Alert archive / Colorado / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 21, NWS Grand Junction, CO

September 5, 2007Routt County, Colorado

NWS Grand Junction, CO issued this severe thunderstorm warning at Sep 5, 2007, 5:50 PM MDT for Routt 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
Sep 5, 2007, 5:50 PM MDT (23:50 UTC)
Expired
Sep 5, 2007, 6:15 PM MDT
In force
25 min
Issued by
NWS Grand Junction, CO
Area
Counties, with a storm outline in the text

County Routt County, CO

The radar

The Cheyenne radar (KCYS), 172 km from the middle of the area, began a volume at 23:52 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

Grand Junction, CO (KGJT), launched 12:00Z, 11.8 hours before the alert went out and 241 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, Grand Junction, CO at 12:00Z on 2007-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 218 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Grand Junction, CO at 12:00Z on 2007-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 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
218 J/kg
Mixed-layer CIN
-197 J/kg
Mixed-layer LCL
1722 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KGJT 052351
SVRGJT
COC107-060015-
/O.NEW.KGJT.SV.W.0021.070905T2350Z-070906T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
550 PM MDT WED SEP 5 2007

THE NATIONAL WEATHER SERVICE IN GRAND JUNCTION HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN ROUTT COUNTY IN NORTHWEST COLORADO...

* UNTIL 615 PM MDT

* AT 545 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 20
  MILES WEST OF MT ZIRKEL...OR ABOUT 33 MILES NORTHEAST OF CRAIG...
  AND MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  HAHNS PEAK BY 555 PM MDT...
  6 MILES NORTHWEST OF MT ZIRKEL BY 615 PM MDT...

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
WEDNESDAY EVENING FOR NORTHWESTERN COLORADO AND NORTHEASTERN UTAH.

LAT...LON 4095 10685 4091 10680 4088 10673 4088 10667
      4086 10664 4081 10664 4070 10707 4087 10716
      4097 10685
TIME...MOT...LOC 2350Z 248DEG 33KT 4082 10700

$$

PF
1 follow-up statement
000 
WWUS55 KGJT 060015
SVSGJT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND JUNCTION CO
613 PM MDT WED SEP 5 2007

COC107-060023-
/O.EXP.KGJT.SV.W.0021.000000T0000Z-070906T0015Z/
ROUTT CO-
613 PM MDT WED SEP 5 2007

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN ROUTT COUNTY
EXPIRES AT 615 PM MDT...

A STRONG THUNDERSTORM WENT THROUGH HAHNS PEAK WITH SMALL HAIL AND 
PEA SIZED HAIL.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM MDT
WEDNESDAY EVENING FOR NORTHWESTERN COLORADO AND NORTHEASTERN UTAH.

LAT...LON 4095 10685 4091 10680 4088 10673 4088 10667
      4086 10664 4081 10664 4070 10707 4087 10716
      4097 10685
TIME...MOT...LOC 0013Z 248DEG 33KT 4090 10674

$$

PF

The office that day

Everything else NWS Grand Junction, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 2:19 PM MDTFlash Flood WarningGJTMesa3 hr
Sep 5, 2:26 PM MDTSevere Thunderstorm WarningGJTMoffat, Routt49 min
Sep 5, 3:12 PM MDTSevere Thunderstorm WarningGJTMoffat, Rio Blanco48 min
Sep 5, 3:42 PM MDTSevere Thunderstorm WarningGJTMoffat48 min
Sep 5, 3:58 PM MDTSevere Thunderstorm WarningGJTMoffat47 min
Sep 5, 4:23 PM MDTSevere Thunderstorm WarningGJTMoffat52 min
Sep 5, 5:47 PM MDTSevere Thunderstorm WarningGJTMoffat, Rio Blanco43 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2007Every severe thunderstorm warning in 2007

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.