Alert archive / Alabama / Flash Flood Warnings in 2017

Flash Flood Warning 22, NWS Birmingham, AL

July 24, 2017Blount County, Alabama

NWS Birmingham, AL issued this flash flood warning at Jul 24, 2017, 2:37 PM CDT for Blount County, Alabama. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 24, 2017, 2:37 PM CDT (19:37 UTC)
Expired: Jul 24, 2017, 5:30 PM CDT
In force: 3 hr
Issued by: NWS Birmingham, AL
Area: Storm-based polygon
Flood severity: None

County Blount County, AL

The radar

The Birmingham radar (KBMX), 91 km from the middle of the area, began a volume at 19:36 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 was reported inside it

Time	Report	Where	Remark
Jul 24, 2:38 PM CDT	FLASH FLOOD	Oneonta, AL	SEVERAL STREETS IN DOWNTOWN ONEONTA UNDER WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 7.6 hours before the alert went out and 90 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: 1296 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 717 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 5 m²/s²
0-3 km storm-relative helicity: 17 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

895 
WGUS54 KBMX 241937
FFWBMX
ALC009-242230-
/O.NEW.KBMX.FF.W.0022.170724T1937Z-170724T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Birmingham AL
237 PM CDT MON JUL 24 2017

The National Weather Service in Birmingham has issued a

* Flash Flood Warning for...
  East central Blount County in Alabama...

* Until 530 PM CDT

* At 236 PM CDT, emergency management reported flooded roads in the 
  Oneonta area. 

* Some locations that will experience flooding include...
  Oneonta, Cleveland, Allgood, Fairview, Rosa, Highland Lake and
  Easley.

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.

&&

LAT...LON 3400 8639 3389 8641 3388 8660 3399 8657

$$

32/Davis

The office that day

Everything else NWS Birmingham, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 24, 1:32 PM CDT	Special Weather Statement	BMX	St. Clair	28 min
Jul 24, 1:37 PM CDT	Areal Flood Advisory	BMX	Jefferson	113 min
Jul 24, 2:01 PM CDT	Areal Flood Advisory	BMX	St. Clair	3 hr
Jul 24, 2:05 PM CDT	Special Weather Statement	BMX	Jefferson	25 min
Jul 24, 2:22 PM CDT	Special Weather Statement	BMX	Shelby	23 min
Jul 24, 2:33 PM CDT	Flash Flood Warning	BMX	Jefferson	3 hr
Jul 24, 2:42 PM CDT	Areal Flood Advisory	BMX	Jefferson	3 hr
Jul 24, 2:54 PM CDT	Flash Flood Warning	BMX	Jefferson	3 hr
Jul 24, 3:17 PM CDT	Areal Flood Advisory	BMX	Clay	3 hr
Jul 24, 3:30 PM CDT	Special Weather Statement	BMX	Cullman	30 min
Jul 24, 3:58 PM CDT	River Flood Warning	BMX	Jefferson	15 hr
Jul 24, 4:04 PM CDT	Special Weather Statement	BMX	Macon	26 min
Jul 24, 4:57 PM CDT	Areal Flood Advisory	BMX	Clay	3 hr
Jul 24, 5:20 PM CDT	Areal Flood Warning	BMX	Jefferson	3 hr
Jul 24, 6:44 PM CDT	Special Weather Statement	BMX	Fayette, Lamar	31 min

Nearby

Flash Flood Warnings in Alabama, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.