Alert archive / Colorado / Special Weather Statements in 2017

Special Weather Statement, NWS Denver/Boulder, CO

July 2, 2017Adams County, Colorado

NWS Denver/Boulder, CO issued this special weather statement at Jul 2, 2017, 2:56 PM MDT for Adams County, Colorado. It was in force for 19 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
Jul 2, 2017, 2:56 PM MDT (20:56 UTC)
Expired
Jul 2, 2017, 3:15 PM MDT
In force
19 min
Issued by
NWS Denver/Boulder, CO

County Adams County, CO

The radar

The Denver radar (KFTG), 1 km from the middle of the area, began a volume at 21:00 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

Denver, CO (KDEN), launched 12:00Z, 8.9 hours before the alert went out and 112 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 2017-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 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 2017-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
2 J/kg
Mixed-layer CIN
-482 J/kg
Mixed-layer LCL
3058 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Jul 2, 10:38 AM MDT, 4 hours 18 minutes earlier.

Area forecast discussion, Jul 2, 10:38 AM MDT, 4 hours 18 minutes before
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</head>
<body>
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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Hazardous weather outlook, Jul 2, 11:03 AM MDT, 3 hours 53 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1103 AM MDT Sun Jul 2 2017

COZ030>051-031715-
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-
1103 AM MDT Sun Jul 2 2017

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

.DAY ONE...This Afternoon and Tonight

Isolated showers and thunderstorms will develop over the
mountains and adjacent plains early this afternoon before
spreading east on the plains through the evening hours. Expect
gusty winds to 45 mph but only brief light rain over the mountains
and adjacent plains. More low level moisture will be available
further east with the potential for a few strong to severe storms
along and ahead of a dry line, generally east of a line from Limon
to Sterling. Damaging winds up to 60 mph and large hail are
possible with the stronger storms on the eastern plains.

An upper level disturbance over the Great Basin will bring the
moisture and better chance for storms this afternoon and evening.
Temperatures will continue to be warm with readings in the lower
90s on the plains.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Expect warmer than average temperatures through Friday, with
cooler temperatures through the weekend.

Isolated thunderstorms are expected over the mountains each day
through the week. There will be a slight chance of storms over
the plains Monday and Tuesday, dry Wednesday and Thursday, then
returning Friday and Saturday. The main impacts from the storms
will be gusty outflow winds and some hail possible.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed on the far eastern plains of
Colorado, mainly east of a line from Limon to Sterling after 2 pm.

In the hours before

Special weather statement, Jul 2, 2:56 PM MDT, 0 minutes before
Special Weather Statement
National Weather Service Denver CO
256 PM MDT SUN JUL 2 2017

COZ040-041-045-022115-
Elbert/Central and East Douglas Counties Above 6000 Feet CO-
Central and East Adams and Arapahoe Counties CO-
North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe
Counties/East Broomfield County CO-
256 PM MDT SUN JUL 2 2017

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN ARAPAHOE...EASTERN DENVER
AND WESTERN ADAMS COUNTIES UNTIL 315 PM MDT...

At 252 PM MDT, Doppler radar was tracking a high based rain showers
producing strong microburst winds over western Arapahoe County. The
strongest wind gusts were detected by radar in the vicinity of
Watkins, or 19 miles east of Denver. These showers were moving
northeast at 30 mph.

Wind gusts of 50 to 55 mph will be possible with these high based
rain showers.

Locations impacted include...
Eastern Denver, Aurora, eastern Centennial, Greenwood Village, Denver
International Airport, Bennett, Watkins, Manila Village, D.I.A
Terminal and Concourses, Arapahoe Park, Strasburg and Buckley AFB.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for sudden gusty winds and considerable blowing dust. Secure
loose objects and move to a safe shelter inside a building or
vehicle. The blowing dust may also reduce visibilities to less than
a few hundred feet.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3986 10431 3970 10425 3957 10459 3957 10488
      3969 10492 4000 10451 4000 10449
TIME...MOT...LOC 2052Z 240DEG 49KT 3974 10459

BAKER

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 8:19 PM MDTSpecial Weather StatementBOULincoln26 min
Jul 1, 8:32 PM MDTSevere Thunderstorm WarningBOULincoln28 min
Jul 2, 3:19 PM MDTSpecial Weather StatementBOUAdams, Denver41 min
Jul 2, 3:48 PM MDTSpecial Weather StatementBOUAdams42 min
Jul 2, 5:12 PM MDTSpecial Weather StatementBOUSedgwick48 min
Jul 2, 5:16 PM MDTSpecial Weather StatementBOULincoln44 min
Jul 2, 5:29 PM MDTSevere Thunderstorm WarningBOULogan, Phillips, Sedgwick46 min
Jul 2, 5:51 PM MDTSpecial Weather StatementBOULincoln39 min

Nearby

Special Weather Statements in Colorado, 2017Every special weather statement in 2017

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.