Alert archive / Colorado / Red Flag Warnings in 2026
Red Flag Warning 41, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Jun 5, 2026, 1:00 PM MDT for 5 counties in Colorado. It took effect at Jun 6, 2026, 12:00 PM MDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Jun 5, 2026, 1:00 PM MDT (19:00 UTC)
- In effect from
- Jun 6, 2026, 12:00 PM MDT
- Expired
- Jun 6, 2026, 7:00 PM MDT
- In force
- 7 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Adams County, CO, Arapahoe County, CO, Logan County, CO, Morgan County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 67 km from the middle of the area, began a volume at 19:01 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The text
As transmitted.
766 WWUS85 KBOU 051900 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 100 PM MDT Fri Jun 5 2026 COZ242>245-248-060300- /O.NEW.KBOU.FW.W.0041.260606T1800Z-260607T0100Z/ Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties-Logan County- 100 PM MDT Fri Jun 5 2026 ...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE NORTHERN PLAINS OF NORTHEAST COLORADO... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from noon to 7 PM MDT Saturday. * AFFECTED AREA...Fire Weather Zones 242, 243, 244, 245 and 248. * TIMING...From noon to 7 PM MDT Saturday. * WINDS...South 15 to 25 mph with gusts up to 40 mph. * RELATIVE HUMIDITY...As low as 12 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
4 follow-up statements
649 WWUS85 KBOU 060254 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 854 PM MDT Fri Jun 5 2026 COZ242>245-248-061800- /O.CON.KBOU.FW.W.0041.260606T1800Z-260607T0100Z/ Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties-Logan County- 854 PM MDT Fri Jun 5 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 7 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE NORTHERN PLAINS OF NORTHEAST COLORADO... * AFFECTED AREA...Fire Weather Zones 242, 243, 244, 245 and 248. * TIMING...From noon to 7 PM MDT Saturday. * WINDS...South 15 to 25 mph with gusts up to 40 mph. * RELATIVE HUMIDITY...As low as 13 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
851 WWUS85 KBOU 060925 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 325 AM MDT Sat Jun 6 2026 COZ242>245-248-062200- /O.CON.KBOU.FW.W.0041.260606T1800Z-260607T0100Z/ Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties-Logan County- 325 AM MDT Sat Jun 6 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE NORTHEAST PLAINS OF COLORADO... * AFFECTED AREA...Fire Weather Zones 242, 243, 244, 245 and 248. * TIMING...From noon today to 7 PM MDT this evening. * WINDS...Southeast 15 to 25 mph with gusts up to 30 mph. * RELATIVE HUMIDITY...As low as 14 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
249 WWUS85 KBOU 061958 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 158 PM MDT Sat Jun 6 2026 COZ242>245-248-070100- /O.CON.KBOU.FW.W.0041.000000T0000Z-260607T0100Z/ Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties-Logan County- 158 PM MDT Sat Jun 6 2026 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE NORTHEAST PLAINS OF COLORADO... * AFFECTED AREA...Fire Weather Zones 242, 243, 244, 245 and 248. * TIMING...Until 7 PM MDT this evening. * WINDS...Southeast 15 to 25 mph with gusts up to 35 mph. * RELATIVE HUMIDITY...As low as 14 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
261 WWUS85 KBOU 070104 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 704 PM MDT Sat Jun 6 2026 COZ242>245-248-070215- /O.EXP.KBOU.FW.W.0041.000000T0000Z-260607T0100Z/ Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties-Logan County- 704 PM MDT Sat Jun 6 2026 ...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE HUMIDITY FOR PORTIONS OF THE NORTHEAST PLAINS OF COLORADO... Relative humidities have improved and therefore the Red Flag Warning has been allowed to expire. $$
What forecasters said that day
The local office's own words before this red flag warning went out, 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 this red flag warning went out at Jun 5, 11:38 AM MDT, 1 hour 22 minutes earlier. Its key messages:
- Warm today with a couple late day thunderstorms mainly south of Denver.
- Hot weekend ahead with high temperatures soaring into the mid 90s across the I-25 Corridor and plains.
- An early season heat wave likely Tuesday and Wednesday, possibly lasting into Thursday of next week. Highs near 100 degrees possible across portions of the plains.
