A lightning strike ignited a wildfire 18 miles northwest of Greystone.
Every event with a place to put it; 1 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 GJT wrote it up.
A lightning strike ignited a wildfire 18 miles northwest of Greystone.
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 Aug 1, 1:34 PM MST, 1 hour 28 minutes earlier.
Area Forecast Discussion National Weather Service Grand Junction CO 234 PM MDT Sat Aug 1 2020 .SHORT TERM...(Tonight through Sunday night) Issued at 234 PM MDT Sat Aug 1 2020 12Z GJT RAOB continues to show a deeply mixed atmosphere with enough moisture sitting on top of the EML to have kept accas w/virga floating around through the morning. In fact satellite imagery suggests either we are either recirculating moisture or advecting it under the ridge. Strong heating and orographic circulations have once again popped storms on about every ridge line with storms drifting southward. The stronger storms will likely survive into adjacent valleys for some brief rainfall...otherwise most valleys will just see some gusty winds from the dissipating storms. The main threat besides outflow will be new fire starts from the lightning. Expect the diurnal trend of storms dying off by sunset to continue tonight. Some of the CAMs show lingering weak echos overnight which will likely be accas and virga showers similar to this morning...that once again sprouts into convection again tomorrow afternoon. A rinse and repeat scenario though the ridge axis is shifting closer and the drier air the previous discussion was mentioning is likely to mix in. A slight downturn in coverage? Possible. More confident in the much above normal high temperatures remaining in place with continued triple digit readings over much of the lower desert valleys. Luckily the dry airmass continues to allow for decent...but only temporary...cooling at night. .LONG TERM...(Monday through Saturday) Issued at 234 PM MDT Sat Aug 1 2020 The ridge axis over the Southwest will shift slightly to the east on Monday, although with PWAT values still forecast to be around 0.5 inches, the chance for showers and thunderstorms on the higher terrain remains. However, with a trough moving into the Pacific Northwest and forcing the ridge to flatten out and break down on Tuesday and into Wednesday, dry conditions with well above normal temperatures are expected. A bit of a pattern shift is forecast to occur mid next week, setting up conditions for a late-week push of monsoonal moisture. The ridge breaking down to the southeast of the CWA combining with a weak trough moving into northern California we help to set up a south-southwesterly flow that will strengthen by Thursday. This flow will transport moisture northward, and is indicated in both of the major global models in both the forecasted dew points and the forecasted PWATs. In addition, a subtle shortwave moving through the base of the trough will provide some additional lift for southeast Utah and much of western Colorado. Should this forecasted situation pan out as currently modeled, heavy rain and flash flooding could be possible. For Friday, and into the weekend, confidence is much lower. An area of drier air has been forecast to form over the Great Basin, and the GFS has been shifting this drier air further and further into western Colorado with each subsequent model run, bringing the return of hot and dry conditions for the weekend. However, the ECMWF has been holding onto the moisture and chances of showers and storms for this period. && .AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon) Issued at 1131 AM MDT Sat Aug 1 2020 Isolated to scattered thunderstorm development is expected through the afternoon and early evening as heating of the day taps into moisture aloft. The main threat to aviation will be the gusty outflow winds which could exceed 40 mph. Confidence not high on timing in forecast due to coverage. Southward drifting storms off the terrain would suggest KDRO has the highest probability of seeing these gusty winds. VFR should prevail over the next 24 hours. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && SHORT TERM...15 LONG TERM...BGB AVIATION...TGJT
Hazardous Weather Outlook National Weather Service Grand Junction CO 801 AM MDT Sat Aug 1 2020 COZ001>014-017>023-UTZ022>025-027>029-021415- 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- 801 AM MDT Sat Aug 1 2020 This hazardous weather outlook is for eastern Utah and western Colorado. .DAY ONE...Today and Tonight Isolated showers and thunderstorms are possible over the higher terrain with some brief gusty winds in the San Juans. .DAYS TWO THROUGH SEVEN...Sunday through Friday No hazardous weather is expected at this time. A better push of monsoon moisture is possible by Thursday and Friday. Until then, only isolated afternoon mountain showers are likely. .SPOTTER INFORMATION STATEMENT... Spotter activation will not be needed.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
346 PM MDT SAT AUG 1 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0231 PM TSTM WND GST 3 WSW OXFORD 37.15N 107.77W
08/01/2020 M62 MPH LA PLATA CO ASOS
ASOS STATION KDRO DURANGO LA PLATA CNTY
AIRPORT.
&&
KJSThe national radar mosaic for the moment the first event began.
1 wildfire. Local standard time, as filed.
The Irish Fire began in early August due to lightning 18 miles northwest of Greystone and grew to 100 acres before it was contained almost a week 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, August 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: 899781.