Temperatures over southern Indiana and central Kentucky had soared well into the 70s by midday, with southern Kentucky setting record highs in the lower 80s ahead of an approaching cold front. The atmosphere became very unstable with extremely strong wind shear (the change in direction and speed of wind with height).  The unstable, humid atmosphere would lead to storm development, and the wind shear would promote tornado development.

The parent low of the system continued to deepen as it raced towards southern Michigan and dragged its attendant cold front into the Ohio and Tennessee Valleys.  Storms erupted throughout the region.  The result was eight tornadoes and many reports of large hail in southern Indiana and central Kentucky.  The strongest wind shear maximized over southern Indiana, where twin supercells tracked from Dubois County to Trimble County.  The lead supercell produced an EF4 tornado that stayed on the ground for 49 miles and caused 11 deaths.  It was the region's strongest tornado since May 28, 1996 and the deadliest since the Brandenburg Tornado of April 3, 1974.

 
  Exceptional Drought, the worst category of drought, in the Lower Ohio Valley

The worst heat of the summer of 2012 first hit in late June. Record highs over 100° were set each of the last three days of the month at Louisville and Bowling Green. On the 29th Bowling Green's temperature soared to 110°, breaking the old all-time record high for June of 108° set back in the Dust Bowl year of 1936. Louisville also set its all-time record high for June that day at 105°. The relentless heat continued into July, with record temperatures of 100° or more recorded somewhere in central Kentucky on 6 of the first 7 days of the month. Lexington and Louisville peaked at 105°, Bowling Green 106°. The morning low in Louisville on the 5th was a muggy 80°. July ended up being the hottest ever experienced in Louisville, and #2 in Lexington and Bowling Green.

While there were occasional storms through the summer, the June-July heat wave baked the region and led to crippling drought, especially west of Interstate 65. Burn bans were in effect and agriculture suffered significantly, especially in southwest Indiana. By the second day of August 95% of Indiana's subsoil was short or very short of moisture.

8 to 10 inches of rain inundated the region, especially from southern Kentucky into middle Tennessee, along a stationary front draped over the area. Atmospheric moisture was very deep and led to rainfall rates of 1 to 2 inches per hour. Impacts included flash flooding, rivers out of their banks, mudslides, a small dam failure, road closures, evacuations, and swift water rescues. In central Kentucky damage totaled $30 million and there were five fatalities.

9.67" of rain drenched Bowling Green setting a new 2-day rainfall record for the city.

Photo:  Allen County Citizen-Times/Matt Pedigo

A slow-moving cold front brought waves of flooding rains March 4-5. Cold air coming in behind the front then turned the rain to snow. Due to the slow movement of the system, a band of very heavy snow, including thundersnow, set up from western to northern Kentucky, along and just south of the Ohio River. Final amounts were in the 18-24" range, including 17.1" at Lexington which broke the old 2-day March snowfall record by almost 7", and the city's all-time 2-day snowfall record (in any month) by almost 4". Louisville received 11.9" and Bowling Green 7.2". 

With the deep, fresh snow cover on the ground on the 5th, temperatures crashed that night. By the morning of the 6th Crab Orchard in Lincoln County was down to -12°, and Frankfort bottomed out at -10° which broke the old March all-time record low by 7 degrees. Lexington tied the record for March at -2°; only the 5th sub-zero temperature in March ever recorded in Lexington.

Frosty weather February 17, 2015

On February 16 high pressure over the Great Lakes pulled cold air southward that interacted with moisture around low pressure traveling from Texas to North Carolina. Up to a foot of snow fell on central Kentucky with the heaviest amounts along and south of the Blue Grass and Western Kentucky Parkways. A weak cold front brought another 2-4" on the 18th, and then Arctic high pressure moved in over the fresh snowpack on the 19th and 20th. As the sun came up on the 20th the mercury plummeted to an astounding -23° at Cynthiana, -21° at Frankfort (#2 all-time coldest temperature) and -18° at Lexington (4th all-time coldest). Bowling Green fell to -7°, Louisville -6°. 

Photo: Wade Bell

Low temperatures February 20, 2015

A squall line erupted ahead of a cold front on the afternoon of the 19th from Illinois to Oklahoma. A low pressure center moving from Kansas to Ohio swung the cold front through the Ohio Valley that night. The squall line intensified as it moved eastward and became a prolific tornado producer. In southern Indiana and central Kentucky no fewer than 24 tornadoes touched down in only about three hours, between 11:22pm and 2:30am EDT. All but two of the tornadoes were north of Interstate 64. The strongest twisters were an EF2 in Dubois County near Bretzville and Saint Anthony, and an EF2 in Orange County at Roland. Even though the outbreak happened late at night when many people were asleep, there wasn't a single injury.

Photo: NWS

A cold front approached the Ohio River during the late afternoon. Several storms developed to the west of Louisville and intensified as they moved east into the city. A very small, brief tornado touched down in Harrison County, Indiana, but the main event was in Jefferson County, Kentucky, where four more tornadoes formed, two of which attained EF2 strength. One of the EF2s damaged apartments and horse barns at Churchill Downs and a large industrial building near the University of Louisville's football stadium. 

Photo: Mike Dossett/KEMA

The first significant winter storm of the 2015-2016 winter season impacted much of Kentucky. A deepening low pressure system across the southern U.S. lifted copious amounts of moisture northward into the lower Ohio Valley where temperatures were in the teens and 20s. The combination of cold air and moisture brought a mix of snow, sleet, and freezing rain initially to southern Kentucky. Precipitation quickly changed over to moderate to heavy snow as several snow bands pivoted through the state. The heaviest snow fell from mid-morning until the mid-evening hours before tapering off around midnight. One to two feet piled up from near Glasgow and Munfordville east through Liberty and into eastern Kentucky.

The snow resulted in very hazardous to impossible driving conditions, especially across central and eastern Kentucky. Portions of Interstate 75 south of Lexington were shut down as several accidents prevented road crews from clearing the interstate. Additionally, strong northeast winds resulted in areas of blowing and drifting snow, further hampering road clearing efforts. Widespread school and business closings were reported.

Photo: Chasity Walters

Brownsboro Road in Louisville

A stalled frontal boundary brought several rounds of showers and thunderstorms to the Ohio Valley. Storms during the afternoon and evening of the 2nd produced large hail and damaging winds. Training storms (multiple storms that follow one another over the same area) during the pre-dawn hours on April 3 resulted in flash flooding. Five to eight inches of rain fell, including 5.64" at Louisville for the city's 4th wettest calendar day on record (6.81" fell from the 2nd into the 3rd). The event garnered national media attention as over 160 water rescues took place in Louisville and several roads were washed out.

To add to the disaster, a massive fire broke out at the General Electric Appliance Park in Louisville. Black smoke billowed into the sky and further stretched the resources of first responders.

Photo: Joe Sullivan/NWS

Flooding in downtown Louisville

Repeated rounds of moderate to heavy rainfall across the entire Ohio River basin totaled 8 to 9 inches along and on either side of the Ohio River from February 15 to March 1. These totals were 200 to 400% above normal for mid to late February. The large areal extent of the excessive rainfall led to significant rises on area rivers, including the Ohio River. This was the biggest flood on the Ohio River in Louisville since March 1997.

The river reached its 7th highest stage on record at Cannelton (50.7') and Tell City (49.3'). The river attained the 10th highest level on record at McAlpine Upper in Louisville (35.6'). At Shepherdsville the Salt River peaked at 35', the 7th highest reading on record.

Photo: NWS