Alert archive / Colorado / Red Flag Warnings in 2018
Red Flag Warning 39, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this red flag warning at Sep 11, 2018, 3:06 PM MDT for 5 counties in Colorado. It took effect at Sep 13, 2018, 10:00 AM MDT. It was in force for 10 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
- Sep 11, 2018, 3:06 PM MDT (21:06 UTC)
- In effect from
- Sep 13, 2018, 10:00 AM MDT
- Expired
- Sep 13, 2018, 8:00 PM MDT
- In force
- 10 hr
- Issued by
- NWS Denver/Boulder, CO
Counties Boulder County, CO, Grand County, CO, Jackson County, CO, Larimer County, CO, Summit County, CO
The radar
The Denver radar (KFTG), 124 km from the middle of the area, began a volume at 21:09 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 (KDEN), launched 12:00Z, 9.1 hours before the alert went out and 229 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
- 39 J/kg
- Mixed-layer CIN
- -278 J/kg
- Mixed-layer LCL
- 3416 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- -7 m²/s²
- 0-3 km storm-relative helicity
- 4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
682 WWUS85 KBOU 112106 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 306 PM MDT Tue Sep 11 2018 ...CRITICAL FIRE CONDITIONS EXPECTED WEDNESDAY AFTERNOON AND EVENING FOR MOST OF GRAND AND JACKSON COUNTIES... .Gusty winds will combine with very low relative humidity and near record temperatures to create critical fire danger conditions across the western mountains and valleys of Jackson and Grand Counties on Wednesday. These critical conditions will also further dry out the vegetation compounding the fire danger on Thursday when another day of hot, dry conditions and strong west winds are expected across the northern mountains. COZ211-213-217-121215- /O.NEW.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ /O.CON.KBOU.FW.W.0038.180912T1700Z-180913T0200Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 306 PM MDT Tue Sep 11 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM TO 8 PM MDT WEDNESDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... ...RED FLAG WARNING IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR Jackson...most of Grand County and parts of Summit County. The National Weather Service in Denver has issued a Red Flag Warning FOR WIND AND LOW RELATIVE HUMIDITY, which is in effect from 10 AM to 8 PM MDT Thursday. * Affected Area...Fire Weather Zones 211...213 and 217. * Timing...Wednesday and Thursday afternoon and evening * Winds...Southwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 10 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ COZ218-121215- /O.NEW.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 306 PM MDT Tue Sep 11 2018 ...RED FLAG WARNING IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR the higher elevations of eastern Grand and Jackson Counties, and western Larimer County including Rocky Mountain National Park. The National Weather Service in Denver has issued a Red Flag Warning FOR WIND AND LOW RELATIVE HUMIDITY, which is in effect from 10 AM to 8 PM MDT Thursday. * Affected Area...Fire Weather Zone 218. * Timing...Thursday afternoon and early evening. * Winds...Southwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 12 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
6 follow-up statements
586 WWUS85 KBOU 121133 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 533 AM MDT Wed Sep 12 2018 ...CRITICAL FIRE CONDITIONS EXPECTED WEDNESDAY AFTERNOON AND EVENING FOR MOST OF GRAND AND JACKSON COUNTIES... .Gusty winds will combine with very low relative humidity and near record temperatures to create critical fire danger conditions across the western mountains and valleys of Jackson and Grand Counties on Wednesday. These critical conditions will also further dry out the vegetation compounding the fire danger on Thursday when another day of hot, dry conditions and gusty west winds are expected across the northern mountains. COZ211-213-217-122200- /O.CON.KBOU.FW.W.0038.180912T1700Z-180913T0200Z/ /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 533 AM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... * Affected Area...Fire Weather Zones 211...213 and 217. * Timing...Wednesday and Thursday afternoon and evening * Winds...Southwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 9 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ COZ218-122200- /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 533 AM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE HIGHER ELEVATIONS OF EASTERN GRAND AND JACKSON COUNTIES, AND WESTERN LARIMER COUNTY INCLUDING ROCKY MOUNTAIN NATIONAL PARK... * Affected Area...Fire Weather Zone 218. * Timing...Thursday afternoon and early evening. * Winds...Southwest 10 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 12 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
032 WWUS85 KBOU 121948 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 148 PM MDT Wed Sep 12 2018 ...CRITICAL FIRE CONDITIONS ONGING INTO THE EVENING AND ARE EXPECTED THURSDAY AFTERNOON FOR THE NORTHERN MOUNTAINS AND VALLEYS... .Strong and gusty southwest winds will combine with very low relative humidity and near record temperatures to create critical fire danger conditions across the mountains and valleys of Jackson, Grand, parts of Summit, and western Larimer Counties though early evening and again on Thursday. COZ211-213-217-130600- /O.CON.KBOU.FW.W.0038.000000T0000Z-180913T0200Z/ /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 148 PM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... * Affected Area...Fire Weather Zones 211...213 and 217. * Timing...Wednesday and Thursday afternoon and evening * Winds...Southwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 9 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ COZ218-130600- /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 148 PM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE HIGHER ELEVATIONS OF EASTERN GRAND AND JACKSON COUNTIES, AND WESTERN LARIMER COUNTY INCLUDING ROCKY MOUNTAIN NATIONAL PARK... * Affected Area...Fire Weather Zone 218. * Timing...Thursday afternoon and early evening. * Winds...Southwest 15 to 25 mph with gusts up to 35 mph. * Relative Humidity...As low as 12 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
