Alert archive / Colorado / Tornado Warnings in 2017

Tornado Warning 1, NWS Denver/Boulder, CO

May 8, 2017Arapahoe County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 8, 2017, 2:50 PM MDT for Arapahoe County, Elbert County, Colorado. It was in force for 28 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: May 8, 2017, 2:50 PM MDT (20:50 UTC)
Expired: May 8, 2017, 3:18 PM MDT
In force: 28 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

Counties Arapahoe County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 56 km from the middle of the area, began a volume at 20:52 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
May 8, 3:20 PM MDT	HAIL 2	2 Se Deer Trail, CO

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
May 8, 12:35 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 8.8 hours before the alert went out and 85 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2189 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

670 
WFUS55 KBOU 082050
TORBOU
COC005-039-082130-
/O.NEW.KBOU.TO.W.0001.170508T2050Z-170508T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
250 PM MDT MON MAY 8 2017

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  North central Elbert County in east central Colorado...
  Southeastern Arapahoe County in northeastern Colorado...

* Until 330 PM MDT
    
* At 249 PM MDT, a severe thunderstorm capable of producing a tornado
  was located 10 miles southwest of Agate, or 22 miles west of Limon,
  moving north at 15 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. 

* Locations impacted include...
  Deer Trail.

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 3932 10401 3935 10417 3963 10422 3963 10390
TIME...MOT...LOC 2049Z 193DEG 15KT 3937 10409 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

BOWEN

2 follow-up statements

934 
WWUS55 KBOU 082100
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
300 PM MDT MON MAY 8 2017

COC005-039-082130-
/O.CON.KBOU.TO.W.0001.000000T0000Z-170508T2130Z/
Elbert CO-Arapahoe CO-
300 PM MDT MON MAY 8 2017

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM MDT FOR NORTH
CENTRAL ELBERT AND SOUTHEASTERN ARAPAHOE COUNTIES...
        
At 259 PM MDT, a severe thunderstorm capable of producing a tornado
was located 7 miles southwest of Agate, or 23 miles northwest of
Limon, moving north at 15 mph.

HAZARD...Tornado and golf ball size hail. 

SOURCE...Weather spotters have reported a funnel cloud 10 miles to 
         the northwest of Simla at 258 PM MDT. 

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...
Deer Trail.

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 3932 10401 3935 10417 3963 10422 3963 10390
TIME...MOT...LOC 2059Z 193DEG 15KT 3941 10408 

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

DANKERS

187 
WWUS55 KBOU 082118
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
318 PM MDT MON MAY 8 2017

COC005-039-082127-
/O.CAN.KBOU.TO.W.0001.000000T0000Z-170508T2130Z/
Elbert CO-Arapahoe CO-
318 PM MDT MON MAY 8 2017

...THE TORNADO WARNING FOR NORTH CENTRAL ELBERT AND SOUTHEASTERN
ARAPAHOE COUNTIES IS CANCELLED...
                
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 cancelled.  However hail up to three-
quarters of an inch in diameter and gusty winds up to 50 MPH are 
still possible with this thunderstorm.

A severe thunderstorm watch remains in effect until 800 PM MDT for
northeastern and east central Colorado.

LAT...LON 3932 10401 3935 10417 3963 10422 3963 10390
TIME...MOT...LOC 2115Z 193DEG 15KT 3949 10406 

$$

DANKERS

The office that day

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

Issued	Product	Office	Counties	Lasted
May 8, 2:25 PM MDT	Severe Thunderstorm Warning	BOU	Clear Creek, Jefferson	21 min
May 8, 2:37 PM MDT	Special Weather Statement	BOU	Elbert	38 min
May 8, 2:44 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	46 min
May 8, 2:45 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Boulder, Broomfield, Denver, Jefferson	45 min
May 8, 3:21 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Broomfield, Denver, Jefferson	39 min
May 8, 3:25 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Elbert	50 min
May 8, 3:33 PM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Denver, Jefferson	57 min
May 8, 3:34 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln, Washington	41 min
May 8, 3:51 PM MDT	Severe Thunderstorm Warning	BOU	Weld	39 min
May 8, 4:15 PM MDT	Areal Flood Advisory	BOU	Weld	90 min
May 8, 4:18 PM MDT	Special Weather Statement	BOU	Adams	42 min
May 8, 4:23 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	37 min
May 8, 4:28 PM MDT	Severe Thunderstorm Warning	BOU	Weld	47 min
May 8, 4:46 PM MDT	Areal Flood Advisory	BOU	Adams	89 min
May 8, 4:59 PM MDT	Severe Thunderstorm Warning	BOU	Elbert, Lincoln	25 min
May 8, 5:00 PM MDT	Flash Flood Warning	BOU	Weld	3 hr
May 8, 5:20 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln, Washington	40 min
May 8, 5:38 PM MDT	Areal Flood Advisory	BOU	Elbert, Lincoln, Washington	112 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.