Alert archive / Colorado / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 155, NWS Denver/Boulder, CO

July 5, 2019Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jul 5, 2019, 10:14 PM MDT for Weld County, Colorado. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 5, 2019, 10:14 PM MDT (04:14 UTC)
Expired: Jul 5, 2019, 11:00 PM MDT
In force: 46 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 1.5 in
Wind: 50.0 mph

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 75 km from the middle of the area, began a volume at 04:13 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 5, 3:36 PM MDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 4.2 hours before the alert went out and 125 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: 1859 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 1778 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 199 m²/s²
0-3 km storm-relative helicity: 284 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 12.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 5, 9:54 PM MDT, 20 minutes earlier.

Area forecast discussion, Jul 5, 9:54 PM MDT, 20 minutes before

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Hazardous weather outlook, Jul 5, 10:31 AM MDT, 11 hours 43 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1031 AM MDT Fri Jul 5 2019

COZ030>051-061645-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1031 AM MDT Fri Jul 5 2019

...SEVERE STORMS POSSIBLE AGAIN LATER TODAY...

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Thunderstorms will develop over the foothills and mountains along
with the Palmer and Cheyenne Ridges this afternoon. Storms will
then spread across the plains during through late tonight. The
main threat today is large hail, with the possibility of a few
storms producing hail over 2 inches in diameter. Heavy rain of up
to 3 inches in two hours producing flash flooding, damaging winds,
and isolated tornadoes are also possible. The severe weather is
most likely between 3 pm and 8 pm in areas just east of the
mountains, and between 6 pm and midnight over the eastern portion
of the plains. The storms should end over the western part of the
area by around midnight, but may continue over the eastern areas
through the early morning hours.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Thunderstorms are likely again on the plains Saturday afternoon
and evening, with scattered storms over the mountains. Chances
will be slightly less on Sunday. The storms could produce heavy
rain with a couple severe storms possible both Saturday and
Sunday. There will be a chance of late day showers and
thunderstorms on Monday, then a slight chance for the rest of the
week. Temperatures will be a little below seasonal normals over
the weekend, then warm to near normal for the coming week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed after 3 pm.

In the hours before

Local storm report, Jul 5, 8:51 PM MDT, 1 hour 23 minutes before

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Local storm report, Jul 5, 8:54 PM MDT, 1 hour 20 minutes before

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Local storm report, Jul 5, 8:57 PM MDT, 1 hour 17 minutes before

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Local storm report, Jul 5, 9:10 PM MDT, 1 hour 4 minutes before

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Local storm report, Jul 5, 9:24 PM MDT, 50 minutes before

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Local storm report, Jul 5, 10:02 PM MDT, 12 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 5, 6:10 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Arapahoe, Denver	50 min
Jul 5, 6:27 PM MDT	Areal Flood Advisory	BOU	Adams, Arapahoe, Denver	112 min
Jul 5, 6:53 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Denver	37 min
Jul 5, 7:01 PM MDT	Severe Thunderstorm Warning	BOU	Adams, Boulder, Broomfield, Jefferson	44 min
Jul 5, 7:20 PM MDT	Severe Thunderstorm Warning	BOU	Adams	25 min
Jul 5, 7:24 PM MDT	Severe Thunderstorm Warning	BOU	Boulder	51 min
Jul 5, 7:38 PM MDT	Areal Flood Advisory	BOU	Adams, Boulder, Broomfield, Jefferson	2 hr
Jul 5, 7:46 PM MDT	Severe Thunderstorm Warning	BOU	Boulder, Weld	44 min
Jul 5, 8:18 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	42 min
Jul 5, 8:26 PM MDT	Areal Flood Advisory	BOU	Boulder, Larimer, Weld	2 hr
Jul 5, 8:32 PM MDT	Severe Thunderstorm Warning	BOU	Boulder	26 min
Jul 5, 8:48 PM MDT	Severe Thunderstorm Warning	BOU	Weld	42 min
Jul 5, 9:01 PM MDT	Severe Thunderstorm Warning	BOU	Larimer	44 min
Jul 5, 9:38 PM MDT	Severe Thunderstorm Warning	BOU	Larimer, Weld	41 min
Jul 5, 10:55 PM MDT	Severe Thunderstorm Warning	BOU	Weld	65 min
Jul 5, 11:40 PM MDT	Special Weather Statement	BOU	Jefferson	50 min
Jul 6, 12:06 AM MDT	Areal Flood Advisory	BOU	Park	2 hr
Jul 6, 12:36 AM MDT	Special Weather Statement	BOU	Logan	39 min
Jul 6, 12:51 AM MDT	Severe Thunderstorm Warning	BOU	Logan	39 min
Jul 6, 11:57 AM MDT	Special Weather Statement	BOU	Gilpin	48 min
Jul 6, 12:02 PM MDT	Special Weather Statement	BOU	Clear Creek	43 min
Jul 6, 1:54 PM MDT	Severe Thunderstorm Warning	BOU	Douglas, Jefferson	51 min
Jul 6, 2:48 PM MDT	Special Weather Statement	BOU	Douglas	27 min

Nearby

Severe Thunderstorm Warnings in Colorado, 2019 Every severe thunderstorm warning 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.