While on the western side of an upper trough, a surface low with associated fronts moved south through west-central Kentucky. This produced thunderstorms along the front, stretching west to east through Kentucky.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LMK wrote it up.
While on the western side of an upper trough, a surface low with associated fronts moved south through west-central Kentucky. This produced thunderstorms along the front, stretching west to east through Kentucky. As this line moved south through the Bluegrass region of Kentucky, areas of severe damage resulted.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Louisville, KY wrote its last area forecast discussion before the first event at Aug 18, 12:31 PM EST, 51 minutes earlier.
Area Forecast Discussion National Weather Service Louisville KY 131 PM EDT Tue Aug 18 2020 ...Updated Aviation Discussion... .Forecast Update... Issued at 1250 PM EDT Mon Aug 17 2020 With convection already starting across the area, the afternoon forecast looks on track with coverage of showers and storms expected to increase through the afternoon hours. Mesonanalysis shows good CAPE (2000-2500 j/kg) and DCAPE (900-1000 j/kg) developing ahead of a sfc low pressure and cold front over southwest Indiana/western KY. Steep low and mid level lapse rates are present as well with 20-30 kt effective bulk shear. These parameters should support strong wind and small hail threats this afternoon/evening. && .Short Term...(This evening through Wednesday) Issued at 231 AM EDT Tue Aug 18 2020 Low pressure centered over southeast Illinois early this morning, and its corresponding 5H shortwave trof and vort max, will slide southeastward across southwest Indiana and central Kentucky into the Tennessee Valley by this evening accompanied by showers and scattered thunderstorms. Mid and upper level winds actually weaken over the course of the day with generally weak deep layer shear. However, there will be enough SBCAPE to suggest thunder. While severe weather is not expected, over southern Kentucky this afternoon during maximum destabilization there will be some dry air aloft and steep low level lapse rates, indicating a few gusty storms aren't out of the question. Precipitable water values will be around 1.5"...not excessive for this time of year, but indicative of the potential for some heavy downpours. 1hr FFG numbers are well over two inches in most locations (except just under two inches in the Lake Cumberland region). Most spots should be able to handle the rain given how green we are plus the fact that the past couple days have been fairly dry. Nevertheless, K Index values progged in the low-mid 30s indicate that there could be some heavier downpours in which some brief local water issues could arise in areas that don't drain easily, especially if storms can repeatedly move over the same spot. With light winds coming in from the north or northeast this afternoon over southern Indiana, temperatures there may struggle to rise out of the 70s. Lower and middle 80s are forecast for central Kentucky. Tonight the low will weaken and move out of the area, with showers gradually tapering off during the evening hours. High pressure building over the Great Lakes and Midwest will usher in cooler and drier air. Lows by Wednesday morning will range from the upper 50s in southeast Indiana and the northern Blue Grass to the mid 60s near the Tennessee border. .Long Term...(Wednesday through Monday) Issued at 235 AM EDT Tue Aug 18 2020 Synoptic Overview...A persistent pattern will be in place across the US throughout the long term period as a blocking high remains rooted roughly over the Four Corners region with troughing over the eastern CONUS. Wednesday...Surface high pressure will build in across the Great Lakes and Ohio Valley resulting in an uncharacteristically cool and dry day for mid August. Expect some cloudiness to linger across south central KY along with a slight chance of showers in the afternoon in the Lake Cumberland area, but otherwise skies should be mostly sunny with highs in the upper 70s to low 80s. Quite the dew point gradient will exist across the CWA with lower values in the upper 50s to low 60s across southern Indiana and north central KY while increasing to the mid to upper 60s across south central KY. Thursday...Pleasant conditions will continue through Thursday as the surface high edges eastward toward the NY coastline. Highs on the day will increase into the low to mid 80s with similar dew points as the previous day. The exception Thursday is another chance for showers and thunderstorms across south central KY, mainly south of the Parkways. Friday through Sunday...A shortwave traveling along the northern stream will pass over the Great Lakes while pulling the upper low from the lower MS Valley northward across the Ohio Valley. As the upper low tracks over the region, southerly flow will see an increase in moisture resulting in an increase in mid and high level clouds with greater areal coverage of diurnal showers and storms for Friday and Saturday. Mugginess returns as well with dew points back in the upper 60s to low 70s as daily high temps range in the mid 80s. By Sunday the upper trough axis will move toward eastern KY as lingering moisture will lend to another afternoon of chance showers and storms, mainly east of I65. Sunday highs will be slightly warmer reaching into the mid to upper 80s with dew points in the upper 60s to low 70s. Monday and beyond...Upper flow becomes more zonal as the eastern CONUS trough begins pushing off to the NE. This should leave the OH Valley under the influence of high pressure with dry conditions yet returning to the hot and muggy days of August for the beginning of the work week. Also worth noting is that some models advertise a tropical disturbance approaching the northern Caribbean by Monday. Will keep an eye on this. && .Aviation...