Alert archive / Colorado / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 21, NWS Denver/Boulder, CO

May 15, 2015Phillips County, Sedgwick County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 15, 2015, 6:22 PM MDT for Phillips County, Sedgwick County, Colorado. It was in force for 38 min. 2 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: May 15, 2015, 6:22 PM MDT (00:22 UTC)
Expired: May 15, 2015, 7:00 PM MDT
In force: 38 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Tornado: Possible
Hail: 1.25 in
Wind: 60.0 mph

Counties Phillips County, CO, Sedgwick County, CO

The radar

The Goodland radar (KGLD), 168 km from the middle of the area, began a volume at 00:22 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 15, 6:59 PM MDT	HAIL 1	Julesburg, CO
May 15, 7:00 PM MDT	HAIL 1.25	6 Ese Fairfield, 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 15, 12:58 PM MDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Denver, CO (KDEN), launched 00:00Z, 0.4 hours before the alert went out and 127 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: 411 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 1427 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: -10 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

942 
WUUS55 KBOU 160022
SVRBOU
COC095-115-160100-
/O.NEW.KBOU.SV.W.0021.150516T0022Z-150516T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
622 PM MDT FRI MAY 15 2015

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL PHILLIPS COUNTY IN NORTHEASTERN COLORADO...
  SEDGWICK COUNTY IN NORTHEASTERN COLORADO...

* UNTIL 700 PM MDT

* AT 621 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED 5 MILES SOUTHWEST
  OF SIXTEEN-MILE CORNER...OR 8 MILES NORTH OF HOLYOKE...MOVING NORTH
  AT 25 MPH.

  HAZARD...60 MPH WIND GUSTS AND HALF DOLLAR SIZE HAIL. 

  SOURCE...LAW ENFORCEMENT. 

  IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE 
           TO ROOFS...SIDING AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  JULESBURG...OVID...SEDGWICK...MARKS BUTTE...SIXTEEN-MILE CORNER AND
  AMHERST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DAMAGING WINDS. PEOPLE OUTSIDE
SHOULD MOVE TO A SHELTER...INSIDE A STRONG BUILDING AND AWAY FROM
WINDOWS. 

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO 
ADVANCED WARNING.

&&

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM MDT FOR NORTHEASTERN
COLORADO.

LAT...LON 4058 10208 4063 10245 4099 10266 4100 10265
      4100 10220
TIME...MOT...LOC 0021Z 163DEG 21KT 4071 10232 

TORNADO...POSSIBLE
HAIL...1.25IN
WIND...60MPH

$$

BARJENBRUCH

The office that day

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

Issued	Product	Office	Counties	Lasted
May 15, 6:26 PM MDT	Severe Thunderstorm Warning	BOU	Phillips	34 min
May 15, 6:45 PM MDT	Tornado Warning	BOU	Phillips, Sedgwick	45 min
May 16, 12:51 PM MDT	Special Weather Statement	BOU	Sedgwick	39 min
May 16, 1:56 PM MDT	Special Weather Statement	BOU	Jefferson	49 min
May 16, 2:04 PM MDT	Areal Flood Advisory	BOU	Douglas, Jefferson	116 min
May 16, 3:17 PM MDT	Special Weather Statement	BOU	Washington	43 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2015 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.