June 15-21, 2004
Midwest Weekly Highlights - June 15-21, 2004
Weather Patterns Change from Wet to Dry
After a very wet beginning to June, the week of June 15 to 21 contained one more episode of
heavy precipitation, followed by a break in the pattern with the introduction of a cool and dry
Canadian air mass to the region. Most of the Midwest received 0.5 to 2 inches of rain during the
week, with especially heavy bands of precipitation afflicting previously soaked areas from Iowa
to Wisconsin and across from central Illinois to the east and south (Figure 1). As a percentage of
normal, most of the wet zones experienced 125-175% of normal precipitation for the week (Figure 2), but there were areas that missed the rains, especially in Minnesota and northwestern
Wisconsin. The time period started with the eastern two-thirds of the Midwest above normal in
temperature, but the abnormally strong cold front arriving after the middle of this week cooled
the air to the point that departures for the whole week tumbled to -4 to -8°F below normal in the
western Midwest, and barely stayed above normal in the eastern Midwest (Figure 3). Several
locations in the northern Midwest indicated new low temperature records for the time of year.
River flooding peaked early in the period (Figure 4, National Weather Service), and then waters
receded in most areas during the week.
One More Multi-Day Heavy Rain Episode Adds to Flooding
The stationary boundary across the northern Midwest that has been responsible for focusing rain events over the last month was temporarily displaced by a cold front passage on the 14th and 15th that brought copious rain to a band from Kansas City to Detroit. However, by mid-day on the 15th, the quasi-stationary boundary between warm and cold air was re-established through the central Midwest. During the day, a substantial mesoscale convective vortex traveled along the boundary (Figure 5, College of DuPage), establishing bands of convection that dropped rain over the southern two-thirds of Illinois, Indiana, and Ohio, and in most of Kentucky. This precipitation exacerbated flooding problems in central Indiana and eastern Kentucky. Jackson, KY, recorded a record 2.28 inches of rain on the 15th. Many rivers in the Midwest were running at record or near-record levels for the time of year (black and blue dots in (Figure 6, USGS). The Wabash River in Indiana and the Grand River in Missouri were more than 5 feet above flood stage on the morning of the 16th, while many other locations were also above flood stage (Figure 7, NWS).
On June 16, a strong cold front entered the Midwest, establishing a very strong dew point
gradient by the afternoon (Figure 8, COD). A low pressure center (Figure 9, COD) triggered the
formation of a large cluster of thunderstorms in Iowa, with more bands of storms arrayed along
associated frontal boundaries (Figure 10, COD). As the initial convection moved into
Wisconsin, more thunderstorms fired up further south over Illinois (Figure 11, COD). These
storms eventually moved over most of the wet areas in the eastern Midwest, once again causing
flash floods on the rain soaked ground (Figure 12, COD). Precipitation totals on
the morning of the 17th were quite prodigious in central Illinois (Figure 13, NWS - from June
14-17), central Indiana (Figure 14, NWS - from June 15-17), northeastern Iowa (Figure 15, NWS
- June 16), and eastern Wisconsin (Figure 16, NWS - from June 15-17). Steven Point, WI,
received about 4 inches of rain in one hour in the early evening on the 16th, exceeding the 100-year storm size for the area by an inch.
Flooding, Storms, and Impacts
Seven of the nine states in the Midwest Region are presently under Federal disaster declarations, the exceptions being Minnesota and Michigan presently. Illinois is still operating under the disaster declaration of April 23 for the tornado outbreak that killed 8 in the north-central part of the state. All of the other declarations have been issued for severe storms and flooding since late May, starting with Iowa (May 25), Indiana and Ohio (June 3), Kentucky (June 10), Missouri (June 11), and Wisconsin (June 19). A number of these declarations have been updated to include more counties as disaster surveys were completed. Brief summaries of the impacts in Kentucky, Wisconsin, and Indiana, the states struck most recently, are given below.
Kentucky. Storm damage, flash flooding, and mud slides occurred in many locations across Kentucky in the last four weeks. Statewide damage estimates have exceeded $25 M to date, and five people died in the flash floods and storms. A tornado in Lexington on May 27 destroyed 26 houses and damaged another 300, while floods in Kentucky destroyed or severely damaged more than 400 homes in the two most impacted counties (Floyd and Martin). Overall, floods damaged more than 2,000 homes in Kentucky, with 233 having major damage and 124 destroyed. The worst flooding was in late May in eastern Kentucky (Figure 17, USGS), but subsequent storms compounded the situation through mid-June. More than 4,000 people applied for federal assistance in the first week after the declaration.
