Alert archive / Montana / Mesoscale Discussions in 2003
Mesoscale Discussion 2129
The Storm Prediction Center issued this mesoscale discussion at Aug 8, 2003, 9:20 PM MDT for 24 counties in Montana; 24 counties in North Dakota. It was in force for 55 min.
The area
The outline as issued.
The facts
- Issued
- Aug 8, 2003, 9:20 PM MDT (03:20 UTC)
- Expired
- Aug 8, 2003, 10:15 PM MDT
- In force
- 55 min
- Issued by
- the Storm Prediction Center
All 48 counties
Cascade County, MT, Chouteau County, MT, Custer County, MT, Dawson County, MT, Fallon County, MT, Fergus County, MT, Garfield County, MT, Golden Valley County, MT, Judith Basin County, MT, Liberty County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Pondera County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Rosebud County, MT, Sheridan County, MT, Teton County, MT, Toole County, MT, Treasure County, MT, Wibaux County, MT, Billings County, ND, Bottineau County, ND, Burke County, ND, Burleigh County, ND, Divide County, ND, Dunn County, ND, Golden Valley County, ND, Hettinger County, ND, Kidder County, ND, McHenry County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Pierce County, ND, Renville County, ND, Rolette County, ND, Sheridan County, ND, Slope County, ND, Stark County, ND, Ward County, ND, Williams County, ND
The radar
The Glasgow radar (KGGW), 84 km from the middle of the area, began a volume at 03:24 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
Glasgow Intl Airport, MT (KGGW), launched 00:00Z, 3.3 hours before the alert went out and 86 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
- 2301 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 2167 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 45 m²/s²
- 0-3 km storm-relative helicity
- 296 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 20.1
The text
As transmitted, in the capitals the NWS used until 2016.
764 ACUS11 KWNS 090321 SWOMCD SPC MCD 090320 NDZ000-MTZ000-090415- MESOSCALE DISCUSSION 2129 NWS STORM PREDICTION CENTER NORMAN OK 1020 PM CDT FRI AUG 08 2003 AREAS AFFECTED...CNTRL/ERN MT AND WRN ND CONCERNING...SEVERE THUNDERSTORM WATCH 851...852... VALID 090320Z - 090415Z WEATHER WATCHES 851 AND 852 EXPIRE AT 0400 UTC. THERE ARE A FEW CLUSTERS OF TSTMS MIGRATING ACROSS MT AND EXTREME SWRN ND ATTM. IT APPEARS TWO MIDLEVEL IMPULSES ARE IN PLAY...ONE MIGRATING NWD ON ERN EDGE OF PACIFIC LOW AND THE OTHER MOVING NEWD ALONG NRN PERIPHERY OF RIDGE AXIS IN NRN WY. THUS...THE LARGE SCALE ENVIRONMENT IS SUPPORTIVE OF TSTMS. STRONGEST INSTABILITY AXIS EXISTS FROM NORTH OF KBIL EWD INTO NWRN ND AND RECENT UPSWING IN ACTIVITY APPROACHING KMLS AND KGDV MAY SIGNAL POTENTIAL WIND/HAIL THREAT ACROSS EXTREME ERN MT INTO WRN ND OVER THE NEXT FEW HOURS. ADDITIONAL ACTIVITY THAT RECENTLY GAVE KGTF A 72 KT WIND GUST IS MOVING INTO CHOUTEAU COUNTY. IN THESE AREAS...EVENING SOUNDINGS SUGGEST AN INVERTED-V THERMODYNAMIC STRUCTURE THAT WILL SUPPORT SEVERE WIND GUSTS. THREAT FOR ISOLD SEVERE STORMS WITH DAMAGING WINDS/HAIL COULD CONTINUE FOR THE REMAINDER OF THE NIGHT...ESPECIALLY FROM ERN MT INTO WRN ND. IF TSTMS APPEAR TO INCREASE RAPIDLY IN COVERAGE...A NEW WW MIGHT BE NEEDED. ..RACY.. 08/09/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...FGF...BIS...GGW...BYZ...TFX... 45890964 46980981 47221299 48671190 48340828 48330562 48810532 49099964 46619973
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 6:03 PM MDT | Mesoscale Discussion | SPC | Dawson, Richland, Roosevelt, Sheridan, Wibaux | 87 min |
| Aug 8, 7:06 PM MDT | Mesoscale Discussion | SPC | Fergus, Garfield, McCone, Petroleum | 114 min |
| Aug 9, 12:19 PM MDT | Mesoscale Discussion | SPC | Richland, Roosevelt, Sheridan | 116 min |
| Aug 9, 10:02 AM MDT | Mesoscale Discussion | SPC | Barnes, Dickey, Emmons, LaMoure, Logan, McIntosh and 2 more | 118 min |
Nearby
Mesoscale Discussions in Montana, 2003Mesoscale Discussions in North Dakota, 2003Every mesoscale discussion in 2003
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.