Alert archive / North Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 2012

September 23, 20076 counties in Minnesota; 13 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Sep 23, 2007, 9:57 PM CDT for 6 counties in Minnesota; 13 counties in North Dakota. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Sep 23, 2007, 9:57 PM CDT (02:57 UTC)
Expired: Sep 23, 2007, 11:00 PM CDT
In force: 63 min
Issued by: the Storm Prediction Center

Counties Kittson County, MN, Marshall County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Roseau County, MN, Barnes County, ND, Cass County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Logan County, ND, Nelson County, ND, Pembina County, ND, Steele County, ND, Stutsman County, ND, Traill County, ND, Walsh County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 37 km from the middle of the area, began a volume at 03:01 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 3.0 hours before the alert went out and 264 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: 2707 m above ground
0-6 km bulk shear: 67 kt
0-1 km storm-relative helicity: -63 m²/s²
0-3 km storm-relative helicity: 66 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.

000 
ACUS11 KWNS 240257
SWOMCD
SPC MCD 240257 
MNZ000-NDZ000-240400-

MESOSCALE DISCUSSION 2012
NWS STORM PREDICTION CENTER NORMAN OK
0957 PM CDT SUN SEP 23 2007

AREAS AFFECTED...CNTRL SD THROUGH ERN ND

CONCERNING...SEVERE THUNDERSTORM WATCH 685...686...

VALID 240257Z - 240400Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
685...686...CONTINUES.

REMAINING VALID PORTION OF WW 685 WILL BE ALLOWED TO EXPIRE AT 04Z.

STRONGER DIVERGENT UPPER FLOW FIELD...AHEAD OF WEAKENING MID-LEVEL
IMPULSE...BUT PERHAPS ENHANCED BY THE RIGHT ENTRANCE REGION OF AN
ANTICYCLONIC UPPER JET STREAK...CONTINUES TO SHIFT NORTHEAST OF THE
NORTH CENTRAL HIGH PLAINS.  BY 06Z...THIS FORCING IS PROGGED TO
BECOME CENTERED ACROSS NORTHEASTERN NORTH DAKOTA...BEFORE SPREADING
INTO SOUTHERN MANITOBA OVERNIGHT.  THE BULK OF THE CONVECTIVE
DEVELOPMENT TO THE SOUTH OF THE NORTH DAKOTA BORDER ALREADY APPEARS 
TO HAVE BEEN UNDERCUT BY AN EASTWARD COLD FRONTAL SURGE.  AND...
STABILIZATION OF NARROWING PRE-FRONTAL THERMAL RIDGE IS NOW WELL
UNDERWAY.  WITH VWP DATA INDICATING 50+ KT SOUTHERLY FLOW WITHIN THE
LOWEST KILOMETER ABOVE GROUND LEVEL...IN THE LINGERING PRE-FRONTAL
INSTABILITY AXIS WHERE SURFACE TEMPERATURES REMAIN NEAR OR JUST
ABOVE 80F...POTENTIAL FOR STRONG GUSTY SURFACE WINDS PROBABLY WILL
CONTINUE NEAR THUNDERSTORM ACTIVITY SPREADING ACROSS EAST
CENTRAL/NORTHEAST NORTH DAKOTA THRU 04-06Z.

..KERR.. 09/24/2007

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

ATTN...WFO...FGF...BIS...

46399981 47259903 48029875 48659814 49119732 49769579
48949518 48289535 47879596 47099699 46099857

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 23, 7:53 PM CDT	Severe Thunderstorm Watch	SPC	Kittson, Marshall, Polk, Roseau	3 hr
Sep 24, 3:54 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Carver, Dakota, Dodge, Faribault, Freeborn and 14 more	2 hr
Sep 24, 4:57 PM CDT	Severe Thunderstorm Watch	SPC	Anoka, Blue Earth, Carlton, Carver, Chisago, Cook and 23 more	5 hr

Nearby

Mesoscale Discussions in North 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.