Archive for August, 2009

Heavy Rainfall

Friday, August 28th, 2009

Thunderstorms dumped over 2 inches of rain last night. We ended up with 2.16 as measured by our CoCoRaHS rain gauge. A cool down is in store for the weekend with expected temperatures more autumnal than summer-like.

Active Weather August 19

Monday, August 24th, 2009

Severe weather moved through August 19th as a line of severe storms raced across northern Illinois into northwest Indiana. The damaging winds fortunately missed us but damage occurred as close as 4 miles from our location.  Here is a brief synopsis of the conditions leading up to the event courtesy of the National Weather Service Office in Lincoln, IL:

Weak high pressure moved into northern Illinois on Tuesday, August 18th, allowing slightly cooler and drier conditions to settle southward into central Illinois. As this high moved off to the east, the warm and very humid airmass that had been temporarily suppressed southward into the Ohio River Valley began making its northward return on August 19th. Scattered showers and thunderstorms began developing along the advancing warm front around midday, then became much more numerous during the afternoon, as an upper-level disturbance approached from the west. In addition, a Mesoscale Convective Vortex (MCV), associated with the remnants of a large thunderstorm complex across Kansas and Oklahoma during the previous night, tracked into central Illinois. This feature provided an extra kick, which enhanced lift and created vigorous updrafts within the developing thunderstorm cells.

The following image depicts the area covered by one of the many severe thunderstorm warnings issued that evening. A tornado warning was also issued for portions of Grundy county just a few miles south. Tornadoes were in fact confirmed in Lily Lake and near Watseka Illinois as well as Chesterton Indiana.

Radar and Severe Thunderstorm Warning Polygon Aug 19 2009

Radar and Severe Thunderstorm Warning Polygon Aug 19 2009

The above image provided by a great web resource IEM Cow.

IEM

Iowa Environmental Mesonet
Iowa State University Department of Agronomy

July Climate Summary

Saturday, August 1st, 2009

No surprise to anyone, July was very cool with an average temperature of only 69.1°. The normal is around 74°. We had 17 days when the max temperature was 80° or higher but it never reached 90° during the month…quite unusual. Precipitation was once again above normal with a total of 5.27 inches.

Average temperature     = 69.1°F
Average humidity        = 81%
Average dewpoint        = 62.4°F
Average barometer       = 29.931 in.
Average windspeed       = 1.7 mph
Average gustspeed       = 3.6 mph
Average direction       = 282° (WNW)
Rainfall for month      = 5.27 in.
Maximum rain per minute = 0.140 in on day 28 at time 18:16
Maximum temperature     = 84.9°F on day 15 at time 15:52
Minimum temperature     = 52.8°F on day 14 at time 05:01
Maximum humidity        = 100% on day 29 at time 06:34
Minimum humidity        = 46% on day 12 at time 14:52
Maximum pressure        = 30.16 in. on day 10 at time 12:19
Minimum pressure        = 29.65 in. on day 25 at time 02:54
Maximum windspeed       = 15.0 mph from 158°(SSE) on day 28 at time 18:16
Maximum gust speed      = 34.5 mph from 180°( S ) on day 28 at time 18:15
Maximum heat index      = 91.0°F on day 15 at time 15:44
Avg daily max temp :78.6°F
Avg daily min temp :59.7°F
Total windrun = 1284.4miles