Alert archive / Montana / Mesoscale Discussions in 2008

Mesoscale Discussion 1925

July 26, 200813 counties in Montana; Billings County, Golden Valley County, Slope County, North Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 26, 2008, 5:48 PM MDT for 13 counties in Montana; Billings County, Golden Valley County, Slope County, North Dakota. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jul 26, 2008, 5:48 PM MDT (23:48 UTC)
Expired
Jul 26, 2008, 7:45 PM MDT
In force
117 min
Issued by
the Storm Prediction Center

Counties Custer County, MT, Dawson County, MT, Fallon County, MT, Fergus County, MT, Garfield County, MT, McCone County, MT, Petroleum County, MT, Phillips County, MT, Prairie County, MT, Richland County, MT, Roosevelt County, MT, Valley County, MT, Wibaux County, MT, Billings County, ND, Golden Valley County, ND, Slope County, ND

The radar

The Glasgow radar (KGGW), 85 km from the middle of the area, began a volume at 23:48 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 11.8 hours before the alert went out and 86 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 2008-07-26Temperature 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 2008-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 327 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
2124 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
327 m²/s²
0-3 km storm-relative helicity
305 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 262349
SWOMCD
SPC MCD 262348 
NDZ000-MTZ000-270145-

MESOSCALE DISCUSSION 1925
NWS STORM PREDICTION CENTER NORMAN OK
0648 PM CDT SAT JUL 26 2008

AREAS AFFECTED...PARTS OF CENTRAL AND ERN MT

CONCERNING...SEVERE THUNDERSTORM WATCH 754...

VALID 262348Z - 270145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 754
CONTINUES.

SEVERAL STRONG/SEVERE STORMS ARE ONGOING WITHIN WW 754/ACROSS THE
NERN QUARTER OF MT.

SCATTERED STORMS -- A FEW EXHIBITING SUSTAINED SUPERCELL
CHARACTERISTICS -- CONTINUE ATTM ACROSS THIS AREA...MOVING ESEWD
INTO ESELY LOW-LEVEL INFLOW.  GENERALLY 1000 TO 2000 J/KG
MIXED-LAYER CAPE IS INDICATED ACROSS ERN MT...WITH THE AXIS OF
INSTABILITY EXTENDING ESEWD INTO W CENTRAL AND SWRN ND/NWRN SD. 
THIS -- AND THE FORECAST DEVELOPMENT OF A SELY LOW-LEVEL JET THIS
EVENING -- SUGGESTS THAT SEVERE STORMS SHOULD CONTINUE SPREADING
SEWD FOR THE NEXT SEVERAL HOURS.  WITH LATEST GGW /GLASGOW MT/ VWP
INDICATING 50 TO 55 KT WLYS AT MID LEVELS...SHEAR IS SUPPORTIVE OF
SUPERCELLS -- AND SHOULD BECOME EVEN MORE FAVORABLE AS LOW-LEVEL
SELYS INCREASE THIS EVENING.  WHILE HIGH LCLS SHOULD CONTINUE TO
LIMIT ANY TORNADO POTENTIAL...LARGE HAIL AND DAMAGING WIND THREAT
WILL PERSIST.

..GOSS.. 07/26/2008

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

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

48680795 48800707 48350458 47450291 46220282 46060419
46440701 46570931 47420970

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 26, 1:44 PM MDTMesoscale DiscussionSPCBig Horn, Carter, Custer, Dawson, Fallon, Fergus and 10 more61 min
Jul 26, 2:41 PM MDTSevere Thunderstorm WatchSPCBlaine, Chouteau, Fergus, Garfield, Hill, Judith Basin and 5 more7 hr

Nearby

Mesoscale Discussions in Montana, 2008Mesoscale Discussions in North Dakota, 2008Every mesoscale discussion in 2008

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.