Alert archive / South Dakota / Mesoscale Discussions in 2009
Mesoscale Discussion 1321
The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2009, 3:49 PM MDT for 4 states. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Jun 25, 2009, 3:49 PM MDT (21:49 UTC)
- Expired
- Jun 25, 2009, 4:45 PM MDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
Counties Carter County, MT, Bowman County, ND, Butte County, SD, Custer County, SD, Fall River County, SD, Harding County, SD, Jackson County, SD, Lawrence County, SD, Meade County, SD, Oglala Lakota County, SD, Pennington County, SD, Crook County, WY
The radar
The Rapid City radar (KUDX), 37 km from the middle of the area, began a volume at 21:51 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
Rapid City, SD (KUNR), launched 12:00Z, 9.8 hours before the alert went out and 40 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.
- Mixed-layer CAPE
- 44 J/kg
- Mixed-layer CIN
- -363 J/kg
- Mixed-layer LCL
- 2033 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 28 m²/s²
- 0-3 km storm-relative helicity
- 143 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
ACUS11 KWNS 252149
SWOMCD
SPC MCD 252149
SDZ000-NDZ000-MTZ000-WYZ000-252245-
MESOSCALE DISCUSSION 1321
NWS STORM PREDICTION CENTER NORMAN OK
0449 PM CDT THU JUN 25 2009
AREAS AFFECTED...WRN SD...SWRN ND...FAR NERN WY...SERN MT
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 252149Z - 252245Z
ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT IS POSSIBLE OVER WRN
SD...SWRN ND...FAR NERN WY...AND SERN MT DURING THE AFTERNOON AND
EVENING. A FEW SUPERCELLS WOULD BE LIKELY...POSING A THREAT OF LARGE
HAIL...DAMAGING WINDS...AND ISOLATED TORNADOES. A WATCH WILL BE
ISSUED SHORTLY.
SOUTHEASTERLY SURFACE WINDS ARE PRESENT BENEATH A MID LEVEL RIDGE
AXIS OVER THE NRN HIGH PLAINS...RESULTING IN A NARROW TONGUE OF LOW
TO MID 60S DEWPOINTS EXTENDING NNW INTO WRN SD...WITH LOW TO MID 50S
DEWPOINTS LOCATED FARTHER N INTO SERN MT. RUC FORECAST SOUNDINGS
INDICATE STEEP MID LEVEL LAPSE RATES /AOA 8 C PER KM/ ARE SPREADING
E OVER THE HIGH PLAINS...AND WHEN COLLOCATED WITH THE LOW LEVEL
MOISTURE AXIS...ARE CONTRIBUTING TOWARD 1000-2000 J/KG MLCAPE
VALUES. SELY LOW LEVEL FLOW OVERLAYED BY 30-40+ KT MID/UPPER LEVEL
FLOW /PER AREA VWP DATA/ IS RESULTING IN FAVORABLE DEEP LAYER SHEAR
FOR SUPERCELLS /EFFECTIVE BULK SHEAR VALUES GREATER THAN 40 KT/. IN
ADDITION...SHORT TERM MODEL GUIDANCE INDICATES LOW LEVEL JET WILL
STRENGTHEN DURING THE EVENING. THEREFORE...ISOLATED SUPERCELLS
APPEAR POSSIBLE WITH STORMS FORMING OVER THE NRN HIGH
PLAINS...POSING A THREAT OF LARGE HAIL AND DAMAGING WINDS. A COUPLE
OF TORNADOES ARE ALSO POSSIBLE...PARTICULARLY TOWARDS EVENING AS LOW
LEVEL HODOGRAPH STRUCTURE ENLARGES AND BOUNDARY LAYER RH INCREASES
WITH LOSS OF DAYTIME HEATING.
..GARNER.. 06/25/2009
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BIS...UNR...CYS...BYZ...
LAT...LON 45010204 44010155 43180174 43010254 43040357 43310422
44780486 45950497 46500382 45010204SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 1:02 PM MDT | Mesoscale Discussion | SPC | Beaverhead, Blaine, Broadwater, Chouteau, Fergus, Gallatin and 10 more | 88 min |
| Jun 24, 6:21 PM MDT | Mesoscale Discussion | SPC | Adams, Dunn, Grant, Hettinger, Stark | 84 min |
| Jun 24, 7:49 PM MDT | Mesoscale Discussion | SPC | Beadle, Brookings, Brown, Campbell, Clark, Codington and 22 more | 86 min |
| Jun 24, 9:53 PM MDT | Mesoscale Discussion | SPC | Bon Homme, Charles Mix, Clay, Hutchinson, Lincoln, Turner and 2 more | 97 min |
| Jun 24, 10:53 PM MDT | Severe Thunderstorm Watch | SPC | Aurora, Bon Homme, Charles Mix, Clay, Davison, Douglas and 7 more | 5 hr |
| Jun 25, 1:13 AM MDT | Mesoscale Discussion | SPC | Clay, Union, Yankton | 92 min |
| Jun 25, 3:50 PM MDT | Tornado Watch | SPC | Bennett, Butte, Custer, Fall River, Haakon, Jackson and 3 more | 5 hr |
| Jun 25, 1:06 PM MDT | Mesoscale Discussion | SPC | Goshen, Laramie | 54 min |
| Jun 25, 1:30 PM MDT | Severe Thunderstorm Watch | SPC | Goshen, Laramie, Platte | 7 hr |
| Jun 25, 4:22 PM MDT | Mesoscale Discussion | SPC | Goshen, Laramie, Platte | 53 min |
| Jun 25, 5:50 PM MDT | Mesoscale Discussion | SPC | Goshen, Laramie, Platte | 55 min |
Nearby
Mesoscale Discussions in South Dakota, 2009Mesoscale Discussions in Montana, 2009Mesoscale Discussions in North Dakota, 2009Every mesoscale discussion in 2009
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.