Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 6, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Apr 7, 2021, 2:49 PM MDT for 11 counties in Colorado. It took effect at Apr 8, 2021, 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
- Apr 7, 2021, 2:49 PM MDT (20:49 UTC)
- In effect from
- Apr 8, 2021, 12:00 PM MDT
- Expired
- Apr 8, 2021, 7:00 PM MDT
- In force
- 7 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Adams County, CO, Arapahoe County, CO, Elbert 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), 80 km from the middle of the area, began a volume at 20:55 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 nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 8.8 hours before the alert went out and 51 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
- 1574 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 180 m²/s²
- 0-3 km storm-relative helicity
- 298 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
410 WWUS85 KBOU 072049 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 249 PM MDT Wed Apr 7 2021 COZ238-242>246-248>251-081100- /O.UPG.KBOU.FW.A.0003.210408T1800Z-210409T0100Z/ /O.NEW.KBOU.FW.W.0006.210408T1800Z-210409T0100Z/ Larimer County Below 6000 Feet/Northwest Weld County- 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-Logan County-Washington County-Sedgwick County- Phillips County- 249 PM MDT Wed Apr 7 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR MUCH OF THE NORTHEAST PLAINS OF COLORADO...INCLUDING FIRE WEATHER ZONES... 238...242...243...244...245...246...248...249...250...and 251... 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 Thursday. The Fire Weather Watch is no longer in effect. * Affected Area...Fire Weather Zones 238, 242, 243, 244, 245, 246, 248, 249, 250 and 251. * Timing...Noon to 7 PM MDT Thursday. * Winds...Northwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 10 percent. * Impacts...Strong winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. 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. && $$ COZ247-081100- /O.NEW.KBOU.FW.W.0006.210408T1800Z-210409T0100Z/ Southeast Elbert County Below 6000 Feet/South Lincoln County- 249 PM MDT Wed Apr 7 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR SOUTHERN lINCOLN COUNTY...FIRE WEATHER ZONE 247... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from noon to 7 PM MDT Thursday. * Affected Area...Fire Weather Zone 247. * Timing...Noon to 7 PM MDT Thursday. * Winds...Northwest 10 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
3 follow-up statements
488 WWUS85 KBOU 080925 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 325 AM MDT Thu Apr 8 2021 COZ238-242>251-081730- /O.CON.KBOU.FW.W.0006.210408T1800Z-210409T0100Z/ Larimer County Below 6000 Feet/Northwest Weld County- 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- 325 AM MDT Thu Apr 8 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MUCH OF THE NORTHEAST PLAINS OF COLORADO...INCLUDING FIRE WEATHER ZONES... 238...242...243...244...245...246...248...249...250...AND 251... * Affected Area...Fire Weather Zones 238, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * Timing...Noon to 7 PM MDT Thursday. * Winds...Northwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. 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. && $$
479 WWUS85 KBOU 081655 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 1055 AM MDT Thu Apr 8 2021 COZ238-242>251-090100- /O.CON.KBOU.FW.W.0006.210408T1800Z-210409T0100Z/ Larimer County Below 6000 Feet/Northwest Weld County- Northeast Weld County-Central and South Weld County-Morgan County- Central and East Adams and Arapahoe Counties- North and Northeast Elbert County Below 6000 Feet/North Lincoln County- Southeast Elbert County Below 6000 Feet/South Lincoln County- Logan County-Washington County-Sedgwick County-Phillips County- 1055 AM MDT Thu Apr 8 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MUCH OF THE NORTHEAST PLAINS OF COLORADO, INCLUDING FIRE WEATHER ZONES, 238, 242, 243, 244, 245, 246, 247, 249, 250, AND 251... * Affected Area...Fire Weather Zones 238, 242, 243, 244, 245, 246, 247, 248, 249, 250 and 251. * Timing...Noon to 7 PM MDT Thursday. * Winds...Northwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
145 WWUS85 KBOU 090100 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 700 PM MDT Thu Apr 8 2021 COZ238-242>251-090200- /O.EXP.KBOU.FW.W.0006.000000T0000Z-210409T0100Z/ Larimer County Below 6000 Feet/Northwest Weld County- 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- 700 PM MDT Thu Apr 8 2021 ...RED FLAG WARNING WILL EXPIRE AT 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MUCH OF THE NORTHEAST PLAINS OF COLORADO, INCLUDING FIRE WEATHER ZONES, 238, 242, 243, 244, 245, 246, 247, 249, 250, AND 251... The warning has been allowed to expire as conditions will gradually improve through the evening. $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 6, 6:08 PM MDT | Winter Weather Advisory | BOU | Arapahoe, Douglas, Elbert | 3 hr |
| Apr 6, 6:47 PM MDT | Special Weather Statement | BOU | Lincoln | 58 min |
| Apr 7, 3:36 AM MDT | Fire Weather Watch | BOU | Adams, Arapahoe, Elbert, Larimer, Lincoln, Logan and 5 more | 11 hr |
Nearby
Red Flag Warnings in Colorado, 2021Every red flag warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.