Alert archive / Colorado / Tornado Warnings in 2009
Tornado Warning 67, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at Jul 20, 2009, 10:22 PM MDT for 4 counties in Colorado. It was in force for 25 min. 4 reports 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 20, 2009, 10:22 PM MDT (04:22 UTC)
- Expired
- Jul 20, 2009, 10:47 PM MDT
- In force
- 25 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Jefferson County, CO
The radar
The Denver radar (KFTG), 46 km from the middle of the area, began a volume at 04:23 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 20, 10:22 PM MDT | HAIL 1 | Arvada, CO | ROOF DAMAGE. SKY LIGHTS ON RV BLOWN OUT. |
| Jul 20, 10:26 PM MDT | HAIL 0.75 | Nne Lakewood, CO | |
| Jul 20, 10:28 PM MDT | HAIL 1 | 6 Wsw Denver, CO | DENTED CARS. BROKEN WINDOWS. DAMAGED SHINGLES. |
| Jul 20, 10:38 PM MDT | HAIL 1 | Arvada, CO |
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 00:00Z, 4.4 hours before the alert went out and 159 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
- 18 J/kg
- Mixed-layer CIN
- -77 J/kg
- Mixed-layer LCL
- 3234 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 38 m²/s²
- 0-3 km storm-relative helicity
- 68 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 WFUS55 KBOU 210422 TORBOU COC001-005-031-059-210515- /O.NEW.KBOU.TO.W.0067.090721T0422Z-090721T0515Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE DENVER CO 1022 PM MDT MON JUL 20 2009 THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A * TORNADO WARNING FOR... EAST CENTRAL JEFFERSON COUNTY IN NORTHEAST COLORADO EXTREME WEST CENTRAL ARAPAHOE COUNTY IN NORTHEAST COLORADO EXTREME WEST CENTRAL ADAMS COUNTY IN NORTHEAST COLORADO SOUTHWESTERN DENVER COUNTY IN NORTHEAST COLORADO * UNTIL 1115 PM MDT * AT 1023 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO OVER NORTHERN LAKEWOOD...OR 9 MILES WEST OF DENVER. THIS STORM WAS MOVING SOUTHEAST AT 15 MPH. * LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHERIDAN... RED ROCKS PARK...MORRISON...FEDERAL HEIGHTS...WHEAT RIDGE... SOUTHERN WESTMINSTER...NORTHERN LITTLETON...LAKEWOOD...EASTERN GOLDEN...ENGLEWOOD...WESTERN DENVER AND ARVADA. PRECAUTIONARY/PREPAREDNESS ACTIONS... THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS. IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A SUBSTANTIAL SHELTER. IF NO SAFE SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS. IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING LARGE DAMAGING HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS. && LAT...LON 3961 10496 3960 10521 3980 10522 3988 10502 TIME...MOT...LOC 0423Z 310DEG 26KT 3974 10512 $$
3 follow-up statements
000 WWUS55 KBOU 210427 SVSBOU SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 1027 PM MDT MON JUL 20 2009 COC001-005-031-059-210515- /O.CON.KBOU.TO.W.0067.000000T0000Z-090721T0515Z/ JEFFERSON CO-ARAPAHOE CO-ADAMS CO-DENVER CO- 1027 PM MDT MON JUL 20 2009 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM MDT FOR SOUTHWESTERN DENVER...EXTREME WEST CENTRAL ADAMS...EXTREME WEST CENTRAL ARAPAHOE AND EAST CENTRAL JEFFERSON COUNTIES... AT 1027 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS STORM WAS LOCATED OVER CENTRAL LAKEWOOD...OR 8 MILES WEST OF DENVER. THIS STORM WAS MOVING SOUTHEAST AT 15 MPH. LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHERIDAN...RED ROCKS PARK...MORRISON...NORTHWESTERN CENTENNIAL... WHEAT RIDGE...SOUTHERN WESTMINSTER...NORTHERN LITTLETON...LAKEWOOD... EASTERN GOLDEN...ENGLEWOOD...WESTERN DENVER AND ARVADA. PRECAUTIONARY/PREPAREDNESS ACTIONS... THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS. IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS. IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING LARGE DAMAGING HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS. && LAT...LON 3961 10496 3960 10521 3980 10522 3988 10502 TIME...MOT...LOC 0427Z 310DEG 26KT 3971 10511 $$
