Alert archive / South Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 1908

August 27, 2007Lincoln County, Yellow Medicine County, Minnesota; 12 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2007, 9:49 PM CDT for Lincoln County, Yellow Medicine County, Minnesota; 12 counties in South Dakota. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued: Aug 27, 2007, 9:49 PM CDT (02:49 UTC)
Expired: Aug 27, 2007, 11:15 PM CDT
In force: 86 min
Issued by: the Storm Prediction Center

Counties Lincoln County, MN, Yellow Medicine County, MN, Brookings County, SD, Charles Mix County, SD, Davison County, SD, Deuel County, SD, Douglas County, SD, Hamlin County, SD, Hanson County, SD, Kingsbury County, SD, Lake County, SD, McCook County, SD, Miner County, SD, Sanborn County, SD

The radar

The Sioux Falls radar (KFSD), 75 km from the middle of the area, began a volume at 02:52 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

Aberdeen, SD (KABR), launched 00:00Z, 2.8 hours before the alert went out and 124 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: 744 J/kg
Mixed-layer CIN: -287 J/kg
Mixed-layer LCL: 484 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: -66 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 280250
SWOMCD
SPC MCD 280249 
MNZ000-SDZ000-NEZ000-280415-

MESOSCALE DISCUSSION 1908
NWS STORM PREDICTION CENTER NORMAN OK
0949 PM CDT MON AUG 27 2007

AREAS AFFECTED...SERN SD THROUGH SWRN MN

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 280249Z - 280415Z

ELEVATED STORMS DEVELOPING OVER SERN SD MAY POSE A THREAT FOR HAIL.
A WW IS UNLIKELY UNLESS STORMS BEGIN TO SHOW EVIDENCE OF
INTENSIFICATION. AREA WILL CONTINUE TO BE MONITORED.

A COLD FRONT EXTENDS FROM A SURFACE LOW IN SWRN MN SWWD THROUGH SERN
SD THROUGH SWRN NEB MOVING SLOWLY SEWD. PRE-FRONTAL WARM SECTOR
REMAINS VERY UNSTABLE...BUT A ZONE OF STRONG MUCAPE PERSISTS IN POST
FRONTAL REGION ACROSS SERN SD. MOST OF THIS CAPE RESULTS FROM
PARCELS THAT CAN BE LIFTED FROM BELOW 800 MB. CHARACTER AND MOTION
OF DEVELOPING STORMS OVER SERN SD SUGGEST THEY ARE STILL ROOTED
ABOVE A STRONG INVERSION THAT WAS EVIDENT ON MOST 00Z RAOBS.
ACTIVITY IS DEVELOPING WITHIN A ZONE OF MID LEVEL ASCENT ASSOCIATED
WITH AN EWD ADVANCING SHORTWAVE TROUGH. GIVEN STRENGTH OF
INVERSION...IT IS UNLIKELY THAT STORMS WILL BE ABLE TO ROOT FARTHER
DOWN. STRENGTHENING SLY LOW LEVEL JET IS ENHANCING ISENTROPIC LIFT
IN FRONTAL ZONE...AND THIS MAY CONTRIBUTE TO SOME COOLING AND
MOISTENING IN THE INVERSION LAYER. HOWEVER...AT THIS TIME CONFIDENCE
IS NOT HIGH THAT INVERSION WILL BE ERODED SUFFICIENTLY FOR UPDRAFTS
TO TAP INTO HIGH THETA-E AIR BELOW 800 MB.

..DIAL.. 08/28/2007

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

ATTN...WFO...MPX...FSD...ABR...LBF...

44849564 43359775 43009848 42969916 43519882 44629754
44979661

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 27, 9:05 PM CDT	Mesoscale Discussion	SPC	Aitkin, Carlton, Crow Wing, Lake, Morrison, Pine	55 min
Aug 28, 1:50 AM CDT	Mesoscale Discussion	SPC	Anoka, Carver, Chisago, Hennepin, Isanti, McLeod and 5 more	55 min
Aug 28, 1:56 AM CDT	Severe Thunderstorm Watch	SPC	Anoka, Brown, Carver, Chisago, Dakota, Goodhue and 10 more	3 hr
Aug 28, 11:58 AM CDT	Mesoscale Discussion	SPC	Dodge, Goodhue, Mower, Olmsted, Wabasha, Winona	62 min
Aug 28, 12:15 PM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Dakota, Dodge, Faribault and 20 more	8 hr
Aug 28, 3:24 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 10 more	66 min

Nearby

Mesoscale Discussions in South Dakota, 2007 Mesoscale Discussions in Minnesota, 2007 Every mesoscale discussion in 2007

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.