Alert archive / Colorado / Tornado Warnings in 2017

Tornado Warning 8, NWS Denver/Boulder, CO

June 7, 2017Washington County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 7, 2017, 7:13 PM MDT for Washington County, Colorado. It was in force for 47 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: Jun 7, 2017, 7:13 PM MDT (01:13 UTC)
Expired: Jun 7, 2017, 8:00 PM MDT
In force: 47 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.5 in

County Washington County, CO

The radar

The Denver radar (KFTG), 118 km from the middle of the area, began a volume at 01:13 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 nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 1.2 hours before the alert went out and 9 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 496 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 1990 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 106 m²/s²
0-3 km storm-relative helicity: 138 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

As transmitted.

762 
WFUS55 KBOU 080113
TORBOU
COC121-080200-
/O.NEW.KBOU.TO.W.0008.170608T0113Z-170608T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
713 PM MDT WED JUN 7 2017

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Southeastern Washington County in northeastern Colorado...

* Until 800 PM MDT

* At 712 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 4 miles north of Anton, or 23 miles south of Akron,
  moving southeast at 10 mph.

  HAZARD...Tornado and ping pong ball size hail. 

  SOURCE...Weather spotters reported funnel cloud. 

  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. 

* Locations impacted include...
  Arickaree School.

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.

&&

LAT...LON 3988 10331 3993 10323 3977 10294 3970 10303
      3966 10315
TIME...MOT...LOC 0112Z 310DEG 10KT 3982 10322 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

GIMMESTAD

3 follow-up statements

433 
WWUS55 KBOU 080135
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
735 PM MDT WED JUN 7 2017

COC121-080200-
/O.CON.KBOU.TO.W.0008.000000T0000Z-170608T0200Z/
Washington CO-
735 PM MDT WED JUN 7 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...
    
At 734 PM MDT, a severe thunderstorm capable of producing a tornado
was located 5 miles northeast of Anton, or 26 miles south of Akron,
moving southeast at 15 mph.

HAZARD...Tornado and half dollar 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. 

Locations impacted include...
Arickaree School.

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.

&&

LAT...LON 3976 10322 3988 10313 3977 10294 3970 10303
      3966 10315
TIME...MOT...LOC 0134Z 298DEG 12KT 3978 10312 

TORNADO...RADAR INDICATED
HAIL...1.25IN

$$

GIMMESTAD

370 
WWUS55 KBOU 080149
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
749 PM MDT WED JUN 7 2017

COC121-080200-
/O.CON.KBOU.TO.W.0008.000000T0000Z-170608T0200Z/
Washington CO-
749 PM MDT WED JUN 7 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM MDT FOR
SOUTHEASTERN WASHINGTON COUNTY...
    
At 748 PM MDT, a severe thunderstorm capable of producing a tornado
was located over Arickaree School, or 29 miles south of Akron, moving
southeast at 15 mph.

HAZARD...Tornado and quarter 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. 

Locations impacted include...
Arickaree School.

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.

&&

LAT...LON 3973 10313 3986 10310 3977 10294 3970 10303
TIME...MOT...LOC 0148Z 295DEG 13KT 3976 10305 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

GIMMESTAD

978 
WWUS55 KBOU 080201
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
801 PM MDT WED JUN 7 2017

COC121-080211-
/O.EXP.KBOU.TO.W.0008.000000T0000Z-170608T0200Z/
Washington CO-
801 PM MDT WED JUN 7 2017

...THE TORNADO WARNING FOR SOUTHEASTERN WASHINGTON COUNTY HAS
EXPIRED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore the warning has been allowed to expire.  However, heavy 
rain, small hail, and gusty winds are still possible with this 
thunderstorm.

LAT...LON 3973 10313 3986 10310 3977 10294 3970 10303
TIME...MOT...LOC 0201Z 310DEG 10KT 3974 10302 

$$

GIMMESTAD

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 7, 6:29 PM MDT	Tornado Warning Tornado observed	BOU	Washington	46 min
Jun 7, 7:45 PM MDT	Areal Flood Advisory	BOU	Washington	2 hr
Jun 7, 8:04 PM MDT	Special Weather Statement	BOU	Washington	41 min
Jun 8, 4:35 PM MDT	River Flood Advisory	BOU	Larimer	5 days

Nearby

Tornado Warnings in Colorado, 2017 Every tornado warning in 2017 Tornadoes in 2017

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.