Alert archive / Colorado / Tornado Warnings in 2015
Tornado Warning 3, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this tornado warning at Apr 17, 2015, 6:11 PM MDT for Washington County, Colorado. It was in force for 19 min. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Apr 17, 2015, 6:11 PM MDT (00:11 UTC)
- Expired
- Apr 17, 2015, 6:30 PM MDT
- In force
- 19 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.75 in
County Washington County, CO
The radar
The Denver radar (KFTG), 120 km from the middle of the area, began a volume at 00:13 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 17, 4:37 PM MDT | Tornado Watch | SPC | 7 hr |
The nearest sounding before it
Denver, CO (KDEN), launched 00:00Z, 0.2 hours before the alert went out and 52 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
- 2 J/kg
- Mixed-layer CIN
- -109 J/kg
- Mixed-layer LCL
- 1370 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- -38 m²/s²
- 0-3 km storm-relative helicity
- -112 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
629
WFUS55 KBOU 180011
TORBOU
COC121-180030-
/O.NEW.KBOU.TO.W.0003.150418T0011Z-150418T0030Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
611 PM MDT FRI APR 17 2015
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A
* TORNADO WARNING FOR...
NORTH CENTRAL WASHINGTON COUNTY IN NORTHEASTERN COLORADO...
* UNTIL 630 PM MDT
* AT 611 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED 6 MILES SOUTH OF PREWITT RESERVOIR...OR 13
MILES NORTHWEST OF AKRON...MOVING NORTHWEST AT 15 MPH.
HAZARD...TORNADO.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...EXPECT DAMAGE TO MOBILE HOMES...ROOFS AND VEHICLES.
* LOCATIONS IMPACTED INCLUDE...
PREWITT RESERVOIR.
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 IN A MOBILE
HOME...A VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4028 10322 4026 10346 4043 10346 4043 10327
TIME...MOT...LOC 0011Z 153DEG 12KT 4033 10333
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
RPK2 follow-up statements
348
WWUS55 KBOU 180018
SVSBOU
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
618 PM MDT FRI APR 17 2015
COC121-180030-
/O.CON.KBOU.TO.W.0003.000000T0000Z-150418T0030Z/
WASHINGTON CO-
618 PM MDT FRI APR 17 2015
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR NORTH
CENTRAL WASHINGTON COUNTY...
AT 617 PM MDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 5 MILES SOUTH OF PREWITT RESERVOIR...OR 14 MILES
NORTHWEST OF AKRON...MOVING NORTHWEST AT 15 MPH.
HAZARD...TORNADO.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...EXPECT DAMAGE TO MOBILE HOMES...ROOFS AND VEHICLES.
LOCATIONS IMPACTED INCLUDE...
PREWITT RESERVOIR.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A
VEHICLE OR OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND
PROTECT YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4028 10322 4026 10346 4043 10346 4043 10327
TIME...MOT...LOC 0017Z 153DEG 12KT 4035 10334
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
RPK418
WWUS55 KBOU 180030
SVSBOU
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
630 PM MDT FRI APR 17 2015
COC121-180039-
/O.EXP.KBOU.TO.W.0003.000000T0000Z-150418T0030Z/
WASHINGTON CO-
630 PM MDT FRI APR 17 2015
...THE TORNADO WARNING FOR NORTH CENTRAL WASHINGTON COUNTY WILL
EXPIRE AT 630 PM MDT...
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE. HOWEVER SMALL HAIL
AND GUSTY WINDS ARE STILL POSSIBLE WITH THIS THUNDERSTORM.
A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MDT FOR NORTHEASTERN
COLORADO.
LAT...LON 4028 10322 4026 10346 4043 10346 4043 10327
TIME...MOT...LOC 0028Z 153DEG 12KT 4035 10334
$$
RPKThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 17, 7:08 PM MDT | Special Weather Statement | BOU | Logan | 37 min |
| Apr 17, 8:14 PM MDT | Special Weather Statement | BOU | Logan | 31 min |
| Apr 17, 8:42 PM MDT | Special Weather Statement | BOU | Logan | 33 min |
| Apr 18, 1:38 PM MDT | Tornado Warning | BOU | Washington | 22 min |
| Apr 18, 2:49 PM MDT | Special Weather Statement | BOU | Logan | 41 min |
Nearby
Tornado Warnings in Colorado, 2015Every tornado warning in 2015Tornadoes in 2015
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.