Alert archive / Colorado / Red Flag Warnings in 2021
Red Flag Warning 25, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Dec 14, 2021, 12:17 PM MST for 16 counties in Colorado. It took effect at Dec 15, 2021, 8:00 AM MST. It was in force for 9 hr. 60 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Dec 14, 2021, 12:17 PM MST (19:17 UTC)
- In effect from
- Dec 15, 2021, 8:00 AM MST
- Expired
- Dec 15, 2021, 5:00 PM MST
- In force
- 9 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Clear Creek County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Gilpin County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Morgan County, CO, Park County, CO, Washington County, CO, Weld County, CO
The radar
The Denver radar (KFTG), 15 km from the middle of the area, began a volume at 19:21 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Dec 15, 8:01 AM MST | NON-TSTM WND GST 55 | 4 Sw Hygiene, CO | MESONET STATION DW1011 LONGMONT. |
| Dec 15, 8:04 AM MST | TSTM WND DMG | 1 Se Brighton, CO | SMALL TREE LIMBS BROKEN. |
| Dec 15, 8:04 AM MST | NON-TSTM WND DMG | 1 Se Brighton, CO | SMALL TREE LIMBS BROKEN. |
| Dec 15, 8:15 AM MST | NON-TSTM WND GST 55 | 3 Se Tolland, CO | AWOS STATION KC99 DAKOTA HILL. |
| Dec 15, 8:16 AM MST | NON-TSTM WND GST 60 | 2 Se Denver Intl Airpor, CO | ASOS STATION KDEN DENVER. |
| Dec 15, 8:19 AM MST | TSTM WND DMG | 3 Wsw Aurora, CO | 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 8:19 AM MST | NON-TSTM WND DMG | 3 Wsw Aurora, CO | 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 8:35 AM MST | NON-TSTM WND GST 59 | 3 Ese Buckeye, CO | MESONET STATION BEYC2 BUCKEYE. |
| Dec 15, 8:47 AM MST | NON-TSTM WND GST 60 | 1 E Limon, CO | ASOS STATION KLIC LIMON. |
| Dec 15, 9:14 AM MST | NON-TSTM WND GST 67 | 3 Sw Rocky Flats, CO | MESONET STATION CO109 ROCKY FLATS HWY 93 AND 72. |
| Dec 15, 9:27 AM MST | NON-TSTM WND GST 64 | 1 Ese Akron, CO | MESONET STATION EW7755 AKRON. |
| Dec 15, 9:29 AM MST | NON-TSTM WND GST 60 | 1 N Glen Haven, CO | MESONET STATION EW4490 GLEN HAVEN. |
| Dec 15, 9:30 AM MST | NON-TSTM WND GST 59 | 2 Nne Rocky Flats, CO | MESONET STATION RFN 1.7 NE ROCKY FLATS (CDPHE). |
| Dec 15, 9:31 AM MST | NON-TSTM WND GST 71 | 3 Nne White Ranch Open, CO | MESONET STATION UP709 2.8 NE WHITE RANCH OPEN SPACE (UPR). |
| Dec 15, 9:34 AM MST | NON-TSTM WND GST 61 | 14 S Hyde, CO | |
| Dec 15, 9:35 AM MST | NON-TSTM WND GST 69 | 3 Ssw Boulder, CO | |
| Dec 15, 9:35 AM MST | NON-TSTM WND GST 71 | 4 Se Pinecliffe, CO | MESONET STATION EW8336 COAL CREEK CANYON. |
| Dec 15, 9:38 AM MST | NON-TSTM WND GST 64 | 3 Ese Pinecliffe, CO | MESONET STATION FW8937 WONDERVU. |
| Dec 15, 9:42 AM MST | NON-TSTM WND GST 55 | 3 W Lyons, CO | MESONET STATION BCFC2 LYONS 3W. |
| Dec 15, 9:48 AM MST | NON-TSTM WND GST 73 | 3 Ese Pinecliffe, CO | MESONET STATION FW8937 WONDERVU. |
| Dec 15, 9:51 AM MST | NON-TSTM WND GST 76 | 4 Ene Nederland, CO | |
| Dec 15, 9:55 AM MST | NON-TSTM WND GST 55 | Wilkerson Pass, CO | MESONET STATION CO027 024W254 WILKERSON PASS. |
| Dec 15, 10:00 AM MST | NON-TSTM WND GST 91 | 3 Ssw Boulder, CO | CORRECTS PREVIOUS NON-TSTM WND GST REPORT FROM 3 SSW BOULDER. |
| Dec 15, 10:00 AM MST | NON-TSTM WND GST 91 | 3 Ssw Boulder, CO | |
| Dec 15, 10:15 AM MST | NON-TSTM WND GST 55 | Aspen Springs, CO | MESONET STATION CW5066 ASPEN SPRINGS. |
