Alert archive / Montana / Mesoscale Discussions in 2012

Mesoscale Discussion 1018

June 2, 201215 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 2, 2012, 9:22 AM MDT for 15 counties in Montana. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Jun 2, 2012, 9:22 AM MDT (15:22 UTC)
Expired
Jun 2, 2012, 10:15 AM MDT
In force
53 min
Issued by
the Storm Prediction Center

Counties Big Horn County, MT, Custer County, MT, Dawson County, MT, Fergus County, MT, Garfield County, MT, Golden Valley County, MT, McCone County, MT, Musselshell County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Rosebud County, MT, Treasure County, MT, Valley County, MT, Yellowstone County, MT

The radar

The Billings radar (KBLX), 142 km from the middle of the area, began a volume at 15:26 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 12:00Z, 3.4 hours before the alert went out and 165 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 12:00Z on 2012-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Glasgow Intl Airport, MT at 12:00Z on 2012-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 135 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1574 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
135 m²/s²
0-3 km storm-relative helicity
181 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

702 
ACUS11 KWNS 021522
SWOMCD
SPC MCD 021522 
MTZ000-021615-

MESOSCALE DISCUSSION 1018
NWS STORM PREDICTION CENTER NORMAN OK
1022 AM CDT SAT JUN 02 2012

AREAS AFFECTED...ERN MT

CONCERNING...OUTLOOK UPGRADE 

VALID 021522Z - 021615Z

SUMMARY...A CATEGORICAL UPGRADE TO SLIGHT RISK IS PLANNED IN THE
UPCOMING 1630Z DAY-1 CONVECTIVE OUTLOOK.

DISCUSSION...CLUSTERS OF STORMS IN ADVANCE OF AN EWD-MOVING
SHORTWAVE TROUGH AND ATTENDANT SFC FRONT WILL POSE A THREAT FOR SVR
WIND GUSTS AND HAIL THIS AFTERNOON INTO EARLY EVENING ACROSS ERN
MT...AS MARGINAL DESTABILIZATION COMMENCES AMIDST MODERATE/STRONG
DEEP SHEAR. PLEASE SEE THE FORTHCOMING 1630Z DAY-1 CONVECTIVE
OUTLOOK FOR ADDITIONAL METEOROLOGICAL ANALYSIS ON THIS
SCENARIO...WHICH WILL INCLUDE A CATEGORICAL UPGRADE TO SLIGHT RISK
ACROSS ERN MT.

..COHEN/CARBIN.. 06/02/2012

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

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

LAT...LON   47040979 48210885 48730781 48750616 47960489 46680490
            45800516 45360587 45040748 45200879 46330983 47040979

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 2, 12:52 PM MDTMesoscale DiscussionSPCBig Horn, Carbon, Custer, Fergus, Gallatin, Garfield and 11 more113 min
Jun 2, 2:10 PM MDTSevere Thunderstorm WatchSPCBig Horn, Broadwater, Carbon, Carter, Cascade, Custer and 27 more7 hr

Nearby

Mesoscale Discussions in Montana, 2012Every mesoscale discussion in 2012

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.