ILLINOIS WATER AND CLIMATE SUMMARY

Transcription

1 ILLINOIS WATER AND CLIMATE SUMMARY May 2017 Figure 1 Statewide departures from normal MAY 2017 OVERVIEW s were below and precipitation was above the long-term average in Illinois in May. Mean streamflow statewide was above the median for the month. Shallow groundwater levels were above the longterm average depths. Air temperatures averaged 61.8 degrees in May, 0.9 degrees below the long-term average (Figure 1). The southwest crop reporting district (CRD) had the highest temperature with 65.6 degrees. The lowest regional temperature was 57.2 degrees, reported from the northeast CRD. Precipitation averaged 5.04 inches, 0.44 inches above the long-term average in May. The east-southeast district had the highest average with 6.48 inches. The central CRD was the driest, with an average of 3.80 inches. Soil moisture declined in May, decreasing 33 percent at depths of 2 inches to an average of 0.29 water fraction by volume (wfv). Similar decreases occurred at 4 and 8 inches, ending the month with averages of 0.31 and 0.33 wfv, respectively. Soil moisture remained high at depths of 20, 39, and 59 inches with averages of 0.40 wfv and greater at the month s end. Mean provisional streamflow aggregated statewide was well above the long-term median flow for May, about 400 percent of median (Figure 1). Monthly mean discharge values ranged from above normal to much above normal for the month. The Illinois, Mississippi, and Ohio Rivers crested above local flood stages at most Illinois gage locations in May. Water levels of the lower Illinois River, lower Mississippi River, and the Ohio River at Cairo remained above local stages throughout the month. Water surface levels at the end of May were below full pool or target level at 8 of 26 reporting reservoirs. At the end of May, Rend Lake was 4.1 feet above its spillway level, Carlyle Lake was 5.7 feet above its seasonal target level, and Lake Shelbyville was 12.2 feet above its seasonal target level. Lake Michigan s level was about 1 foot above its long-term mean for the month. Shallow groundwater levels statewide were above normal this month with an average departure of 1.4 feet (Figure 1). A decrease of 0.4 feet in departure was observed from the deviation in normal groundwater levels between April and May. Levels averaged 0.9 feet below April levels and were 0.4 feet above May levels of last year. Water and Atmospheric Resources Monitoring Program Contact Jennie R. Atkins: (217) , jatkins@illinois.edu

2 WEATHER/CLIMATE INFORMATION Jim Angel and Jennie Atkins The following description of precipitation, temperatures, and severe weather comes from data compiled by a number of networks that report to the National Oceanic and Atmospheric Administration (NOAA). There are over 650 reporting sites in Illinois alone. These data are provisional and may change slightly over time. s in May were cooler in Illinois, averaging 61.8 degrees, or 0.9 degrees below the long-term average. High temperatures were in the 80s for most of the state, though several stations reported monthly highs in the low 90s. Low temperatures fell into the 30s and 40s. Despite the cooler May, spring (March May) was warmer than normal. s averaged 53.8 degrees, or 1.6 degrees above the long-term average. This follows the general trend for 2017 in which four out of the first five months had temperatures that were warmer than the long-term average. Growing degree days (GDDs, base 50, April 1) ranged from 400 in northern Illinois to 1000 in the south at the end of May. For the northern third of the state, GDDs were up to 60 DDs below the long-term average. GDDs in the rest of the state ranged from 0 to 90 DDs above normal. Precipitation for Illinois averaged 5.04 inches in May, 0.44 inches above the long-term average. The heaviest precipitation was in the central third of the state with areas receiving 5 to 8 inches. The highest totals were in Vermillion County as stations near Danville and Henning reported more than 10 inches for the month. There were drier areas near Bloomington and the Quad Cities. The station at the Bloomington Water Works reported 2.66 inches for May. Spring was wet as the state received inches, 4.07 inches more than the long-term average. The weather led to flooding and disruptions for agricultural work in April and May. Illinois received inches in 2017 as of May 31, 2.79 inches more than normal. Severe weather reports from the NOAA Storm Prediction Center totaled 123 for May with 11 reports for tornadoes, 23 for hail, and 89 for wind. (A single event may generate multiple reports.) Illinois remained drought-free. The May 30 report from the U.S. Drought Monitor listed 0 percent of the state as abnormally dry or in drought. Table 1a. and Precipitation for May 2017 ( F) Departure from long-term average ( ) Precipitation (in) Departure from long-term average ( ) Illinois CRD 1 (northwest) CRD 2 (northeast) CRD 3 (west) CRD 4 (central) CRD 5 (east) CRD 6 (west southwest) CRD 7 (east southeast) CRD 8 (southwest) CRD 9 (southeast) Data from NOAA s National Centers for Environmental Information, accessed 6/7/2017. Table 1b. and Precipitation for Spring (March-May) 2017 ( F) Departure from long-term average ( ) Precipitation (in) Departure from long-term average ( ) Illinois CRD 1 (northwest) CRD 2 (northeast) CRD 3 (west) CRD 4 (central) CRD 5 (east) CRD 6 (west southwest) CRD 7 (east southeast) CRD 8 (southwest) CRD 9 (southeast) Data from NOAA s National Centers for Environmental Information, accessed 6/7/

