Alert archive / Montana / Mesoscale Discussions in 2004

Mesoscale Discussion 1813

August 1, 20047 counties in Montana; Golden Valley County, North Dakota

The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2004, 2:43 AM MDT for 7 counties in Montana; Golden Valley County, North Dakota. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: Aug 1, 2004, 2:43 AM MDT (08:43 UTC)
Expired: Aug 1, 2004, 4:15 AM MDT
In force: 92 min
Issued by: the Storm Prediction Center

Counties Daniels County, MT, Dawson County, MT, McCone County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Wibaux County, MT, Golden Valley County, ND

The radar

The Glasgow radar (KGGW), 107 km from the middle of the area, began a volume at 08:44 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, 8.7 hours before the alert went out and 105 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: 81 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 2257 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 141 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

667 
ACUS11 KWNS 010843
SWOMCD
SPC MCD 010843 
NDZ000-MTZ000-011015-

MESOSCALE DISCUSSION 1813
NWS STORM PREDICTION CENTER NORMAN OK
0343 AM CDT SUN AUG 01 2004

AREAS AFFECTED...NERN MT INTO WRN ND

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 010843Z - 011015Z

DAMAGING WIND POTENTIAL SHOULD TEND TO DIMINISH WITH EWD EXTENT AND
A WW IS NOT ANTICIPATED.

LEADING EDGE OF FAST-MOVING MCS EXTENDED FROM WRN DANIELS COUNTY SWD
ACROSS ERN VALLEY AND INTO NRN GARFIELD COUNTY AS OF 0830Z...WITH A
RECENT WIND GUST TO 72 MPH REPORTED AT GGW. WHILE INSTABILITY
REMAINS QUITE LIMITED /I.E. MUCAPES AOB 250 J/KG/ IT APPEARS THAT
FAST SYSTEM SPEED /EWD MOVEMENT AT 40-45KTS/ COUPLED WITH PRESENCE
OF REAR INFLOW JET /OBSERVED IN THE LOWEST 2KM PER GGW VWP/ SHOULD
CONTINUE TO SUPPORT AT LEAST ISOLATED DAMAGING WIND GUSTS FOR THE
NEXT HOUR OR SO. LATEST RUC ANALYSIS FIELDS INDICATE THAT DOWNSTREAM
AIRMASS OVER WRN ND IS NEARLY STABLE WITH MUCAPES OF 50 J/KG OR
LESS. THUS...MCS SHOULD TEND TO WEAKEN AS IT PROGRESSES EWD AND
ENCOUNTERS INCREASINGLY STABLE ENVIRONMENT.

..MEAD.. 08/01/2004

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

ATTN...WFO...BIS...GGW...

49000622 49000361 46870361 46880626

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 1, 2:15 PM MDT	Tornado Watch	SPC	Sargent	7 hr
Aug 1, 3:39 PM MDT	Mesoscale Discussion	SPC	Adams, Benson, Burleigh, Dunn, Emmons, Grant and 13 more	66 min
Aug 1, 4:00 PM MDT	Severe Thunderstorm Watch	SPC	Adams, Benson, Bottineau, Burleigh, Cavalier, Eddy and 22 more	5 hr

Nearby

Mesoscale Discussions in Montana, 2004 Mesoscale Discussions in North 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.