Alert archive / Georgia / Tornado Watches in 2009
Tornado Watch 177
The Storm Prediction Center issued this tornado watch at Apr 20, 2009, 12:42 AM EDT for 25 counties in Georgia; 8 counties in North Carolina; 17 counties in South Carolina. It was in force for 5 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 20, 2009, 12:42 AM EDT (04:42 UTC)
- Expired
- Apr 20, 2009, 6:00 AM EDT
- In force
- 5 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 50 counties
Baldwin County, GA, Banks County, GA, Clarke County, GA, Columbia County, GA, Elbert County, GA, Franklin County, GA, Greene County, GA, Habersham County, GA, Hancock County, GA, Hart County, GA, Jackson County, GA, Jones County, GA, Lincoln County, GA, Madison County, GA, McDuffie County, GA, Morgan County, GA, Oconee County, GA, Oglethorpe County, GA, Putnam County, GA, Richmond County, GA, Stephens County, GA, Taliaferro County, GA, Warren County, GA, White County, GA, Wilkes County, GA, Catawba County, NC, Cleveland County, NC, Gaston County, NC, Henderson County, NC, Lincoln County, NC, Mecklenburg County, NC, Polk County, NC, Rutherford County, NC, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Edgefield County, SC, Fairfield County, SC, Greenville County, SC, Greenwood County, SC, Laurens County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Pickens County, SC, Saluda County, SC, Spartanburg County, SC, Union County, SC, York County, SC
The radar
The Greer radar (KGSP), 76 km from the middle of the area, began a volume at 04:44 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 20%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 20, 12:56 AM EDT | Severe Thunderstorm Warning | GSP | Oconee | 45 min |
| Apr 20, 1:19 AM EDT | Severe Thunderstorm Warning | GSP | Anderson, Pickens | 42 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 4.7 hours before the alert went out and 193 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
- 182 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 1004 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 212 m²/s²
- 0-3 km storm-relative helicity
- 248 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 19, 8:51 PM EDT | Tornado Watch | SPC | Barrow, Bartow, Butts, Carroll, Catoosa, Chattooga and 42 more | 6 hr |
| Apr 19, 11:21 PM EDT | Mesoscale Discussion | SPC | Barrow, Bartow, Butts, Carroll, Chattooga, Cherokee and 35 more | 84 min |
| Apr 20, 12:20 AM EDT | Mesoscale Discussion | SPC | Elbert, Franklin, Greene, Hart, Lincoln, McDuffie and 4 more | 55 min |
| Apr 20, 1:22 AM EDT | Mesoscale Discussion | SPC | Barrow, Bibb, Butts, Chattahoochee, Clayton, Coweta and 26 more | 53 min |
| Apr 20, 2:52 PM EDT | Mesoscale Discussion | SPC | Chatham | 83 min |
| Apr 20, 3:16 PM EDT | Severe Thunderstorm Watch | SPC | Bryan, Chatham, Effingham, Liberty, Long, McIntosh | 6 hr |
| Apr 20, 4:55 PM EDT | Mesoscale Discussion | SPC | Bryan, Bulloch, Chatham, Effingham, Evans, Liberty and 1 more | 95 min |
| Apr 20, 7:36 PM EDT | Mesoscale Discussion | SPC | Chatham | 84 min |
| Apr 20, 12:22 PM EDT | Mesoscale Discussion | SPC | Beaufort, Bertie, Camden, Chowan, Craven, Edgecombe and 19 more | 83 min |
| Apr 20, 2:09 PM EDT | Mesoscale Discussion | SPC | Alamance, Caswell, Durham, Edgecombe, Franklin, Granville and 11 more | 2 hr |
| Apr 20, 2:50 PM EDT | Tornado Watch | SPC | Alamance, Bertie, Camden, Caswell, Chatham, Chowan and 18 more | 7 hr |
| Apr 20, 4:57 PM EDT | Mesoscale Discussion | SPC | Alamance, Camden, Caswell, Chatham, Chowan, Durham and 13 more | 93 min |
| Apr 20, 7:15 PM EDT | Mesoscale Discussion | SPC | Gates, Halifax, Hertford, Northampton, Warren | 90 min |
Nearby
Tornado Watches in Georgia, 2009Tornado Watches in South Carolina, 2009Tornado Watches in North Carolina, 2009Every tornado watch 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.