| Dec 15, 10:16 AM MST | NON-TSTM WND GST 59 | 3 Wnw Mishawaka, CO | MESONET STATION EW0853 LIVERMORE. |
| Dec 15, 10:16 AM MST | NON-TSTM WND GST 68 | 2 Sse Pleasant View, CO | MESONET STATION FW8940 LAKEWOOD. |
| Dec 15, 10:23 AM MST | NON-TSTM WND GST 73 | 2 S Cheesman Reservoir, CO | MESONET STATION CHRC2 CHEESMAN. |
| Dec 15, 10:24 AM MST | NON-TSTM WND GST 65 | 2 Wnw Aspen Springs, CO | MESONET STATION PKLC2 PICKLE GULCH. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 59 | Downieville, CO | MESONET STATION CO141 DOWNIEVILLE. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 67 | 1 Wsw Chatfield Reservo, CO | MESONET STATION CO007 470W014 WADSWORTH. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 67 | Floyd Hill, CO | MESONET STATION CO071 I-70 FLOYD HILL. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 80 | 2 Nnw Genesee, CO | MESONET STATION CO065 GENESEE. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 82 | 3 Sw Rocky Flats, CO | MESONET STATION CO109 ROCKY FLATS HWY 93 AND 72. |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 95 | 3 Nne White Ranch Open, CO | MESONET STATION UP709 2.8 NE WHITE RANCH OPEN SPACE (UPR). |
| Dec 15, 10:25 AM MST | NON-TSTM WND GST 95 | 3 Nne White Ranch Open, CO | |
| Dec 15, 10:28 AM MST | NON-TSTM WND GST 85 | 3 Ssw Boulder, CO | |
| Dec 15, 10:30 AM MST | NON-TSTM WND GST 56 | 3 Nnw Longmont, CO | MESONET STATION EW2670 LONGMONT. |
| Dec 15, 10:30 AM MST | NON-TSTM WND GST 79 | 4 Se Pinecliffe, CO | MESONET STATION EW8336 COAL CREEK CANYON. |
| Dec 15, 10:35 AM MST | TSTM WND DMG | 2 Wsw Lakewood, CO | 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 10:35 AM MST | NON-TSTM WND GST 71 | 3 Ese Buckeye, CO | MESONET STATION BEYC2 BUCKEYE. |
| Dec 15, 10:35 AM MST | NON-TSTM WND GST 71 | 3 Se Tolland, CO | AWOS STATION KC99 DAKOTA HILL. |
| Dec 15, 10:35 AM MST | NON-TSTM WND GST 77 | 2 S Eldorado Springs, CO | |
| Dec 15, 10:35 AM MST | NON-TSTM WND GST 87 | 2 Nw Rocky Flats, CO | NATIONAL WIND TECHNOLOGY CENTER. |
| Dec 15, 10:35 AM MST | NON-TSTM WND DMG | 2 Wsw Lakewood, CO | 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 10:36 AM MST | NON-TSTM WND GST 66 | 1 Ne Aspen Springs, CO | MESONET STATION DW4381 BLACK HAWK. |
| Dec 15, 10:37 AM MST | NON-TSTM WND GST 60 | 1 Ene Estes Park, CO | |
| Dec 15, 10:41 AM MST | TSTM WND DMG | 3 E Lakewood, CO | REPORT FROM MPING: 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 10:41 AM MST | NON-TSTM WND DMG | 3 E Lakewood, CO | REPORT FROM MPING: 1-INCH TREE LIMBS BROKEN. |
| Dec 15, 10:45 AM MST | NON-TSTM WND GST 59 | 1 Ne Ken Caryl, CO | MESONET STATION FW5793 LITTLETON. |
| Dec 15, 10:45 AM MST | NON-TSTM WND GST 69 | 3 Ene Nederland, CO | MESONET STATION FW1761 NEDERLAND. |
| Dec 15, 10:45 AM MST | NON-TSTM WND GST 75 | 2 Nnw Marshall, CO | MESONET STATION BLD01 BOULDER SOUTH WEST. |
| Dec 15, 10:45 AM MST | NON-TSTM WND GST 79 | 4 Ene Nederland, CO | |
| Dec 15, 10:45 AM MST | NON-TSTM WND GST 84 | 2 Sw Broomfield, CO | AWOS STATION KBJC BROOMFIELD ROCKY MTN METRO AIRPORT. |
| Dec 15, 10:45 AM MST | NON-TSTM WND DMG | Superior, CO | LIGHT POLE DAMAGED. |
| Dec 15, 10:46 AM MST | NON-TSTM WND GST 56 | 11 Wnw Westplains, CO | AWOS STATION K1LW STONEHAM 22 N. |