(18Z TAF Issuance) Issued at 130 PM EDT Tue Aug 18 2020 Scattered to at times numerous showers and storms are expected over the area this afternoon and evening courtesy of a sfc low and cold front passing through the region. Have included VCTS at all TAF sites through this evening and added tempo groups at SDF/LEX which are most likely to see a t-storm with reduced flight conditions in the 18-22Z time frame. After sunset, convection will weaken and begin to diminish in coverage. Winds will become predominantly from the NE tonight and remain elevated in the 5-7 kt range behind the departing sfc low/cold front. A few of the short range models also indicate low cigs could develop at BWG/LEX during the pre-dawn hours so have included an MVFR group late tonight into tomorrow morning for those sites. VFR conditions are expected to return for all TAF sites around or after sunrise tomorrow. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && Update...AMS Short Term...13 Long Term...CG Aviation...AMS
Hazardous Weather Outlook National Weather Service Louisville KY 102 PM EDT Tue Aug 18 2020 INZ076>079-083-084-089>092-KYZ023>043-045>049-053>057-061>067- 070>078-081-082-191715- Orange-Washington-Scott-Jefferson-Dubois-Crawford-Perry-Harrison- Floyd-Clark-Hancock-Breckinridge-Meade-Ohio-Grayson-Hardin-Bullitt- Oldham-Trimble-Henry-Shelby-Franklin-Spencer-Anderson-Woodford- Fayette-Bourbon-Nicholas-Nelson-Mercer-Jessamine-Larue-Marion-Boyle- Garrard-Madison-Butler-Edmonson-Hart-Green-Taylor-Casey-Lincoln- Logan-Warren-Simpson-Allen-Barren-Monroe-Metcalfe-Adair-Russell- Cumberland-Clinton- Including the cities of Paoli, Salem, Scottsburg, Madison, Jasper, English, Tell City, Corydon, New Albany, Jeffersonville, Lewisport, Hawesville, Hardinsburg, Brandenburg, Hartford, Leitchfield, Elizabethtown, Shepherdsville, Louisville, La Grange, Bedford, Milton, New Castle, Shelbyville, Frankfort, Georgetown, Cynthiana, Taylorsville, Lawrenceburg, Versailles, Lexington, Paris, Carlisle, Bardstown, Springfield, Harrodsburg, Nicholasville, Winchester, Hodgenville, Lebanon, Danville, Lancaster, Richmond, Morgantown, Brownsville, Horse Cave, Greensburg, Campbellsville, Liberty, Stanford, Russellville, Bowling Green, Franklin, Providence, Scottsville, Glasgow, Tompkinsville, Edmonton, Columbia, Jamestown, Burkesville, and Albany 102 PM EDT Tue Aug 18 2020 /1202 PM CDT Tue Aug 18 2020/ This hazardous weather outlook is for portions of south central Indiana and Central Kentucky. .DAY ONE...This Afternoon and Tonight. Scattered storms are expected today, especially south of the Ohio River. Locally heavy downpours,brief gusty winds and small hail will be the main threats. Storms will taper off from north to south this evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Isolated to scattered thunderstorms will be possible each afternoon from Wednesday through the weekend, especially across south central Kentucky. The greatest coverage will be on Friday. The main hazards will be brief heavy rainfall and lightning. .SPOTTER INFORMATION STATEMENT... Spotters are welcome to report gusty winds, hail and flooding this afternoon. 13/CG/AMS
Special Weather Statement
National Weather Service Louisville KY
128 PM EDT Tue Aug 18 2020
INZ079-KYZ032-181800-
Jefferson-Trimble-
128 PM EDT Tue Aug 18 2020
...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL JEFFERSON AND
NORTHWESTERN TRIMBLE COUNTIES...
At 128 PM EDT, a strong thunderstorm was located near Madison, moving
east at 15 mph.
Wind gusts up to 50 mph and nickel size hail are possible with this
storm.
Locations impacted include...
Madison, Bedford, Hanover, Saluda, Milton, Monitor, Trout, Hanover
Beach and Swanville.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3874 8540 3872 8532 3866 8526 3858 8532
3868 8557 3875 8551
TIME...MOT...LOC 1728Z 292DEG 13KT 3871 8547
DMSpecial Weather Statement
National Weather Service Louisville KY
133 PM EDT Tue Aug 18 2020
KYZ033>035-181800-
Shelby-Henry-Franklin-
133 PM EDT Tue Aug 18 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT CENTRAL SHELBY...
SOUTHEASTERN HENRY AND NORTHERN FRANKLIN COUNTIES...
At 133 PM EDT, radar indicated strong thunderstorms were located
along a line extending from 9 miles southwest of Owenton to
Shelbyville. Movement was southeast at 25 mph.
Winds in excess of 40 mph and half inch hail are possible with these
storms.
Locations impacted include...
Shelbyville, Simpsonville, Pleasureville, North Pleasureville,
Montclair, Elmburg, Harvieland, Elmville, Old Christianburg and
Hatton.
