Alert archive / Colorado / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 7, NWS Denver/Boulder, CO

May 5, 2012Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 5, 2012, 8:20 PM MDT for Weld County, Colorado. It was in force for 25 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 5, 2012, 8:20 PM MDT (02:20 UTC)
Expired
May 5, 2012, 8:45 PM MDT
In force
25 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Hail
1.25 in
Wind
50.0 mph

County Weld County, CO

The radar

The Denver radar (KFTG), 73 km from the middle of the area, began a volume at 02:20 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 (KDNR), launched 00:00Z, 2.3 hours before the alert went out and 117 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 00:00Z on 2012-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 102 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 00:00Z on 2012-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.19395878Sfc1 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
102 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
3786 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
45 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, in the capitals the NWS used until 2016.

115 
WUUS55 KBOU 060220
SVRBOU
COC123-060245-
/O.NEW.KBOU.SV.W.0007.120506T0220Z-120506T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
820 PM MDT SAT MAY 5 2012

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 845 PM MDT

* AT 820 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL. 
  THIS STORM WAS LOCATED 10 MILES SOUTHEAST OF BARNESVILLE...OR 20
  MILES EAST OF GREELEY...MOVING NORTHEAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MILTON
  RESERVOIR...KERSEY...BRIGGSDALE AND BARNESVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

&&

LAT...LON 4069 10427 4042 10415 4012 10454 4024 10472
TIME...MOT...LOC 0220Z 231DEG 18KT 4038 10434
WIND...HAIL <50MPH 1.25IN

$$
2 follow-up statements
005 
WWUS55 KBOU 060236
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
836 PM MDT SAT MAY 5 2012

COC123-060245-
/O.CON.KBOU.SV.W.0007.000000T0000Z-120506T0245Z/
WELD CO-
836 PM MDT SAT MAY 5 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM MDT
FOR CENTRAL WELD COUNTY...

AT 836 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING ONE INCH DIAMETER HAIL. 
THIS STORM WAS LOCATED 9 MILES NORTHEAST OF HARDIN...OR 25 MILES EAST
OF GREELEY...MOVING NORTHEAST AT 20 MPH.

LOCATIONS REMAINING IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
MILTON RESERVOIR...KERSEY...BRIGGSDALE AND BARNESVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS IN
EXCESS OF 58 MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

&&

LAT...LON 4069 10427 4042 10415 4012 10454 4024 10472
TIME...MOT...LOC 0236Z 231DEG 18KT 4043 10426
WIND...HAIL <50MPH 1.00IN

$$
726 
WWUS55 KBOU 060243
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
843 PM MDT SAT MAY 5 2012

COC123-060252-
/O.EXP.KBOU.SV.W.0007.000000T0000Z-120506T0245Z/
WELD CO-
843 PM MDT SAT MAY 5 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL WELD COUNTY WILL
EXPIRE AT 845 PM MDT...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND IS NO 
LONGER EXPECTED TO PRODUCE SEVERE WEATHER. HEAVY RAIN AND SMALL HAIL 
CAN STILL BE EXPECTED WTIH THIS STORM. 

LAT...LON 4069 10427 4042 10415 4012 10454 4024 10472
TIME...MOT...LOC 0242Z 231DEG 18KT 4045 10423

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 5, 6:32 PM MDTTornado WarningBOULogan43 min
May 5, 7:39 PM MDTSpecial Weather StatementBOUWeld51 min
May 5, 9:29 PM MDTSpecial Weather StatementBOUDenver46 min
May 5, 9:56 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver49 min
May 5, 10:39 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver, Weld51 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2012Every severe thunderstorm warning in 2012

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.