Alert archive / Kansas / Mesoscale Discussions in 2012

Mesoscale Discussion 501

April 12, 20127 counties in Colorado; 10 counties in Kansas; 10 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2012, 4:02 PM MDT for 7 counties in Colorado; 10 counties in Kansas; 10 counties in Nebraska. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: Apr 12, 2012, 4:02 PM MDT (22:02 UTC)
Expired: Apr 12, 2012, 5:30 PM MDT
In force: 88 min
Issued by: the Storm Prediction Center

All 27 counties

Cheyenne County, CO, Kit Carson County, CO, Phillips County, CO, Prowers County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Cheyenne County, KS, Greeley County, KS, Hamilton County, KS, Kearny County, KS, Logan County, KS, Rawlins County, KS, Sherman County, KS, Thomas County, KS, Wallace County, KS, Wichita County, KS, Arthur County, NE, Chase County, NE, Deuel County, NE, Dundy County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, McPherson County, NE, Perkins County, NE, Thomas County, NE

The radar

The Goodland radar (KGLD), 72 km from the middle of the area, began a volume at 22:03 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 (KDNR), launched 12:00Z, 10.0 hours before the alert went out and 91 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: 34 J/kg
Mixed-layer CIN: -126 J/kg
Mixed-layer LCL: 946 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 201 m²/s²
0-3 km storm-relative helicity: 121 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.

039 
ACUS11 KWNS 122203
SWOMCD
SPC MCD 122202
NEZ000-KSZ000-COZ000-122330-

MESOSCALE DISCUSSION 0501
NWS STORM PREDICTION CENTER NORMAN OK
0502 PM CDT THU APR 12 2012

AREAS AFFECTED...EASTERN CO/SOUTHWEST NEB/WESTERN KS

CONCERNING...TORNADO WATCH 157...

VALID 122202Z - 122330Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 157 CONTINUES.

TORNADO WATCH 157 CONTINUES UNTIL 02Z...WITH CONTINUED POTENTIAL FOR
TORNADOES/LARGE HAIL THROUGH LATE AFTERNOON/EARLY EVENING. A SEVERE
THREAT /MAINLY HAIL/ MAY DEVELOP NORTHWARD OUT OF WW 157...SUCH THAT
A WATCH EXTENSION/NEW SEVERE TSTM WATCH COULD BE NEEDED.

PRIMARY SHORT-TERM SEVERE THREAT WILL LIKELY REMAIN ACROSS THE
NORTHEAST CO/SOUTHWEST NEB/NORTHWEST KS BORDER REGION THROUGH LATE
AFTERNOON/EARLY EVENING. SATELLITE IMAGERY SUGGESTS THAT FORCING FOR
ASCENT/UPPER JET EXIT REGION IS INFLUENCING THIS REGION...AND THIS
CORRIDOR IS LOCATED NEAR/JUST NORTH OF A SURFACE TRIPLE POINT WITH A
SURFACE LOW ACROSS EAST-CENTRAL/NORTHEAST CO AND A SOUTHWARD
EXTENDING DRYLINE ACROSS THE HIGH PLAINS. SUPERCELLS CAPABLE OF
LARGE HAIL AND A TORNADO THREAT WILL REMAIN POSSIBLE INTO EARLY
EVENING WITHIN A HIGHLY SHEARED ENVIRONMENT...WITH A LARGE HAIL
THREAT ALSO POSSIBLE WITH INCREASINGLY ELEVATED STORMS SPREADING
NORTH OF THE SURFACE WARM FRONT ACROSS FAR SOUTHWEST NEB.

FARTHER SOUTH...RECENT SATELLITE TRENDS ARE INDICATIVE OF DEEPENING
CU FIELD NEAR THE DRYLINE ALONG CO/KS BORDER...WHICH COULD LEAD TO
AN UPSWING OF DEEP CONVECTION OVER THE NEXT FEW HOURS...AT LEAST ON
AN ISOLATED BASIS. GIVEN SUCH DEVELOPMENT...SUPERCELLS CAPABLE OF
LARGE HAIL WILL BE POSSIBLE...AND A TORNADO THREAT WILL EXIST AS
WELL ESPECIALLY GIVEN NEAR/POST-SUNSET POTENTIAL FOR A NOCTURNAL LOW
LEVEL JET INCREASE AND ABATED BOUNDARY LAYER MIXING.

..GUYER.. 04/12/2012

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

ATTN...WFO...LBF...DDC...GLD...PUB...BOU...CYS...

LAT...LON   40090349 41500257 41970047 40360098 37830116 37970257
            39460263 40090349

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 11, 10:50 PM MDT	Mesoscale Discussion	SPC	Crowley, Douglas, Elbert, El Paso, Jefferson, Pueblo and 1 more	85 min
Apr 12, 12:24 PM MDT	Mesoscale Discussion	SPC	Phillips, Yuma	2 hr
Apr 12, 12:47 PM MDT	Tornado Watch	SPC	Cheyenne, Kiowa, Kit Carson, Logan, Phillips, Prowers and 3 more	7 hr
Apr 12, 1:28 PM MDT	Mesoscale Discussion	SPC	Grant, Haskell, Meade, Seward, Stevens	2 hr
Apr 12, 5:54 PM MDT	Severe Thunderstorm Watch	SPC	Blaine, Buffalo, Custer, Dawson, Franklin, Furnas and 12 more	6 hr

Nearby

Mesoscale Discussions in Kansas, 2012 Mesoscale Discussions in Nebraska, 2012 Mesoscale Discussions in Colorado, 2012 Every mesoscale discussion in 2012

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.