Thunderstorms developed in a very moist and unstable airmass producing heavy rain and some strong winds.
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 ILN wrote it up.
Thunderstorms developed in a very moist and unstable airmass producing heavy rain and some strong winds.
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 13, 12:33 PM EST, 1 hour 29 minutes earlier.
Area Forecast Discussion
National Weather Service Wilmington OH
133 PM EDT SAT AUG 13 2016
.SYNOPSIS...
A warm and very moist airmass will remain parked over the region
through the weekend as a slow-moving frontal boundary moves
southeast through the area. This front will serve as a focus for
shower and thunderstorm activity today into Sunday. The front
will stall across southern parts of the area early Monday before
pivoting back north, allowing for the unsettled pattern to
continue into the work week.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Deep southerly / southwesterly flow remains in place over the Ohio
Valley region, with a very slow-moving frontal boundary currently
extending from Saginaw Bay to near St. Louis.
To begin with a discussion of non-flooding issues, the overall
forecast for temperatures and dewpoints today appeared to
generally be on track. The temperature trends were adjusted for
timing, based on expectations for convection, especially in the
northwestern half of the forecast area. In the southeastern corner
of the forecast area, where conditions will be less favorable for
rain during the first half of the day, temperatures are likely to
approach 90 degrees. This will bring heat indices into the mid to
upper 90s, which has been included in the HWO. Also included in
the HWO is the threat for some strong winds with convection.
Though this moist environment is not favorable for severe weather
in a typical sense, there should be enough instability to allow
for strong precip-loaded downdrafts. In addition, though quite
unidirectional, deep-layer shear (0-3km of 25 knots and 0-6km of
35 knots) appears sufficient enough to support a few forward
propagating segments or clusters. Thus, some strong winds are
expected, with at least some chance of a storm or two reaching
severe levels.
The main concern continues to be the threat for heavy rainfall and
flash flooding. The 12Z KILN sounding recorded a precipitable
water value of right around 2.00", give or take a hundredth or two
depending on the math used in the calculation. This value actually
matches up quite well with the 12Z NAM initialization, though the
NAM initialized about 0.10"-0.20" too high over Arkansas, where
precipitable water values are highest. Nonetheless, its forecast
of values of around 2.10"-2.20" over the ILN CWA this afternoon
appears reasonable -- in slight contrast to the 06Z GFS / 09Z
SREF, which are both a little higher. Regardless of the exact
value, this is a significant amount of available moisture -- a
tropical environment that changes the nature of convection and
flash flood monitoring. For example, in environments like this,
even lowest-slice radar echoes of around 50 dBZ can produce
incredible rainfall rates. Though near-surface forcing is not
especially strong, initial convection this morning has developed
within the right entrance region of an upper jet, and just on the
warm side of the aforementioned frontal boundary. This boundary is
oriented roughly parallel to the overall wind flow through the
majority of the troposphere, and thus it has been no surprise that
echoes are already showing signs of training.
As this front very slowly moves to the southeast, storm coverage
over the ILN forecast area is expected to increase, especially
between 16Z-18Z. Individual storm motions are expected to be
toward the northeast, but with some degree of eastward
propagation. The greatest convective chances appear to exist for
the western and northwestern sections of the CWA. In fact, with
how slow the front is progressing, convective chances for the
southeastern CWA appear somewhat limited this afternoon -- perhaps
a little higher this evening. Overall, though, models are
suggesting a waning trend in convective coverage after 22Z. This
doesn't necessarily make sense with regards to the diurnal cycle,
so perhaps the diminishing trend will occur slightly later than
that. Some degree of a break in precipitation is expected for the
first half of the overnight period, as influence from a passing
mid-level wave moves on to the northeast.
In convective situations like this, it is never easy to forecast
an area-wide, averaged-out widespread rainfall amount, especially
when high rainfall rates within storms will further increase the
disparity from location to location. With that said, 09Z SREF
plumes provide a nice snapshot of the potential -- a mean of just
over an inch in the SW CWA, with lower members coming in with
around a half inch, and higher members coming in with 2-3 inches.
Storm placement and alignment (especially training) will determine
where flooding ends up being possible, but it is a threat that
certainly exists, and the flash flood watch will be continued as
currently oriented. Low flows on rivers in the area will likely
preclude any significant threat for river flooding, though a few
of the faster-rising streams could be impacted. Recent OHRFC
MMEFS forecasts suggest little concern for river flooding.
All three climate sites are currently in the running to set record
high minimum temperatures for August 13. Here are the records as
they currently stand.
CVG...76 degrees...set in 1918
CMH...75 degrees...set in 1995
DAY...76 degrees...set in 1995
Daily rainfall records for August 13 are also listed below.
