Alert archive / Mississippi / Mesoscale Discussions in 2017
Mesoscale Discussion 280
The Storm Prediction Center issued this mesoscale discussion at Mar 9, 2017, 6:39 PM CST for 6 counties in Alabama; 23 counties in Mississippi. It was in force for 96 min.
The area
The outline as issued.
The facts
- Issued
- Mar 9, 2017, 6:39 PM CST (00:39 UTC)
- Expired
- Mar 9, 2017, 8:15 PM CST
- In force
- 96 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
All 29 counties
Fayette County, AL, Greene County, AL, Lamar County, AL, Marion County, AL, Pickens County, AL, Sumter County, AL, Chickasaw County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Covington County, MS, Itawamba County, MS, Jasper County, MS, Jones County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Scott County, MS, Smith County, MS, Wayne County, MS, Webster County, MS, Winston County, MS
The radar
The Columbus AFB radar (KGWX), 112 km from the middle of the area, began a volume at 00:42 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
Jackson, MS (KJAN), launched 00:00Z, 0.7 hours before the alert went out and 134 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
- 1195 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 1034 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- 93 m²/s²
- 0-3 km storm-relative helicity
- 177 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 3.6
The text
As transmitted.
378
ACUS11 KWNS 100039
SWOMCD
SPC MCD 100039
ALZ000-MSZ000-100215-
Mesoscale Discussion 0280
NWS Storm Prediction Center Norman OK
0639 PM CST Thu Mar 09 2017
Areas affected...Eastern MS and far western AL
Concerning...Severe potential...Watch unlikely
Valid 100039Z - 100215Z
Probability of Watch Issuance...5 percent
SUMMARY...Isolated hail is possible for the next hour or two within
the widely scattered thunderstorms across eastern MS and far western
AL.
DISCUSSION...Widely scattered thunderstorms have developed across
eastern MS and far northwest AL, likely as a result of forcing for
ascent associated with a subtle lead shortwave trough interacting
with the unstable airmass across the region. Low-level flow is weak
but strong flow in the mid and upper level is promoting effective
bulk shear around 40-50 kt, which is supportive of organized storms
and rotating updrafts. Given the weak low-level flow, the main
threat for the next hour or two will be large hail. The loss of
daytime heating and eastward progression of these storms into an
environment characterized by less low-level moisture and less
overall instability is expected to result in gradually waning storm
intensity. Widely scattered nature of the threat and expectation for
diminishing storm strength preclude the need for a watch.
..Mosier/Hart.. 03/10/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BMX...HUN...MOB...MEG...JAN...
LAT...LON 33728927 34508855 34358753 33038778 31668846 31508967
31978988 32668973 33728927SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 9, 10:42 PM CST | Mesoscale Discussion | SPC | Blount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 10 more | 63 min |
| Mar 9, 11:18 PM CST | Severe Thunderstorm Watch | SPC | Blount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 10 more | 4 hr |
| Mar 10, 12:50 AM CST | Mesoscale Discussion | SPC | Blount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 12 more | 85 min |
| Mar 10, 3:09 AM CST | Mesoscale Discussion | SPC | Chambers, Clay, Cleburne, Coosa, Randolph, Shelby and 3 more | 96 min |
Nearby
Mesoscale Discussions in Mississippi, 2017Mesoscale Discussions in Alabama, 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.