Alert archive / North Dakota / Mesoscale Discussions in 2004

Mesoscale Discussion 1921

August 8, 200414 counties in Minnesota; 21 counties in North Dakota; Marshall County, Roberts County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 8, 2004, 12:37 PM CDT for 14 counties in Minnesota; 21 counties in North Dakota; Marshall County, Roberts County, South Dakota. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Aug 8, 2004, 12:37 PM CDT (17:37 UTC)
Expired: Aug 8, 2004, 2:00 PM CDT
In force: 83 min
Issued by: the Storm Prediction Center

All 37 counties

Becker County, MN, Clay County, MN, Douglas County, MN, Grant County, MN, Kittson County, MN, Mahnomen County, MN, Marshall County, MN, Norman County, MN, Otter Tail County, MN, Pennington County, MN, Polk County, MN, Red Lake County, MN, Traverse County, MN, Wilkin County, MN, Barnes County, ND, Benson County, ND, Cass County, ND, Cavalier County, ND, Dickey County, ND, Eddy County, ND, Foster County, ND, Grand Forks County, ND, Griggs County, ND, LaMoure County, ND, Nelson County, ND, Pembina County, ND, Ramsey County, ND, Ransom County, ND, Richland County, ND, Rolette County, ND, Sargent County, ND, Steele County, ND, Towner County, ND, Traill County, ND, Walsh County, ND, Marshall County, SD, Roberts County, SD

The radar

The Fargo/Grand Forks radar (KMVX), 17 km from the middle of the area, began a volume at 17:40 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

Bismarck Municip, ND (KBIS), launched 12:00Z, 5.6 hours before the alert went out and 262 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: 17 J/kg
Mixed-layer CIN: -284 J/kg
Mixed-layer LCL: 1229 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 40 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.

188 
ACUS11 KWNS 081738
SWOMCD
SPC MCD 081737 
MNZ000-SDZ000-NDZ000-081900-

MESOSCALE DISCUSSION 1921
NWS STORM PREDICTION CENTER NORMAN OK
1237 PM CDT SUN AUG 08 2004

AREAS AFFECTED...ERN ND...NWRN MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 081737Z - 081900Z

STORMS ARE EXPECTED TO INCREASE IN COVERAGE THROUGH THE
AFTERNOON...WITH LARGE HAIL THE MAIN SEVERE THREAT.  A WW COULD BE
REQUIRED.

STRONG VORTICITY MAXIMUM OVER ND CONTINUES MOVING EWD. VERY COLD
AIR ALOFT EXISTS WITH THIS FEATURE WITH 500 MB TEMPERATURES NEAR -17
C.

ALTHOUGH SURFACE FLOW IS VEERING...DEWPOINTS WILL REMAIN IN THE 50S
F.  COMBINED WITH SURFACE HEATING AND TEMPERATURES IN THE MID TO
UPPER 70S F...THIS WILL PRODUCE FAVORABLE ENVIRONMENT FOR HAIL.

WIND PROFILES ARE WEAK UNDERNEATH UPPER LOW...BUT STRONG FORCING AND
CONVERGENCE WILL ALLOW A FEW STORMS TO BE RATHER LONG LIVED.  DEEP
LAYER SHEAR INCREASES OVER SRN ND AND NRN SD...UNDERNEATH COMPACT
MID LEVEL JET STREAK.  THEREFORE...BEST COMBINATION OF PARAMETERS
APPEARS TO BE OVER SERN ND...EXTENDING INTO NWRN MN LATER THIS
AFTERNOON.  ALTHOUGH LOW LEVEL SHEAR IS WEAK...DEGREE OF AMBIENT
VORTICITY AND INCREASING LOW LEVEL CAPE SUGGEST ISOLATED...BRIEF
TORNADOES CANOT BE RULED OUT.

..JEWELL.. 08/08/2004

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

ATTN...WFO...MPX...FGF...ABR...BIS...

48999606 47149518 45639491 45629656 45629858 47019895
48379973 49010012

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 8, 12:17 PM CDT	Mesoscale Discussion	SPC	Anoka, Blue Earth, Carver, Dakota, Dodge, Faribault and 19 more	58 min
Aug 8, 12:55 PM CDT	Severe Thunderstorm Watch	SPC	Becker, Clay, Kittson, Mahnomen, Marshall, Norman and 5 more	5 hr
Aug 8, 4:02 PM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Cass, Clay, Clearwater, Hubbard and 11 more	88 min
Aug 8, 4:35 PM CDT	Severe Thunderstorm Watch	SPC	Becker, Beltrami, Cass, Clay, Clearwater, Crow Wing and 17 more	5 hr
Aug 8, 5:03 PM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Blue Earth, Carver, Chisago, Dakota and 31 more	117 min
Aug 8, 5:20 PM CDT	Severe Thunderstorm Watch	SPC	Anoka, Benton, Brown, Carver, Chisago, Dakota and 21 more	7 hr
Aug 7, 7:34 PM CDT	Mesoscale Discussion	SPC	Haakon, Jackson, Jones, Lyman, Mellette, Tripp	56 min

Nearby

Mesoscale Discussions in North Dakota, 2004 Mesoscale Discussions in Minnesota, 2004 Mesoscale Discussions in South Dakota, 2004 Every mesoscale discussion in 2004

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.