Area forecast discussion, Jun 5, 11:38 AM MDT, 1 hour 22 minutes before
Area Forecast Discussion National Weather Service Denver/Boulder CO 1138 AM MDT Fri Jun 5 2026 .KEY MESSAGES... - Warm today with a couple late day thunderstorms mainly south of Denver. - Hot weekend ahead with high temperatures soaring into the mid 90s across the I-25 Corridor and plains. - An early season heat wave likely Tuesday and Wednesday, possibly lasting into Thursday of next week. Highs near 100 degrees possible across portions of the plains. && .DISCUSSION /Through Thursday/... Issued at 241 AM MDT Fri Jun 5 2026 A weak cool front was pushing southward through southeast Wyoming and the Nebraska Panhandle in these wee morning hours. Given surface pressure rises are still organizing to the north, that front is expected to push across all of the plains early this morning. Only slight cooling can be expected today, however, as the front will be rather shallow and offset by warm air aloft and plenty of morning sunshine. We will see boundary layer moistening, but also some low level stability given the slightly cooler temperatures but still very warm airmass aloft. Thus, it will be hard to reach convective temperatures over the plains and for the most part they should stay capped off. However, the mountains and elevated heat sources of the foothills and Palmer Divide will be more prone to surface based convection given expectations of dry adiabatic warming. Thus, we expect to see isolated high based convection originate in the early to mid afternoon hours there. Despite slight stability in the lower elevations, they will still attempt to move eastward into the adjacent lower elevations with perhaps even the southern portions of metro Denver seeing an isolated late day or early evening storm, although gusty outflow winds would be more likely than any rain. Full on summer heat will arrive this weekend underneath upper level ridging. We'll be essentially caught in between a weak upper low drifting north through the Southern and Central Plains and a deep mid latitude trough over the Pacific Northwest (PNW). That supports development of southwest mid level flow and warm advection. High temperatures will warm into the mid 90s over most of the plains, with potentially a few spots getting into the upper 90s (depending on any influence from the trough to our east). Denver's record for Saturday is 95F, and we should be very close to that. Sunday's is a bit warmer (98F). While we should stay just shy of Heat Advisory criteria, the record/near record heat early in the season could put added stress on people who plan to be outside for a majority of the day. Stay hydrated and avoid strenuous outdoor activity during peak heating. We will see isolated high based convection once again on Saturday as limited low/mid level moisture remains under the ridge. Sunday should trend mostly dry. For Monday, we'll likely see a brief respite in the heat due to a weak backdoor cold front - courtesy of the ejecting PNW trough. We're confident (>80% chance) that we'll be right back to the frying pan, however, for Tuesday and Wednesday. A strong ridge aloft will develop over the Central Plains while a trough moves into the western United States. That will lead to increasing southwest flow across Colorado, further warm advection, and downslope compressional warming. The combination of these factors will lead to record/near record heat. Denver's record high of 95F on Tuesday seems likely (60% chance) to be tied or broken, while the record high of 99F on Wednesday has a chance (20-30%) of being reached. Although recent greenup has been helpful, locally critical fire weather conditions may start entering the picture again if fuels dry sufficiently in the hot, dry, and windier weather. In contrast to yesterday's models, there is now some uncertainty as to how long this heat wave will last, as both the latest EPS and GEFS have cooled things off for Thursday. There seemed to be better agreement with a quicker ejecting trough across the Northern Rockies. Whether this is just a one-off or a meaningful trend is yet to be seen, so something to watch in upcoming runs. && .AVIATION /18Z TAFS through 18Z Saturday/... Issued at 1135 AM MDT Fri Jun 5 2026 VFR conditions are expected throughout the TAF period. GOES-19 satellite imagery earlier this morning depicted some low clouds across northeast Colorado as close to the TAF sites as northeast Morgan County. These clouds have since scattered out. Some mid- level clouds are moving over KDEN at the present time. For this afternoon, virga showers are expected mainly for areas near the Palmer Divide, potentially including KAPA where a TEMPO is in place. KDEN could narrowly avoid these virga showers today, but some gusty southerly winds to around 25 kts are still possible from these showers located to the south. No impacts from virga are expected today at KBJC. Winds will turn to drainage tonight, but will still be around 10 kts. Winds should have a southerly to southwesterly component for most of the day tomorrow. For tomorrow afternoon, have introduced a PROB30 for virga showers. The latest HRRR model runs have depicted scattered virga showers, DCAPE as high as 1500 J/kg, and decent mid-level moisture. Other CAMs are also showing some scattered virga showers near the TAF sites. These showers could produce wind gusts as high as 30 kts and briefly lower the cloud deck to about 10000 ft AGL. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && DISCUSSION...20 AVIATION...MV
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 5, 4:33 PM MDT | Special Weather Statement | BOU | Elbert | 27 min |
| Jun 5, 5:03 PM MDT | Special Weather Statement | BOU | Elbert | 27 min |
| Jun 5, 5:10 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 35 min |
| Jun 5, 5:44 PM MDT | Special Weather Statement | BOU | Elbert | 31 min |
Nearby
Red Flag Warnings in Colorado, 2026Every red flag warning in 2026
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.