Alert archive / Colorado / Tornado Warnings in 2018

Tornado Warning 14, NWS Denver/Boulder, CO

May 28, 2018Logan County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at May 28, 2018, 6:04 PM MDT for Logan County, Colorado. It was in force for 26 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: May 28, 2018, 6:04 PM MDT (00:04 UTC)
Expired: May 28, 2018, 6:30 PM MDT
In force: 26 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Logan County, CO

The radar

The Cheyenne radar (KCYS), 134 km from the middle of the area, began a volume at 00:06 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
May 28, 2:01 PM MDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 0.1 hours before the alert went out and 237 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: 410 J/kg
Mixed-layer CIN: -333 J/kg
Mixed-layer LCL: 1525 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 59 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

847 
WFUS55 KBOU 290004
TORBOU
COC075-290030-
/O.NEW.KBOU.TO.W.0014.180529T0004Z-180529T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
604 PM MDT MON MAY 28 2018

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  Western Logan County in northeastern Colorado...

* Until 630 PM MDT.
    
* At 603 PM MDT, a severe thunderstorm capable of producing a tornado
  was located near Logan Corners, or 6 miles west of Sterling, moving
  northeast at 10 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...
  Logan Corners, North Sterling Reservoir, Padroni, Pawnee Pass and
  Willard.

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 4049 10338 4058 10357 4089 10334 4083 10310
TIME...MOT...LOC 0003Z 212DEG 8KT 4068 10334 

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

$$

MEIER

2 follow-up statements

393 
WWUS55 KBOU 290021
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
621 PM MDT MON MAY 28 2018

COC075-290030-
/O.CON.KBOU.TO.W.0014.000000T0000Z-180529T0030Z/
Logan CO-
621 PM MDT MON MAY 28 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 630 PM MDT FOR
SOUTHWESTERN LOGAN COUNTY...
    
At 620 PM MDT, a severe thunderstorm capable of producing a tornado
was located near Pawnee Pass, or 11 miles west of Sterling, moving
northeast at 25 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...
Logan Corners and Pawnee Pass. 

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 4049 10338 4062 10352 4065 10352 4081 10340
      4076 10320 4069 10322
TIME...MOT...LOC 0020Z 209DEG 21KT 4063 10343 

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

$$

MEIER

144 
WWUS55 KBOU 290031
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
631 PM MDT MON MAY 28 2018

COC075-290040-
/O.EXP.KBOU.TO.W.0014.000000T0000Z-180529T0030Z/
Logan CO-
631 PM MDT MON MAY 28 2018

...THE TORNADO WARNING FOR SOUTHWESTERN LOGAN COUNTY HAS EXPIRED...
                
The storm which prompted the warning no longer appears capable of 
producing a tornado. Therefore, the warning has been allowed to 
expire.  However hail is still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
northeastern Colorado.

LAT...LON 4049 10338 4062 10352 4065 10352 4081 10340
      4076 10320 4069 10322
TIME...MOT...LOC 0030Z 212DEG 8KT 4065 10341 

$$

MEIER

The office that day

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

Issued	Product	Office	Counties	Lasted
May 28, 6:28 PM MDT	Severe Thunderstorm Warning	BOU	Weld	32 min
May 28, 6:35 PM MDT	Tornado Warning	BOU	Morgan	25 min
May 28, 6:37 PM MDT	Tornado Warning	BOU	Weld	23 min
May 28, 6:52 PM MDT	Severe Thunderstorm Warning	BOU	Logan	23 min
May 29, 12:43 AM MDT	Special Weather Statement	BOU	Lincoln	47 min
May 29, 1:30 AM MDT	Special Weather Statement	BOU	Lincoln	45 min
May 29, 1:43 AM MDT	Severe Thunderstorm Warning	BOU	Lincoln	32 min
May 29, 12:18 PM MDT	Severe Thunderstorm Warning	BOU	Logan	27 min
May 29, 1:31 PM MDT	Severe Thunderstorm Warning	BOU	Washington	26 min
May 29, 2:29 PM MDT	Special Weather Statement	BOU	Lincoln	46 min
May 29, 3:29 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	46 min
May 29, 5:02 PM MDT	Special Weather Statement	BOU	Washington	43 min

Nearby

Tornado Warnings in Colorado, 2018 Every tornado warning in 2018 Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.