by Ken Scheeringa
Note: A PDF formatted summary with additional maps is
available at the Indiana State Climate office website: www.iclimate.org/summary.asp
Moderate weather conditions at the start of June escalated into record setting heat and extreme drought at the end of the month that would catch the interest of national news media. June becomes the 8th consecutive month with above normal temperature and the 5th consecutive month of below normal precipitation in Indiana. After June 13th additional counties joined almost daily a growing list of those with mandatory burn bans in response to locally extreme dry conditions. Widespread rain producing storms were rare as persistent high pressure over Indiana virtually shut down the transport of moisture and humidity from the Gulf of Mexico. A notable storm event did occur on June 29th: a derecho which began in Indiana causing widespread wind damage across the northeastern section of the state and continuing to the Atlantic coast. One injury was reported in Indiana during this event but no deaths. There were no reported tornadoes this month in our state.
The state average June temperature was 72.1°F, which is 1.2°F above the month normal. This ties 2007 and 1988 as the 32nd warmest June since 1895. Last year was the most recent warmer June with a 72.6°F state average temperature in 26th place. Go back one more year to find the 11th warmest June with 74.2°F in 2010. Another recent warm June was the 73.4°F state average in 2005, good for 17th place.
The day split for June 2012 was more balanced than in recent months with 11 days of below normal temperature, 3 days at normal, and 16 days with above normal temperature. Given the cool start to June the daily state mean temperature was at least 10°F above normal on just 1 day. There was also just 1 day when the temperature was at least 10° below normal. The highest local daily temperature in the state was 109°F at the National Weather Service office in Indianapolis, although the official record for that city is taken at the International Airport which had 104°F on June 28th. To comprehend the extent of the heat wave, 69 cooperative weather stations recorded temperatures of at least 100°F in June while 25 of these stations reached or exceeded 105°F! The coolest daily official June temperature was 40°F recorded twice, at Spencer on June 2nd and again on June 14th at Rockville.
The state precipitation total was a meager 1.30 inch, about 31% of normal. This is the 3rd driest June on record. June 1933 with 1.18 inch was the 2nd driest June in Indiana while June 1988 was the driest on record with a state average 0.74 inch. The cooperative station at Lowell received 3.72 inches as recorded on June 17th. But the highest overall daily amount measured was 5.08 inches in a locally heavy thunderstorm at the CoCoRaHS station in Attica for that same date. While daily amounts tended to be small precipitation generally fell on about 9 days around Indiana this month.
Severe weather was mostly limited to wind and hail damage on two June dates. On June 16th wind and hail damage was reported in the northwest quarter of Indiana. The derecho on June 29th was more intense in the northeastern portion of the state. Details with damage reports on this event are found in the last weekly narrative below.
Due to the scarce rainfall the Indiana drought intensified week by week throughout June. The late month heat wave just magnified drought related problems. By the end of the month northeast and southwest areas of the state were classified in the extreme D3 drought category. Concerns about the corn crop, most of which would pollinate the first week of July, would soon become reality. Livestock losses were now occurring as well. Wildfire problems increased along with the intensity of the drought. Details on these and other drought impacts are detailed in the weekly narratives which follow.
June 1st – 9th
The first week of June seemed almost cold to folks after unseasonably warm temperatures last month in Indiana. Daily state average temperatures bottomed at near 12°F below normal after a cold front moved through the state as the new month began. But another warm high pressure ridge, a common feature on the weather map recently, then sprawled over the east half of the country. A fast warm up quickly followed and temperatures crawled back to normal by June 4th. A family of fronts was approaching Indiana, but a strong Canadian high pressure center blasted through to Indiana, forcing all these fronts into our southern states far south of Indiana. Temperatures fell again to about 7°F below normal by June 6th. This high pressure center slid east of Indiana over the final 3 days. The southerly wind flow behind this high center allowed temperatures to recover gradually each day to end the interval at 2°F above normal. For the 9 days temperatures averaged about 4°F below normal. Typical daily maximum temperatures the first week of June range from 76°F in northern counties to 83°F in the far southwest. Daily minimums normally vary between 55°F to 61°F north to south across the state.
