Alert archive / Alabama / Flash Flood Warnings in 2013

Flash Flood Warning 20, NWS Huntsville, AL

July 7, 2013Marshall County, Alabama

NWS Huntsville, AL issued this flash flood warning at Jul 7, 2013, 5:49 PM CDT for Marshall County, Alabama. 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 counties it named.

The facts

Issued: Jul 7, 2013, 5:49 PM CDT (22:49 UTC)
Expired: Jul 7, 2013, 8:45 PM CDT
In force: 3 hr
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

County Marshall County, AL

The radar

The Northeast Alabama radar (KHTX), 66 km from the middle of the area, began a volume at 22:49 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, 10.8 hours before the alert went out and 200 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: 98 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 552 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Huntsville, AL wrote its last area forecast discussion before this flash flood warning went out at Jul 7, 2:02 PM CDT, 3 hours 47 minutes earlier.

Area forecast discussion, Jul 7, 2:02 PM CDT, 3 hours 47 minutes before

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Hazardous weather outlook, Jul 7, 12:27 PM CDT, 5 hours 22 minutes before

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In the hours before

Special weather statement, Jul 7, 5:03 PM CDT, 46 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HUNTSVILLE AL
503 PM CDT SUN JUL 7 2013

ALZ006>008-072245-
MARSHALL AL-MORGAN AL-MADISON AL-
503 PM CDT SUN JUL 7 2013

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN MARSHALL...EASTERN
MORGAN AND SOUTHEASTERN MADISON COUNTIES UNTIL 545 PM CDT...

AT 501 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED AN
AREA OF VERY HEAVY RAINFALL 7 MILES SOUTHWEST OF NEW HOPE...OR 11
MILES NORTH OF ARAB...MOVING NORTHEAST AT 10 MPH.

RAINFALL TOTALS OF HALF AN INCH TO AN INCH ARE POSSIBLE THROUGH 6 PM
CDT.

LOCATIONS IMPACTED INCLUDE...
NEW HOPE...OWENS CROSSROADS...HEBRON...AND GRANT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

HEAVY RAINFALL MAY LEAD TO MINOR FLOODING ON ROADS AND IN LOW LYING
AREAS. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS.

&&

LAT...LON 3446 8618 3442 8653 3452 8666 3474 8641
      3468 8636 3463 8636 3460 8632 3460 8630
TIME...MOT...LOC 2156Z 237DEG 5KT 3449 8653

12

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 1:48 AM CDT	River Flood Warning	HUN	Madison, Marshall, Morgan	6 days
Jul 7, 5:03 PM CDT	Special Weather Statement	HUN	Madison	42 min

Nearby

Flash Flood Warnings in Alabama, 2013 Every flash flood warning in 2013

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.