Slow moving thunderstorms developed ahead of a weak low pressure system in eastern Kentucky.
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The episode as NWS ILN wrote it up.
Slow moving thunderstorms developed ahead of a weak low pressure system in eastern Kentucky.
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 Wilmington, OH wrote its last area forecast discussion before the first event at Aug 15, 12:55 PM EST, 40 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Wilmington OH 155 PM EDT Sat Aug 15 2020 .SYNOPSIS... Weak low pressure in eastern Kentucky will slowly move northeast today and tonight. A weak cold front will cross the region on Sunday followed by a secondary front on Monday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... An inverted trough extending north from a weak surface low in Kentucky looks like it will provide enough convergence for additional showers and storms to develop in the afternoon across the middle of the forecast area. Like yesterday, this activity will propagate westward. Temperatures will rise into the mid 80s in western counties. In the east decreasing cloudiness may be late enough to keep temperatures from getting out of the upper 70s or lower 80s. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... Some showers may linger in western counties in the early evening before dissipating. Skies will clear out at least for the evening but then may redevelop late at night. A weak cold front will approach and move through the area on Sunday. Showers and thunderstorms will increase in coverage ahead of this boundary as it sweeps across the area. There will be some shear as a mid level short wave moves through with the front. Even though lapse rates are not all that impressive, some stronger storms are not out of the question. Lows will be in the lower to mid 60s with highs back in the upper 70s to mid 80s. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... As the cold front exits to the southeast earlier in the evening, any lingering showers or thunderstorms will quickly exit and die out, in favor of clearing skies and cooler temperatures with lows near 60 degrees. Some cold pool showers may occur over northern reaches of the CWA in the afternoon, as the daytime heating combines with some lingering upper level spin still present after the mean l/w trof moves east. Highs will be a degree or sow warmer but relatively similar to Sunday's highs in the lower 80s, mainly due to less rainfall and some sunshine. High pressure building to the west and another digging upper level trough will keep cool air and some instability showers possible during peak heating on Tuesday. Overnight lows will drop 2-3 degrees for Mon night and again Tues night, bottoming out then in the mid 50s northwest to near 60 in the southeast. Low temps beyond Wed morning will remain in the upper 50s to low 60s through the remainder of the forecast. Highs take a similar turn, bottoming out within a degree or three of 80 Tue and Wed, rising to the low and mid 80s for the rest of the week. The cool air is due to a surface high to the west or north of the region and a continued deep northwest to west flow. This flow will gradually weaken late in the period with an upper low developing southwest of the Ohio Valley and gradually nose into the region Saturday, being pushed east on Sunday. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... An inverted low level trough over central and south central Ohio this afternoon is forecast to propagate west for the remainder of the afternoon hours. Some scattered showers/storms are expected with this feature as the drift toward the south/southwest. Have placed a TEMPO TSRA at KCMH/KLCK at the onset of the terminals with VCTS elsewhere. Locally MVFR/IFR conditions can occur in the more robust storms. For tonight, convection will wane with the loss of heating, allowing skies to become mostly clear. Some patchy to perhaps areas of mist/fog will form across central/south central Ohio and along and south of the Ohio River. Have brought some MVFR/IFR visibilities at the various terminals for now to get the forecast to trend in this direction should mist/fog become more prevalent or lower in conditions. On Sunday, any fog/mist will lift between 12Z and 14Z. A cold