The front that passed through the state on June 1st produced a heavy 2 inch rainfall along the Ohio River but only a moderate half inch in most areas to the north. A trough in the upper atmosphere helped add a few more hundreths of rain over the next few days, but then it turned dry through the remainder of the interval. Overall for the 9 days rainfall averaged near 0.5 inch across northern Indiana, about 0.3 inch in central counties, and about 0.7 inch in southern Indiana. These totals equate to about 40% of normal in the north, just 25% of normal in central Indiana, and 50% of normal in the south. The heaviest thunderstorms of the week drenched far southern Indiana on June 1st. Some CoCoRaHS reports that morning included 2.50 inches in Sellersburg, while two observers in Aurora measured 2.10 and 2.08 inches. The Milltown volunteer noted 2.09 inches while Leopold had 2.03 inches in the gage. For the week the Aurora observers total rainfall was 2.19 inches and 2.16 inches. The rain watcher at Moores Hill had 2.09 inches while Birdseye measured 2.03 inches.
High pressure has dominated the Midwest in recent weeks, shutting down the transport of summer moisture and humidity into Indiana from the Gulf of Mexico. Fronts have been mostly dry as the low humidity has evaporated showers approaching our state. Evapotranspiration is occurring at high rates causing Indiana soils to dry out more quickly. The June 5th edition of the US Drought Monitor shows one half of total Indiana area is now in drought status or abnormally dry. While the total coverage has not increased from a week earlier the intensity within drought areas has increased. The moderate drought area (D1 category) in northern Indiana has expanded eastward to include most of Allen and Noble counties. Drought conditions in most of Posey and Vanderburgh counties in southwest Indiana are now rated severe (D2 category), the first time any portion of Indiana has fallen into this category this year. In summary abnormally dry (D0) conditions now claim 32% of total Indiana area while 17% is rated to be in moderate drought (D1 category). The newly rated severe drought area (D2 category) totals 1% of Indiana. The June 11th edition of the Indiana Weekly Weather and Crops survey rates 74% of Indiana topsoil as short or very short of moisture while 68% of Indiana sub-soils are rated this way.
June 10th – 16th
This week began and ended warmer than normal but the middle of the week was cool. A high pressure ridge covered the east half of the country as the week started, lifting Indiana temperatures to 6°F above normal by June 11th. A cold front pushed through the state the next day and temperatures quickly fell to 6°F below normal. The front moved rapidly to the Atlantic coast on June 13th and another high pressure center moved into Indiana. A warm up was underway that would continue to the end of the week. This high center traveled into eastern Canada, making way for a storm system approaching Indiana from the Dakotas. A dry warm front crossed our state on June 15th and temperatures rebounded to 4°F above normal to close out the week. Overall for the week state temperatures averaged 1°F above normal. Typical daily maximum temperatures this second week of June range from 79°F in northern counties to 85°F in the southwest corner of the state. Daily minimums normally vary from 58°F to 64°F north to south across Indiana.
The cold front of June 12th produced mostly very light rainfall in scattered spots around Indiana. Locally heavy showers were limited to the far southwest counties of Indiana where up to an inch of rain was noted. The rain was appreciated in this driest area of Indiana where it fell but the showers missed the majority of the Indiana landscape. At the very end of this week it was raining in northwestern counties after another very dry week overall across the state. On average about a tenth inch of rain fell in southern Indiana but lesser amounts fell in northern and central sections. This translates to about 15% of normal rainfall in southern regions but only about 5% of normal in northern and central Indiana. Four CoCoRaHS observers in Newburgh measured 1.18 inch, 1.09 inch, 0.94 inch, and 0.63 inch for the week. In nearby Evansville 1.13 inch was recorded on June 12th which was also the week total.
High winds on June 16th caused scattered damage around the state. Fallen trees blocked roads in DeKalb county while festival tents were blown away in St Joseph county where trees also came down. In Porter county trees fell on power lines. Hail up to 1.75 inch was reported in adjacent Lake county. In central Indiana a round of strong thunderstorms caused a wall in a pre-Civil War era hotel in Fountain county to collapse but the hotel was able to continue operating. Nearby more trees fell tearing down some power lines. Jay county also noted tree damage while winds up to 60 mph in Clark county took down still more trees. Overall minor damage resulted from this storm which netted no injuries.