000 WWUS55 KBOU 210436 CCA SVSBOU SEVERE WEATHER STATEMENT...CORRECTED NATIONAL WEATHER SERVICE DENVER CO 1027 PM MDT MON JUL 20 2009 COC001-005-031-059-210515- /O.COR.KBOU.TO.W.0067.000000T0000Z-090721T0515Z/ JEFFERSON CO-ARAPAHOE CO-ADAMS CO-DENVER CO- 1027 PM MDT MON JUL 20 2009 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM MDT FOR SOUTHWESTERN DENVER...EXTREME WEST CENTRAL ADAMS...EXTREME WEST CENTRAL ARAPAHOE AND EAST CENTRAL JEFFERSON COUNTIES... AT 1027 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS STORM WAS LOCATED OVER CENTRAL LAKEWOOD...OR 10 MILES WEST OF DENVER. THIS STORM WAS MOVING SOUTHEAST AT 20 MPH. LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SHERIDAN...RED ROCKS PARK...MORRISON...NORTHWESTERN CENTENNIAL... WHEAT RIDGE...SOUTHERN WESTMINSTER...NORTHERN LITTLETON...LAKEWOOD... EASTERN GOLDEN...ENGLEWOOD...WESTERN DENVER AND ARVADA. PRECAUTIONARY/PREPAREDNESS ACTIONS... THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS. IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS. IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING LARGE DAMAGING HAIL AND DESTRUCTIVE STRAIGHT LINE WINDS. && LAT...LON 3961 10496 3960 10521 3980 10522 3988 10502 TIME...MOT...LOC 0427Z 310DEG 26KT 3968 10514 $$
000 WWUS55 KBOU 210447 SVSBOU SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 1047 PM MDT MON JUL 20 2009 COC001-005-031-059-210458- /O.CAN.KBOU.TO.W.0067.000000T0000Z-090721T0515Z/ JEFFERSON CO-ARAPAHOE CO-ADAMS CO-DENVER CO- 1047 PM MDT MON JUL 20 2009 ...THE TORNADO WARNING FOR SOUTHWESTERN DENVER...EXTREME WEST CENTRAL ADAMS...EXTREME WEST CENTRAL ARAPAHOE AND EAST CENTRAL JEFFERSON COUNTIES IS CANCELLED... THE THUNDERSTORM THAT PROMPTED THE WARNING HAS EXITED THE AREA. LAT...LON 3961 10496 3960 10521 3980 10522 3988 10502 TIME...MOT...LOC 0448Z 310DEG 26KT 3958 10499 $$
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 20, 9:47 PM MDT | Special Weather Statement | BOU | Broomfield | 28 min |
| Jul 20, 9:56 PM MDT | Severe Thunderstorm Warning | BOU | Broomfield, Weld | 34 min |
| Jul 20, 10:04 PM MDT | Severe Thunderstorm Warning | BOU | Larimer, Weld | 41 min |
| Jul 20, 10:06 PM MDT | Severe Thunderstorm Warning | BOU | Boulder, Broomfield, Denver, Jefferson | 39 min |
| Jul 20, 10:24 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Denver, Weld | 51 min |
| Jul 20, 10:31 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 44 min |
| Jul 20, 10:34 PM MDT | Areal Flood Advisory | BOU | Larimer, Weld | 86 min |
| Jul 20, 10:39 PM MDT | Areal Flood Advisory | BOU | Adams, Arapahoe, Denver, Jefferson | 81 min |
| Jul 20, 10:43 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Denver, Douglas, Jefferson | 47 min |
| Jul 20, 10:56 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 34 min |
| Jul 20, 11:18 PM MDT | Areal Flood Advisory | BOU | Arapahoe, Douglas, Elbert | 117 min |
| Jul 20, 11:24 PM MDT | Severe Thunderstorm Warning | BOU | Douglas | 51 min |
| Jul 20, 11:27 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver | 31 min |
| Jul 20, 11:36 PM MDT | Tornado Warning | BOU | Douglas | 24 min |
| Jul 21, 12:02 AM MDT | Areal Flood Advisory | BOU | Adams, Arapahoe, Denver, Weld | 88 min |
| Jul 21, 3:28 PM MDT | Special Weather Statement | BOU | Douglas | 47 min |
Nearby
Tornado Warnings in Colorado, 2009Every tornado warning in 2009Tornadoes in 2009
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.