ILLINOIS WATER AND CLIMATE SUMMARY

Transcription

1 ILLINOIS WATER AND CLIMATE SUMMARY April 2017 Figure 1 Statewide departures from normal APRIL 2017 OVERVIEW s and precipitation in April were above the long-term average in Illinois. Mean streamflow statewide was above the median for the month. Shallow groundwater levels were above the long-term average depths. Air temperatures averaged 56.5 degrees in April, 3.9 degrees above the long-term average (Figure 1). The northwest and northeast crop reporting districts (CRDs) had the lowest monthly temperature with 52.8 degrees. The highest average of 60.2 degrees was reported in the southwest district. Precipitation averaged 6.43 inches, 2.65 inches above the longterm average (Figure 1). The east CRD received the least amount with an average of 4.73 inches. The wettest for the month was the southwest district with 8.91 inches. Soil moisture was high at the end of April with network averages ranging from 0.44 water fraction by volume (wfv) at 2 inches to 0.43 wfv at 59 inches. Levels were above the field capacity at most monitoring locations. Mean provisional streamflow aggregated statewide was above the long-term median flow for April, about 160 percent of median (Figure 1). Monthly mean discharge values ranged generally from normal for the month in southern Illinois to above normal in northern Illinois. River stages exceeded local flood stages in mid-april and at the end of the month at many Illinois River stations, on middle and lower Mississippi River reaches along the Illinois border, and at Cairo on the Ohio River. Water surface levels at the end of April were above or near the full pool or target level at all reporting reservoirs. At the end of April, Rend Lake was 5.1 feet above the spillway level, Carlyle Lake was 1.0 foot above the May 1 target level, and Lake Shelbyville was 0.1 foot above the May 1 target level. Lake Michigan s level was above its long-term mean for the month. Shallow groundwater levels statewide were above normal this month with an average departure of 1.8 feet (Figure 1). An increase of 1.7 feet in departure was observed from the deviation in normal groundwater levels between March and April. Levels averaged 1.7 feet above March levels and were 1.5 feet above April 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, temperature, and snowfall (in winter) 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 averaged 56.5 degrees for April, 3.9 degrees above the long-term average. Highs reached into the 80s at most stations. The month s highest temperature was 89 degrees, recorded on April 20 at the Kaskaskia Lock and Dam in Randolph County. Monthly lows were in the 20s and 30s. Two stations, Aurora in Kane County and Neoga 4NW in Shelby County, tied for April s lowest temperature with 22 degrees. So far, every month in 2017 has had above-average temperatures. January April temperatures averaged 43.2 degrees, 5.4 degrees above the long-term average. It was the second warmest January April on record. The warmest year on record was 2012 with an average of 44.4 degrees. Growing Degree Days (DD, base 50, since April 1) ranged from 150 to 450 DD across Illinois, 20 to 80 DD above the long-term average. Precipitation was above normal in April, averaging 6.43 inches or 2.65 inches above the long-term average. April 2017 was the second wettest on record. Most stations reported totals of 5 inches or more. Twelve stations, all in southern Illinois, had totals of more than 10 inches. The majority of the rain fell in the last week of the month. The state averaged 4.25 inches from April 23 to 30, more than 60 percent of the month s total. The last weekend, April 28 30, was especially wet. Most stations reported three-day totals of more than 3 inches. A Carbondale station in Jackson County recorded 9.03 inches that weekend, 5.21 inches on April 29. This year has been wetter than average for most of the state. Illinois received inches in January April, 2.00 inches above the long-term average. Severe weather reports from the NOAA Storm Prediction Center totaled 100 in April with four reports for tornadoes, 34 for hail, and 62 for wind. (A single event may generate multiple reports.) Illinois was drought free at the end of April. The May 2 report from the U.S. Drought Monitor listed 0 percent of the state as abnormally dry or in drought. Table 1. and Precipitation for April 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) Notes: Data from NOAA s National Centers for Environmental Information, accessed 5/8/

