Alert archive / Colorado / Red Flag Warnings in 2026
Red Flag Warning 21, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Mar 12, 2026, 8:58 PM MDT for 16 counties in Colorado. It took effect at Mar 14, 2026, 11:00 AM MDT. It was in force for 10 hr. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Mar 12, 2026, 8:58 PM MDT (02:58 UTC)
- In effect from
- Mar 14, 2026, 11:00 AM MDT
- Expired
- Mar 14, 2026, 9:00 PM MDT
- In force
- 10 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 42 km from the middle of the area, began a volume at 03:00 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Mar 14, 5:00 PM MDT | NON-TSTM WND GST 100 | Sunshine, CO | XCEL Energy Wind Sensor XL168. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 3.0 hours before the alert went out and 325 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 3781 m above ground
- 0-6 km bulk shear
- 62 kt
- 0-1 km storm-relative helicity
- 289 m²/s²
- 0-3 km storm-relative helicity
- 262 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
195 WWUS85 KBOU 130258 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 858 PM MDT Thu Mar 12 2026 COZ238>249-132100- /O.EXP.KBOU.FW.W.0019.000000T0000Z-260313T0300Z/ /O.UPG.KBOU.FW.A.0016.260314T1700Z-260315T0300Z/ /O.NEW.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ /O.CON.KBOU.FW.W.0020.260313T1700Z-260314T0200Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County- 858 PM MDT Thu Mar 12 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 8 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... ...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 11 AM to 9 PM MDT Saturday. The Fire Weather Watch is no longer in effect. * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248 and 249. * TIMING...For Friday, from 11 AM to 8 PM MDT. For Saturday, from 11 AM to 9 PM MDT Saturday. * WINDS...On Friday, west winds 15 to 25 mph with gusts 25 to 40 mph. On Saturday, west winds 20 to 30 mph with gusts 35 to 50 mph. * RELATIVE HUMIDITY...On Friday, 12 to 17 percent. On Saturday, 10 to 15 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. && $$ COZ250-251-132100- /O.EXP.KBOU.FW.W.0019.000000T0000Z-260313T0300Z/ /O.NEW.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ /O.EXA.KBOU.FW.W.0020.260313T1700Z-260314T0200Z/ Sedgwick County-Phillips County- 858 PM MDT Thu Mar 12 2026 ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 8 PM MDT FRIDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR SEDGWICK AND PHILLIPS COUNTIES... ...RED FLAG WARNING IN EFFECT FROM 11 AM TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR SEDGWICK AND PHILLIPS COUNTIES... ...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR SEDGWICK AND PHILLIPS COUNTIES... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 11 AM to 8 PM MDT Friday. A Red Flag Warning has also been issued from 11 AM to 9 PM MDT Saturday. * AFFECTED AREA...Fire Weather Zones 250 and 251. * TIMING...For Friday, from 11 AM to 8 PM MDT. For Saturday, from 11 AM to 9 PM MDT Saturday. * WINDS...On Friday, west winds 15 to 20 mph with gusts up to 35 mph. On Saturday, west winds 15 to 25 mph with gusts up to 40 mph. * RELATIVE HUMIDITY...As low as 13 to 18 percent both days. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ Rodriguez
6 follow-up statements
873 WWUS85 KBOU 130906 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 306 AM MDT Fri Mar 13 2026 COZ238>251-140015- /O.CON.KBOU.FW.W.0020.260313T1700Z-260314T0200Z/ /O.CON.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 306 AM MDT Fri Mar 13 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * TIMING...For the first Red Flag Warning, from 11 AM this morning to 8 PM MDT this evening. For the second Red Flag Warning, from 11 AM to 9 PM MDT Saturday. * WINDS...Today, west winds 15 to 25 mph with gusts 25 to 40 mph. On Saturday, west winds 20 to 30 mph with gusts 35 to 50 mph. * RELATIVE HUMIDITY...Today, 12 to 17 percent. On Saturday, 10 to 15 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. && $$
558 WWUS85 KBOU 132320 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 520 PM MDT Fri Mar 13 2026 COZ238>251-140200- /O.CON.KBOU.FW.W.0020.000000T0000Z-260314T0200Z/ /O.CON.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 520 PM MDT Fri Mar 13 2026 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * TIMING...For the first Red Flag Warning, until 8 PM MDT this evening. For the second Red Flag Warning, from 11 AM to 9 PM MDT Saturday. * WINDS...Today, west winds 15 to 25 mph with gusts 25 to 35 mph. On Saturday, west winds 20 to 30 mph with gusts 35 to 60 mph, strongest west of I-25. * RELATIVE HUMIDITY...Today, 12 to 17 percent. On Saturday, 8 to 15 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. && $$ Rodriguez
128 WWUS85 KBOU 140158 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 758 PM MDT Fri Mar 13 2026 COZ238>251-141200- /O.EXP.KBOU.FW.W.0020.000000T0000Z-260314T0200Z/ /O.CON.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 758 PM MDT Fri Mar 13 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 9 PM MDT SATURDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * TIMING...From 11 AM to 9 PM MDT Saturday. * WINDS...West winds 20 to 35 mph with gusts 35 to 60 mph, strongest west of I-25 mid to late afternoon. * RELATIVE HUMIDITY...As low as 7 to 14%. * 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. && $$ Rodriguez
837 WWUS85 KBOU 140936 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 336 AM MDT Sat Mar 14 2026 COZ238>251-142145- /O.CON.KBOU.FW.W.0021.260314T1700Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 336 AM MDT Sat Mar 14 2026 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * TIMING...From 11 AM this morning to 9 PM MDT this evening. * WINDS...West 25 to 35 mph with gusts up to 60 mph. Areas near the foothills, from Boulder county into northern Jefferson county, may see winds gusts from 65 to 70 mph for a few hours this afternoon, * RELATIVE HUMIDITY...As low as 8 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
749 WWUS85 KBOU 142028 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 228 PM MDT Sat Mar 14 2026 COZ238>251-150300- /O.CON.KBOU.FW.W.0021.000000T0000Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 228 PM MDT Sat Mar 14 2026 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE URBAN CORRIDOR AND PLAINS... * AFFECTED AREA...Fire Weather Zones 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * TIMING...Until 9 PM MDT this evening. * WINDS...West 20 to 30 mph with gusts up to 60 mph. * RELATIVE HUMIDITY...As low as 7 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. && $$
537 WWUS85 KBOU 150230 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 830 PM MDT Sat Mar 14 2026 COZ238>251-150330- /O.EXP.KBOU.FW.W.0021.000000T0000Z-260315T0300Z/ Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 830 PM MDT Sat Mar 14 2026 ...RED FLAG WARNING WILL EXPIRE AT 9 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR THE PLAINS AND URBAN CORRIDOR. $$ Rodriguez
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 12, 11:12 PM MDT | Winter Weather Advisory | BOU | Arapahoe, Boulder, Clear Creek, Douglas, Elbert, Gilpin and 6 more | 61 hr |
| Mar 13, 11:25 AM MDT | High Wind Watch | BOU | Adams, Arapahoe, Broomfield, Denver, Douglas, Elbert and 7 more | 27 hr |
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.