Alert archive / Colorado / Red Flag Warnings in 2020
Red Flag Warning 21, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Aug 18, 2020, 3:27 PM MDT for 10 counties in Colorado. It took effect at Aug 19, 2020, 12:00 PM 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
- Aug 18, 2020, 3:27 PM MDT (21:27 UTC)
- In effect from
- Aug 19, 2020, 12:00 PM MDT
- Expired
- Aug 19, 2020, 8:00 PM MDT
- In force
- 8 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Boulder County, CO, Clear Creek County, CO, Douglas County, CO, Gilpin County, CO, Grand County, CO, Jackson County, CO, Jefferson County, CO, Larimer County, CO, Park County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 94 km from the middle of the area, began a volume at 21:28 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, 9.5 hours before the alert went out and 206 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
- 3 J/kg
- Mixed-layer CIN
- -326 J/kg
- Mixed-layer LCL
- 3087 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 25 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
400 WWUS85 KBOU 182127 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 327 PM MDT Tue Aug 18 2020 ...INCREASING CHANCES OF THUNDERSTORMS WEDNESDAY... .Moisture levels over northern Colorado are expected to increase slightly on Wednesday which will cause the chance of thunderstorms over the high country to also increase. Fuel moisture levels are very low in the mountain areas due to a lack of precipitation over the past several weeks. Recent forest fire activity in Larimer and Grand Counties demonstrates how dry the forests are. As the chances of thunderstorms increases tomorrow, the chance of lightning starting additional fires will also increase. COZ211>213-215>218-190530- /O.UPG.KBOU.FW.A.0013.200819T1800Z-200820T0200Z/ /O.NEW.KBOU.FW.W.0021.200819T1800Z-200820T0200Z/ Jackson County Below 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Grand and Summit Counties Below 9000 Feet- Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 327 PM MDT Tue Aug 18 2020 ...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT WEDNESDAY FOR THUNDERSTORMS OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... The National Weather Service in Denver has issued a Red Flag Warning FOR THUNDERSTORMS POSSIBLY CAUSING FIRE STARTS, which is in effect from noon to 8 PM MDT Wednesday. The Fire Weather Watch is no longer in effect. * Affected Area...Fire Weather Zones 211...212...213...215... 216...217 and 218. * Winds...North 5 to 10 mph. * Timing...Wednesday afternoon into early evening. * Impacts...Lightning and localized gusty winds from thunderstorms may cause new fire starts and rapid spread of fires. * Thunderstorms...Scattered thunderstorms are expected to move over the mountains, high parks and foothills Wednesday afternoon. They are not expected to produce much rainfall, so fuel moisture levels will remain very low. 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. && $$
4 follow-up statements
687 WWUS85 KBOU 190329 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 929 PM MDT Tue Aug 18 2020 ...INCREASING CHANCES OF THUNDERSTORMS WEDNESDAY... .Moisture levels over northern Colorado are expected to increase slightly on Wednesday which will cause the chance of thunderstorms over the high country to also increase. Fuel moisture levels are very low in the mountain areas due to a lack of precipitation over the past several weeks. Recent forest fire activity in Larimer and Grand Counties demonstrates how dry the forests are. As the chances of thunderstorms increases tomorrow, the chance of lightning starting additional fires will also increase. COZ211>213-215>218-191130- /O.CON.KBOU.FW.W.0021.200819T1800Z-200820T0200Z/ Jackson County Below 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Grand and Summit Counties Below 9000 Feet- Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 929 PM MDT Tue Aug 18 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TO 8 PM MDT WEDNESDAY FOR THUNDERSTORMS OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... * Affected Area...Fire Weather Zones 211...212...213...215... 216...217 and 218. * Winds...North 5 to 10 mph. * Timing...Wednesday afternoon into early evening. * Impacts...Lightning and localized gusty winds from thunderstorms may cause new fire starts and rapid spread of fires. * Thunderstorms...Scattered thunderstorms are expected to move over the mountains, high parks and foothills Wednesday afternoon. They are not expected to produce much rainfall, so fuel moisture levels will remain very low. 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. && $$
905 WWUS85 KBOU 190946 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 346 AM MDT Wed Aug 19 2020 .Moisture levels over northern Colorado are expected to increase today which will cause the chance of thunderstorms over the high country to also increase. Fuel moisture levels are very low in the mountain areas due to a lack of precipitation over the past several weeks. Recent forest fire activity in Larimer and Grand Counties demonstrates how dry the forests are. As the chances of thunderstorms increases today, the chance of lightning starting additional fires will also increase. The main impact from showers today will be gusty outflow winds from 30 to 50 mph possible. COZ211>213-215>218-192215- /O.CON.KBOU.FW.W.0021.200819T1800Z-200820T0200Z/ Jackson County Below 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Grand and Summit Counties Below 9000 Feet- Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 346 AM MDT Wed Aug 19 2020 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR THUNDERSTORMS OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... * Affected Area...Fire Weather Zones 211...212...213...215... 