3 Figure 2a Illinois precipitation, temperature, and their departures from average for May 2017 Source: cli-mate, Midwestern Regional Climate Center. accessed on June 1, 2017 Figure 2b Illinois growing degree days and departure from average for May 2017 Source: Midwestern Regional Climate Center. accessed on: June 1,

4 Figure 3 Illinois precipitation and precipitation departure from average for year to date (top), last 6 months (middle), and last 3 months (bottom) Source: cli-mate, Midwestern Regional Climate Center. accessed on May 1,

5 Figure 4 U.S. Drought Monitor report for Illinois Source: U.S. Drought Monitor. accessed on June 1, 2017 ILLINOIS CLIMATE NETWORK (ICN) Jennie Atkins The Illinois Climate Network (ICN) consists of 19 stations across the state that collect hourly weather and soil information. ICN data for May are presented in Table 2. Wind speeds averaged 7.5 mph, 0.8 mph lower than in April and 0.3 mph below the long-term network average. Bondville had the month s highest average at 12.8 mph. The highest wind gust was 66.5 mph, recorded at the DeKalb station on May 17. Air temperatures rose 5.0 degrees from April to an average of 63.1 degrees. Highs reached the mid-80s and low 90s. The month s highest temperature was 90.9 degrees, reported at Big Bend on May 15. Lows were in the 30s and 40s, with the lowest temperature, 32.9 degrees, recorded at St. Charles on May 3. Soil temperatures increased 12 to 18 degrees during May, ending the month in the high 60s and low 70s. s were 0.2 to 0.4 degrees above the long-term averages. Under sod, temperatures ranged from 85.1 to 46.0 degrees at 4-inch depths and 86.4 to 47.7 degrees at 8 inches. s under bare soil varied from 95.9 to 38.6 degrees at 2 inches and 95.3 to 39.3 degrees at 4 inches. Precipitation averaged 4.99 inches, 0.97 inches higher than the network long-term average. All but four stations recorded monthly totals that were higher than average. The largest totals were in central Illinois where the Springfield station recorded 7.18 inches, the month s highest. Monmouth had the lowest recorded precipitation for the month with 2.93 inches. Soil moisture declined across the network in May. Moisture levels were high at the beginning of the month because of the large amount of rainfall the state received at the end of April. Warmer temperatures and drier weather resulted in declines in soil moisture in all regions, at least in comparison to the last week of April. At depths of 2 inches, levels declined an average of 33 percent during May to end the month with an average of 0.29 water fraction by volume (wfv). Moisture levels declined 24 percent at 4 inches and 17 percent at 8 inches, ending the month with network averages of 0.31 and 0.33 wfv, respectively. Levels remained high at depths of 20 inches and greater, with averages of 0.40 wfv at 20 inches, 0.44 wfv at 39 inches, and 0.42 wfv at 59 inches on May 31. 5

6 Table 2. Data from the Illinois Climate Network (ICN), May 2017 Station Ave Wind Speed (mph) Ave Wind Direction ( ) Maximum Wind Gust (mph) Maximum Air ( F) Minimum Air ( F) Average Air ( F) Belleville Big Bend Bondville Brownstown Carbondale Champaign DeKalb Dixon Springs Fairfield Freeport Monmouth Olney Peoria Perry Rend Lake Snicarte M 39.9 M 63.1 M Springfield St. Charles Stelle Table 2 continued Station Total Solar Radiation (MJ/m 2 ) Average Relative Humidity (%) Total Precipitation (in) Average Dew Point ( F) Total Potential Evapotranspiration (in) Ave Soil at 4" under Sod ( F) Ave Soil at 8" under Sod ( F) Ave Soil at 2" under Bare Soil ( F) Ave Soil at 4" under Bare Soil ( F) Belleville Big Bend Bondville Brownstown M Carbondale Champaign DeKalb M Dixon Springs Fairfield Freeport Monmouth Olney Peoria Perry Rend Lake M Snicarte M 5.57 M Springfield M St. Charles Stelle M = Missing data. 6

