Alert archive / Mississippi / Mesoscale Discussions in 2017
Mesoscale Discussion 331
The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2017, 1:34 PM CDT for 15 counties in Mississippi. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Mar 25, 2017, 1:34 PM CDT (18:34 UTC)
- Expired
- Mar 25, 2017, 3:30 PM CDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Leake County, MS, Madison County, MS, Montgomery County, MS, Rankin County, MS, Webster County, MS, Yalobusha County, MS, Yazoo County, MS
The radar
The Jackson/Brandon,MS radar (KDGX), 72 km from the middle of the area, began a volume at 18:35 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
Little Rock, AR (KBYH), launched 12:00Z, 6.6 hours before the alert went out and 211 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
- 233 J/kg
- Mixed-layer CIN
- -20 J/kg
- Mixed-layer LCL
- 545 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 131 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.2
The text
As transmitted.
323
ACUS11 KWNS 251834
SWOMCD
SPC MCD 251834
MSZ000-252030-
Mesoscale Discussion 0331
NWS Storm Prediction Center Norman OK
0134 PM CDT Sat Mar 25 2017
Areas affected...central through north central Mississippi
Concerning...Severe potential...Watch unlikely
Valid 251834Z - 252030Z
Probability of Watch Issuance...20 percent
SUMMARY...Storms will pose some risk for a few instances of hail and
strong to locally damaging wind gusts this afternoon. A ww issuance
will probably not be necessary unless more storms begin to show
signs of further intensification and organization.
DISCUSSION...a small cluster of thunderstorms which appears to have
initiated within pre-frontal confluence zone and in association with
a northeastward-ejecting vorticity maximum has intensified over west
central MS. Destabilization of the boundary layer has occurred, and
objective analysis is indicating MLCAPE from 500 to 800 J/kg.
However, the instability corridor is relatively narrow due to
widespread clouds and convective precipitation attending a squall
line just downstream. The cluster of storms will develop northeast
into northern MS next couple hours where effective bulk shear from
30-40 kt is sufficient for updraft rotation. However tendency will
be for mid level winds and deep-layer vertical shear to gradually
weaken as the upper trough advances east. The narrow instability
corridor and weakening winds aloft suggest the severe threat will
likely remain relatively confined in space and time. In the
meantime, the stronger storms will remain capable of a few instances
of large hail and damaging wind.
..Dial/Guyer.. 03/25/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...MEG...JAN...
LAT...LON 32349056 33279020 34048973 34038884 33188907 32188991
32059045 32349056SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 24, 11:41 PM CDT | Mesoscale Discussion | SPC | Adams, Claiborne, Humphreys, Issaquena, Jefferson, Sharkey and 2 more | 64 min |
| Mar 25, 12:05 AM CDT | Severe Thunderstorm Watch | SPC | Adams, Bolivar, Claiborne, Humphreys, Issaquena, Jefferson and 5 more | 5 hr |
| Mar 25, 1:05 AM CDT | Mesoscale Discussion | SPC | Benton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 4 more | 115 min |
| Mar 25, 3:06 AM CDT | Mesoscale Discussion | SPC | Adams, Claiborne, Copiah, Franklin, Hinds, Holmes and 10 more | 54 min |
| Mar 25, 12:08 PM CDT | Mesoscale Discussion | SPC | George, Hancock, Harrison, Jackson | 3 hr |
Nearby
Mesoscale Discussions in Mississippi, 2017Every mesoscale discussion in 2017
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.