Wisconsin. As of this time, more than $6.7 M in damage to municipal structures and more than $9 M in damage to private residences and businesses have been identified. Many of these losses have been along the Fox River, which crested this week above the previous record level in Berlin, WI, by more than a foot (Figure 18, USGS). A large section of North Fond Du Lac, WI, was also evacuated this week. In Cambria, WI, almost 9 inches of rain fell on the 16th and 17th, most of it coming in a 5-hour period. More than 250 houses were damaged in North Fond Du Lac alone. Perhaps the largest losses, though, will prove to be agricultural. In the three most impacted counties (Sheboygan, Ozaukee, and Washington), more than $35 M in crop losses have occurred. Overall, 26 counties are asking for physical loss declarations from the Department of Agriculture. Total agricultural losses will be much larger when reduced yields and unplanted fields are factored in for a wider area. Finally, LaCrosse, WI, has received more than 10 inches of precipitation above normal for this year to date. Given a drought experienced last year, La Crosse actually has received more rain from January 1 to June 16, 2004, than it received in all of 2003.
Indiana. Substantial flooding returned to central Indiana for the fourth time in about a year, with previous major floods in May, July, and September 2003. The highest flooding in the city of Lafayette, IN, occurred just before this week, on June 13, when the Wabash River was more than 10 feet over flood stage (Figure 19, USGS). Prior to the 13th, more than 7 inches of rain fell in the Lafayette area within 48-hours, which is close to a 100-yr storm event for that increment of duration. Heavy rain during this week sustained levels above flood stage longer than otherwise would have happened, and an entire neighborhood was cut-off from the rest of the city during the flood peak. The flood wave moving down the Wabash covered large areas of agricultural bottomland, causing complete agricultural losses to many of these areas. No loss estimates have been released yet.
Miscellaneous Benefits and Problems. Quite clearly, the greatest benefit to the recent wet period in the Midwest has been a complete elimination of drought concerns in the major row crop growing regions of the central and eastern Corn Belt. Unfortunately, this has been replaced by concerns about flooded fields with dead crops. Even soybean fields that are not flooded are often too wet to drive tractors for overdue spraying. In addition, the Great Lakes have recovered substantially from previous drought-induced lows, with Lakes Michigan and Huron now only 11 inches below normal (12 inch recovery since June 2003), Lake Superior only 4 inches below normal (5 inch recovery since June 2003), Lake St. Clair only 3 inches below normal (9 inch recovery since June 2003) and Lake Erie at the normal level now. Flooding in southeastern Michigan, on the other hand, has brought lots of debris into Lake St. Clair, making recreational boating hazardous. In fact, there is enough flooding in southeastern parts of the state that Michigan may become that eighth state in the Midwest with a disaster declaration. Newspapers in Minnesota, Wisconsin, Michigan, Illinois, Indiana, and Iowa have all indicated concern regarding favorable breeding conditions for mosquitoes that carry the West Nile Virus. Finally, the region of the Midwest with the most persistent drought recently, northwestern Missouri, has moved out of drought status, but has suffered from large scale flooding along the Grand River, and widespread crop damage from hail and high winds in severe storms.
Drier and Cooler Weather Ends the Week
After the frontal passage on June 18, a large high pressure center with cool, dry air from Canada settled in the Midwest. Low temperature records were set on the morning of the 19th in Eau Claire, WI (40°F), International Falls, MN (34°F), and Hibbing, MN (29°F). The temperature in Embarrass, MN, reached 24°F, just one day before the start of astronomical summer. A large area started the day below 45°F for the daily minimum temperature (Figure 20) and stayed below 70°F for the daily maximum temperature (Figure 21), yielding daily departures of -12 to -18°F below normal. As the cold air moved eastward, Muskegon, MI, tied its record low for the 19th (46°F) just before midnight, while Youngstown (40°F) and Cleveland (46°F) tied their low temperature records on the morning of the 20th. As the period ended, another cold front entered from the west, reinforcing the cool, dry air mass and leaving one significant streak of precipitation across northern Iowa.