7 Figure 5 May soil moisture levels at ICN stations. 2 in, 4 in, and 8 in 7

8 Figure 5 May soil moisture levels at ICN stations. 2 in, 4 in, and 8 in 8

9 OTHER PRECIPITATION NETWORKS Erin Bauer Imperial Valley. Average network precipitation was 3.45 inches during May 2017, which is below the monthly normal (Figure 6a). Total monthly precipitation amounts were largest along the southwestern corner of the network. The smallest gage totals were along the eastern edge of the IVWA boundary. Monthly gage totals varied 3.41 inches across the network, from 2.27 inches (site 23) east of Mason City to 5.68 inches (site 18) near Snicarte. The , 30-year average precipitation amounts for May at Havana and Mason City are 4.79 and 4.07 inches, respectively. The May 2017 network average of 3.45 inches is about 82 percent of the 24-year ( ) IVWA May network average of 4.21 inches. The Imperial Valley Water Authority funds this 20-station precipitation network operated by the Illinois State Water Survey. Cook County. During May 2017, precipitation in Cook County was below normal (Figure 6b). Total monthly precipitation amounts were highest in the central portion of the network and lowest along the eastern edges of the network. Precipitation values ranged from 4.51 inches at site #9 (Cicero, near W. Roosevelt Rd. and S. Laramie) to 2.18 inches at site #23 (Lansing, near E. 170th St. and Burnham Ave). The May 2017 network average of 2.91 inches is about 72 percent of the 27-year ( ) May network average of 4.04 inches. The Illinois State Water Survey operates this 25-station precipitation network funded by the U.S. Army Corps of Engineers. a. Imperial Valley b. Cook County Figure 6 Long-term raingage network precipitation totals (inches) for May