The most significant weather impact however continues to be the intensifying drought across Indiana. The June 12th edition of the US Drought Monitor classifies 5% of total Indiana area in severe drought condition (D2 category), which includes parts of 7 counties in the extreme southwest corner of the state. One third of Indiana is now rated to be in moderate drought (D1 category) which includes two areas of the state: a ring of counties surrounding the severe drought region just described, and most of northern Indiana generally east of a line from South Bend to Attica to Bluffton. Southeast Indiana, generally east of a line from Liberty to Seymour to Corydon, is rated drought free, about 12% of the state. The remaining half of the state is considered to be abnormally dry (D0 category). According to the June 17th edition of the Indiana Weekly Weather and Crop report, 85% of Indiana topsoils are rated as short or very short of moisture. About 79% of subsoils are rated in these categories.
The dry soil conditions have been key to an increased number of wildfires in rural areas. A section of I-74 had to be closed southeast of Indianapolis for a time as firefighters battled brush fires. Trains which throw sparks from their wheels on railroad tracks have been especially troublesome in starting brush fires along the miles they travel.
In response to the tinder box conditions counties have begun to issue mandatory open burn bans. Counties which have implemented bans this week and the date enforcement began are:
June 13 – Marshall
June 14 - Grant, Knox, Noble, Steuben, Wabash
June 15 - Allen, Carroll, Fountain, Fulton, Kosciusko, Laporte, Monroe, Sullivan, Vigo
June 16 – Warren
Reports from crop specialists indicate that our major field crops, corn and soybeans, are holding on in these drought conditions surprisingly well. Growth progress has stalled for the most part until rains return. The critical reproductive stage for corn, which lasts about 7 days, will likely occur about the first week of July so weather conditions will be watched closely at that time. Soybeans are more drought tolerant and the reproductive timeline is a few weeks longer than corn and will occur later this season.
June 17th – 23rd
Warm temperatures held most of this week before falling back to normal. The week began at 6°F above normal. A nearby cold front in Illinois stalled and failed to enter our state, allowing temperatures to slowly rise to 8°F above normal by June 19th. Still in this warm air mass, temperatures fell back slightly to 6°F above normal by June 21st. Finally a stronger cold front muscled its way across Indiana on June 22nd. Cooler air filtered in and temperatures fell a bit to 2°F above normal. The Canadian air flow continued into Indiana causing temperatures to drop a few more degrees to end the week at right about normal. Overall for the week the state temperature averaged 5°F above normal. Usually daily maximum temperatures in mid-June range from 81°F in far northern Indiana to 87°F in the far southwest. Daily minimums normally vary between 60°F in the north to 65°F in the south.
Rain was falling in northwest Indiana as the week started. Heavy thunderstorms dumped torrential rainfall in isolated spots of border counties but less than an inch was more typical in this region. Elsewhere across the state the meager totals seen in recent weeks were again common. Minimal rain fell the rest of the week with only slightly more during the late week cold front passage. Overall for the week an average 0.9 inch fell in northern Indiana, about 0.2 inch in central areas, and just a tenth in the south. As a percentage these totals were about 10% above normal across northern counties, but just 20% of normal in central Indiana and near 10% of normal in the southern region. Rain gages in the path of the torrential storms in northwest Indiana were about half full on the morning of June 17th. In Attica three CoCoRaHS observers measured 5.08 inches, 4.27 inches, and 3.64 inches that day. In Lake Village 4.38 inches was recorded and the Wheatfield volunteer caught 3.79 inches in the rain gage. The top rainfall totals for the week included two Attica reports of 5.13 inches and 4.31 inches with 3.45 inches at Wheatfield. The Hebron observer noted 3.13 inches while at DeMotte 2.81 inches was received.
