National Weather Service United States Department of Commerce

Above Normal Temperatures, Strong Thunderstorms, Tropical Development Being Monitored

Well above normal temperatures are forecast to shift from the northern Plains through the Northeast U.S. over the long holiday weekend. A few strong to severe thunderstorm will be possible as well along with a potential for excessive rainfall. A tropical or subtropical depression could form off the Southeast U.S. coast over the weekend while drifting northward to northeastward. Read More >

Additional Information About Storm Reports Received Can Be Viewed Here.


Tornado Surveys Completed 
(Click on an entry in the 1st column to see an official storm survey summary and under the last column for more detailed

tornado track location/data)


 

 Detailed Summary
Link
EF Scale/Max Wind Speed (mph) 

Injuries/
Fatalities

Path Length (Miles)

Path Width (Yards) 

Starting Lat/.Long

Ending Lat/.Long

Track Images/Files

EF-1

90 MPH 

0/0

 6.6

300

 34.6146/ -86.6387

 34.6651/ -86.5405

KMZ - Points 

EF-1

105 MPH

0/0

 1.33 

75

 34.7017/ -86.5049

 34.7148/ -86.4876

KMZ - Points 

 

Summary:

On April 11th, a line of heavy showers and scattered thunderstorms extended just ahead of a cold front at 10 am (see below, left).  As the late morning and early afternoon hours progressed, breaks in cloud cover increased instability as the cold front pushed east into northwestern Alabama. This line quickly intensified shortly after 2 pm, as it moved into north central and eastern portions of Alabama.  Scattered severe thunderstorms occurred along the line between 2 pm and 7 pm, creating straight line wind damage,small hail, and two weak tornadoes in the Huntsville area.  The image below on the right shows the Day 1 Severe Weather Outlook from the Storm Prediction Center, which was issued at 8 am on April the 11th. Overlayed are severe weather reports which were received on the 11th. Click on either image below to see a more detailed and larger image. 

 

Surface Analysis at 10 AM on 04/11/2013 Storm Prediction Center Day 1 Outlook (8 AM) 

 

 

The slow movement of this line also produced some heavier rainfall.  Below is a image of rainfall totals from 7 am on Thursday (April 11th) through 7 am Friday (April 12th). Most of the heavier rainfall fell in a short 2 to 4 hour period.