Alert archive / Colorado / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 21, NWS Denver/Boulder, CO

May 23, 2008Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 23, 2008, 5:47 PM MDT for Weld County, Colorado. It was in force for 16 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 23, 2008, 5:47 PM MDT (23:47 UTC)
Expired: May 23, 2008, 6:03 PM MDT
In force: 16 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 76 km from the middle of the area, began a volume at 23:48 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 23, 6:00 PM MDT	TORNADO	21 N New Raymer, CO	FOUR POWER LINES AND FENCE SNAPPED. STOCK TRAILERS OVER TURNED.

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 23, 12:41 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 11.8 hours before the alert went out and 132 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: 974 m above ground
0-6 km bulk shear: 87 kt
0-1 km storm-relative helicity: 96 m²/s²
0-3 km storm-relative helicity: 149 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.

000 
WUUS55 KBOU 232347
SVRBOU
COC123-240015-
/O.NEW.KBOU.SV.W.0021.080523T2347Z-080524T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
547 PM MDT FRI MAY 23 2008

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

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

* UNTIL 615 PM MDT

* AT 546 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL.  THIS
  STORM WAS LOCATED ABOUT 5 MILES NORTHEAST OF PAWNEE BUTTES...OR
  41 MILES NORTHWEST OF STERLING...MOVING NORTH AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL REMAIN OVER MAINLY RURAL AREAS OF THE
  WARNED COUNTY.

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE
SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A STRONG
BUILDING. DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...AND DEADLY
LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS. STAY INSIDE AWAY
FROM WINDOWS UNTIL THE STORM HAS PASSED.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM MDT FRIDAY EVENING FOR
NORTHEASTERN COLORADO.

LAT...LON 4100 10409 4100 10380 4080 10379 4083 10399
TIME...MOT...LOC 2346Z 175DEG 35KT 4089 10392

$$
BARJENBRUCH

1 follow-up statement

000 
WWUS55 KBOU 240003
SVSBOU

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
603 PM MDT SAT MAY 23 2008

COC123-240013-
/O.CAN.KBOU.SV.W.0021.000000T0000Z-080524T0015Z/
WELD CO-
603 PM MDT SAT MAY 23 2008

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WELD COUNTY IS
CANCELLED...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND EXITED 
THE AREA.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 PM MDT FRIDAY EVENING FOR
NORTHEASTERN COLORADO.

LAT...LON 4100 10409 4100 10380 4080 10379 4083 10399
TIME...MOT...LOC 0003Z 175DEG 35KT 4105 10394

$$

BARJENBRUCH

The office that day

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

Issued	Product	Office	Counties	Lasted
May 23, 4:14 AM MDT	Flash Flood Watch	BOU	Boulder, Larimer, Weld	15 hr
May 23, 3:35 PM MDT	Tornado Warning	BOU	Weld	25 min
May 23, 3:49 PM MDT	Tornado Warning	BOU	Morgan	41 min
May 23, 3:54 PM MDT	Tornado Warning	BOU	Weld	21 min
May 23, 4:01 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	42 min
May 23, 4:22 PM MDT	Tornado Warning	BOU	Weld	38 min
May 23, 4:31 PM MDT	Tornado Warning	BOU	Morgan	44 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2008 Every severe thunderstorm warning in 2008

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.