Alert archive / Colorado / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 262, NWS Denver/Boulder, CO

September 8, 2019Grand County, Jackson County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Sep 8, 2019, 3:18 PM MDT for Grand County, Jackson County, Colorado. It was in force for 42 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: Sep 8, 2019, 3:18 PM MDT (21:18 UTC)
Expired: Sep 8, 2019, 4:00 PM MDT
In force: 42 min
Issued by: NWS Denver/Boulder, CO
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Grand County, CO, Jackson County, CO

The radar

The Cheyenne radar (KCYS), 147 km from the middle of the area, began a volume at 21:19 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
Sep 8, 2:56 PM MDT	Severe Thunderstorm Watch	SPC	6 hr

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 Sep 8, 11:43 AM MDT, 3 hours 35 minutes earlier.

Area forecast discussion, Sep 8, 11:43 AM MDT, 3 hours 35 minutes before

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Hazardous weather outlook, Sep 8, 11:00 AM MDT, 4 hours 18 minutes before

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1100 AM MDT Sun Sep 8 2019

COZ030>051-091700-
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-
1100 AM MDT Sun Sep 8 2019

...SEVERE STORMS POSSIBLE OVER THE FOOTHILLS AND PLAINS TODAY..

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

.DAY ONE...Today and Tonight

Today will be an active weather day. thunderstorms will develop
over the mountains early this afternoon and move east across the
plains from late afternoon through the evening. A fairly well
organized line of thunderstorms is expected to push east across
the area, with most storms producing gusty winds of 40 to 50 mph,
a period of heavy rain and small hail, and frequent lightning.
However, embedded severe storms may produce damaging winds up to
65 mph and hail greater than 1 inch in diameter. There is a small
threat of tornadoes from just east and southeast of Denver to the
Limon area in the late afternoon and early evening.

The main threat of severe weather will be between 2 PM and 5 PM in
the foothills, 4 PM and 7 PM in the Denver area, and from 6 PM
through 10 PM on the plains.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Dry conditions can be expected for Monday with a better chance for
afternoon showers and thunderstorms Tuesday afternoon, especially
across the far eastern plains. Another disturbance and
accompanying cold front will bring a better chance of showers and
thunderstorms Wednesday afternoon and night over the area. Dry
conditions and much cooler temperatures can be expected for
Thursday. Trending gradually warmer into the weekend, but remaining
mostly dry across the region.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed after 2 PM.

Gimmestad/Fredin

In the hours before

Special weather statement, Sep 8, 2:46 PM MDT, 32 minutes before

Special Weather Statement
National Weather Service Denver CO
246 PM MDT Sun Sep 8 2019

COZ034-037-082130-
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet CO-Central and Southeast Park County CO-
246 PM MDT Sun Sep 8 2019

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN PARK COUNTY UNTIL
330 PM MDT...

At 245 PM MDT, Doppler radar was tracking a strong thunderstorm near
Nathrop, or 35 miles northwest of Hayden Pass Burn Scar, moving
northeast at 45 mph.

Wind gusts of 50 to 55 mph will be possible with this storm.

Locations impacted include...
Fairplay, Alma, Antero Reservoir, Red Hill Pass, Trout Creek Pass and
Hartsel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for sudden gusty winds. Secure loose objects and move to a
safe shelter inside a building or vehicle.

&&

LAT...LON 3871 10591 3879 10592 3881 10591 3883 10593
      3886 10594 3887 10592 3894 10603 3894 10606
      3896 10611 3897 10610 3899 10613 3919 10619
      3923 10617 3924 10618 3935 10595 3902 10568
      3871 10559
TIME...MOT...LOC 2045Z 232DEG 42KT 3875 10611

ENTREKIN

Special weather statement, Sep 8, 3:05 PM MDT, 13 minutes before

Special Weather Statement
National Weather Service Denver CO
305 PM MDT Sun Sep 8 2019

COZ030>034-082145-
Jackson County Below 9000 Feet CO-
South and Southeast Grand/West Central and Southwest
Boulder/Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet CO-Grand and Summit Counties Below 9000 Feet CO-
West Jackson and West Grand Counties Above 9000 Feet CO-
South and East Jackson/Larimer/North and Northeast Grand/Northwest
Boulder Counties Above 9000 Feet CO-
305 PM MDT Sun Sep 8 2019

...SIGNIFICANT WEATHER ADVISORY FOR JACKSON...NORTHWESTERN SUMMIT AND
GRAND COUNTIES UNTIL 345 PM MDT...

At 304 PM MDT, Doppler radar was tracking strong thunderstorms along
a line extending from 7 miles southeast of Steamboat Springs to 8
miles northeast of Avon, or along a line extending from 42 miles east
of Craig to 48 miles east of Glenwood Springs. Movement was northeast
at 40 mph.

Wind gusts of 50 to 55 mph will be possible with these storms.

Locations impacted include...
Silverthorne, Kremmling, Hot Sulphur Springs, Walden, Lake John,
Parshall, Rand, Brownlee, Cowdrey, Hot Sulphur Spring, Williams Fork
Reservoir, Pearl, Green Mountain Reservoir, Coalmont and Radium.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for sudden gusty winds. Secure loose objects and move to a
safe shelter inside a building or vehicle.

&&

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
central and north central Colorado.

LAT...LON 4100 10630 3986 10591 3960 10611 3975 10633
      3992 10643 3994 10662 4048 10665 4082 10664
      4100 10681
TIME...MOT...LOC 2104Z 242DEG 35KT 4038 10676 3976 10646

ENTREKIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 7, 6:15 PM MDT	Special Weather Statement	BOU	Teller	45 min
Sep 7, 6:53 PM MDT	Special Weather Statement	BOU	Douglas	37 min
Sep 7, 8:28 PM MDT	Special Weather Statement	BOU	Jefferson	32 min
Sep 8, 2:46 PM MDT	Special Weather Statement	BOU	Park	44 min
Sep 8, 3:05 PM MDT	Special Weather Statement	BOU	Grand, Jackson, Summit	40 min
Sep 8, 3:51 PM MDT	Special Weather Statement	BOU	Park	39 min
Sep 8, 4:06 PM MDT	Special Weather Statement	BOU	Grand, Jackson	39 min
Sep 8, 4:32 PM MDT	Special Weather Statement	BOU	Jefferson	28 min
Sep 8, 5:04 PM MDT	Special Weather Statement	BOU	Douglas	41 min
Sep 8, 5:34 PM MDT	Special Weather Statement	BOU	Broomfield, Denver	41 min
Sep 8, 5:53 PM MDT	Special Weather Statement	BOU	Adams	37 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; radar from the NEXRAD Level II archive.