Torrential rainfall is also occurring with these storms, and may
cause localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3846 8491 3845 8491 3844 8493 3842 8488
3838 8490 3837 8487 3836 8487 3836 8484
3834 8479 3835 8474 3833 8474 3809 8510
3823 8537 3847 8495 3844 8496 3843 8496
3843 8494 3846 8493
TIME...MOT...LOC 1733Z 296DEG 21KT 3841 8491 3820 8525
DMSpecial Weather Statement
National Weather Service Louisville KY
140 PM EDT Tue Aug 18 2020
KYZ037-043-181815-
Nicholas-Harrison-
140 PM EDT Tue Aug 18 2020
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN NICHOLAS AND EAST
CENTRAL HARRISON COUNTIES...
At 140 PM EDT, a strong thunderstorm was located near Cynthiana,
moving southeast at 25 mph.
Winds in excess of 40 mph and pea size hail are possible with this
storm.
Locations impacted include...
Cynthiana, Carlisle, Barefoot, Blue Licks Springs, Oddville, Morning
Glory, Ellisville, Venus, Headquarters and Hooktown.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3827 8405 3832 8414 3835 8416 3837 8419
3836 8422 3840 8431 3851 8424 3850 8419
3849 8417 3849 8415 3848 8415 3848 8413
3846 8410 3844 8402 3843 8400 3842 8400
3844 8398 3842 8395
TIME...MOT...LOC 1740Z 296DEG 21KT 3842 8419
DMSpecial Weather Statement
National Weather Service Louisville KY
202 PM EDT Tue Aug 18 2020
KYZ034-035-039-181830-
Shelby-Franklin-Anderson-
202 PM EDT Tue Aug 18 2020
...A STRONG THUNDERSTORM WILL AFFECT EASTERN SHELBY...NORTHEASTERN
ANDERSON AND SOUTHWESTERN FRANKLIN COUNTIES...
At 202 PM EDT, a strong thunderstorm was located 7 miles southeast of
Shelbyville, moving east at 15 mph.
Winds in excess of 40 mph and penny size hail are possible with this
storm.
Locations impacted include...
Frankfort, Lawrenceburg, Bryant, Benson, Farmdale, Capital City
Airport, Broadville Manor, Avenstoke, Harvieland and Alton.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3825 8480 3815 8485 3814 8487 3811 8486
3805 8489 3814 8519 3829 8507
TIME...MOT...LOC 1802Z 286DEG 15KT 3815 8512
DMSpecial Weather Statement
National Weather Service Louisville KY
207 PM EDT Tue Aug 18 2020
KYZ043-181830-
Nicholas-
207 PM EDT Tue Aug 18 2020
...A STRONG THUNDERSTORM WILL AFFECT CENTRAL NICHOLAS COUNTY...
At 207 PM EDT, a strong thunderstorm was located near Carlisle,
moving east at 15 mph.
Winds in excess of 40 mph and half inch hail are possible with this
storm.
Locations impacted include...
Carlisle, Blue Licks Springs, Weston, Ellisville, Pleasant Valley,
Headquarters, Sprout, Barterville and Myers.
Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 3827 8389 3835 8414 3846 8409 3846 8407
3844 8403 3844 8402 3843 8400 3842 8400
3844 8398 3843 8395 3836 8392 3836 8389
3835 8390 3836 8387 3833 8386 3834 8384
3832 8385 3831 8383
TIME...MOT...LOC 1807Z 286DEG 15KT 3839 8405
DMSpecial Weather Statement National Weather Service Louisville KY 216 PM EDT Tue Aug 18 2020 INZ077-090>092-181845- Washington-Floyd-Clark-Harrison- 216 PM EDT Tue Aug 18 2020 ...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL HARRISON...WEST CENTRAL CLARK...NORTHWESTERN FLOYD AND SOUTH CENTRAL WASHINGTON COUNTIES... At 216 PM EDT, a strong thunderstorm was located 11 miles north of Corydon, moving east at 15 mph. Winds in excess of 40 mph and pea size hail are possible with this storm. Locations impacted include... Galena, Palmyra, Borden, Greenville, Fredericksburg, Navilleton, Starlight, Byrneville, Martinsburg and Bradford. Torrential rainfall is also occurring with this storm, and may cause localized flooding. Do not drive your vehicle through flooded roadways. LAT...LON 3837 8621 3848 8615 3847 8587 3829 8593 TIME...MOT...LOC 1816Z 281DEG 14KT 3838 8612 DM
The Louisville radar (KLVX), 95 km away, was scanning. The volume nearest the first event began at 18:22 UTC.
3 thunderstorm wind, 1 lightning. Local standard time, as filed.
A large tree branch was snapped in Juniper Hills Park in Frankfort.
There was a tree on a power line on Highway 62.
A tree fell down on a car on Old Lawrenceburg Road.
Lightning struck a tree which brought down power lines and landed on a house.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Kentucky in 2020Every state in 2020This day in weather historyWarnings in Kentucky, August 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 918711, 918713, 918714, 918710.