Alert archive / Nebraska / Mesoscale Discussions in 2003

Mesoscale Discussion 2004

July 27, 2003Logan County, Phillips County, Sedgwick County, Colorado; 11 counties in Nebraska; Goshen County, Laramie County, Platte County, Wyoming

The Storm Prediction Center issued this mesoscale discussion at Jul 27, 2003, 4:09 PM MDT for Logan County, Phillips County, Sedgwick County, Colorado; 11 counties in Nebraska; Goshen County, Laramie County, Platte County, Wyoming. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 27, 2003, 4:09 PM MDT (22:09 UTC)
Expired: Jul 27, 2003, 6:15 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO, Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Garden County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Goshen County, WY, Laramie County, WY, Platte County, WY

The radar

The Cheyenne radar (KCYS), 98 km from the middle of the area, began a volume at 22:09 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.

Severe Thunderstorm Watch 810Jul 27, 4:35 PM MDT

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 10.2 hours before the alert went out and 151 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1517 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -34 m²/s²
0-3 km storm-relative helicity: 59 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.

580 
ACUS11 KWNS 272209
SWOMCD
SPC MCD 272209 
NEZ000-COZ000-WYZ000-280015-

MESOSCALE DISCUSSION 2004
NWS STORM PREDICTION CENTER NORMAN OK
0509 PM CDT SUN JUL 27 2003

AREAS AFFECTED...SERN WY...NEB PANHANDLE/FAR SWRN NEB AND NERN CO

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 272209Z - 280015Z

THUNDERSTORMS DEVELOPING ALONG AND JUST EAST OF THE LARAMIE MTNS AND
OVER THE NEB PANHANDLE...WILL CONTINUE TO INTENSIFY AND SHOULD BEGIN
TO POSE A THREAT FOR LARGE HAIL AND DAMAGING WINDS IN THE NEXT HOUR.
THUS A WW WILL LIKELY BE ISSUED SHORTLY FOR THE AREA. FARTHER SOUTH
ALONG THE FRONT RANGE...OUTFLOW DOMINANT CONVECTION MAY POSE A
THREAT FOR VERY ISOLATED LARGE HAIL DAMAGING WINDS AND THUS A WW IS
NOT ANTICIPATED FOR THIS AREA.

TEMPERATURES HAVE RECOVERED BEHIND MCS/CLOUD COVER FROM EARLIER
TODAY WITH 21Z OBS INDICATING READINGS IN THE MID 80S. DEWPOINTS IN
THE LOWER-MID 60S HAVE SUPPORTED MLCAPES AROUND 2000 J/KG ALONG AN
AXIS FROM GOSHEN COUNTY WY SEWD INTO KEITH COUNTY NEB. MID LEVEL 30
KT SPEED MAX NOTED ON 12Z RIW SOUNDING AND RECENT MEDICINE BOW
PROFILER ALONG WITH 10-15 KT SELY BOUNDARY LAYER WINDS...WILL
SUPPORT 40-45 KT DEEP LAYER SHEAR AND THE POTENTIAL FOR SUPERCELL
THUNDERSTORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY
THREATS. DESPITE RELATIVELY LOW LCL HEIGHTS...WEAK LOW LEVEL S-R
WIND FIELDS AND SHEAR WILL LIMIT THE THREAT FOR ISOLATED TORNADOES.
CONVECTION WILL MOST LIKELY ORGANIZE INTO A FORWARD PROPAGATING MCS
EARLY THIS EVENING IN THE NEB PANHANDLE WHEN CURRENT SERN WY
CONVECTION MERGES WITH DEVELOPING CONVECTION OVER THE WRN NEB
PANHANDLE IN THE NEXT 2-3 HOURS.

..CROSBIE.. 07/27/2003

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

ATTN...WFO...LBF...GLD...BOU...CYS...

40210371 41010498 42680547 42830227 40230166

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 4:35 PM MDT	Severe Thunderstorm Watch	SPC	Logan, Morgan, Phillips, Sedgwick, Weld	5 hr

Nearby

Mesoscale Discussions in Nebraska, 2003 Mesoscale Discussions in Colorado, 2003 Mesoscale Discussions in Wyoming, 2003 Every mesoscale discussion in 2003

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.