20 miles west of Gunnison.
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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.
A wildfire began from unknown causes 20 miles west of Gunnison.
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 4, 4:20 AM MST, 5 hours 10 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 420 AM MST Wed Nov 4 2020 .SHORT TERM...(Today through Thursday) Issued at 204 AM MST Wed Nov 4 2020 A weak upper-level low pressure center will continue to deamplify and shift east of the divide this Wednesday morning. Lingering mid-level cloud cover this morning is expected to scatter out through the late morning leading to a mainly sunny afternoon. Forecast high temperatures will continue to run near 10 degrees above average over much of the western slope. High pressure will build over the southern Rockies overnight and into Thursday. Expect afternoon highs to tick upward a few more degrees on Thursday afternoon...with temperatures near 70 degrees possible in the Grand Valley and low 70s farther west into Utah canyon country. Forecast confidence remains high through the short term and only minimal adjustments to temperatures were made in this package. .LONG TERM...(Thursday night through Tuesday) Issued at 204 AM MST Wed Nov 4 2020 A potent low pressure system will crash into the Pacific Coast on Friday. As it does, the pressure gradient between this low pressure and high pressure over the southern Rockies/Plains will strengthen, leading to a windy afternoon over the Four Corners states. Temperatures will remain quite warm...around 10-15 degrees above average...under dry southwesterly flow. On Saturday, a stream of moisture will push inland under strong southwesterly flow ahead of the area of low pressure. Forecast guidance has not handled the timing and placement of this pre- frontal moisture stream well. Have opted to decrease the amount of QPF in the San Juan mountains on Saturday in this forecast compared to model blends/WPC guidance, given fast flow and lingering dry low-levels. As better forcing and a deeper moisture plume arrive on Saturday evening and overnight, confidence in precipitation increases dramatically. A strong cold front will surge eastward on Saturday evening and overnight, pushing well east of the divide by sunrise Sunday. Temperatures will crash behind this front, resulting in snow for much of the western slope. It does not appear as though much moisture will linger behind this boundary in the lower valleys however, and any snowfall here will likely be brief with limited/no accumulations. The northern and central mountains are on track for around 2-6 inches from this front/low pressure system, with over 6 inches likely in the San Juans. A secondary low pressure system arrives on Sunday evening into Monday. The GFS and ECMWF are in better agreement with this secondary system, supporting temperatures 10-15 degrees below average and a good chance of snow for much of central and southern Utah and Colorado. Snow ratios will be much higher with this colder system, and a chance for accumulating snow does exist for the lower valleys such as Grand Junction, Montrose, Durango and Cortez. Regarding storm total liquid by the time precipitation ends on Tuesday afternoon, 1-2" is certainly possible for the San Juans. The central and northern mountains will likely see 0.5-1", with 0.25-0.5" likely for most lower valleys in Colorado. Eastern Utah will see slightly less liquid, however mountain locations will still likely approach 0.4-0.5" total. Snow ratios will change dramatically through this event, with a heavy wet snow falling initially on Saturday-Saturday night, changing to a much lighter snow by Sunday and Monday. It is possible that some locations in the San Juan mountains may see snow totals in the 1-2 foot range by Tuesday. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 415 AM MST Wed Nov 4 2020 Mid-level clouds have persisted overnight in the central and northern terminals in the wake of the departing upper-level low. These clouds will remain above ILS thresholds however may linger through the morning hours. Clouds will clear by later afternoon with light winds, except a few afternoon gusts at DRO. VFR is expected at all terminals. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...MAC LONG TERM...MAC AVIATION...MAC
Hazardous Weather Outlook National Weather Service Grand Junction CO 238 AM MST Wed Nov 4 2020 COZ001>014-017>023-UTZ022>025-027>029-050945- 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- 238 AM MST Wed Nov 4 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 cold front will bring rain and then snow to the western slope from Saturday through Monday. Expect some isolated thunder on Saturday with snow accumulating from Saturday night onwards through Monday. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
The national radar mosaic for the moment the first event began.
1 wildfire. Local standard time, as filed.
The Poison Springs Fire began in early November 20 miles west of Gunnison from unknown causes. The fire grew to 105 acres before it was contained two weeks later.
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: 922679.