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Severe Weather Outbreak of May 30, 2004
Severe weather reports from May 29 |
Severe weather reports from May 30 |
Severe Weather Outlook, issued 3 pm May 30 |
Significant severe weather outbreaks occurred across
the nation Memorial Day weekend. This had been expected for a number
of days. The outbreak on May 29 was across the Plains, and across
the Midwest on May 30.
In Illinois, there were two periods of severe weather
on May 30. The first outbreak was during the morning, covering
generally the northern half of the state. The second outbreak
occurred during the afternoon, affecting much of the state.
In the Lincoln NWS
county warning area, there were several dozen reports of severe
weather (tornadoes, wind damage or gusts above 58 mph, or hail at least
3/4 inch in diameter). Three tornadoes occurred. One was a
brief touchdown near Green Valley during the morning. The other two,
near Lincoln and Secor, are detailed below.
Woodford County(click image to enlarge)
On Memorial Day, the NWS and ESDA conducted a damage survey of
eastern Woodford County
A small tornado touched down around 5:05 pm, about
1.5 miles southeast of Eureka. The tornado was on the ground for 9
miles, lifting 2 miles northeast of Secor around 5:25 pm. The
maximum width was about 75 yards.
At a farm 3 miles west-southwest of Secor, the
tornado destroyed 2 farm buildings, one grain bin, and a corn crib.
As it tracked east-northeast, it damaged trees, destroyed two old farm
buildings, moved hay bales, and threw a medium size gas tank 1/2 mile.
This tornado was ranked F1 on the Fujita scale, with
estimated wind speeds around 100 mph.
Logan County (click image to enlarge)
On Memorial Day, NWS personnel also conducted a storm
damage survey in areas just south of Lincoln.
A small tornado briefly touched down around 5:57 pm
in the Morningside mobile home park about 2 miles south of downtown Lincoln.
This tornado was about 40 yards wide, traveled about a tenth of a mile,
and was of intensity F0 (with winds around 70 mph). Similar strength
straight-line winds caused damage in the surrounding area. The
tornado moved through a trailer park, damaging 28 of the 36 trailers;
three others were demolished. Three people were injured.
At this time, a wind gust of 57 mph was measured at
the NWS office on the south side of the airport grounds.
Weather and
Radar Images: (click to enlarge)
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Surface weather observations for Illinois and
nearby areas at 7 am. Convective Available Potential Energy
(CAPE) is indicated by the shaded areas (blue areas range from 1000
to 2000 J/kg), and Lifted Index values are in the blue lines. |
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The 7 am upper-air observation for Lincoln.
At this location, CAPE value is 1935 J/kg, with a lifted index of -6.8. |
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The surface weather map at 1 pm. Areas
of northern Illinois had received strong to severe thunderstorms
earlier, and the map indicates the cooler air in place over northern
parts of the state as a result. Across the south, CAPE values
were surpassing 3,000 J/kg, and were over 4,500 J/kg in the red and
pink areas. |
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A special upper-air observation was taken at
Lincoln at 1 pm. Conditions had become a bit more stable at
this location, due to earlier thunderstorms. |
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By 4 pm, skies had cleared somewhat over much
of Illinois, helping to refuel the atmosphere for the oncoming
storms. CAPE values had surpassed 5,000 J/kg in some areas,
with lifted index values of -12. |
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Another special upper-air observation was
taken at 4 pm. This indicated the air was recovering from the
earlier storms and clouds, to help fuel the new storms. |
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The Lincoln radar image from 4:16 pm showed
the main line of severe thunderstorms moving in from Missouri,
especially in the area from Galesburg to Quincy. Isolated
storms were developing ahead of the main line. |
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In this radar image from 4:46 pm, one of the
isolated storms was beginning to indicate a hook-shape feature in
northern Tazewell County, indicating potential tornado development.
Funnel clouds were reported in this area, but no tornado was on the
ground at the time. |
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The Storm Relative Motion image from 4:51 pm
shows 3 angles of this storm; from top left, 1.5 degrees elevation,
2.4 degrees, and 3.4 degrees. Rotation is indicated east of
Washington, where the red and green shades come together near the
Woodford County line. (The radar site is located south of this location.) |
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At 4:56 pm, the potentially tornadic storm
was crossing the Woodford/Tazewell County line between Washington and Eureka. |
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At 5:06 pm, the hook echo was persisting as
the storm was in the Eureka area. A tornado touched down about
a mile southeast of Eureka at 5:05 pm. |
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The storm was lifting northeast across
Woodford County at 5:16 pm. A tornado is still on the
ground southwest of Secor. |
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By 5:26 pm, the tornado had dissipated at a
point 2 miles northeast of Secor. Another round of storms in
the lower left part of the picture would move over Woodford County a
little later. |
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At 5:15 pm, radar showed the main line of
storms approaching the Illinois River, while storms were increasing
across south central Illinois along the I-70 corridor. |
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This radar image of Logan County was taken at
5:59 pm. The radar site is in the middle of the black hole in
the center of the picture. Much of Logan County was covered by
storms, except for the southwest quarter. |
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The Storm Relative Motion image from 5:59 pm
shows a small area of high wind speeds (greater than 65 mph) in the
pink shades just south of the radar. This is in the area where
the tornado touched down in the Morningside mobile home park.
At this time, a wind gust of 57 mph occurred at the NWS office. |
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By 6:30 pm, the storms were concentrated in
areas east of the I-55 corridor. |
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