Alert archive / Colorado / Tornado Warnings in 2018
Tornado Warning 35, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at Jul 27, 2018, 4:10 PM MDT for Adams County, Arapahoe County, Colorado. It was in force for 35 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 27, 2018, 4:10 PM MDT (22:10 UTC)
- Expired
- Jul 27, 2018, 4:45 PM MDT
- In force
- 35 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.75 in
Counties Adams County, CO, Arapahoe County, CO
The radar
The Denver radar (KFTG), 57 km from the middle of the area, began a volume at 22:12 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 |
|---|---|---|---|
| Jul 27, 4:21 PM MDT | TORNADO | 11 Sse Leader, CO | WE RECEIVED TWO SEPARATE REPORTS OF THE SAME TORNADO IN THIS LOCATION. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 27, 1:04 PM MDT | Tornado Watch | SPC | 8 hr |
The nearest sounding before it
Denver, CO (KDEN), launched 12:00Z, 10.2 hours before the alert went out and 58 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
- 735 J/kg
- Mixed-layer CIN
- -87 J/kg
- Mixed-layer LCL
- 574 m above ground
- 0-6 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 13 m²/s²
- 0-3 km storm-relative helicity
- 91 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.1
The text
As transmitted.
032
WFUS55 KBOU 272210
TORBOU
COC001-005-272245-
/O.NEW.KBOU.TO.W.0035.180727T2210Z-180727T2245Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
410 PM MDT FRI JUL 27 2018
The National Weather Service in Denver Colorado has issued a
* Tornado Warning for...
Northeastern Arapahoe County in northeastern Colorado...
Southeastern Adams County in northeastern Colorado...
* Until 445 PM MDT.
* At 410 PM MDT, a severe thunderstorm capable of producing a tornado
was located 10 miles northwest of Cottonwood Valley, or 36 miles
north of Limon, moving southeast at 25 mph.
HAZARD...Tornado and golf ball size hail.
SOURCE...Radar indicated rotation.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed.
Damage to roofs, windows, and vehicles will occur. Tree
damage is likely.
* This tornadic thunderstorm will remain over mainly rural areas of
northeastern Arapahoe and southeastern Adams Counties.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 3976 10406 3988 10383 3973 10371 3972 10371
3961 10394
TIME...MOT...LOC 2210Z 316DEG 20KT 3975 10394
TORNADO...RADAR INDICATED
HAIL...1.75IN
$$
RPK3 follow-up statements
410
WWUS55 KBOU 272220
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
420 PM MDT FRI JUL 27 2018
COC001-005-272245-
/O.CON.KBOU.TO.W.0035.000000T0000Z-180727T2245Z/
Arapahoe CO-Adams CO-
420 PM MDT FRI JUL 27 2018
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM MDT FOR
NORTHEASTERN ARAPAHOE AND SOUTHEASTERN ADAMS COUNTIES...
At 419 PM MDT, a confirmed tornado was located 6 miles northwest of
Cottonwood Valley, or 32 miles north of Limon, moving southeast at 25
mph.
HAZARD...Damaging tornado and golf ball size hail.
SOURCE...Law enforcement confirmed tornado.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
This tornadic thunderstorm will remain over mainly rural areas of
northeastern Arapahoe and southeastern Adams Counties.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 3976 10406 3988 10383 3973 10371 3972 10371
3961 10394
TIME...MOT...LOC 2219Z 316DEG 20KT 3971 10389
TORNADO...OBSERVED
HAIL...1.75IN
$$
RPK099
WWUS55 KBOU 272231
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
431 PM MDT FRI JUL 27 2018
COC001-272240-
/O.CAN.KBOU.TO.W.0035.000000T0000Z-180727T2245Z/
Adams CO-
431 PM MDT FRI JUL 27 2018
...THE TORNADO WARNING FOR SOUTHEASTERN ADAMS COUNTY IS CANCELLED...
The tornadic thunderstorm which prompted the warning has moved out
of the warned area.
A Tornado Watch remains in effect until 900 PM MDT for northeastern
Colorado.