216...217 and 218. * Winds...North to Northwest winds 5 to 10 mph with gusts up to 25 mph during the afternoon. * Timing...This afternoon into early evening. * Impacts...Lightning and localized gusty winds from thunderstorms may cause new fire starts and rapid spread of fires. * Thunderstorms...Scattered thunderstorms are expected to move over the mountains, high parks and foothills this afternoon. They are not expected to produce much rainfall, so fuel moisture levels will remain very low. However, Front Range foothills may see some wetting rains due to higher moisture levels. 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. && $$
449 WWUS85 KBOU 191841 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 1241 PM MDT Wed Aug 19 2020 .Moisture levels over northern Colorado are expected to increase today and Thursday which will cause the chance of thunderstorms over the high country to also increase. Fuel moisture levels are very low in the mountain areas due to a lack of precipitation over the past several weeks. Recent forest fire activity in Larimer and Grand Counties demonstrates how dry the forests are. As the chances of thunderstorms increases each afternoon, the chance of lightning starting additional fires will also increase. The main impact from showers today will be gusty outflow winds from 30 to 50 mph possible. COZ211>213-215>218-200245- /O.NEW.KBOU.FW.A.0014.200820T1800Z-200821T0300Z/ /O.CON.KBOU.FW.W.0021.000000T0000Z-200820T0200Z/ Jackson County Below 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Grand and Summit Counties Below 9000 Feet- Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 1241 PM MDT Wed Aug 19 2020 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR THUNDERSTORMS OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... ...FIRE WEATHER WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR THUNDERSTORMS FOR OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... The National Weather Service in Denver has issued a Fire Weather Watch FOR THUNDERSTORMS, which is in effect from Thursday afternoon through Thursday evening. * Affected Area...Fire Weather Zones 211...212...213...215... 216...217 and 218. * Winds...Northwest 10 to 15 mph with gusts up to 25 mph. Outflow winds near showers and storms could gust to 40 mph. * Timing...Afternoon through early evening each day. * Impacts...Lightning and localized gusty winds from thunderstorms may cause new fire starts and rapid spread of fires. * Thunderstorms...Scattered thunderstorms are expected to move over the mountains, high parks and foothills each afternoon. They are not expected to produce much rainfall, so fuel moisture levels will remain very low. However, a few spots may see some wetting rains due to higher moisture levels, with better chances on Thursday afternoon. 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. && $$
628 WWUS85 KBOU 200159 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 759 PM MDT Wed Aug 19 2020 .Moisture levels over northern Colorado are expected to increase again on Thursday which will cause the chance of thunderstorms over the high country to also increase. Fuel moisture levels are very low in the mountain areas due to a lack of precipitation over the past several weeks. Recent forest fire activity in Larimer and Grand Counties demonstrates how dry the forests are. As the chances of thunderstorms increases tomorrow afternoon, the chance of lightning starting additional fires will also increase. The main impact from showers will be possible gusty outflow winds from 30 to 50 mph. COZ211>213-215>218-201000- /O.EXP.KBOU.FW.W.0021.000000T0000Z-200820T0200Z/ /O.CON.KBOU.FW.A.0014.200820T1800Z-200821T0300Z/ Jackson County Below 9000 Feet- South and Southeast Grand/West Central and Southwest Boulder/ Gilpin/Clear Creek/Summit/North and West Park Counties Above 9000 Feet-Grand and Summit Counties Below 9000 Feet- Larimer and Boulder Counties Between 6000 and 9000 Feet- Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear Creek/Northeast Park Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 759 PM MDT Wed Aug 19 2020 ...FIRE WEATHER WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON THROUGH THURSDAY EVENING FOR THUNDERSTORMS FOR OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR THUNDERSTORMS OVER THE NORTHERN MOUNTAINS AND HIGH PARKS... * Affected Area...Fire Weather Zones 211...212...213...215... 216...217 and 218. * Winds...West 5 to 10 mph with gusts up to 25 mph. * Timing...Afternoon through early evening each day. * Impacts...Lightning and localized gusty winds from thunderstorms may cause new fire starts and rapid spread of fires. * Thunderstorms...Scattered thunderstorms are expected to move over the mountains, high parks and foothills each afternoon. They are not expected to produce much rainfall, so fuel moisture levels will remain very low. However, a few spots may see some wetting rains due to higher moisture levels on Thursday afternoon. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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 |
|---|---|---|---|---|
| Aug 18, 3:28 AM MDT | Fire Weather Watch | BOU | Boulder, Clear Creek, Douglas, Gilpin, Grand, Jackson and 4 more | 12 hr |
Nearby
Red Flag Warnings in Colorado, 2020Every red flag warning in 2020
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.