Weather Hits Southeast Colorado
Strong thunderstorms battered portions of the southeast plains
the first few weeks of August,
with numerous reports of hail, wind and tornadoes reported
to the Pueblo weather office.
Monday the 9th
The two busiest days of the week, in terms of the number of severe
thunderstorms, were Monday the 9th and Tuesday the 10th. Storms began
to form across the Eastern Plains early in the afternoon, with the
first warnings issued for Baca and Huerfano counties between 2:30 and
3:30 pm. A Tornado Warning was issued for El Paso county as numerous
reports of funnel clouds were called in, and a storm chaser later
reported a brief touchdown of a tornado in the vicinity of Calhan from
4:51 pm to 4:45 pm. Severe weather continued across El Paso
county later in the evening, with storms producing hail as large as
softballs in Ramah around 7:20 pm, and baseball sized hail reported
in Rush around 8:10 pm. The city of Colorado Springs was spared
the large hail, but did receive reports of hail up to an inch in diameter.
Next in line for severe storms was Pueblo county, as
strong thunderstorms began to rapidly develop along a boundary and ahead
of an upper shortwave around 6 pm. A severe thunderstorm warning was
issued for Pueblo county at 6:06 pm. By 6:37 pm, several reports of
golf ball sized hail were reported from Pueblo West.
The author was
caught in this hailstorm, receiving occasional golf ball sized
hail intermixed with copious amounts of near one inch hailstones and
very heavy rainfall. Other thunderstorms developed concurrently along the
St. Charles Mesa, bringing reports of 2 inch hail to this area. A flash
flood warning was issued for Pueblo county, as creeks and arroyos ran
bankfull, and streets turned into creeks in many areas as the one to
two inches of rainfall made its way to drainages.
Photos Courtesy D. Metze
23 warnings were issued by the Pueblo office this day - 17 severe
thunderstorm warnings, 5 tornado warnings, and one flash flood warning.
Fortunately, no damage has been reported so far from the brief tornado
near Calhan, and only funnel clouds have been reported with the other
tornado warnings. See the summary local storm report for
Tuesday the 10th
Round two occurred on the 10th, as the strongest in the series of cold
fronts made its way across the plains late in the evening. A few
warnings were issued early in the day for El Paso and Las Animas
counties ahead of the main coldfront. By 7 pm, the front had raced into
into El Paso County, bringing with it hail reports of up to 3 inches in
diameter, and wind gusts near 70 mph.
Large hail and strong winds
continued into Pueblo county, with a brief tornado touchdown reported
10 miles northwest of Onley Springs at 7:45 pm. As the front progressed
across the eastern plains, strong winds moved through Baca county after
10 pm, with another public report of a tornado 12 miles southeast of
Walsh at 10:38 pm. 25 warnings were issued this day, 5 of which
were Tornado Warnings, 2 Flash Flood warnings, and 18 severe thunderstorm
"It was by far the busiest 2 days in my 13 years as a NOAA
employee. The good news was we knew it was coming a day ahead of time
and we were prepared, " said lead forecaster Steve Hodanish, who worked
as a radar warning forecaster both days. (See the summary
local storm report for this day.)
The storms put on quite a show at sunset, as many photos came into the
office email of mammatus clouds and thunderstorms as they continued
across the plains.
Photos Courtesy T. Magnuson, Copyright 2004
Special thanks to all of our spotters who reported in during the severe
weather, as well as the hard work and dedication of Ham radio.
strong upper level trof was forming over the eastern US for this time
period. As a result, strong north to northwest winds in the upper
levels of the atmosphere aided in pushing a series of cooler high
pressure systems into our area from the north. You can see a
representation of this pattern in the figures below. The first chart
depicts whats going on higher up in the atmosphere. Notice the
northerly wind "barbs" over the Central US, and the strong upper trof
(the large "U" shaped feature) over the eastern US.
(Click to Enlarge)
second chart depicts what is occurring at the surface as high pressure
moves into the area from the north - note the southeast to east winds
across the Colorado Plains.
These two wind directions, north to
northwest aloft, and east to southeast at the surface, created strong
wind shear which is important in the formation of long lived severe
thunderstorms. Another important factor, instability, was also
strong over the area. Increased instability allows air to rise
and aids in the production of severe thunderstorms. Last but not
least, a series of upper level impulses moved across the state in the
northwest flow, acting as the "trigger" to start air rising and
therefore for strong storms to begin.
(Click to Enlarge)