Alert archive / Montana / Mesoscale Discussions in 2012

Mesoscale Discussion 1287

June 26, 20126 counties in Montana

The Storm Prediction Center issued this mesoscale discussion at Jun 26, 2012, 6:16 AM MDT for 6 counties in Montana. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jun 26, 2012, 6:16 AM MDT (12:16 UTC)
Expired
Jun 26, 2012, 7:45 AM MDT
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Glacier County, MT, Hill County, MT, Liberty County, MT, Pondera County, MT, Teton County, MT, Toole County, MT

The radar

The Great Falls radar (KTFX), 123 km from the middle of the area, began a volume at 12:16 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 12:00Z, 0.3 hours before the alert went out and 162 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 12:00Z on 2012-06-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1099 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 12:00Z on 2012-06-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 223 square meters per square second.1939587897Sfc1 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
1099 J/kg
Mixed-layer CIN
-173 J/kg
Mixed-layer LCL
763 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
481 m²/s²
Significant tornado parameter
0.0
Supercell composite
20.6

Open this sounding in Storm Lab

The text

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

473 
ACUS11 KWNS 261217
SWOMCD
SPC MCD 261216
MTZ000-261345-

MESOSCALE DISCUSSION 1287
NWS STORM PREDICTION CENTER NORMAN OK
0716 AM CDT TUE JUN 26 2012

AREAS AFFECTED...PARTS OF NWRN/N CNTRL MT

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 261216Z - 261345Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THE NEED FOR A WW IS NOT ANTICIPATED IN THE NEAR
TERM...BUT TRENDS WILL HAVE TO BE MONITORED FOR AN INCREASING SEVERE
WEATHER THREAT THAT COULD DEVELOP DURING THE MIDDAY
HOURS...INCLUDING POTENTIAL FOR AN ISOLATED TORNADO OR TWO.

DISCUSSION...SCATTERED...VIGOROUS DISCRETE STORM DEVELOPMENT HAS
PERSISTED THROUGH MUCH OF THE NIGHT ACROSS THE REGION.  THIS HAS
BEEN ..SUPPORTED BY...AND BASED WITHIN...AN ELEVATED WARM ADVECTION
REGIME...ABOVE A STABILIZING BOUNDARY LAYER...DOWNSTREAM OF A STRONG
SHORT WAVE TROUGH NOW LIFTING NORTHEASTWARD ACROSS THE NORTHERN
INTERMOUNTAIN REGION.  LITTLE CHANGE IN THE LARGE-SCALE FORCING IS
EXPECTED THROUGH THE 15-18Z TIME FRAME...SO CONVECTIVE ACTIVITY
APPEARS LIKELY TO PERSIST.  OCCASIONAL SEVERE HAIL APPEARS TO BE THE
PRIMARY THREAT FOR THE NEXT SEVERAL HOURS...BUT BOUNDARY LAYER
DESTABILIZATION MAY EVENTUALLY YIELD A MORE SUBSTANTIVE SEVERE
WEATHER THREAT...WITH INTENSIFYING SUPERCELLS POSSIBLE CLOSER TO
18Z...PARTICULARLY NORTH OF GREAT FALLS...NEAR THE CANADIAN
BORDER...BETWEEN CUT BANK AND HAVRE.

..KERR/CORFIDI.. 06/26/2012

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

ATTN...WFO...TFX...MSO...

LAT...LON   48721415 49301174 48860930 47571130 47231295 48721415

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 25, 7:12 PM MDTMesoscale DiscussionSPCBlaine, Chouteau, Dawson, Fergus, Garfield, Hill and 11 more93 min
Jun 25, 10:27 PM MDTMesoscale DiscussionSPCBlaine, Chouteau, Fergus, Garfield, Hill, Liberty and 3 more93 min
Jun 26, 12:23 AM MDTMesoscale DiscussionSPCBlaine, Chouteau, Hill67 min
Jun 26, 11:08 AM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Glacier, Hill, Liberty and 3 more37 min
Jun 26, 11:20 AM MDTSevere Thunderstorm WatchSPCBlaine, Cascade, Chouteau, Glacier, Hill, Lewis and Clark and 4 more6 hr
Jun 26, 2:06 PM MDTMesoscale DiscussionSPCDaniels, Dawson, Fallon, McCone, Phillips, Prairie and 5 more54 min
Jun 26, 2:21 PM MDTMesoscale DiscussionSPCBlaine, Cascade, Chouteau, Hill, Lewis and Clark, Liberty and 3 more54 min

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.