Alert archive / Georgia / Flash Flood Warnings in 2019

Flash Flood Warning 29, NWS Atlanta, GA

August 21, 2019White County, Georgia

NWS Atlanta, GA issued this flash flood warning at Aug 21, 2019, 4:23 PM EDT for White County, Georgia. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 21, 2019, 4:23 PM EDT (20:23 UTC)
Expired
Aug 21, 2019, 10:15 PM EDT
In force
6 hr
Issued by
NWS Atlanta, GA
Area
Storm-based polygon
Flood severity
None

County White County, GA

The radar

The Greer radar (KGSP), 135 km from the middle of the area, began a volume at 20:22 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 8.4 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.

Skew-T log-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 12:00Z on 2019-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 140 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 12:00Z on 2019-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
140 J/kg
Mixed-layer CIN
-188 J/kg
Mixed-layer LCL
988 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

449 
WGUS52 KFFC 212023
FFWFFC
GAC311-220215-
/O.NEW.KFFC.FF.W.0029.190821T2023Z-190822T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Peachtree City GA
423 PM EDT Wed Aug 21 2019

The National Weather Service in Peachtree City has issued a

* Flash Flood Warning for...
  Northeastern White County in northeastern Georgia...

* Until 1015 PM EDT.

* At 422 PM EDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to three inches of rain have 
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Helen, Unicoi State Park, Anna Ruby Falls, Smithgall Woods
  Conservation Are, Robertstown and Sautee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3479 8368 3477 8365 3477 8364 3476 8363
      3473 8362 3472 8364 3469 8364 3466 8366
      3469 8378 3475 8379 3480 8376 3480 8373
      3479 8370

$$

The office that day

Everything else NWS Atlanta, GA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 20, 8:36 PM EDTSpecial Weather StatementFFCWilkes24 min
Aug 21, 1:53 PM EDTSpecial Weather StatementFFCWheeler37 min
Aug 21, 3:48 PM EDTSpecial Weather StatementFFCJohnson27 min
Aug 21, 4:04 PM EDTSpecial Weather StatementFFCWhite41 min
Aug 21, 4:16 PM EDTSpecial Weather StatementFFCEmanuel29 min
Aug 21, 4:28 PM EDTSevere Thunderstorm WarningFFCEmanuel, Johnson30 min
Aug 21, 5:28 PM EDTSpecial Weather StatementFFCPulaski32 min

Nearby

Flash Flood Warnings in Georgia, 2019Every flash flood warning in 2019

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.