Alert archive / Georgia / Flash Flood Warnings in 2017

Flash Flood Warning 4, NWS Jacksonville, FL

July 27, 2017Glynn County, Georgia

NWS Jacksonville, FL issued this flash flood warning at Jul 27, 2017, 9:29 AM EDT for Glynn County, Georgia. It was in force for 3 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: Jul 27, 2017, 9:29 AM EDT (13:29 UTC)
Expired: Jul 27, 2017, 12:00 PM EDT
In force: 3 hr
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Flood severity: None

County Glynn County, GA

The radar

The Jacksonville radar (KJAX), 70 km from the middle of the area, began a volume at 13:32 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

Jacksonville, FL (KJAX), launched 12:00Z, 1.5 hours before the alert went out and 68 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1688 J/kg
Mixed-layer CIN: -22 J/kg
Mixed-layer LCL: 639 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -62 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

091 
WGUS52 KJAX 271329
FFWJAX
GAC127-271600-
/O.NEW.KJAX.FF.W.0004.170727T1329Z-170727T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Jacksonville FL
929 AM EDT THU JUL 27 2017

The National Weather Service in Jacksonville has issued a

* Flash Flood Warning for...
  South central Glynn County in southeastern Georgia...

* Until noon EDT

* At 928 AM EDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain has
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Brunswick, St. Simons Island and Country Club Estates. 

Additional rainfall amounts of 2 to 4 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3104 8145 3106 8153 3107 8153 3107 8155
      3108 8154 3108 8155 3107 8156 3108 8156
      3124 8147 3119 8139

$$

HESS

2 follow-up statements

448 
WGUS72 KJAX 271402
FFSJAX

Flash Flood Statement
National Weather Service Jacksonville FL
1002 AM EDT THU JUL 27 2017

GAC127-271600-
/O.CON.KJAX.FF.W.0004.000000T0000Z-170727T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Glynn GA-
1002 AM EDT THU JUL 27 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON EDT FOR SOUTH
CENTRAL GLYNN COUNTY...

At 1002 AM EDT, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. 3 to 5 inches of rain has fallen. 
Flash flooding is expected.

Some locations that will experience flooding include...
Brunswick, St. Simons Island and Country Club Estates. 

Additional rainfall amounts of 2 to 3 inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3104 8145 3106 8153 3107 8153 3107 8155
      3108 8154 3108 8155 3107 8156 3108 8156
      3124 8147 3119 8139

$$

HESS

623 
WGUS72 KJAX 271433
FFSJAX

Flash Flood Statement
National Weather Service Jacksonville FL
1033 AM EDT THU JUL 27 2017

GAC127-271442-
/O.CAN.KJAX.FF.W.0004.000000T0000Z-170727T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Glynn GA-
1033 AM EDT THU JUL 27 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL GLYNN COUNTY IS
CANCELLED...

Flash Flooding is no longer expected at this time, although areal 
flooding of low lying areas and roadways is still possible. Please 
continue to heed any remaining road closures.

LAT...LON 3104 8145 3106 8153 3107 8153 3107 8155
      3108 8154 3108 8155 3107 8156 3108 8156
      3124 8147 3119 8139

$$

HESS

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 27, 7:14 AM EDT	Areal Flood Advisory	JAX	Brantley, Camden, Glynn	3 hr
Jul 27, 7:40 AM EDT	Areal Flood Warning	JAX	Brantley, Camden, Glynn	3 hr
Jul 27, 8:36 AM EDT	Areal Flood Advisory	JAX	Glynn	114 min
Jul 27, 9:16 AM EDT	Areal Flood Advisory	JAX	Camden, Glynn	119 min
Jul 27, 10:12 AM EDT	Areal Flood Warning	JAX	Camden, Glynn	3 hr
Jul 27, 1:29 PM EDT	Areal Flood Advisory	JAX	Camden	2 hr

Nearby

Flash Flood Warnings in Georgia, 2017 Every flash flood warning 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.