Midwest Weekly Highlights - July 18 - 24, 2007

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Overview ...

The period of July 18 - 24 got off to an active start as a slow moving frontal boundary (Figure 1) triggered thunderstorms and severe weather in the central portion of the Midwest (Figure 2). High pressure in the wake of the front (Figure 3) then brought unseasonal cool and dry conditions into the area, with some parts of Illinois, Indiana and Ohio at up to seven degrees below average for the week (Figure 4). Warmer air built back into the region late and the far northwest ended with record warmth, including International Falls, MN, which tied a record high temperature on Tuesday, July 24.
 

Rain Rain Go Away ...

Triggered by storms on the 17th and 18th (Figure 5), flash flooding occurred in areas of Iowa and Wisconsin on Wednesday, July 18th. Storm totals included an unofficial amount of 9.47 inches in McGregor, IA (Clayton County) and in Bagley, WI (Grant County), almost seven inches of rain fell in just four hours. The town was flooded when debris plugged a major drainage area and sent water into Bagley instead of allowing it into rush to the nearby Mississippi River. Fifty people had to be rescued from their homes by boat and damage occurred to most of the 400 homes in the village - 51 sustained major damage, 100 had water in their basements and 250 had backed-up sewers. Railroad tracks for the Burlington Northern Santa Fe Railroad were also washed out. Damage estimates are over one million dollars.

Iowa continued its streak of severe weather as more storms struck the state on the evening of July 18th (SPC storm reports). An EF-1 torndao was confirmed to have touched down in Linn County near Paris, IA, destroying a farm shed and damaging local crops and trees. In nearby Jones County, the storms struck during the opening night of the county fair but fortunately organizers were able to clear out most of the crowd before their arrival. Dubuque and Sioux City also set precipitation records with the system.

Additional storms hit Michigan on Wednesday, July 18 and Thursday, July 19. In Midland County, straight line winds from a downburst pushed trees from the ground - leaving gaping holes and bare roots. Local homes sustained heavy damage as some trees as tall as 50 to 60 feet tall were uprooted and local fire departments were kept busy responding to calls from fires caused by downed power lines. The local high school's baseball field visitor dugout and fencing were damaged from winds that ranged from 60 - 80 miles per hour. Quarter- to golf ball-size hail was also reported.
 

And Come to Again Another Day!

While some of the above areas coped with an excess of moisture, other parts of the Midwest continued dessicate with no precipitation in sight. The US Drought Monitor expanded its abnormally dry rating into northwestern Missouri and south-central Iowa and expanded the moderate/severe drought characterization in Wisconsin and Minnesota. Central Indiana is also in moderate drought and east central Indiana is categorized as D2 - severe drought. Most of Ohio and Kentucky received timely rains that helped to halt intensification of the drought, but long term moisture concerns still exist in both areas (Figure 6).

In contrast to the flooding series of rains that battered the eastern part of the state mid-month, western Iowa is experiencing moderate drought conditions and to the very far northwest, severe drought. At Sioux Center, IA (Sioux County), they have had 31 consecutive days without measurable rainfall. To the south, in Missouri, lightly scattered rain showers have failed to improve soil moisture levels in the northern third of the state and concerns over short hay crops and poor pasture conditions are forcing cattle producers into supplemental feeding or consideration of liquidaton of part of their herd.

Pasture conditions are also worsening to the north with Minnesota and Wisconsin experiencing the biggest increase in the Midwest of very poor/poor pasture/range conditions over the last four weeks (Figure 7). Below normal rainfall, above average temperatures, abundant sunshine and moderate winds have increased the stress on vegetation and browned the landscape across much of Minnesota and Wisconsin. According to the Wisconsin Department Natural Resources, several suburban communities of Milwaukee have ordered lawn sprinkling restrictions and even bans for municipal water supply users. In New Berlin, WI (Waukesha County), an indefinite ban on lawn watering for municipal users was issued and Hartford, WI (Washington/Dodge Counties) also issued restrictions on lawn & garden watering. Across southeast Minnnesota and west-central Wisconsin, drought conditions also continue as areas such as LaCrosse, WI (LaCrosse County) went 17 days without measurable precipiation during July. Furthermore, the drought is triggering burning bans in parts ofLaCrosse & Trempealeau Counties in Wisconsin and in Houston County, MN.

In central and east central Indiana, precipitation is also badly needed as crops are in critical stages with, according to the Indiana Crop and Weather Report, two-thirds of the corn silking and half of the soybean crop blooming. Purdue agronomists say that without timely rains, corn yields could be cut by 25% to 38% - almost to the loss levels of the 1983 and 1988 droughts. One farmer in Johnson County, IN, reports that it hasn't rained at his location since May and in Indianapolis (Marion County), they are experiencing their 4th driest May to July time period. Stress on crops is increasing as the long term deficits increase. Deep soil moisture that was present during an earlier dry spell in June is now gone and the current dryness is having more of an impact.
 

Daily Records during July 18-24

Date	Location	Record Type	New Record	Old Record & Year
July 18	Dubuque, IA	Precip	3.48"	1.61"/1963
	Sioux City, IA	Precip	2.15"	1.68"/1999
July 20	International Falls, MN	Low Min	40°	42°/1992
July 21	Lincoln, IL	Low Min	50°	50°/1913
	Springfield, IL	Low Min	51°	54°/1971
	Jackson, KY	Low Min	57°
	Mansfield, OH	Low Min	49°	49°/1996
July 22	Eau Claire, WI	Precip	2.07"	1.67"/1995
	Jackson, Ky	Low Min	58°
July 23	West Plains, MO	Low Min	55°	58°/1988
July 24	International Falls, MN	High Max	91°	91°/1951

MCP