Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 11, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Jun 21, 2021, 2:18 PM MDT for Grand County, Jackson County, Summit County, Colorado. It took effect at Jun 22, 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
- Jun 21, 2021, 2:18 PM MDT (20:18 UTC)
- In effect from
- Jun 22, 2021, 12:00 PM MDT
- Expired
- Jun 22, 2021, 7:00 PM MDT
- In force
- 7 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Grand County, CO, Jackson County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 146 km from the middle of the area, began a volume at 20:17 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, 8.3 hours before the alert went out and 227 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
- 2600 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -50 m²/s²
- 0-3 km storm-relative helicity
- 88 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
807 WWUS85 KBOU 212018 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 218 PM MDT Mon Jun 21 2021 COZ211-213-217-220830- /O.UPG.KBOU.FW.A.0007.210622T1800Z-210623T0100Z/ /O.NEW.KBOU.FW.W.0011.210622T1800Z-210623T0100Z/ /O.NEW.KBOU.FW.A.0008.210623T1700Z-210624T0100Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 218 PM MDT Mon Jun 21 2021 ...RED FLAG WARNING IN EFFECT FROM NOON TO 7 PM MDT TUESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND, JACKSON AND SUMMIT COUNTIES BELOW 9000 FEET, AND WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET... ...FIRE WEATHER WATCH IN EFFECT FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND, JACKSON AND SUMMIT COUNTIES BELOW 9000 FEET, AND WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET... 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 Tuesday. A Fire Weather Watch has also been issued. This Fire Weather Watch for wind and low relative humidity is in effect from Wednesday morning through Wednesday evening. The Fire Weather Watch is no longer in effect. * Affected Area...Fire Weather Zones 211, 213 and 217. * Timing...Red Flag Warning in effect from 12 PM MDT Tuesday through 7 PM MDT Tuesday evening. Fire Weather Watch in effect from late Wednesday morning until early Wednesday evening. * Winds...West-Northwest 10 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 13 percent. * Impacts...Gusty 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. A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$
1 follow-up statement
870 WWUS85 KBOU 221042 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 442 AM MDT Tue Jun 22 2021 COZ211-213-217-230245- /O.CON.KBOU.FW.W.0011.210622T1800Z-210623T0100Z/ /O.CON.KBOU.FW.A.0008.210623T1700Z-210624T0100Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 442 AM MDT Tue Jun 22 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND, JACKSON AND SUMMIT COUNTIES BELOW 9000 FEET, AND WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET... ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND, JACKSON AND SUMMIT COUNTIES BELOW 9000 FEET, AND WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET... * Affected Area...Fire Weather Zones 211, 213 and 217. * Timing...Red Flag Warning in effect from noon today through 7 PM MDT this evening. Fire Weather Watch in effect from late Wednesday morning until early Wednesday evening. * Winds...Southwest 10 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 13 percent. * Impacts...Gusty winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 5:10 AM MDT | Fire Weather Watch | BOU | Grand, Jackson, Summit | 9 hr |
| Jun 21, 2:18 PM MDT | Fire Weather Watch | BOU | Grand, Jackson, Summit | 38 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.