Alert archive / Montana / Mesoscale Discussions in 2018

Mesoscale Discussion 613

June 1, 20184 states

The Storm Prediction Center issued this mesoscale discussion at Jun 1, 2018, 3:04 PM MDT for 4 states. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
Jun 1, 2018, 3:04 PM MDT (21:04 UTC)
Expired
Jun 1, 2018, 4:30 PM MDT
In force
86 min
Issued by
the Storm Prediction Center

Counties Carter County, MT, Custer County, MT, Dawson County, MT, Fallon County, MT, Powder River County, MT, Prairie County, MT, Wibaux County, MT, Billings County, ND, Bowman County, ND, Golden Valley County, ND, Slope County, ND, Butte County, SD, Custer County, SD, Harding County, SD, Lawrence County, SD, Campbell County, WY, Crook County, WY, Johnson County, WY, Weston County, WY

The radar

The Rapid City radar (KUDX), 221 km from the middle of the area, began a volume at 21:07 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

Rapid City, SD (KRAP), launched 12:00Z, 9.1 hours before the alert went out and 222 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, Rapid City, SD at 12:00Z on 2018-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1239 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, Rapid City, SD at 12:00Z on 2018-06-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 68 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
1239 J/kg
Mixed-layer CIN
-286 J/kg
Mixed-layer LCL
1849 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
68 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

416 
ACUS11 KWNS 012104
SWOMCD
SPC MCD 012104 
SDZ000-NDZ000-MTZ000-WYZ000-012230-

Mesoscale Discussion 0613
NWS Storm Prediction Center Norman OK
0404 PM CDT Fri Jun 01 2018

Areas affected...Southeast Montana...northeast Wyoming...far western
South Dakota...far southwestern North Dakota

Concerning...Severe Thunderstorm Watch 143...

Valid 012104Z - 012230Z

The severe weather threat for Severe Thunderstorm Watch 143
continues.

SUMMARY...Severe threat continues across Severe Thunderstorm Watch
0143.

DISCUSSION...A few bowing segments and transient supercells are
currently located across eastern Montana into far northeast Wyoming
and are moving northeastward towards the east portions of the watch.
The 40-50 kts effective bulk shear and 1500+ J/kg MLCAPE that remain
in place across the pre-convective environment will continue to
support a continued hail/wind threat over the next few hours.

Storms in far northeast Wyoming are projected to move into an
environment of higher instability, and the associated severe threat
may increase as the storms move into northwest South Dakota within
the next one and a half hours. 

Substantial low-level turning has occurred across western portions
of the watch and early cancellation may be needed. Please refer to
Watch Status messages for further updates.

..Squitieri/Cook/Guyer.. 06/01/2018

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...BIS...UNR...CYS...BYZ...GGW...RIW...

LAT...LON   43660678 44240651 44710638 45030630 45800627 46380624
            47050621 47340602 47530580 47550463 47530282 47170277
            46790280 45900290 44500295 43890299 43420298 43400504
            43400603 43380666 43660678

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 31, 8:18 PM MDTMesoscale DiscussionSPCBig Horn, Carter, Custer, Fallon, Musselshell, Powder River and 4 more57 min
Jun 1, 11:03 AM MDTMesoscale DiscussionSPCBig Horn, Carter, Custer, Dawson, Fallon, McCone and 4 more117 min
Jun 1, 11:45 AM MDTSevere Thunderstorm WatchSPCBig Horn, Carter, Custer, Dawson, Fallon, Garfield and 6 more6 hr
May 31, 6:00 PM MDTMesoscale DiscussionSPCAdams, Burleigh, Emmons, Grant, Hettinger, Kidder and 3 more90 min
Jun 1, 1:13 PM MDTMesoscale DiscussionSPCAdams, Billings, Burke, Burleigh, Dunn, Emmons and 19 more2 hr
Jun 1, 2:30 PM MDTTornado WatchSPCBottineau, Burke, Burleigh, Divide, Dunn, Emmons and 18 more6 hr
Jun 1, 5:02 PM MDTMesoscale DiscussionSPCBottineau, Burke, Burleigh, Divide, Dunn, Emmons and 15 more88 min
Jun 1, 1:53 PM MDTSevere Thunderstorm WatchSPCAurora, Bon Homme, Brule, Buffalo, Campbell, Charles Mix and 22 more7 hr
Jun 1, 5:32 PM MDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brule, Buffalo, Campbell and 22 more88 min

Nearby

Mesoscale Discussions in Montana, 2018Mesoscale Discussions in North Dakota, 2018Mesoscale Discussions in South Dakota, 2018Every mesoscale discussion in 2018

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.