Alert archive / North Dakota / Mesoscale Discussions in 2007

Mesoscale Discussion 2011

September 23, 2007Kittson County, Marshall County, Polk County, Minnesota; 17 counties in North Dakota

The Storm Prediction Center issued this mesoscale discussion at Sep 23, 2007, 6:45 PM CDT for Kittson County, Marshall County, Polk County, Minnesota; 17 counties in North Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Sep 23, 2007, 6:45 PM CDT (23:45 UTC)
Expired: Sep 23, 2007, 8:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Kittson County, MN, Marshall County, MN, Polk County, MN, Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, Nelson County, ND, Pembina County, ND, Ramsey County, ND, Ransom County, ND, Steele County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Wells County, ND

The radar

The Fargo/Grand Forks radar (KMVX), 35 km from the middle of the area, began a volume at 23:49 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 686Sep 23, 7:50 PM CDT

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 11.8 hours before the alert went out and 260 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: 636 J/kg
Mixed-layer CIN: -504 J/kg
Mixed-layer LCL: 1467 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 315 m²/s²
0-3 km storm-relative helicity: 210 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 232346
SWOMCD
SPC MCD 232345 
MNZ000-NDZ000-240145-

MESOSCALE DISCUSSION 2011
NWS STORM PREDICTION CENTER NORMAN OK
0645 PM CDT SUN SEP 23 2007

AREAS AFFECTED...EASTERN ND/FAR NORTHWEST MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 232345Z - 240145Z

SEVERE THREAT MAY INCREASE THROUGH EARLY EVENING ACROSS EASTERN ND
INTO FAR NORTHWEST MN...WITH A RISK OF DAMAGING WINDS AND HAIL WITH
THE STRONGEST STORMS. WILL CONTINUE TO MONITOR DEVELOPMENTAL
TRENDS...CURRENT THINKING IS THAT A WATCH COULD BE NEEDED BY AROUND
01Z.

LATEST SURFACE ANALYSIS FEATURES 999 MB SURFACE LOW ACROSS SOUTH
CENTRAL ND...WITH ATTENDANT COLD FRONT ANGLING NNE-SSW ACROSS
CENTRAL ND/WEST CENTRAL SD. WHILE SUFFICIENT INHIBITION/LACK OF
FORCING ACROSS THE WARM SECTOR HAS LIMITED DEEP CONVECTIVE
DEVELOPMENT THUS FAR...FRONTAL FORCING/HEIGHT FALLS AHEAD OF WESTERN
STATES UPPER TROUGH IS EXPECTED TO LEAD TO AN INCREASE IN
THUNDERSTORMS THROUGH EARLY/MID EVENING...PERHAPS LIKELY BY AROUND
01Z-02Z ALONG A JAMESTOWN-DEVILS LAKE CORRIDOR. ALTHOUGH MAXIMIZED
BEHIND THE COLD FRONT...MODERATELY STRONG VERTICAL SHEAR EXISTS
ACROSS THE WARM SECTOR...WITH EFFECTIVE BULK SHEAR OF 40-45 KT
ACROSS MUCH OF EASTERN ND INTO NORTHWEST MN. IN SPITE OF MODEST
INSTABILITY...AMPLE DEEP LAYER SHEAR/LONG HODOGRAPHS WITH SOME LOW
LEVEL VEERING WILL FAVOR THE POSSIBILITY OF SOME BRIEF SUPERCELL
STRUCTURES/POSSIBLE LEWP EVOLUTION...WITH SMALL BOWING SEGMENTS
POTENTIALLY POSING AN ENHANCED RISK OF DAMAGING WINDS. SOME LARGE
HAIL WILL BE POSSIBLE AS WELL.

..GUYER.. 09/23/2007

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

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

48829639 48139619 47119666 46319695 46109779 47139845
47589977 48819984 49059754

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 23, 3:23 PM CDT	Severe Thunderstorm Watch	SPC	Burleigh, Dickey, Emmons, Foster, Grant, Kidder and 8 more	8 hr
Sep 23, 6:29 PM CDT	Mesoscale Discussion	SPC	Barnes, Dickey, Emmons, Kidder, LaMoure, Logan and 2 more	91 min

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.