front is expected to move into the area during the afternoon. Diurnal heating will allow the atmosphere to destabilize. And with just enough deep wind shear and low level forcing, scattered showers and thunderstorms are forecast to develop. Have placed a VCSH in the terminals for now since it is still quite a way out in the future. As usual, aviators can expect MVFR/IFR conditions in the more robust thunderstorms. The winds through the period will vary quite a bit given the inverted trough then the approach of the cold front. OUTLOOK...No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && SYNOPSIS...Hickman NEAR TERM...Hickman SHORT TERM... LONG TERM...Franks AVIATION...Hickman
Hazardous Weather Outlook National Weather Service Wilmington OH 1108 AM EDT Sat Aug 15 2020 INZ050-058-059-066-073>075-080-KYZ089>100-OHZ026-034-035-042>046- 051>056-060>065-070>074-077>082-088-161515- Wayne-Fayette IN-Union IN-Franklin IN-Ripley-Dearborn-Ohio- Switzerland-Carroll-Gallatin-Boone-Kenton-Campbell-Owen-Grant- Pendleton-Bracken-Robertson-Mason-Lewis-Hardin-Mercer-Auglaize-Darke- Shelby-Logan-Union OH-Delaware-Miami-Champaign-Clark-Madison- Franklin OH-Licking-Preble-Montgomery-Greene-Fayette OH-Pickaway- Fairfield-Butler-Warren-Clinton-Ross-Hocking-Hamilton-Clermont-Brown- Highland-Adams-Pike-Scioto- 1108 AM EDT Sat Aug 15 2020 This Hazardous Weather Outlook is for East Central Indiana, Southeast Indiana, Northeast Kentucky, Northern Kentucky, Central Ohio, South Central Ohio, Southwest Ohio and West Central Ohio. .DAY ONE...This afternoon and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Sunday through Friday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
1016 AM EDT SAT AUG 15 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0648 PM TSTM WND DMG 1 SSE MARYSVILLE 40.23N 83.37W
08/14/2020 UNION OH PUBLIC
LARGE TREE SPLIT IN HALF. REPORT VIA SOCIAL MEDIA.
PICTURE VERIFIED. TIME ESTIMATED.
&&
BINAUSpecial Weather Statement
National Weather Service Wilmington OH
142 PM EDT Sat Aug 15 2020
OHZ056-151815-
Licking OH-
142 PM EDT Sat Aug 15 2020
...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN LICKING COUNTY
UNTIL 215 PM EDT...
At 141 PM EDT, radar indicated a strong thunderstorm over Marne,
moving southwest at 15 mph.
STORM HAZARDS INCLUDE...
Winds to 35 mph...
Very heavy rain...
Locations impacted include...
Newark, Heath, Granville, Buckeye Lake, Hebron, Hanover, Granville
South, Marne, Harbor Hills, Beechwood Trails, Kirkersville, Toboso,
Interstate 70 at State Route 37 and Fallsburg.
This includes I-70 in Ohio between mile markers 121 and 132.
Water will pond on roads and may quickly fill roadside ditches and
small streams.
To report hazardous weather conditions, go to our website at
weather.gov/iln and submit your report via social media, when you can
do so safely.
LAT...LON 4003 8220 3993 8246 3993 8264 4003 8264
4023 8219
TIME...MOT...LOC 1741Z 055DEG 12KT 4009 8230
ConiglioSpecial Weather Statement
National Weather Service Wilmington OH
214 PM EDT Sat Aug 15 2020
OHZ056-151845-
Licking OH-
214 PM EDT Sat Aug 15 2020
...A STRONG THUNDERSTORM WILL AFFECT LICKING COUNTY UNTIL 245 PM
EDT...
At 214 PM EDT, radar indicated a strong thunderstorm over Granville,
moving southwest at 15 mph.
STORM HAZARDS INCLUDE...
Winds to 35 mph...
Very heavy rain...
Locations impacted include...
Newark, Reynoldsburg, Heath, Granville, Pataskala, Johnstown, Hebron,
Utica, Hanover, Granville South, Marne, Beechwood Trails, Summit
Station, Etna, New Albany, Jersey, Kirkersville, Alexandria, St.
Louisville and Purity.
This includes I-70 in Ohio between mile markers 114 and 125.
Water will pond on roads and may quickly fill roadside ditches and
small streams.
To report hazardous weather conditions, go to our website at
weather.gov/iln and submit your report via social media, when you can
do so safely.
LAT...LON 3999 8220 3993 8262 3994 8278 4012 8276
4022 8249 4024 8219
TIME...MOT...LOC 1814Z 061DEG 11KT 4009 8250
ConiglioThe national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
High water was reported on OH-16 between Church Street and 21st Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2020Every state in 2020This day in weather historyWarnings in Ohio, 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: 902249.