The increasing soil moisture deficit across the state is reflected in the weekly update of the US Drought Monitor. The June 19th edition now rates 5% of Indiana land area, generally Posey, Vanderburgh, Gibson, and Pike counties in the far southwest corner of the state, to be in extreme drought (D3 category). This rating is a deterioration from last week and the first time this season this category has appeared in Indiana. Counties surrounding this extreme area, generally west of a line from Sullivan to Shoals to Tell City, are classified in severe drought (D2 category). About two-thirds of northern Indiana generally east of a South Bend to Lafayette to Bluffton line are also declared in severe drought, together placing about 31% of the state in this category. This is an increase of 26% of land area in this category from a week ago. Northwest Indiana, mostly west of a South Bend to Attica line, and southeast Indiana, mostly east of a Liberty to Seymour to Corydon line, are depicted as abnormally dry (D0 category), the least harsh drought category. This is about 22% of total Indiana land area. This leaves the rest of the state, about 42% in area, in moderate drought (D1 category), an increase of 8% from the previous week. The Indiana Drought Monitor map for this week is shown near the end of this monthly summary. In its weekly survey of soil moisture the Indiana Weekly Weather and Crops report rates 91% of topsoil as short or very short of moisture. Subsoils are rated at 87% in these categories.
The ongoing drought and its impact on crop conditions and wildfires is a great and growing concern around Indiana. News media interest has risen sharply this week. Field corn has only about a one week window in which to pollinate and this event will occur in most areas about the first of July. The continued lack of rain will hurt pollination and lower yield expectations. Soybeans are more adaptable to drought and can retry setting pods later in the season when weather may be more favorable.
Several more counties have adopted mandatory burn bans this week, changing the total count to 45 counties. Counties which have implemented bans this week and the date enforcement began are:
June 18 – Adams, DeKalb, Huntington, Lagrange, Miami, Pulaski, Tippecanoe, Warrick
June 19 – Daviess, Elkhart, Johnson, Lawrence, Pike, Shelby, Starke
June 20 – Bartholomew, Clinton, Decatur, Delaware, Gibson, Spencer,Vanderburgh, Vermillion
June 21 – Jay, Martin, Union, Wells
June 22 – Dubois, Madison, Owen, White
And these counties have lifted burn bans that were in effect:
June 19 - Warren
June 22 – Kosciusko
A map showing the status of all burn bans as of the end of this week follows here. Red shading indicates new burn bans in effect while green shading indicates bans lifted.
June 24th – 30th
This last week of June began and ended warmer than normal. There was a brief two day cool down in mid-week with temperatures dipping below normal. At the start of the week Indiana was located on the front side of a hot upper atmospheric dome of high pressure in the Great Plains. The northerly winds in the upper atmosphere ahead of this ridge supported a surface cold front which pushed through Indiana on June 25th. Temperatures fell from 4°F above normal ahead of the front to 5°F below normal behind it. As high pressure at ground level slid over Indiana and then east, warm southerly winds returned. The hot upper atmospheric dome was now on the move toward Indiana. A surface warm front crossed our state on June 28th. Temperatures quickly rebounded to 11°F above normal. A cold front the next day triggered a derecho in Indiana that would ripple all the way to the Atlantic Ocean causing massive weather damages in Indiana and in many states to our east. Overall for the week Indiana temperatures averaged about 4°F above normal. Typically daily maximum temperatures would range between 82°F and 88°F north to south across Indiana. Normal daily minimums vary from 62°F in northern Indiana counties to 67°F in our far southwest.
The cold front early in the week was dry and produced no rainfall. The second storm system late in the week triggered thunderstorms in the derecho which generated about a half inch of rain in northern and central Indiana but only sprinkles in much of southern Indiana. Normally at this time of year Indiana receives about an inch of rain per week so these amounts are about half of normal in northern and central areas but less than 5% of normal in the south. Half of normal rainfall has been a common theme in Indiana throughout this year’s drought. Northwest counties have benefited most often when storms do move through and this pattern continues. The heaviest single day rainfall amounts this week included 1.55 inch and 1.39 inch as reported by two CoCoRaHS observers in Highland in Lake county. Nearby Crown Point had 1.45 inch. The highest day totals were actually found in central Indiana. The CoCoRaHS volunteer in Kokomo noted 1.68 inch while Tipton measured 1.65 inch. For the week four Lake county observers totaled the most: Highland with 2.14 inches; St John with 1.83 inch; Winfield had 1.75 inch; and Dyer 1.73 inch.
Temperatures the last 3 days of this week soared to triple digits all across the state. Of the 101 Indiana cooperative stations reporting thus far, 87 of these locations reached 100°F or higher on at least one of these dates. Amazingly 35 of these stations have reached 105°F or higher. Among the hottest readings were 108°F recorded at Terre Haute. This level of intense heat has not been seen in Indiana since the summer of 1988.