| Dec 15, 10:46 AM MST | NON-TSTM WND GST 59 | 3 Ne Englewood, CO | MESONET STATION CO145 UNIVERSITY BLVD. |
| Dec 15, 10:46 AM MST | NON-TSTM WND GST 60 | 2 Ssw Boulder, CO | MESONET STATION CO040 036E03750RWS1RP1 AT BASELINE RD. |
| Dec 15, 10:46 AM MST | NON-TSTM WND GST 68 | 1 N Georgetown, CO | MESONET STATION CO162 I-70 GEORGETOWN LAKE. |
| Dec 15, 10:46 AM MST | NON-TSTM WND GST 70 | 1 Ne Aspen Springs, CO | MESONET STATION FW0549 BLACK HAWK. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Denver, CO (KDNR), launched 12:00Z, 7.3 hours before the alert went out and 128 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
- 3648 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- -45 m²/s²
- 0-3 km storm-relative helicity
- -27 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
539 WWUS85 KBOU 141917 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 1217 PM MST Tue Dec 14 2021 COZ215-216-238>241-243>247-249-150330- /O.NEW.KBOU.FW.W.0025.211215T1500Z-211216T0000Z/ 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- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- 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- Washington County- 1217 PM MST Tue Dec 14 2021 ...RED FLAG WARNING IN EFFECT FROM 8 AM TO 5 PM MST WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS...PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS... The National Weather Service in Denver has issued a Red Flag Warning for wind and low relative humidity, which is in effect from 8 AM to 5 PM MST Wednesday. * Affected Area...Fire Weather Zones 215, 216, 238, 239, 240, 241, 243, 244, 245, 246, 247 and 249. * Timing...8 am to 5 pm MST Wednesday * Winds...West 35 to 45 mph with gusts up to 80 mph. * Relative Humidity...As low as 15 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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
713 WWUS85 KBOU 150230 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 730 PM MST Tue Dec 14 2021 ...RED FLAG WARNING IN EFFECT FROM 8 AM TO 5 PM MST WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS...PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS...FIRE WEATHER ZONES...215...216...238 THROUGH 241... 243 THROUGH 247 AND 249... COZ215-216-238>241-243>247-249-151030- /O.CON.KBOU.FW.W.0025.211215T1500Z-211216T0000Z/ 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- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- 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- Washington County- 730 PM MST Tue Dec 14 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 8 AM TO 5 PM MST WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS...PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS... * Affected Area...Fire Weather Zones 215, 216, 238, 239, 240, 241, 243, 244, 245, 246, 247 and 249. * Timing...8 am to 5 pm MST Wednesday * Winds...West 30 to 50 mph with gusts up to 80 mph. * Relative Humidity...As low as 17 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$