857 WWUS85 KBOU 130202 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 802 PM MDT Wed Sep 12 2018 ...CRITICAL FIRE CONDITIONS EXPECTED AGAIN THURSDAY AFTERNOON FOR THE NORTHERN MOUNTAINS AND VALLEYS... .Strong and gusty southwest winds will combine with very low relative humidity and near record temperatures to create critical fire danger conditions across the mountains and valleys of Jackson, Grand, parts of Summit, and western Larimer Counties on Thursday. COZ211-213-217-131215- /O.EXP.KBOU.FW.W.0038.000000T0000Z-180913T0200Z/ /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- 802 PM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... ...RED FLAG WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR MOST OF GRAND AND JACKSON COUNTIES... * Affected Area...Fire Weather Zones 211...213 and 217. * Timing...Wednesday and Thursday afternoon and evening * Winds...Southwest 10 to 20 mph with gusts up to 30 mph. * Relative Humidity...As low as 9 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. 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. && $$ COZ218-131215- /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 802 PM MDT Wed Sep 12 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM TO 8 PM MDT THURSDAY FOR WIND AND LOW RELATIVE HUMIDITY FOR THE HIGHER ELEVATIONS OF EASTERN GRAND AND JACKSON COUNTIES, AND WESTERN LARIMER COUNTY INCLUDING ROCKY MOUNTAIN NATIONAL PARK... * Affected Area...Fire Weather Zone 218. * Timing...Thursday afternoon and early evening. * Winds...Southwest 10 to 20 mph with gusts up to 35 mph. * Relative Humidity...As low as 11 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with anticipated gusty winds. These gusty and erratic winds may create unpredictable fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
268 WWUS85 KBOU 131035 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 435 AM MDT Thu Sep 13 2018 ...CRITICAL FIRE CONDITIONS EXPECTED AGAIN TODAY FOR THE NORTHERN MOUNTAINS AND VALLEYS... .Gusty southwest winds will combine with very low relative humidity and near record temperatures to create critical fire danger conditions across the mountains and valleys of Jackson, Grand, parts of Summit, and western Larimer Counties today. The very warm and dry conditions are expected to prevail through the weekend, however winds will not be as strong as today. COZ211-213-217-218-132200- /O.CON.KBOU.FW.W.0039.180913T1600Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit 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- 435 AM MDT Thu Sep 13 2018 ...RED FLAG WARNING REMAINS IN EFFECT FROM 10 AM THIS MORNING TO 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND AND JACKSON COUNTIES, AND WESTERN LARIMER COUNTY INCLUDING ROCKY MOUNTAIN NATIONAL PARK... * Affected Area...Fire Weather Zones 211...213...217 and 218. * Timing...Late this morning through early evening. * Winds...Southwest 15 to 25 mph with gusts up to 40 mph. * Relative Humidity...As low as 7 percent. * Impacts...Fires may start easily with the dry fuels and spread rapidly with the anticipated gusty winds. These gusty winds and very dry conditions may create extreme fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
686 WWUS85 KBOU 131901 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 101 PM MDT Thu Sep 13 2018 ...CRITICAL FIRE CONDITIONS ARE OCCURING ACROSS THE NORTHERN MOUNTAINS AND VALLEYS... .Gusty southwest winds, very low relative humidity, and near record temperatures are creating critical fire danger conditions across the mountains and valleys of Jackson, Grand, parts of Summit, and western Larimer Counties today. Critical fire weather condictions will continue through this evening. The very warm and dry conditions are expected to prevail through the weekend, however winds will not be as strong as today. COZ211-213-217-218-140200- /O.CON.KBOU.FW.W.0039.000000T0000Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit Counties Below 9000 Feet- West Jackson and West Grand Counties Above 9000 Feet- South and East Jackson/Larimer/North and Northeast Grand/ Northwest Boulder Counties Above 9000 Feet- 101 PM MDT Thu Sep 13 2018 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR GRAND AND JACKSON COUNTIES, NORTHERN SUMMIT, AND WESTERN LARIMER COUNTY INCLUDING ROCKY MOUNTAIN NATIONAL PARK... * Affected Area...Fire Weather Zones 211...213...217 and 218. * Timing...Ongoing through 8PM. * Winds...Southwest 15 to 25 mph with gusts up to 40 mph. * Relative Humidity...As low as 8 percent. * Impacts...Existing fires will spread quickly to the northeast. New fires will start easily with the dry fuels and spread rapidly with the anticipated gusty winds. These gusty winds and very dry conditions may create extreme fire behavior. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are expected. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
419 WWUS85 KBOU 140202 RFWBOU URGENT - FIRE WEATHER MESSAGE National Weather Service Denver/Boulder CO 802 PM MDT Thu Sep 13 2018 COZ211-213-217-218-140315- /O.EXP.KBOU.FW.W.0039.000000T0000Z-180914T0200Z/ Jackson County Below 9000 Feet- Grand and Summit 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- 802 PM MDT Thu Sep 13 2018 ...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE HUMIDITY FOR THE NORTHERN MOUNTAINS AND MOUNTAIN VALLEYS... Winds have decreased to around 10 mph in most locations this evening. As a result, the Red Flag Warning has been allowed to expire. However, humidities will be very low with extremely poor humidity recovery overnight. An extended period of hot and dry weather is still in the forecast for the next few days. But generally lighter winds can be expected through most of the weekend. $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 11, 11:58 AM MDT | Special Weather Statement | BOU | Broomfield, Denver | 32 min |
| Sep 11, 12:37 PM MDT | Special Weather Statement | BOU | Denver | 23 min |
| Sep 11, 2:05 PM MDT | Special Weather Statement | BOU | Broomfield, Denver, Douglas | 40 min |
| Sep 11, 4:25 PM MDT | Special Weather Statement | BOU | Sedgwick | 35 min |
Nearby
Red Flag Warnings in Colorado, 2018Every red flag warning in 2018
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.