10 SURFACE WATER INFORMATION Bill Saylor River and stream discharge and stage data are obtained from gaging stations operated by the U.S. Geological Survey (USGS) or the U.S. Army Corps of Engineers (USACE). The USGS gaging station network is supported, in part, by the Illinois Department of Natural Resources Office of Water Resources, the Illinois State Water Survey (ISWS), and the USACE. Provisional discharge data are obtained from the USGS. Table 3 lists the provisional peak stage for the current month compared to flood stage at selected streamgaging stations located on the Illinois, Mississippi, and Ohio Rivers. Peak stage is represented here by morning readings posted daily by the USACE or the National Weather Service. Flood stage is defined locally for each gage location. The Illinois, Mississippi, and Ohio Rivers all crested above local flood stages at most Illinois gage locations at some point in May. The Illinois River remained above local flood stages throughout the entire month from Havana to the Mississippi River. The Mississippi River remained above local flood stages throughout May downstream of Lock & Dam No. 22 (Pike County) to the Ohio River confluence, except at St. Louis. The Ohio River remained above flood stage at Cairo throughout the month. The Mississippi River crest stage at Chester this month was the third highest in the period of record of that station. Provisional monthly mean flows for 26 streamgaging stations located throughout Illinois are shown in Table 4. Mean values posted by the USGS are listed if available; otherwise, daily mean discharge data posted by the USGS are used to estimate the mean flow for the month. Long-term mean flows for each month are published by the USGS. The month s median flow for each station listed in Table 4 was determined by ranking the May mean flow for each year of record, and selecting the middle value, 50 percent exceedence probability. The statewide percent of historical mean flow and percent of historical median flow are calculated by dividing the sum of the average flows this month at stations in Table 4 by the sum of the historical mean and median flows calculated for the month, respectively, at the same stations. This method is intended to weight individual observations proportionately in the aggregate comparison. (The Illinois River and Rock River stations are excluded from the statewide calculation because other rivers listed in Table 4 contribute to their flow.) Mean provisional flow aggregated statewide, using the available monthly mean data shown this month in Table 4, was well above the median value for May (approximately 400 percent of the median) and above the long-term mean for the month (about 290 percent of the mean). Monthly mean discharge values ranged from above normal to much above normal for the month. The May 2017 monthly average streamflow values were provisionally the second highest calendar month averages for any month in the period of record at the South Fork Sangamon River near the Rochester streamgage (since 1949) and the Shoal Creek near the Breese streamgage (since 1945). The May 2017 monthly average streamflow at the Big Muddy River at the Plumfield streamgage was the second highest of any calendar month since the completion of Rend Lake, upstream, in This month s monthly average streamflow at the Little Wabash River below the Clay City streamgage was the third highest of any calendar month in the period of record of the gage (since 1914). Water-Supply Lakes and Major Reservoirs. Table 5 lists reservoirs in Illinois, their normal pool or target water surface elevation, and other data related to observed variations in water surface elevations. Reservoir levels are obtained from a network of cooperating reservoir operators who are contacted each month by ISWS staff for the current water levels. Reservoir levels are reported in terms of their difference from normal pool (or target level). The average of the month-end readings for the period of record is reported in terms of the difference from normal pool or target level (column 6 of Table 5), and the number of years of record for each reservoir also is given (column 7). Most reservoirs serve as public water supplies, with the exceptions noted in the last column. Compared to end-of-april water levels at 26 reservoirs for which levels were reported last month and this month, reported end-of-may water levels were lower at 20 reservoirs, higher at 4 reservoirs, and about the same as at the end of last month at 2 reservoirs. For the 26 reservoirs with measurements reported at the end of May, water levels were below the normal target pool or spillway level at 8 reservoirs, at about the full pool level at 6 reservoirs, and above the seasonal target or fixed spillway level at 12 reservoirs. Major Reservoirs. Compared to water levels at the end of April, at the end of May the water level at Rend Lake was 0.9 feet lower, Carlyle Lake was 4.7 feet higher, and Lake Shelbyville s level was 12.1 feet higher. At the end of May, Rend Lake was 4.1 feet above the spillway level, Carlyle Lake was 5.7 feet above the seasonal target level, and Lake Shelbyville was 12.2 feet above the seasonal target level. Great Lakes. Current month mean and end-of-month values are provisional and are relative to International Great Lakes Datum The May 2017 mean level for Lake Michigan was feet. The monthly mean level one year ago (May 2016) was feet. The longterm average lake level for May is feet, based on data. In this period of record, the lowest mean level for Lake Michigan for May occurred in 1964 at feet, and the highest level for May occurred in 1986 at feet. The month-end level of Lake Michigan was feet. All values are provided by the U.S. Army Corps of Engineers Detroit District. 10

11 Table 3. Peak Stages for Major Rivers during May 2017 River Station River mile* Flood stage (feet)* Peak stage (feet)** Date Illinois Morris La Salle Peoria Havana Beardstown Hardin Mississippi Dubuque Keokuk Quincy Grafton St. Louis Chester Thebes Ohio Cairo * River mile and flood stage from River Stages in Illinois: Flood and Damage Data, Illinois Department of Natural Resources, Office of Water Resources, August 2004 (and Addendum, February 2007). ** Peak stage based on daily a.m. readings, not instantaneous peak. Stage data obtained from U.S. Army Corps of Engineers. Table 4. Provisional Mean Flows, May 2017 Station Drainage area (sq mi) Years of record 2017 mean flow (cfs) Long-term flows Mean* Median (cfs) (cfs) Flow condition Percent chance of exceedence Days of data this month Rock River at Rockton , above normal Rock River near Joslin , much above normal 4 31 Pecatonica River at Freeport much above normal 9 30 Green River near Geneseo much above normal 6 31 Edwards River near New Boston above normal Kankakee River at Momence above normal Iroquois River near Chebanse much above normal 9 31 Fox River at Dayton much above normal 3 31 Vermilion River at Pontiac above normal Spoon River at Seville above normal LaMoine River at Ripley much above normal 8 31 Bear Creek near Marceline N/A N/A N/A 17 Mackinaw River near Congerville above normal Salt Creek near Greenview above normal Sangamon River at Monticello above normal South Fork Sangamon near Rochester much above normal 3 31 Illinois River at Valley City 26, ,050 37,250 34,760 much above normal 8 31 Macoupin Creek near Kane much above normal 4 31 Vermilion River near Danville much above normal 2 31 Kaskaskia River at Vandalia much above normal 6 31 Shoal Creek near Breese much above normal 3 31 Embarras River at Ste. Marie much above normal 3 31 Skillet Fork at Wayne City much above normal 7 31 Little Wabash below Clay City much above normal 2 31 Big Muddy at Plumfield much above normal 4 31 Cache River at Forman much above normal 1 31 Source streamflow data are obtained from the U.S. Geological Survey. N/A = not available (due to ice or equipment problems). Much below normal flow = % chance of exceedence. Below normal flow = 70-90% chance of exceedence. Normal flow = 30-70% chance of exceedence. Above normal flow = 10-30% chance of exceedence. Much above normal flow = 0-10% chance of exceedence. *As reported in U.S. Geological Survey (USGS) Water Resources Data, Illinois, Water Year

