Alert archive / Colorado / Tornado Watches in 2010

Tornado Watch 442

July 4, 201014 counties in Colorado; 4 counties in Nebraska; Albany County, Carbon County, Laramie County, Wyoming

The Storm Prediction Center issued this tornado watch at Jul 4, 2010, 12:39 PM MDT for 14 counties in Colorado; 4 counties in Nebraska; Albany County, Carbon County, Laramie County, Wyoming. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2010, 12:39 PM MDT (18:39 UTC)
Expired
Jul 4, 2010, 9:00 PM MDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 21 counties

Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Jefferson County, CO, Larimer County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Washington County, CO, Weld County, CO, Banner County, NE, Cheyenne County, NE, Kimball County, NE, Morrill County, NE, Albany County, WY, Carbon County, WY, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 66 km from the middle of the area, began a volume at 18:43 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
10%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

49 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jul 4, 1:54 PM MDTSevere Thunderstorm WarningCYSCarbon46 min
Jul 4, 2:16 PM MDTTornado WarningCYSLaramie, Platte44 min
Jul 4, 2:38 PM MDTSevere Thunderstorm WarningCYSAlbany, Carbon27 min
Jul 4, 2:51 PM MDTTornado WarningCYSGoshen, Laramie, Platte39 min
Jul 4, 3:02 PM MDTTornado WarningCYSAlbany, Carbon43 min
Jul 4, 3:07 PM MDTSevere Thunderstorm WarningBOUElbert38 min
Jul 4, 3:26 PM MDTTornado WarningCYSGoshen, Laramie29 min
Jul 4, 3:28 PM MDTSevere Thunderstorm WarningBOUAdams, Denver47 min
Jul 4, 3:35 PM MDTSevere Thunderstorm WarningCYSAlbany, Platte42 min
Jul 4, 3:38 PM MDTTornado WarningCYSGoshen, Laramie40 min
Jul 4, 3:57 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver48 min
Jul 4, 3:58 PM MDTTornado WarningCYSAlbany, Laramie30 min
Jul 4, 4:00 PM MDTSevere Thunderstorm WarningBOUAdams, Weld19 min
Jul 4, 4:15 PM MDTSevere Thunderstorm WarningBOUDouglas45 min
Jul 4, 4:32 PM MDTSevere Thunderstorm WarningCYSBanner, Kimball33 min
Jul 4, 4:40 PM MDTSevere Thunderstorm WarningBOUElbert50 min
Jul 4, 4:47 PM MDTSevere Thunderstorm WarningBOULarimer58 min
Jul 4, 4:56 PM MDTSevere Thunderstorm WarningBOUDouglas34 min
Jul 4, 5:01 PM MDTTornado WarningCYSBanner, Kimball44 min
Jul 4, 5:09 PM MDTSevere Thunderstorm WarningCYSAlbany, Laramie, Platte66 min
Jul 4, 5:12 PM MDTFlash Flood WarningBOUElbert3 hr
Jul 4, 5:21 PM MDTTornado WarningBOUElbert24 min
Jul 4, 5:22 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver38 min
Jul 4, 5:35 PM MDTSevere Thunderstorm WarningBOULarimer, Weld55 min
Jul 4, 5:41 PM MDTTornado WarningCYSBanner, Cheyenne, Kimball49 min
Jul 4, 5:42 PM MDTTornado WarningBOUElbert33 min
Jul 4, 5:55 PM MDTTornado WarningCYSKimball50 min
Jul 4, 6:09 PM MDTSevere Thunderstorm WarningCYSKimball51 min
Jul 4, 6:11 PM MDTTornado WarningBOUElbert49 min
Jul 4, 6:13 PM MDTSevere Thunderstorm WarningBOULarimer, Weld47 min
Jul 4, 6:24 PM MDTTornado WarningCYSCheyenne, Kimball51 min
Jul 4, 6:29 PM MDTTornado WarningBOUElbert31 min
Jul 4, 6:31 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver, Douglas, Jefferson29 min
Jul 4, 6:40 PM MDTTornado WarningCYSKimball50 min
Jul 4, 6:45 PM MDTFlash Flood WarningBOULarimer2 hr
Jul 4, 6:52 PM MDTSevere Thunderstorm WarningCYSKimball38 min
Jul 4, 6:57 PM MDTTornado WarningBOUElbert, Lincoln48 min
Jul 4, 7:13 PM MDTSevere Thunderstorm WarningCYSCheyenne, Morrill62 min
Jul 4, 7:20 PM MDTSevere Thunderstorm WarningBOUElbert40 min
Jul 4, 7:21 PM MDTSevere Thunderstorm WarningCYSKimball18 min
Jul 4, 7:25 PM MDTSevere Thunderstorm WarningCYSKimball35 min
Jul 4, 7:39 PM MDTFlash Flood WarningCYSBanner, Cheyenne, Kimball, Morrill4 hr
Jul 4, 7:43 PM MDTTornado WarningBOULincoln47 min
Jul 4, 7:55 PM MDTSevere Thunderstorm WarningBOUElbert50 min
Jul 4, 8:00 PM MDTTornado WarningBOUElbert30 min
Jul 4, 8:28 PM MDTTornado WarningBOULincoln47 min
Jul 4, 8:31 PM MDTFlash Flood WarningBOUElbert, Lincoln2 hr
Jul 4, 8:38 PM MDTFlash Flood WarningCYSMorrill3 hr
Jul 4, 8:47 PM MDTSevere Thunderstorm WarningBOULincoln43 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 6.7 hours before the alert went out and 255 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 2010-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 269 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 12:00Z on 2010-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.1939587897Sfc1 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
269 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
628 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 11:30 AM MDTMesoscale DiscussionSPCLarimer, Weld90 min
Jul 4, 2:42 PM MDTMesoscale DiscussionSPCGarfield, Mesa, Montrose, Rio Blanco, San Miguel63 min
Jul 4, 3:44 PM MDTMesoscale DiscussionSPCBaca, Bent, Crowley, Custer, Fremont, Huerfano and 3 more91 min
Jul 4, 4:10 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Crowley, Custer, El Paso, Huerfano and 6 more7 hr
Jul 3, 6:06 PM MDTMesoscale DiscussionSPCArthur, Banner, Box Butte, Cherry, Cheyenne, Dawes and 11 more54 min
Jul 3, 7:45 PM MDTMesoscale DiscussionSPCAntelope, Blaine, Boyd, Brown, Cedar, Garfield and 8 more60 min
Jul 3, 9:04 PM MDTMesoscale DiscussionSPCAntelope, Blaine, Boyd, Brown, Cedar, Garfield and 8 more56 min
Jul 3, 10:48 PM MDTMesoscale DiscussionSPCAntelope, Boyd, Garfield, Holt, Knox, Loup and 2 more57 min
Jul 4, 1:34 PM MDTMesoscale DiscussionSPCRichardson116 min

Nearby

Tornado Watches in Colorado, 2010Tornado Watches in Nebraska, 2010Tornado Watches in Wyoming, 2010Every tornado watch in 2010

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.