Alert archive / Montana / Mesoscale Discussions in 2004

Mesoscale Discussion 1113

June 6, 20046 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 6, 2004, 4:40 AM MDT for 6 counties in Montana. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jun 6, 2004, 4:40 AM MDT (10:40 UTC)
Expired
Jun 6, 2004, 6:15 AM MDT
In force
95 min
Issued by
the Storm Prediction Center

Counties Chouteau County, MT, Fergus County, MT, Judith Basin County, MT, Meagher County, MT, Petroleum County, MT, Wheatland County, MT

The radar

The Great Falls radar (KTFX), 102 km from the middle of the area, began a volume at 10:43 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

Great_falls, MT (KTFX), launched 00:00Z, 10.7 hours before the alert went out and 46 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, Great_falls, MT at 00:00Z on 2004-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 537 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2004-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 square meters per square second.193958Sfc1 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
537 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
2966 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

306 
ACUS11 KWNS 061040
SWOMCD
SPC MCD 061040 
MTZ000-061215-

MESOSCALE DISCUSSION 1113
NWS STORM PREDICTION CENTER NORMAN OK
0540 AM CDT SUN JUN 06 2004

AREAS AFFECTED...N CENTRAL MT...

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 061040Z - 061215Z

LOCALIZED THREAT FOR DAMAGING WINDS EVOLVING ACROSS N CENTRAL MT
ATTM...BUT NEW WW NOT EXPECTED ATTM BARRING MESOSCALE STORM / COLD
POOL ORGANIZATION.

LATEST DATA INDICATES AXIS OF MARGINAL /UNDER 1000 J/KG
MOST-UNSTABLE CAPE/ INSTABILITY ACROSS CENTRAL MT ATTM...AHEAD OF
60-PLUS KT MID-LEVEL JET STREAK NOW EJECTING EWD ACROSS WRN AND INTO
CENTRAL MT.  ALTHOUGH DEGREE OF INSTABILITY SHOULD CONTINUE TO LIMIT
THE SEVERE THREAT...INCREASINGLY-STRONG LOW- TO MID-LEVEL WIND FIELD
SUPPORTS STRONG / LOCALLY DAMAGING WIND GUSTS WITH A FEW STRONGER
STORMS.  

MINI BOW MOVING RAPIDLY ACROSS ERN CASCADE COUNTY ATTM -- WHICH
MOVED 15 MILES S OF TFX /GREAT FALLS MT/ RADAR -- INDICATED 65-PLUS
KT WIND JUST ABOVE THE GROUND FOR ABOUT A HALF HOUR -- INDICATIVE OF
INCREASINGLY-STRONG WIND FIELD ACROSS THIS REGION.

WITH ELY COMPONENT OF LOW-LEVEL JET STILL INDICATED ACROSS THE ERN
HALF OF MT BENEATH WLY FLOW ALOFT...AT LEAST SOME POTENTIAL FOR AN
ORGANIZED / FORWARD-PROPAGATING BOW EXISTS.  AGAIN...IT APPEARS ATTM
THAT THIS THREAT SHOULD BE MODULATED BY LIMITED INSTABILITY. 
HOWEVER...GIVEN THAT A FEW ORGANIZED / SEVERE STORMS HAVE
PERSISTED...THIS REGION BEARS WATCHING.  WE WILL CONTINUE TO MONITOR
THE AREA FOR SIGNS OF POTENTIAL CONVECTIVE ORGANIZATION AT GREATER
THAN STORM SCALE...WHICH COULD NECESSITATE WW ISSUANCE.

..GOSS.. 06/06/2004

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

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

48121115 48351049 47990911 47160793 46480854 46390968
46211101 46701140

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 5, 6:35 PM MDTMesoscale DiscussionSPCBroadwater, Cascade, Chouteau, Glacier, Hill, Jefferson and 9 more115 min
Jun 5, 9:10 PM MDTMesoscale DiscussionSPCBlaine, Broadwater, Cascade, Chouteau, Deer Lodge, Fergus and 19 more95 min

Nearby

Mesoscale Discussions in Montana, 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.