Alert archive / Georgia / Mesoscale Discussions in 2017
Mesoscale Discussion 91
The Storm Prediction Center issued this mesoscale discussion at Jan 21, 2017, 3:06 PM EST for 26 counties in Georgia; 12 counties in South Carolina. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Jan 21, 2017, 3:06 PM EST (20:06 UTC)
- Expired
- Jan 21, 2017, 4:30 PM EST
- In force
- 84 min
- Issued by
- the Storm Prediction Center
All 38 counties
Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Jeff Davis County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Pierce County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Ware County, GA, Wayne County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Calhoun County, SC, Colleton County, SC, Dorchester County, SC, Edgefield County, SC, Hampton County, SC, Jasper County, SC, Orangeburg County, SC
The radar
The Charleston,SC radar (KCLX), 70 km from the middle of the area, began a volume at 20:06 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
Charleston AFB, SC (KCHS), launched 12:00Z, 8.1 hours before the alert went out and 171 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
- 138 J/kg
- Mixed-layer CIN
- -38 J/kg
- Mixed-layer LCL
- 581 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 37 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
535
ACUS11 KWNS 212006
SWOMCD
SPC MCD 212006
SCZ000-GAZ000-212130-
Mesoscale Discussion 0091
NWS Storm Prediction Center Norman OK
0206 PM CST Sat Jan 21 2017
Areas affected...portions of southeast GA into southeast SC
Concerning...Tornado Watch 13...
Valid 212006Z - 212130Z
The severe weather threat for Tornado Watch 13 continues.
SUMMARY...The tornado and damaging wind threat will continue across
WW 13 this afternoon. A greater tornado threat may be developing
across portions southeast GA into southeast SC in the vicinity of
the Savannah River Valley and coastal plain.
DISCUSSION...There has been an increase in coverage and intensity
during the last hour or so of low level rotation signatures near the
Savannah River. Latest surface analysis and investigation of
regional VWP data shows that some backing of low level winds has
enhance 0-1km shear in this vicinity. This area, indicated by the
black hatched area in the MCD graphic, may have a greater tornado
and widespread wind damage threat than further south along the ling
where low level flow has veered. That aside, damaging winds also
will still be possible within the entire watch area. Some local
aerial extension of the watch my be necessary over parts of SC and
far southeast GA and trends will continue to be monitored closely.
..Leitman.. 01/21/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...CHS...CAE...JAX...FFC...TAE...
LAT...LON 32178231 32638201 33088208 33608223 33828202 33868120
33868098 33678039 33098001 32518013 31668082 31018145
30858181 30808229 30888301 31408311 31868273 32178231SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jan 21, 8:41 AM EST | Mesoscale Discussion | SPC | Baker, Baldwin, Ben Hill, Berrien, Bibb, Bleckley and 53 more | 94 min |
| Jan 21, 9:04 AM EST | Tornado Watch | SPC | Baker, Baldwin, Ben Hill, Berrien, Bibb, Bleckley and 70 more | 6 hr |
| Jan 21, 10:19 AM EST | Mesoscale Discussion | SPC | Baker, Baldwin, Ben Hill, Bibb, Bleckley, Butts and 50 more | 86 min |
| Jan 21, 1:06 PM EST | Mesoscale Discussion | SPC | Appling, Atkinson, Bacon, Baker, Baldwin, Ben Hill and 73 more | 114 min |
| Jan 21, 1:51 PM EST | Tornado Watch | SPC | Appling, Atkinson, Bacon, Bryan, Bulloch, Burke and 19 more | 4 hr |
| Jan 21, 2:12 PM EST | Tornado Watch | SPC | Berrien, Brooks, Colquitt, Cook, Grady, Lanier and 2 more | 5 hr |
Nearby
Mesoscale Discussions in Georgia, 2017Mesoscale Discussions in South Carolina, 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.