Alert archive / Montana / Mesoscale Discussions in 2003

Mesoscale Discussion 2113

August 6, 20038 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Aug 6, 2003, 7:25 PM MDT for 8 counties in Montana. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 6, 2003, 7:25 PM MDT (01:25 UTC)
Expired
Aug 6, 2003, 9:30 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Blaine County, MT, Fergus County, MT, Garfield County, MT, Golden Valley County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Valley County, MT

The radar

The Glasgow radar (KGGW), 145 km from the middle of the area, began a volume at 01:28 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, 1.4 hours before the alert went out and 148 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-pSkew-T log-p diagram, Glasgow Intl Airport, MT at 00:00Z on 2003-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 29 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Glasgow Intl Airport, MT at 00:00Z on 2003-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 139 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
29 J/kg
Mixed-layer CIN
-218 J/kg
Mixed-layer LCL
3137 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
139 m²/s²
0-3 km storm-relative helicity
299 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

550 
ACUS11 KWNS 070126
SWOMCD
SPC MCD 070125 
MTZ000-070330-

MESOSCALE DISCUSSION 2113
NWS STORM PREDICTION CENTER NORMAN OK
0825 PM CDT WED AUG 06 2003

AREAS AFFECTED...CNTRL/NERN MT

CONCERNING...SEVERE THUNDERSTORM WATCH 848...

VALID 070125Z - 070330Z

A LINE OF SEVERE THUNDERSTORMS IS CURRENTLY MOVING THROUGH WW
848...WITH THE THREAT FOR LARGE HAIL AND DAMAGING WIND CONTINUING
THROUGH 04 UTC.

100 MB MLCAPE REMAINS AOA 2000 J/KG IN REGION OF LOW LEVEL
INSTABILITY AXIS EXTENDING FROM SERN MT TO JUST WEST OF GLASGOW. 
DEEP LAYER SHEAR OVER NERN MT EXCEEDS 45 KTS...AND WITH SELY LOW
LEVEL INFLOW AROUND 25 KTS CONVECTION CONTINUES TO MOVE E/NEWD
THROUGH WATCH 848.

MESOANALYSIS INDICATES GLASGOW IS JUST EAST OF INSTABILITY
AXIS...AND 00 UTC RAOB CONFIRMS MESOANALYSIS WITH ONLY 600 J/KG
MUCAPE. WARM MID LEVEL TEMPERATURES SHOULD CAP/LIMIT CONVECTIVE
DEVELOPMENT FARTHER SEWD INTO DEEPER MOISTURE. WITH CAPPING TO THE
SOUTH AND CONVECTIVE LINE MOVING INTO A REGION OF LESSER CAPE EAST
OF VALLEY AND GARFIELD COUNTIES...DO NOT ANTICIPATE AN ADDITIONAL WW
AT THIS TIME.

..BRIGHT.. 08/07/2003

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

ATTN...WFO...GGW...BYZ...TFX...

48420943 48950835 48890645 47690639 46620733 46200860
46400979 47641000

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 12:16 AM MDTMesoscale DiscussionSPCMcCone, Richland59 min
Aug 7, 2:18 PM MDTMesoscale DiscussionSPCBroadwater, Cascade, Chouteau, Deer Lodge, Gallatin, Granite and 12 more117 min
Aug 7, 3:45 PM MDTSevere Thunderstorm WatchSPCBlaine, Chouteau, Daniels, Dawson, Fergus, Garfield and 14 more6 hr
Aug 7, 5:56 PM MDTMesoscale DiscussionSPCBlaine, Chouteau, Daniels, Dawson, Fergus, Garfield and 14 more2 hr

Nearby

Mesoscale Discussions in Montana, 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.