Alert archive / Colorado / Special Weather Statements in 2018

Special Weather Statement, NWS Denver/Boulder, CO

August 4, 2018Adams County, Colorado

NWS Denver/Boulder, CO issued this special weather statement at Aug 4, 2018, 10:42 PM MDT for Adams County, Colorado. It was in force for 48 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
Aug 4, 2018, 10:42 PM MDT (04:42 UTC)
Expired
Aug 4, 2018, 11:30 PM MDT
In force
48 min
Issued by
NWS Denver/Boulder, CO

County Adams County, CO

The radar

The Denver radar (KFTG), 22 km from the middle of the area, began a volume at 04:45 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 00:00Z, 4.7 hours before the alert went out and 93 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 00:00Z on 2018-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 191 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 00:00Z on 2018-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.19395878Sfc1 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
191 J/kg
Mixed-layer CIN
-111 J/kg
Mixed-layer LCL
3300 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
102 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 Aug 4, 8:42 PM MDT, 2 hours earlier.

Area forecast discussion, Aug 4, 8:42 PM MDT, 2 hours before
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Hazardous weather outlook, Aug 4, 10:37 AM MDT, 12 hours 5 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1037 AM MDT Sat Aug 4 2018

COZ030>051-051645-
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-
1037 AM MDT Sat Aug 4 2018

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

.DAY ONE...Today and Tonight

Isolated to widely scattered showers and thunderstorms will
develop this afternoon, mainly over the northern mountains and
along the Wyoming border in northeast Colorado. These high based
storms will have the potential to produce wind gusts over 50 mph.
Cloud-to-ground lightning and brief light to moderate rainfall are
also possible with these storms. The last of the storm activity
on the plains should end by around midnight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Isolated strong to severe storms will be possible over the
northeast plains Sunday and Monday, during the afternoon and
evening period. The main threat would be large hail and damaging
winds. Elsewhere expect a chance of thunderstorms each day. Storm
coverage will be higher in the mountains than over the plains
through the week. Temperatures will not be as hot, generally in
the lower to mid 80s across the I-25 corridor and adjacent plains.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight. Although
reports of wind gusts in excess of 50 mph would be appreciated.

Baker/Cooper

In the hours before

Special weather statement, Aug 4, 10:42 PM MDT, 0 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 3:22 PM MDTSevere Thunderstorm WarningBOULogan, Sedgwick38 min
Aug 5, 3:52 PM MDTSevere Thunderstorm WarningBOULincoln23 min
Aug 5, 4:05 PM MDTSevere Thunderstorm WarningBOUPhillips, Sedgwick40 min

Nearby

Special Weather Statements in Colorado, 2018Every special weather statement in 2018

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.