Alert archive / Colorado / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 13, NWS Denver/Boulder, CO

May 13, 2018Adams County, Arapahoe County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 13, 2018, 4:10 PM MDT for Adams County, Arapahoe County, Colorado. It was in force for 35 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 13, 2018, 4:10 PM MDT (22:10 UTC)
Expired
May 13, 2018, 4:45 PM MDT
In force
35 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

Counties Adams County, CO, Arapahoe County, CO

The radar

The Denver radar (KFTG), 59 km from the middle of the area, began a volume at 22:13 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 12:00Z, 10.2 hours before the alert went out and 59 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-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2018-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2018-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 49 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
643 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

939 
WUUS55 KBOU 132210
SVRBOU
COC001-005-132245-
/O.NEW.KBOU.SV.W.0013.180513T2210Z-180513T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Denver CO
410 PM MDT SUN MAY 13 2018

The National Weather Service in Denver Colorado has issued a

* Severe Thunderstorm Warning for...
  Eastern Arapahoe County in northeastern Colorado...
  Southeastern Adams County in northeastern Colorado...

* Until 445 PM MDT.

* At 410 PM MDT, a severe thunderstorm was located 5 miles northeast
  of Deer Trail, or 30 miles northwest of Limon, moving northeast at
  15 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Cottonwood Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3971 10406 3984 10374 3970 10371 3959 10371
      3957 10386 3957 10398
TIME...MOT...LOC 2210Z 231DEG 15KT 3966 10396 

HAIL...1.00IN
WIND...<50MPH
 
$$

BOWEN
1 follow-up statement
644 
WWUS55 KBOU 132234
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
434 PM MDT SUN MAY 13 2018

COC001-005-132245-
/O.CON.KBOU.SV.W.0013.000000T0000Z-180513T2245Z/
Arapahoe CO-Adams CO-
434 PM MDT SUN MAY 13 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM MDT
FOR NORTHEASTERN ARAPAHOE AND SOUTHEASTERN ADAMS COUNTIES...

At 434 PM MDT, a severe thunderstorm was located 6 miles northwest of
Cottonwood Valley, or 32 miles north of Limon, moving northeast at 15
mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Cottonwood Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3975 10394 3984 10374 3970 10371 3967 10373
      3964 10379 3962 10384
TIME...MOT...LOC 2234Z 231DEG 15KT 3972 10386 

HAIL...1.00IN
WIND...<50MPH
 
$$

BOWEN

The office that day

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

IssuedProductOfficeCountiesLasted
May 12, 7:10 PM MDTSpecial Weather StatementBOUBroomfield35 min
May 13, 12:22 AM MDTDense Fog AdvisoryBOUArapahoe, Boulder, Clear Creek, Douglas, Elbert, Gilpin and 4 more9 hr
May 13, 4:00 PM MDTSpecial Weather StatementBOUArapahoe30 min
May 13, 4:40 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Washington20 min
May 13, 4:41 PM MDTSpecial Weather StatementBOUBoulder49 min
May 13, 5:16 PM MDTSpecial Weather StatementBOUWeld29 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2018Every severe thunderstorm warning 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.