Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 10, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Jun 20, 2021, 3:13 AM MDT for Grand County, Jackson County, Summit County, Colorado. It took effect at Jun 20, 2021, 11:00 AM MDT. It was in force for 8 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 20, 2021, 3:13 AM MDT (09:13 UTC)
- In effect from
- Jun 20, 2021, 11:00 AM MDT
- Expired
- Jun 20, 2021, 7:00 PM MDT
- In force
- 8 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 09:13 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 00:00Z, 9.2 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
- 126 J/kg
- Mixed-layer CIN
- -161 J/kg
- Mixed-layer LCL
- 3244 m above ground
- 0-6 km bulk shear
- 40 kt
- 0-1 km storm-relative helicity
- 100 m²/s²
- 0-3 km storm-relative helicity
- 158 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
255 WWUS85 KBOU 200913 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 313 AM MDT Sun Jun 20 2021 COZ211-213-217-201715- /O.UPG.KBOU.FW.A.0006.210620T1700Z-210621T0100Z/ /O.NEW.KBOU.FW.W.0010.210620T1700Z-210621T0100Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 313 AM MDT Sun Jun 20 2021 ...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING 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... 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 this morning to 7 PM MDT this evening. The Fire Weather Watch is no longer in effect. * Affected Area...Fire Weather Zones 211, 213 and 217. * Timing...11 am mdt Sunday morning to 7 pm mdt Sunday evening. * Winds...West 15 to 25 mph with gusts up to 40 mph. * Relative Humidity...As low as 14 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. && $$ HANSON
1 follow-up statement
791 WWUS85 KBOU 201704 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 1104 AM MDT Sun Jun 20 2021 COZ211-213-217-210100- /O.CON.KBOU.FW.W.0010.000000T0000Z-210621T0100Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 1104 AM MDT Sun Jun 20 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND, JACKSON AND SUMMIT COUNTIES BELOW 9000 FEET, AND WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET... * Affected Area...Fire Weather Zones 211, 213 and 217. * Timing...11 am MDT Sunday morning to 7 pm MDT Sunday evening. * Winds...West 15 to 25 mph with gusts up to 40 mph. * Relative Humidity...As low as 10 percent. * Impacts...Gusty winds combined with low relative humidity may cause new fire starts to rapidly spread and grow. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now....or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ Gimmestad
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.