Alert archive / Alabama / Flash Flood Warnings in 2017

Flash Flood Warning 30, NWS Birmingham, AL

August 10, 2017Blount County, St. Clair County, Alabama

NWS Birmingham, AL issued this flash flood warning at Aug 10, 2017, 7:16 PM CDT for Blount County, St. Clair County, Alabama. It was in force for 89 min. 5 reports 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: Aug 10, 2017, 7:16 PM CDT (00:16 UTC)
Expired: Aug 10, 2017, 8:45 PM CDT
In force: 89 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon
Flood severity: None

Counties Blount County, AL, St. Clair County, AL

The radar

The Birmingham radar (KBMX), 77 km from the middle of the area, began a volume at 00:18 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
Aug 10, 7:45 PM CDT	FLASH FLOOD	1 E Highland Lake, AL	NUMEROUS ROADS WITHIN SUGARLAND LAKE IMPASSABLE DUE TO FLOODING.
Aug 10, 7:45 PM CDT	FLASH FLOOD	1 Ene Highland Lake, AL	NUMEROUS ROADS WITHIN SUGARLAND LAKE IMPASSABLE DUE TO FLOODING.
Aug 10, 7:45 PM CDT	FLASH FLOOD	Springville, AL	SEVERAL ROADS FLOODED IN DOWNTOWN SPRINGVILLE.
Aug 10, 7:50 PM CDT	FLASH FLOOD	1 Ene Springville, AL	FLOODING ALONG PORTIONS OF MAIN ST IN SPRINGVILLE. LAW ENFORCEMENT ON SCENE. VIDEO VIA SOCIAL MEDIA.
Aug 10, 7:50 PM CDT	FLASH FLOOD	2 Ene Springville, AL	FLOODING ALONG PORTIONS OF MAIN ST IN SPRINGVILLE. LAW ENFORCEMENT ON SCENE. VIDEO VIA SOCIAL MEDIA.

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 00:00Z, 0.3 hours before the alert went out and 77 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: 897 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 1203 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

As transmitted.

191 
WGUS54 KBMX 110016
FFWBMX
ALC009-115-110145-
/O.NEW.KBMX.FF.W.0030.170811T0016Z-170811T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Birmingham AL
716 PM CDT THU AUG 10 2017

The National Weather Service in Birmingham has issued a

* Flash Flood Warning for...
  Southeastern Blount County in central Alabama...
  Northwestern St. Clair County in central Alabama...

* Until 845 PM CDT

* At 716 PM CDT, the public reported flash flooding across the warned
  area. Up to two inches of rain have already fallen. Flash flooding
  is already occurring.

* Some locations that will experience flooding include...
  Oneonta, Springville, Margaret, Argo, Ashville, Allgood, Highland
  Lake, Whitney Junction, St. Clair Springs, Holly Springs, Caldwell,
  Horse Pens Forty and I 59 Rest Areas At Oneonta.

Additional rainfall amounts of one to two 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.

&&

LAT...LON 3396 8635 3394 8637 3394 8633 3387 8624
      3367 8648 3371 8653 3372 8653 3372 8654
      3373 8653 3374 8654 3376 8654 3377 8658
      3381 8663 3400 8641

$$

25/Owen

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 7:28 PM CDT	Areal Flood Advisory	BMX	Fayette, Tuscaloosa	3 hr
Aug 10, 7:31 PM CDT	Areal Flood Advisory	BMX	Chambers, Clay, Randolph, Tallapoosa	3 hr
Aug 10, 7:52 PM CDT	Areal Flood Advisory	BMX	Barbour, Russell	3 hr
Aug 10, 7:58 PM CDT	Flash Flood Warning	BMX	Chambers, Clay, Randolph	5 hr
Aug 10, 9:13 PM CDT	Areal Flood Advisory	BMX	Winston	2 hr
Aug 10, 9:38 PM CDT	Areal Flood Advisory	BMX	Blount, Jefferson, St. Clair, Shelby, Talladega	3 hr
Aug 10, 10:13 PM CDT	Areal Flood Advisory	BMX	Calhoun, Cherokee, Cleburne, Etowah, Randolph, St. Clair	2 hr
Aug 10, 10:22 PM CDT	Flash Flood Warning	BMX	Blount, Jefferson	4 hr
Aug 11, 3:10 AM CDT	Flash Flood Watch	BMX	Autauga, Barbour, Blount, Bullock, Calhoun, Chambers and 19 more	16 hr
Aug 11, 4:55 AM CDT	Dense Fog Advisory	BMX	Autauga, Barbour, Bibb, Bullock, Chambers, Chilton and 19 more	3 hr

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.