Alert archive / Colorado / Mesoscale Discussions in 2013

Mesoscale Discussion 1613

August 3, 201314 counties in Colorado

The Storm Prediction Center issued this mesoscale discussion at Aug 3, 2013, 1:50 PM MDT for 14 counties in Colorado. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Aug 3, 2013, 1:50 PM MDT (19:50 UTC)
Expired
Aug 3, 2013, 3:15 PM MDT
In force
85 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Adams County, CO, Arapahoe County, CO, Broomfield County, CO, Denver County, CO, Douglas County, CO, Elbert County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Washington County, CO, Weld County, CO, Yuma County, CO

The radar

The Denver radar (KFTG), 96 km from the middle of the area, began a volume at 19:51 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Denver, CO (KDEN), launched 12:00Z, 7.8 hours before the alert went out and 35 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 2013-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 46 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 2013-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 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
46 J/kg
Mixed-layer CIN
-295 J/kg
Mixed-layer LCL
2189 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

834 
ACUS11 KWNS 031950
SWOMCD
SPC MCD 031950 
KSZ000-COZ000-032115-

MESOSCALE DISCUSSION 1613
NWS STORM PREDICTION CENTER NORMAN OK
0250 PM CDT SAT AUG 03 2013

AREAS AFFECTED...NORTHEAST COLORADO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 031950Z - 032115Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THUNDERSTORMS WILL CONTINUE TO DEVELOP INTO THE EVENING
HOURS ACROSS MUCH OF NORTHEAST COLORADO. ISOLATED LARGE HAIL AND
DAMAGING WIND GUSTS ARE THE PRIMARY THREAT...HOWEVER AN ISOLATED
NON-SUPERCELL TORNADO CANNOT BE RULED OUT.

DISCUSSION...AT 1945 UTC THUNDERSTORMS WERE BEGINNING TO DEVELOP
ACROSS NORTHEAST COLORADO ALONG A REMNANT OUTFLOW BOUNDARY. MLCAPE
VALUES IN THE 1500-2500 J/KG RANGE COUPLED WITH DEEP-LAYER SHEAR
VALUES OF 25-35 KTS WILL YIELD THE POTENTIAL FOR MULTI-CELL CLUSTERS
AND TRANSIENT SUPERCELL-LIKE STRUCTURES. ISOLATED LARGE HAIL AND
DAMAGING WIND GUSTS WILL BE POSSIBLE WITH ANY OF THE STRONGER
UPDRAFTS. ADDITIONALLY...STRONG LOW-LEVEL INSTABILITY /0-3KM CAPE
VALUES NEARING 200 J/KG/ COUPLED WITH THE PRESENCE OF REMNANT
OUTFLOW BOUNDARIES WILL YIELD THE POTENTIAL FOR AN ISOLATED
NON-SUPERCELLULAR TORNADO. AT THIS TIME...A WW IS NOT CURRENTLY
ANTICIPATED. HOWEVER...IF THUNDERSTORM INTENSITY IS MORE THAN
CURRENTLY EXPECTED A WW MAY BECOME NECESSARY.

..MARSH/GOSS.. 08/03/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...GLD...PUB...BOU...

LAT...LON   40710445 40960340 40920250 40150211 39450195 38770268
            38920486 40350513 40710445

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 3, 1:06 PM MDTMesoscale DiscussionSPCBaca, Bent, Crowley, Huerfano, Kiowa, Las Animas and 3 more84 min
Aug 3, 2:35 PM MDTTornado WatchSPCAdams, Arapahoe, Boulder, Broomfield, Cheyenne, Denver and 11 more6 hr
Aug 3, 2:40 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Crowley, El Paso, Kiowa, Las Animas and 4 more7 hr
Aug 3, 5:21 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Broomfield, Denver, Elbert, Lincoln and 3 more54 min

Nearby

Mesoscale Discussions in Colorado, 2013Every mesoscale discussion in 2013

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.