During the late evening of the 8th, light snow developed over Eastern Colorado, gradually spreading east through the night and into the following morning. Snowfall amounts ranged from a trace to as much as six inches, with the higher amounts in far southwest Yuma County and northwest Kit Carson County where the band of snow was the strongest.
Every event with a place to put it; 3 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 GLD wrote it up.
During the late evening of the 8th, light snow developed over Eastern Colorado, gradually spreading east through the night and into the following morning. Snowfall amounts ranged from a trace to as much as six inches, with the higher amounts in far southwest Yuma County and northwest Kit Carson County where the band of snow was the strongest. Snowfall amounts generally declined to the east to less than an inch east of the Colorado border. The snow changed to rain during the morning before ending. This snow event broke the record for the earliest snowfall of the season. Prior records for the first snow of the season ranged from the 11th to the 27th of September.
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 Goodland, KS wrote its last area forecast discussion before the first event at Sep 8, 10:18 PM MST, 27 minutes earlier.
Area Forecast Discussion National Weather Service Goodland KS 1118 PM MDT Tue Sep 8 2020 .UPDATE... Issued at 944 PM MDT Tue Sep 8 2020 Have issued an update to the forecast for the addition of isolated thunderstorms for areas along and east of a line from the McCook area southwest to Colby and down to Greeley. Most of the lightning with any that do pop up is in-cloud, with very few cloud-to-ground strikes. Any cells that do pop up are on a northeast track. && .SHORT TERM...(This evening through Wednesday night) Issued at 345 PM MDT Tue Sep 8 2020 Overview: An upper level low, presently situated in eastern Utah, will meander invof the 4-Corners tonight and Wednesday. Exceedingly challenging forecast, particularly with regard to precipitation type/amounts. Diffluent flow aloft, broad mid-level warm advection (on the eastern periphery of the upper low), and DPVA assoc/w shortwave energy rounding the base of the upper low (and ejecting northeast into the Central Plains) -- will aid in the development of widespread precipitation across the Tri-State area late this evening into Wednesday. Although confidence is high that precipitation will occur, significant uncertainty persists w/regard to the magnitude/distribution of precipitation -- and marginal (i.e. near-to-above freezing) thermodynamic profiles and a relatively homogeneous airmass in place over/upstream of the region suggest that precipitation type (RA|SN) will be rate- driven in nature. With this in mind, the relative best potential for wet snow accumulation appears to be above ~4,000 ft ASL (i.e. west of the KS/CO border).. mainly between Midnight and Noon Wednesday. .LONG TERM...(Thursday through Tuesday) Issued at 125 PM MDT Tue Sep 8 2020 The main focus for the extended period will be rain chances on Thursday and Friday and the rebounding to near normal temperatures into the weekend. Starting Thursday, guidance has come into agreement that an upper level low is slated to be over the Four Corners region providing southwesterly flow into the region; timing appears to have slowed down since yesterday mornings discussion. Rain chances remain possible on Thursday evening and Friday a few thunderstorms may be possible on Friday as well as guidance is hinting at some instability across western Kansas. Below normal high temperatures are expected but warming up compared to the beginning of the week temperatures with highs in the upper 50's to upper 60's are likely. Low temperatures will still remain below normal with lower 40's's across east Colorado. Highs on Friday will reach the lower 70's. Into the weekend, drier weather looks to be in store with the passage of a weak cold front associated with a surface trough to our NE early Saturday morning. The main threat as of right now with this weak cold front is just a wind shift from south to north and maybe a brief period of gusty winds with the passage. Northwest flow is expected to develop over the Tri-State area as ridging develops over the NW CONUS. Temperatures for the weekend will continue to warm back up into the upper 70's on Saturday and Sunday. Low temperatures will also begin climbing back up to near normal as well from the 40's up to near 50 by Sunday morning. Monday and Tuesday continue to look dry as well with ridging firmly over the Central Plains. Temperatures will max out in the low to mid 80's. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1118 PM MDT Tue Sep 8 2020 For KGLD, MVFR skies to start the forecast, with a trend to IFR conditions by 10z Wednesday. Ceilings will range OVC015 to start, down to OVC005-008. Visibility will range from 2-6sm in rain/fog. Winds, NNE around 15-30kts. For KMCK, MVFR ceilings thru 11z Wednesday, then IFR/MVFR mix. A range of OVC009 up to OVC012-025. 3-6sm in light rain/fog. Winds, NNE 10-15kts with gusts up to 25kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...Freeze Warning until noon MDT Wednesday for COZ090>092. NE...NONE. && UPDATE...JN SHORT TERM...VINCENT LONG TERM...TT AVIATION...JN
Hazardous Weather Outlook National Weather Service Goodland KS 652 PM MDT Tue Sep 8 2020 COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-100100- Yuma County-Kit Carson County-Cheyenne County-Cheyenne-Rawlins- Decatur-Norton-Sherman-Thomas-Sheridan-Graham-Wallace-Logan-Gove- Greeley-Wichita-Dundy-Hitchcock-Red Willow- 652 PM MDT Tue Sep 8 2020 /752 PM CDT Tue Sep 8 2020/ This hazardous weather outlook is for extreme southwest Nebraska... northwest Kansas and east central Colorado. .DAY ONE...TONIGHT... A Freeze Warning remains in effect for Eastern Colorado until noon Wednesday. As temperatures decrease to near or below freezing, snow will begin to mix in with some locales seeing mostly snow during the later hours of the night. 1 to 4 inches will be possible with lower amounts being more common. The wintry precipitation and freezing temperatures may extend slightly further east into portions of northwest Kansas or southwest Nebraska. However, most of this area will see light to moderate rain through the night. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH TUESDAY... Freezing temperatures from the prior night will begin to warm during the morning hours and all remaining precipitation will turn to rain. Freezing temperatures may be possible Wednesday night into Thursday morning for far western portions of the Tri-State area. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated.
The national radar mosaic for the moment the first event began.
3 winter weather. Local standard time, as filed.
Snowfall amounts for the county were around an inch.
Snowfall amounts ranged from a trace to as much as six inches across the county. The highest amounts occurred in the northwest part of the county, with snow amounts around an inch or two being more common elsewhere.
Snowfall amounts ranged from two to four and a half inches across the county, with the highest amounts over the southwest. Snow amounts of two to three inches were most common.
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, September 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: 921955, 921957, 921958.