Alert archive / North Dakota / Mesoscale Discussions in 2004
Mesoscale Discussion 1621
The Storm Prediction Center issued this mesoscale discussion at Jul 11, 2004, 5:34 PM MDT for 20 counties in Montana; 25 counties in North Dakota; 5 counties in South Dakota. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Jul 11, 2004, 5:34 PM MDT (23:34 UTC)
- Expired
- Jul 11, 2004, 7:00 PM MDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
All 50 counties
Big Horn County, MT, Carter County, MT, Custer County, MT, Daniels County, MT, Dawson County, MT, Fallon County, MT, Garfield County, MT, McCone County, MT, Petroleum County, MT, Phillips County, MT, Powder River County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Treasure County, MT, Valley County, MT, Wibaux County, MT, Yellowstone County, MT, Adams County, ND, Billings County, ND, Bottineau County, ND, Bowman County, ND, Burke County, ND, Burleigh County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Grant County, ND, Hettinger County, ND, McHenry County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Renville County, ND, Sheridan County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Ward County, ND, Williams County, ND, Corson County, SD, Dewey County, SD, Harding County, SD, Perkins County, SD, Ziebach County, SD
The radar
The Glasgow radar (KGGW), 200 km from the middle of the area, began a volume at 23:34 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
Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 11.6 hours before the alert went out and 201 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.
- Mixed-layer CAPE
- 98 J/kg
- Mixed-layer CIN
- -523 J/kg
- Mixed-layer LCL
- 1856 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 212 m²/s²
- 0-3 km storm-relative helicity
- 221 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
035 ACUS11 KWNS 112335 SWOMCD SPC MCD 112334 NDZ000-SDZ000-MTZ000-120100- MESOSCALE DISCUSSION 1621 NWS STORM PREDICTION CENTER NORMAN OK 0634 PM CDT SUN JUL 11 2004 AREAS AFFECTED...CENTRAL/ERN MT...WRN ND AND NWRN SD CONCERNING...SEVERE THUNDERSTORM WATCH 605... VALID 112334Z - 120100Z SCATTERED SEVERE THUNDERSTORMS OVER CENTRAL/SERN MT SHOULD CONTINUE TO MOVE EWD AROUND 30 KTS. LEAD SUPERCELL OVER POWDER RIVER COUNTY WILL MOVE OUT OF WW 605 BY 01Z. THUS A NEW WW WILL BE NEEDED FOR PORTIONS OF NWRN SD AND WRN ND BEFORE 01Z. CONVECTIVE COVERAGE SHOULD CONTINUE TO INCREASE AS NEW THUNDERSTORM ACTIVITY OCCURS AND CONSOLIDATES INTO A LINE AHEAD OF COLD FRONT/LEE TROUGH INTERSECTION OVER CENTRAL MT DURING THE NEXT FEW HOURS. IN THE MEAN TIME...THE LEAD OF SEVERAL SUPERCELLS OVER ERN MT WILL BEGIN TO MOVE OUT OF WW 605 AND INTO WRN ND BY AROUND 01Z. RELATIVELY HIGH LCL/LFC HEIGHTS SHOULD CONTINUE TO MAKE DAMAGING WINDS AND LARGE HAIL THE PRIMARY SEVERE THREATS FOR THE NEXT SEVERAL HOURS. IF CONVECTION CAN MAINTAIN SUPERCELL CHARACTERISTICS BEFORE BECOMING LINEAR EWD INTO LOW LEVEL MOISTURE AXIS/LOWER LCL ENVIRONMENT OVER NWRN ND...LOW LEVEL SHEAR INCREASING AROUND SUNSET MAY SUPPORT A THREAT FOR ISOLATED TORNADOES IN THIS AREA. ..CROSBIE.. 07/11/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...TFX... 45020815 46280839 49020838 49010011 44920037
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 10, 6:56 PM MDT | Mesoscale Discussion | SPC | Blaine, Carter, Cascade, Chouteau, Custer, Dawson and 21 more | 94 min |
| Jul 10, 9:40 PM MDT | Mesoscale Discussion | SPC | Dawson, Prairie, Wibaux | 2 hr |
| Jul 10, 11:40 PM MDT | Mesoscale Discussion | SPC | Custer, Dawson, Fallon, Garfield, Prairie, Rosebud and 1 more | 35 min |
| Jul 11, 11:48 AM MDT | Mesoscale Discussion | SPC | Blaine, Carter, Custer, Daniels, Dawson, Fallon and 8 more | 117 min |
| Jul 11, 1:52 PM MDT | Mesoscale Discussion | SPC | Big Horn, Blaine, Carbon, Carter, Chouteau, Custer and 19 more | 83 min |
| Jul 11, 2:40 PM MDT | Severe Thunderstorm Watch | SPC | Big Horn, Carter, Custer, Daniels, Dawson, Fallon and 12 more | 6 hr |
| Jul 10, 7:51 PM MDT | Mesoscale Discussion | SPC | Barnes, Cass, Dickey, LaMoure, Ransom, Richland and 2 more | 54 min |
| Jul 10, 8:10 PM MDT | Severe Thunderstorm Watch | SPC | Cass, Ransom, Richland, Sargent, Steele, Traill | 6 hr |
| Jul 10, 10:19 PM MDT | Mesoscale Discussion | SPC | Richland | 116 min |
| Jul 10, 8:02 PM MDT | Mesoscale Discussion | SPC | Aurora, Beadle, Brule, Buffalo, Clark, Davison and 12 more | 118 min |
| Jul 11, 12:43 PM MDT | Mesoscale Discussion | SPC | Bennett, Butte, Custer, Fall River, Haakon, Jackson and 5 more | 2 hr |
Nearby
Mesoscale Discussions in North Dakota, 2004Mesoscale Discussions in Montana, 2004Mesoscale Discussions in South Dakota, 2004Every 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.