3 Figure 2a Illinois precipitation, temperature, and their departures from average for April 2017 Source: cli-mate, Midwestern Regional Climate Center. accessed on May 1, 2017 Figure 2b Illinois growing degree days and departure from average for April 2017 Source: Midwestern Regional Climate Center. accessed on: May 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 May 4, 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 April are presented in Table 2. Wind speeds were slightly lower than in March, averaging 8.3 mph for the network. Bondville had the highest average wind speed with 13.5 mph. The highest wind gust was 53.9 mph, recorded at the Olney station on April 26. Air temperatures rose 14 degrees from March to an average of 58.1 degrees, and 4.7 degrees above the long-term average. Highs reached into the 80s at all except one station with monthly lows in the 30s. The month s highest temperature was 86.4 degrees recorded at Belleville on April 19. The lowest was 30.6 degrees, which was reported at Freeport on April 1. Soil temperatures rose 10 to 13 degrees from the March averages to the mid- to high 50s. s were 3 to 4 degrees above the long-term network averages. Lows reached into the 30s under bare soil but remained above freezing at all stations. Under sod, temperatures ranged from 74.1 to 40.2 degrees at depths of 4 inches and 75.4 to 41.3 degrees at 8 inches. s under bare soil ranged from 85.2 to 34.9 degrees at 2 inches and 85.4 to 34.4 at 4 inches. Precipitation was heavy across the network in April, averaging 7.70 inches, which is 4.42 inches higher than in March and 4.10 inches higher than April s long-term average. Station totals were 50 to more than 200 percent greater than their long-term averages. The majority of the rain fell the last week of the month when the network received 4.94 inches, or 64 percent of the month s total. The highest totals were in southern Illinois where Carbondale reported inches, the largest amount of precipitation for the month. Soil moisture steadily declined for the first three weeks of April. Levels at 2 inches fell 30 percent from April 1 to April 25. Heavy precipitation the last week led to soil moisture increases of more than 50 percent to end the month with a network average of 0.44 water fraction by volume (wfv). Similar patterns were seen in soil moisture levels at 4 and 8 inches. Slight increases also occurred at 20-inch depths. Soil moisture remained high at 39 and 59 inches with April 30 averages of 0.44 and 0.43 wfv, respectively. 5

6 Table 2. Data from the Illinois Climate Network (ICN), April 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 11.8 M M 46.2 M 82.0 M 32.4 M 56.0 M Olney Peoria Perry Rend Lake Snicarte Springfield M 38.3 M 60.4 M 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 Carbondale Champaign DeKalb Dixon Springs Fairfield Freeport Monmouth M M 44.8 M 4.08 M 53.6 M 52.7 M 55.7 M 55.4 M Olney Peoria Perry Rend Lake Snicarte Springfield M M 3.79 M St. Charles Stelle Notes: M = Missing data. 6

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

8 Figure 5 April 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 during April 2017 was 6.35 inches, well above average (Figure 6a). Total monthly precipitation amounts were largest along the southern edge of the network. The smallest gage totals were along the eastern edge of the IVWA boundary and north of Havana, IL. Monthly gage totals varied 2.54 inches across the network, from 7.83 inches (site 21) northeast of Revis Hill Prairie Nature Preserve to 5.29 inches (site 7) east of Green Valley. For most gages, over half of the monthly precipitation came during the April 29 storm with gage storm totals ranging from 4.20 inches over a 40-hour period to 2.96 inches. The , 30-year average precipitation amounts for April at Havana and Mason City are 3.67 and 3.61 inches, respectively. The April 2017 network average of 6.35 inches is about 184 percent of the 24-year ( ) IVWA April network average of 3.43 inches. The Imperial Valley Water Authority funds this 20-station precipitation network operated by the Illinois State Water Survey. Cook County. During April 2017, precipitation in Cook County was well above normal (Figure 6b). Total monthly precipitation amounts were greatest in the east-central portion of the network and lowest along the southern edge of the network. Precipitation values ranged from 6.75 inches at site #4 (Skokie, near Lincoln Ave and Oakton St) to 4.28 inches at site #24 (Matteson, near S. Cicero Ave and Lincoln Hwy). The April 2017 network average of 5.56 inches is about 155 percent of the 27-year ( ) April network average of 3.59 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 April