12 Table 5. Reservoir Levels in Illinois, May 2017 Normal pool Current level Monthly Average difference Years April or target difference from normal change from normal of reported pumpage Reservoir County level (feet) or target (feet) (feet) or target (feet) record (million gallons) Altamont Effingham Bloomington McLean N/A Carlinville Macoupin N/A Carlyle (1) Clinton N/A Decatur (1,3) Macon Evergreen (4) Woodford N/A Glenn Shoals (2) Montgomery w/hillsboro Highland Madison Hillsboro (2) Montgomery Jacksonville (2) Morgan N/A N/A w/mauvaise Terre Kinkaid Jackson Lake of Egypt Williamson N/A Mattoon Coles w/paradise Mauvaise Terre (2) Morgan N/A N/A no meter Mt. Olive (new) Macoupin N/A N/A w/mt. Olive (old) Mt. Olive (old) Macoupin Pana Christian N/A Paradise Coles Paris (east) Edgar Not PWS Paris (west) Edgar w/paris (east) Raccoon (1) Marion N/A N/A 97.3 Rend Franklin N/A Salem (3) Marion Shelbyville (1) Shelby Not PWS Sparta (3) Randolph N/A Spring (3,4) McDonough Springfield (1,3) Sangamon Taylorville Christian Vermilion (4) Vermilion Normal pool and target level datum is NGVD Current levels reported represent water surface levels at the end of the month, not the monthly average. Average difference from normal or target level is the arithmetic average of reported month-end values for the period of record indicated. Years of record = total number of monthly readings included in month-end average. Total period of record may be longer. Not PWS = not a public water supply. N/A = not available. (1) Target operating level may vary. Seasonal target levels this month represent June 1 values. (2) Instrumentation not available to measure height of water elevation above spillway. (3) Natural inflow can be supplemented by other sources. (4) Normal pool elevations have changed during period of record reported. 12

13 GROUNDWATER INFORMATION Ken Hlinka Comparison to Average Levels. Shallow groundwater levels in 11 observation wells, which are remote from pumping centers, were above normal for the month of May. Levels averaged 1.4 feet above and ranged from 1.7 feet below to 9.2 feet above normal levels (Table 6). Comparison to Previous Month. Shallow groundwater levels were below those of the previous month. Levels averaged 0.9 feet below and ranged from 5.4 feet below to 4.7 feet above levels of April. Comparison to Same Month, Previous Year. Shallow groundwater levels in May were above levels measured one year ago. Levels averaged 0.4 feet above this month and ranged from 3.5 feet below to 4.9 feet above levels of May Table 6. Month-End Shallow Groundwater Level Data Sites, May 2017 Number Well name County Well depth (feet) This month s reading (depth to water, feet) 15-year avg. level (feet) Period of record avg. (feet) Deviation from Previous month (feet) Previous year (feet) 1 Galena JoDaviess Mt. Morris Ogle Crystal Lake McHenry Fermi Lab DuPage Good Hope McDonough Snicarte Mason Coffman Pike NA NA NA NA NA 8 Greenfield Greene Janesville Coles St. Peter Fayette NA NA NA NA NA 11 SWS #2 St. Clair Boyleston Wayne NA NA NA NA NA 13 Sparta Randolph NA NA NA NA NA 14 SE College Saline Bondville Champaign N/A = Data not available. Averages Data sources for information in this publication include the following: CPC - Climate Prediction Center, ISWS - Illinois State Water Survey, MRCC - Midwestern Regional Climate Center, NCDC - National Climatic Data Center, NWS - National Weather Service, USACE - U.S. Army Corps of Engineers, USGS - U.S. Geological Survey, WARM - Water and Atmospheric Resources Monitoring Program, Illinois State Water Survey 2204 Griffith Drive Champaign, IL Tel (217)