Alert archive / Colorado / Tornado Watches in 2019

Tornado Watch 485

July 4, 201920 counties in Colorado

The Storm Prediction Center issued this tornado watch at Jul 4, 2019, 3:01 PM MDT for 20 counties in Colorado. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jul 4, 2019, 3:01 PM MDT (21:01 UTC)
Expired
Jul 4, 2019, 10:00 PM MDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt

Counties Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Cheyenne County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Jefferson County, CO, Kit Carson County, CO, Larimer County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Yuma County, CO

The radar

The Denver radar (KFTG), 44 km from the middle of the area, began a volume at 21:04 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
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 4, 3:25 PM MDTSevere Thunderstorm WarningPUBEl Paso50 min
Jul 4, 3:42 PM MDTSevere Thunderstorm WarningBOUDouglas33 min
Jul 4, 4:12 PM MDTSevere Thunderstorm WarningPUBEl Paso48 min
Jul 4, 4:13 PM MDTSevere Thunderstorm WarningBOUDouglas47 min
Jul 4, 4:44 PM MDTSevere Thunderstorm WarningBOUDouglas46 min
Jul 4, 5:26 PM MDTSevere Thunderstorm WarningBOUArapahoe15 min
Jul 4, 5:31 PM MDTSevere Thunderstorm WarningBOUAdams, Denver22 min
Jul 4, 5:33 PM MDTSevere Thunderstorm WarningBOUDouglas42 min
Jul 4, 5:39 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver23 min
Jul 4, 5:48 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln27 min
Jul 4, 5:59 PM MDTSevere Thunderstorm WarningBOUJefferson31 min
Jul 4, 6:12 PM MDTSevere Thunderstorm WarningBOUAdams, Denver, Jefferson48 min
Jul 4, 6:16 PM MDTSevere Thunderstorm WarningBOUElbert, Lincoln44 min
Jul 4, 6:18 PM MDTSevere Thunderstorm WarningBOUDouglas31 min
Jul 4, 6:33 PM MDTSevere Thunderstorm WarningBOUArapahoe, Denver18 min
Jul 4, 6:46 PM MDTSevere Thunderstorm WarningBOULincoln44 min
Jul 4, 6:48 PM MDTSevere Thunderstorm WarningBOUArapahoe27 min
Jul 4, 6:56 PM MDTSevere Thunderstorm WarningBOUAdams, Broomfield17 min
Jul 4, 7:24 PM MDTSevere Thunderstorm WarningBOULincoln27 min
Jul 4, 7:31 PM MDTSevere Thunderstorm WarningBOUWashington44 min
Jul 4, 7:39 PM MDTSevere Thunderstorm WarningBOUBoulder19 min
Jul 4, 7:48 PM MDTSevere Thunderstorm WarningBOULarimer27 min
Jul 4, 7:49 PM MDTSevere Thunderstorm WarningGLDYuma41 min
Jul 4, 7:50 PM MDTSevere Thunderstorm WarningBOUAdams, Morgan, Washington25 min
Jul 4, 8:18 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington27 min
Jul 4, 8:41 PM MDTSevere Thunderstorm WarningBOULarimer, Weld34 min
Jul 4, 8:53 PM MDTSevere Thunderstorm WarningBOUWashington37 min
Jul 4, 9:24 PM MDTSevere Thunderstorm WarningGLDYuma36 min
Jul 4, 9:41 PM MDTSevere Thunderstorm WarningBOULogan, Washington49 min
Jul 4, 9:57 PM MDTSevere Thunderstorm WarningGLDYuma63 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, 9.0 hours before the alert went out and 83 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 2019-07-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 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 2019-07-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
8 J/kg
Mixed-layer CIN
-514 J/kg
Mixed-layer LCL
2696 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 2:10 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Boulder, Broomfield, Cheyenne, Denver and 13 more2 hr
Jul 4, 5:40 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Boulder, Broomfield, Cheyenne, Denver and 14 more95 min

Nearby

Tornado Watches in Colorado, 2019Every tornado watch in 2019

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.