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 with the 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. In mid-april, the Illinois River crested above the flood stage at most stations below the Fox River confluence, the Mississippi River crested above the flood stage at locations below the Des Moines River confluence to the Ohio River confluence (except at St. Louis), and the Ohio River reached the flood stage at Cairo. At the end of April, the Illinois River was rising and above local flood stages from Ottawa to La Salle, and from Havana to the Mississippi River. Also by the end of the month, the Mississippi River had risen above flood stage at most stations from New Boston to the Ohio River confluence, and the Ohio River was above local flood stages below Paducah, Kentucky. 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 April 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 above the median value for April (approximately 160 percent of the median) and above the long-term mean for the month (about 130 percent of the mean). Monthly mean discharge values ranged generally from normal for April in southern Illinois to above normal in the north. 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-march water levels at 26 reservoirs for which levels were reported last month and this month, reported end-of-april water levels were lower at one reservoir, higher at 22 reservoirs, and about the same as at the end of last month at three reservoirs. For the 28 reservoirs with measurements reported at the end of April, water levels were below normal target pool or spillway level at two reservoirs, at about the full pool level at four reservoirs, and above the seasonal target or fixed spillway levels at 22 reservoirs. (Note that some operators do not report differences above the spillway level when water is over the spillway/full pool.) Major Reservoirs. Compared to water levels at the end of March, at the end of April the water level at Rend Lake was 3.3 feet higher, Carlyle Lake was 2.6 feet higher, and the Lake Shelbyville level was 5.5 foot higher. At the end of April, Rend Lake was 5.1 feet above the spillway level, Carlyle Lake was 1.0 foot above the May 1 target level, and Lake Shelbyville was 0.1 foot above the May 1 target level. (Lake Shelbyville s and Carlyle Lake s target operating levels increased from March to May.) Great Lakes. Current month mean and endof-month values are provisional and are relative to International Great Lakes Datum The April 2017 mean level for Lake Michigan was feet. The monthly mean level one year ago (April 2016) was feet. The long-term average lake level for April is feet, based on data. In this period of record, the lowest mean level for Lake Michigan for April occurred in 1964 at feet, and the highest level for April 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 April 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 Notes: * 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, April 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 ,240 11,190 10,252 above normal Pecatonica River at Freeport above normal Green River near Geneseo above normal Edwards River near New Boston above normal Kankakee River at Momence above normal Iroquois River near Chebanse above normal Fox River at Dayton much above normal 7 30 Vermilion River at Pontiac above normal Spoon River at Seville above normal LaMoine River at Ripley normal Bear Creek near Marceline above normal Mackinaw River near Congerville above normal Salt Creek near Greenview above normal Sangamon River at Monticello normal South Fork Sangamon near Rochester above normal Illinois River at Valley City 26, ,410 37,230 33,940 above normal Macoupin Creek near Kane above normal Vermilion River near Danville above normal Kaskaskia River at Vandalia normal Shoal Creek near Breese normal Embarras River at Ste. Marie normal Skillet Fork at Wayne City normal Little Wabash below Clay City normal Big Muddy at Plumfield normal Cache River at Forman normal Notes: 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, April 2017 Normal pool Current level Monthly Average difference Years March 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 N/A N/A 23.1 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 w/mauvaise Terre Kinkaid Jackson Lake of Egypt Williamson N/A Mattoon Coles w/paradise Mauvaise Terre (2) Morgan N/A no meter Mt. Olive (new) Macoupin 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 Rend Franklin N/A Salem (3) Marion Shelbyville (1) Shelby Not PWS Sparta (3) Randolph N/A Spring (3,4) McDonough N/A N/A Springfield (1,3) Sangamon N/A Taylorville Christian Vermilion (4) Vermilion Notes: 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 May 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 13 observation wells, which are remote from pumping centers, were above normal for the month of April. Levels averaged 1.8 feet above and ranged from 2.5 feet below to 5.4 feet above normal levels (Table 6). One well, S.E. College (Saline County), reported its highest measurement for April. Comparison to Previous Month. Shallow groundwater levels were above those of the previous month. Levels averaged 1.7 feet above and ranged from 0.8 feet below to 5.8 feet above levels of March. Comparison to Same Month, Previous Year. Shallow groundwater levels in April were above levels measured one year ago. Levels averaged 1.5 feet above this month and ranged from 0.3 feet below to 5.50 feet above levels of April Table 6. Month-End Shallow Groundwater Level Data Sites, April 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 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 SE College Saline ** Bondville Champaign Notes: ** Highest level of record for the month 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)