Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 9, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Jun 9, 2021, 2:54 PM MDT for Grand County, Jackson County, Colorado. It took effect at Jun 10, 2021, 12:00 PM MDT. It was in force for 12 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 9, 2021, 2:54 PM MDT (20:54 UTC)
- In effect from
- Jun 10, 2021, 12:00 PM MDT
- Expired
- Jun 11, 2021, 12:00 AM MDT
- In force
- 12 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Grand County, CO, Jackson County, CO
The radar
The Cheyenne radar (KCYS), 147 km from the middle of the area, began a volume at 20:58 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
Grand Junction, CO (KGJT), launched 12:00Z, 8.9 hours before the alert went out and 239 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
- 4295 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 166 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
767 WWUS85 KBOU 092054 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 254 PM MDT Wed Jun 9 2021 COZ217-101200- /O.NEW.KBOU.FW.W.0009.210610T1800Z-210611T0600Z/ West Jackson and West Grand Counties Above 9000 Feet- 254 PM MDT Wed Jun 9 2021 ...RED FLAG WARNING IN EFFECT FROM NOON THURSDAY TO MIDNIGHT MDT THURSDAY NIGHT FOR WIND AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS OF WESTERN GRAND AND JACKSON COUNTIES...FIRE WEATHER ZONE 217... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from noon Thursday to midnight MDT Thursday night. * Affected Area...Fire Weather Zone 217. * Timing...Noon Thursday to midnight Thursday night. * Winds...Southwest 20 to 30 mph with gusts up to 45 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds and low humidity may result in rapid fire spread through dry and beetle-killed trees. 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. && $$
2 follow-up statements
131 WWUS85 KBOU 101139 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 539 AM MDT Thu Jun 10 2021 COZ217-102100- /O.CON.KBOU.FW.W.0009.210610T1800Z-210611T0600Z/ West Jackson and West Grand Counties Above 9000 Feet- 539 AM MDT Thu Jun 10 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO MIDNIGHT MDT TONIGHT FOR WIND AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS OF WESTERN GRAND AND JACKSON COUNTIES...FIRE WEATHER ZONE 217... * Affected Area...Fire Weather Zone 217. * Timing...Noon Thursday to midnight Thursday night. * Winds...Southwest 20 to 30 mph with gusts up to 45 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds and low humidity may result in rapid fire spread through dry and beetle-killed trees. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
954 WWUS85 KBOU 102028 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 228 PM MDT Thu Jun 10 2021 COZ217-110600- /O.CON.KBOU.FW.W.0009.000000T0000Z-210611T0600Z/ West Jackson and West Grand Counties Above 9000 Feet- 228 PM MDT Thu Jun 10 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR WIND AND LOW RELATIVE HUMIDITY FOR THE MOUNTAINS OF WESTERN GRAND AND JACKSON COUNTIES...FIRE WEATHER ZONE 217... * Affected Area...Fire Weather Zone 217. * Timing...until midnight tonight. * Winds...Southwest 20 to 30 mph with gusts up to 45 mph. * Relative Humidity...As low as 11 percent. * Impacts...Strong winds and low humidity may result in rapid fire spread through dry and beetle-killed trees. 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. && $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 6:47 PM MDT | Special Weather Statement | BOU | Larimer | 28 min |
| Jun 8, 7:15 PM MDT | Special Weather Statement | BOU | Larimer | 30 min |
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.