615 WWUS85 KBOU 151023 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 323 AM MST Wed Dec 15 2021 ...RED FLAG WARNING IN EFFECT FROM 8 AM TO 5 PM MST WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS... PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS...FIRE WEATHER ZONES...215...216...238 THROUGH 241... 243 THROUGH 247 AND 249... COZ215-216-238>241-243>247-249-160000- /O.CON.KBOU.FW.W.0025.211215T1500Z-211216T0000Z/ 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- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- 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- Washington County- 323 AM MST Wed Dec 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT FROM 8 AM THIS MORNING TO 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS...PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS... * Affected Area...Fire Weather Zones 215, 216, 238, 239, 240, 241, 243, 244, 245, 246, 247 and 249. * Timing...8 am to 5 pm MST Wednesday * Winds...West 40 to 50 mph with gusts up to 85 mph. * Relative Humidity...As low as 17 percent. * Impacts...Conditions will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$
310 WWUS85 KBOU 152109 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 209 PM MST Wed Dec 15 2021 ...RED FLAG WARNING IN EFFECT UNTIL 5 PM MST TODAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS... PALMER DIVIDE...AND PORTIONS OF THE NORTHEAST PLAINS...FIRE WEATHER ZONES...215...216...238 THROUGH 241...243 THROUGH 247...AND 249... COZ215-216-238>241-243>247-249-160000- /O.CON.KBOU.FW.W.0025.000000T0000Z-211216T0000Z/ 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- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- 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- Washington County- 209 PM MST Wed Dec 15 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS...PALMER DIVIDE...AND A LARGE PORTION OF THE NORTHEAST PLAINS... * Affected Area...Fire Weather Zones 215, 216, 238, 239, 240, 241, 243, 244, 245, 246, 247 and 249. * Timing...8 am to 5 pm MST Wednesday * Winds...Northwest 35 to 45 mph with gusts up to 70 mph. * Relative Humidity...As low as 18 percent. * Impacts...The extreme winds will be conducive to the rapid spread of new fires. Probability of ignition will increase. Avoid any burning or outdoor activities that may cause sparks, and abide by established fire restrictions. 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. && $$
043 WWUS85 KBOU 152356 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 456 PM MST Wed Dec 15 2021 COZ215-216-238>241-243>247-249-160100- /O.EXP.KBOU.FW.W.0025.000000T0000Z-211216T0000Z/ 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- Larimer County Below 6000 Feet/Northwest Weld County- Boulder And Jefferson Counties Below 6000 Feet/West Broomfield County- North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County- Elbert/Central and East Douglas Counties Above 6000 Feet- 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- Washington County- 456 PM MST Wed Dec 15 2021 ...RED FLAG WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON FOR WIND AND LOW RELATIVE HUMIDITY FOR THE FRONT RANGE FOOTHILLS... PALMER DIVIDE...AND A LARGE PORTION OF THE NORTHEAST PLAINS... $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 14, 4:34 AM MST | High Wind Warning | BOU | Adams, Arapahoe, Boulder, Broomfield, Clear Creek, Denver and 13 more | 36 hr |
| Dec 14, 11:54 AM MST | Winter Weather Advisory | BOU | Boulder, Clear Creek, Gilpin, Grand, Jackson, Jefferson and 3 more | 32 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.