Alert archive / Colorado / Mesoscale Discussions in 2011

Mesoscale Discussion 1990

August 16, 201134 counties in Colorado; Colfax County, Mora County, New Mexico; 5 counties in Utah

The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2011, 1:48 PM MDT for 34 counties in Colorado; Colfax County, Mora County, New Mexico; 5 counties in Utah. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Aug 16, 2011, 1:48 PM MDT (19:48 UTC)
Expired: Aug 16, 2011, 3:45 PM MDT
In force: 117 min
Issued by: the Storm Prediction Center

All 41 counties

Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Chaffee County, CO, Clear Creek County, CO, Costilla County, CO, Crowley County, CO, Custer County, CO, Denver County, CO, Douglas County, CO, Eagle County, CO, El Paso County, CO, Elbert County, CO, Fremont County, CO, Garfield County, CO, Gilpin County, CO, Grand County, CO, Huerfano County, CO, Jackson County, CO, Jefferson County, CO, Lake County, CO, Larimer County, CO, Las Animas County, CO, Moffat County, CO, Otero County, CO, Park County, CO, Pitkin County, CO, Pueblo County, CO, Rio Blanco County, CO, Routt County, CO, Summit County, CO, Teller County, CO, Weld County, CO, Colfax County, NM, Mora County, NM, Carbon County, UT, Daggett County, UT, Duchesne County, UT, Uintah County, UT, Wasatch County, UT

The radar

The Grand Junction radar (KGJX), 135 km from the middle of the area, began a volume at 19:49 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

Grand Junction, CO (KGJT), launched 12:00Z, 7.8 hours before the alert went out and 161 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: 46 J/kg
Mixed-layer CIN: -384 J/kg
Mixed-layer LCL: 2300 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 136 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

900 
ACUS11 KWNS 161948
SWOMCD
SPC MCD 161948 
COZ000-NMZ000-WYZ000-UTZ000-162145-

MESOSCALE DISCUSSION 1990
NWS STORM PREDICTION CENTER NORMAN OK
0248 PM CDT TUE AUG 16 2011

AREAS AFFECTED...CNTRL/NRN CO...NERN UT...FAR NERN NM...FAR SRN WY

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 161948Z - 162145Z

AN ISOLATED SVR THREAT MAY OCCUR THIS AFTERNOON...THOUGH THE THREAT
IS EXPECTED TO REMAIN TOO ISOLATED FOR THE ISSUANCE OF A WW.

VISIBLE SATELLITE AND RADAR IMAGERY SUGGEST CONVECTION DEVELOPING
OVER PORTIONS OF THE CNTRL/SRN ROCKIES INTO NERN UT...ESPECIALLY
FROM THE PALMER DIVIDE NWD TOWARD THE FOOTHILLS AROUND BOULDER/FORT
COLLINS. THIS ACTIVITY IS BEING DRIVEN BY A COMBINATION OF
OROGRAPHIC ASCENT AND STEEP MID-LEVEL LAPSE RATES -- E.G. 7.9 C/KM
AND 8.1 C/KM 700-500-MB LAPSE RATES PER DENVER AND GRAND JUNCTION
12Z RAOBS...RESPECTIVELY. FURTHERMORE...SFC WINDS HAVE BEEN VEERING
FROM NLY TO NELY DURING THE PAST FEW HOURS ACROSS THE HIGH PLAINS OF
ERN CO. THE VEERING TREND IS FORECAST TO CONTINUE INTO LATE
AFTERNOON AS AN ISALLOBARIC RESPONSE TO SFC PRESSURE RISES OF 1.5-2
MB PER 2 HOURS ACROSS N-CNTRL NEB AND S-CNTRL SD. THIS LOW-LEVEL
FLOW REGIME WILL SUPPORT UPSLOPE FLOW INTO THE FRONT RANGE OF THE
ROCKIES...WHILE MODESTLY RICHER LOW-LEVEL MOISTURE -- SFC DEWPOINTS
IN THE LOWER 50S -- EDGE WWD AND POTENTIALLY YIELD SOME INCREASE IN
BUOYANCY. THESE FACTORS SHOULD FOSTER AN INCREASE IN CONVECTIVE
COVERAGE/INTENSITY. FURTHERMORE...ASCENT IN CONJUNCTION WITH THE
RIGHT-ENTRANCE REGION OF AN UPPER-LEVEL JET STREAK -- TRAILING FROM
ERN ND INTO NERN UT -- WILL OFFER SUPPORT FOR MORE ISOLATED
CONVECTION ACROSS PARTS OF NERN UT AND NWRN CO. EFFECTIVE BULK SHEAR
MAGNITUDES OF 30-40 KT COULD SUPPORT OCCASIONALLY SUSTAINED UPDRAFTS
WITH A THREAT FOR MARGINALLY SVR HAIL AND POSSIBLY GUSTY WINDS ON AN
ISOLATED BASIS. THIS THREAT WILL BE PRIMARILY CONFINED TO THE HIGHER
TERRAIN...AS AMPLE MLCINH OVER THE ADJACENT PLAINS MAY MITIGATE
CONVECTIVE STRENGTH/SUSTENANCE THERE.

..COHEN.. 08/16/2011

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

ATTN...WFO...PUB...BOU...CYS...ABQ...RIW...GJT...SLC...

LAT...LON   38380592 38850687 39180853 39481096 40461151 41101036
            41400854 41350651 40900440 39770363 37870362 36620388
            35790482 35930556 37390552 38380592

Nearby

Mesoscale Discussions in Colorado, 2011 Mesoscale Discussions in Utah, 2011 Mesoscale Discussions in New Mexico, 2011 Every mesoscale discussion in 2011

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.