LAT...LON 3966 10394 3974 10377 3973 10371 3972 10371
3962 10392
TIME...MOT...LOC 2230Z 316DEG 20KT 3966 10383
$$
COC005-272245-
/O.CON.KBOU.TO.W.0035.000000T0000Z-180727T2245Z/
Arapahoe CO-
431 PM MDT FRI JUL 27 2018
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM MDT FOR
NORTHEASTERN ARAPAHOE COUNTY...
At 430 PM MDT, a confirmed tornado was located near Cottonwood
Valley, or 28 miles north of Limon, moving southeast at 25 mph.
HAZARD...Damaging tornado.
SOURCE...Public confirmed tornado.
IMPACT...Flying debris will be dangerous to those caught without
shelter. Mobile homes will be damaged or destroyed. Damage
to roofs, windows, and vehicles will occur. Tree damage is
likely.
This tornadic thunderstorm will remain over mainly rural areas of
northeastern Arapahoe County.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.
Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!
&&
LAT...LON 3966 10394 3974 10377 3973 10371 3972 10371
3962 10392
TIME...MOT...LOC 2230Z 316DEG 20KT 3966 10383
TORNADO...OBSERVED
HAIL...0.00IN
$$
RPK661
WWUS55 KBOU 272239 RRA
SVSBOU
Severe Weather Statement
National Weather Service Denver CO
439 PM MDT FRI JUL 27 2018
COC005-272249-
/O.EXP.KBOU.TO.W.0035.000000T0000Z-180727T2245Z/
Arapahoe CO-
439 PM MDT FRI JUL 27 2018
...THE TORNADO WARNING FOR NORTHEASTERN ARAPAHOE COUNTY WILL EXPIRE
AT 445 PM MDT...
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.
A Tornado Watch remains in effect until 900 PM MDT for northeastern
Colorado.
LAT...LON 3966 10394 3974 10377 3973 10371 3972 10371
3962 10392
TIME...MOT...LOC 2239Z 316DEG 20KT 3963 10379
$$
RPKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 26, 6:28 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 47 min |
| Jul 26, 6:43 PM MDT | Tornado Warning | BOU | Weld | 17 min |
| Jul 26, 6:50 PM MDT | Severe Thunderstorm Warning | BOU | Larimer | 40 min |
| Jul 26, 7:12 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 32 min |
| Jul 26, 8:00 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 30 min |
| Jul 26, 8:24 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 36 min |
| Jul 26, 9:10 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 35 min |
| Jul 26, 9:45 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe | 30 min |
| Jul 26, 10:38 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 52 min |
| Jul 27, 1:53 PM MDT | Severe Thunderstorm Warning | BOU | Phillips, Sedgwick | 52 min |
| Jul 27, 3:08 PM MDT | Severe Thunderstorm Warning | BOU | Elbert | 37 min |
| Jul 27, 3:26 PM MDT | Tornado Warning | BOU | Morgan, Weld | 34 min |
| Jul 27, 3:43 PM MDT | Tornado Warning | BOU | Washington | 32 min |
| Jul 27, 3:45 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Morgan, Weld | 25 min |
| Jul 27, 3:47 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Elbert | 43 min |
| Jul 27, 4:08 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Elbert, Lincoln, Washington | 41 min |
| Jul 27, 4:28 PM MDT | Tornado Warning | BOU | Arapahoe | 32 min |
| Jul 27, 4:35 PM MDT | Tornado Warning | BOU | Washington | 25 min |
| Jul 27, 4:57 PM MDT | Severe Thunderstorm Warning | BOU | Douglas, Jefferson | 33 min |
| Jul 27, 4:57 PM MDT | Tornado Warning | BOU | Lincoln | 19 min |
| Jul 27, 5:09 PM MDT | Areal Flood Advisory | BOU | Washington | 2 hr |
| Jul 27, 5:29 PM MDT | Areal Flood Advisory | BOU | Lincoln | 2 hr |
| Jul 27, 5:56 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 34 min |
Nearby
Tornado Warnings in Colorado, 2018Every tornado warning in 2018Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.