The intense heat in place over Indiana clashed with the cold front moving in on June 28th and 29th. Severe weather developed on June 28th in northwest Indiana, then evolved into a derecho as it moved into eastern Indiana late that day and into June 29th. The core of high wind damage reported on June 28th followed a line from Valparaiso to Peru. Trees fell and brought down power lines all along this damage path. Telephone poles snapped in Laporte county. One inch diameter hail fell in Lake, Fulton, and Miami counties with isolated 2.75 inch hail in Lake county, denting cars.
By far the most significant damage occurred on June 29th as the derecho which started in Indiana fanned outward to New Jersey and the Atlantic Coast. The storm caused 15 deaths, none in Indiana, and left 3 million people without power during the sweltering heat wave. West Virginia was hardest hit by the storm. A derecho is an intense wind storm associated with the bow echo radar signature of a rapidly moving line of showers and thunderstorms that travels at least 240 miles. In the June 29th event the derecho caused damage along a 600 mile long path with wind speeds near 100 mph at times. Unlike tornadoes derechos cause straight line wind damage.
In Indiana the bulk of derecho damage occurred in the northeast quadrant of the state, generally east of a line from South Bend to Indianapolis to Richmond. No damage was noted in the extreme northeast counties of Lagrange and Steuben. Fallen trees and downed power lines were reported from nearly all counties in the affected region. Wind speed reports ranged from about 60 mph on the west side of the damage area up to 91 mph reported at Fort Wayne on the east edge. While damage reports of trees falling on roads and cars were common in western areas, damages increased to include homes, barns, and even fires in eastern Indiana counties. In Whitley county two radio station towers were snapped, the roof was ripped off a fire station, and two homes caught on fire. In Allen county 30 trees in a park were toppled, trees fell on cars, siding was torn from homes, and a wood shed was blown over. In Adams county there was massive damage including buildings on fire and trucks blown over. Windows were blown out and barn roofs torn off in Blackford county. A barn was blown down in Henry county while roofs were taken off a home and school in Wayne county. One injury was reported in Tipton county when a tree fell on the driver of a truck. To the west of the derecho area small hail was noted in Lake county while 1.75 inch hail was observed in Warren county. Hail of 1.25 inch diameter fell in Fountain county and 1.00 inch hail in Tippecanoe county.
The other major Indiana weather story this week is the worsening drought and its impacts on crops and burn bans. Severe to extreme drought now covers two thirds of Indiana with abnormally dry conditions across the remainder of the state. According to the June 26th edition of the US Drought Monitor, the extreme drought coverage has increased from 5% of Indiana area last week to 23% this week (D3 category). Severe drought (D2 category) has increased from 31% a week ago to 46% this week, nearly half the state area. The increasing areas of D3 and D2 categories resulted in a shrinkage of the moderate drought region to 18% coverage this week (D1 category). Just 13% of Indiana area remains in the abnormally dry D0 category. The Indiana drought map for this week is found near the end of this monthly summary for reference. In its July 2nd edition of Weekly Weather and Crops, the Indiana Ag Statistics office rates 91% of Indiana topsoil as short or very short of moisture. The subsoil rating in these categories is 92% of total area.
The intense heat and drought conditions are taking a toll on Indiana crops and livestock. Indiana corn condition is rated 19% good to excellent this week, its worst rating at this point in the growing season since 1988 when 0% was rated good or excellent. About 30% of Indiana corn is now in the critical pollination stage. Some livestock has been lost to the extreme heat already, especially poultry.
Worsening drought conditions have prompted more Indiana counties to issue mandatory burn bans. Counties which have added burn bans this week and the effective dates are:
June 24 – Henry
June 25 – Franklin, Greene, Jackson, Jefferson, Rush, Washington, Whitley
June 26 – Floyd, Hancock, Hendricks
June 27 – Boone, Jennings, Morgan, Orange, Parke, Scott
June 28 – Benton, Blackford, Brown, Clay, Crawford, Fayette, Howard, Jasper, Marion, Montgomery, Switzerland
June 29 – Clark, Hamilton, Ripley, Tipton