CVG...1.85"...set in 1997
CMH...1.03"...set in 1896
DAY...1.12"...set in 1939
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
Difficult forecast exists tonight in that a few models are
shunting the storms into southern CWA while others keep a
continued moisture feed in the northwest. GFS has an alarming void
of rain in the northwest tonight from 6-12z and has some support
from the NAM and the ARW. ARW is still showing a swath of rain
northwest of the I-71 corridor albeit a very narrow swath. Am
hesitant to lower the rain chances tonight given that this is when
the southwest is expected to be ramping up the heavier rain.
Confidence in the placement of rain remains low but the occurrence
of tremendous rainfall rates over a narrow swath where
regenerating storms may be found is high. Need to balance the
possibility of a lull with the continued heavy rain threat and err
on the side of caution. Thus have not cut back the chance of
rain tonight at this moment in time.
Sunday will see lingering storms over the boundary that may shift
northwest overnight. Unfortunately, the Bermuda high will keep
some upper level trough over the western portion of the CWA
through the forecast period and keep the threat for a band of
showers and thunderstorms over the region. Airmass does not modify
at all through this time and 2"+ PWAT values will keep the heavy
rain threat over the region in the foreseeable future.
Temperatures will drop slightly from the precipitation from Sunday
onward, but the uncomfortably moist air will remain in place.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Tuesday into Wednesday PV will continue to stream over the area
as the mid-level trough over southern Canada and the mid-level
ridge off the eastern seaboard remain quasi- stationary. PWATs on
the GFS also continue around 2.00". These prolonged high moisture
values along with upper level lift will help keep the chance of
rain in the forecast through at least Thursday morning. Have
raised PoPs Tuesday into Wednesday to account for this.
Thursday into Friday PWATs will slowly fall to around 1.5" as the
mid-level ridge finally breaks down allowing the trough axis over
southern Canada to push east out of the area. Instability remains
across the region though so have kept the mention of precip in the
forecast through the extended. Towards the end of the extended an
upper level shortwave will dive south near the Pacific Northwest
pushing a cold front south through the midwest. The ECMWF is slower
with the wave and the corresponding surface front while the GFS is
much more progressive. Either way the front is still west of the
area next Saturday but could be the next cold front to cross the
area.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
The chance of thunderstorms is the main item of concern for the
aviation forecasts this afternoon. An area of widespread rain,
with embedded areas of storms and heavy rain, is currently
northwest of the TAF sites -- with a few small cells developing
out in front. As these storms move into the area, MVFR conditions
can be expected, and some MVFR ceilings already exist even outside
of the storms. If a heavy storm moves over one of the airports,
IFR visibilities can be expected, and this will be adjusted in
the TAFs if necessary.
Widespread are likely to come to an end early this evening, with a
respite expected to continue into the overnight hours. Some MVFR
visibilities or ceilings will be possible overnight. Another round
of storms is expected to develop early Sunday morning, primarily
between 09Z-15Z. These storms will again be capable of MVFR/IFR
conditions and heavy rainfall.
Southwest winds this afternoon (with gusts of up to 20 knots) will
subside tonight, and gradually shift to the west. Winds outside
of storms should remain under 10 knots overnight and on Sunday.
OUTLOOK...Showers and thunderstorms are expected on occasion through
Wednesday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...Flash Flood Watch through Sunday evening for OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...Flash Flood Watch through Sunday evening for KYZ089>100.
IN...Flash Flood Watch through Sunday evening for INZ050-058-059-
066-073>075-080.
&&
SYNOPSIS...Franks
NEAR TERM...Hatzos
SHORT TERM...Franks
LONG TERM...Haines
AVIATION...HatzosHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE WILMINGTON OH 938 AM EDT SAT AUG 13 2016 INZ050-058-059-066-073>075-080-KYZ089>096-OHZ026-034-035-042>046- 051>056-060>065-070>072-077-078-141345- WAYNE-FAYETTE IN-UNION IN-FRANKLIN IN-RIPLEY-DEARBORN-OHIO- SWITZERLAND-CARROLL-GALLATIN-BOONE-KENTON-CAMPBELL-OWEN-GRANT- PENDLETON-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-HAMILTON-CLERMONT- 938 AM EDT SAT AUG 13 2016 ...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH SUNDAY EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL INDIANA...SOUTHEAST INDIANA...NORTHERN KENTUCKY...CENTRAL OHIO...SOUTHWEST OHIO AND WEST CENTRAL OHIO. .DAY ONE...TODAY AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. IN ADDITION TO THE THE THREAT FOR FLOODING...WHILE WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...SOME STORMS THIS AFTERNOON MAY BE CAPABLE OF PRODUCING STRONG WIND GUSTS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL TOTALS TO THE NATIONAL WEATHER SERVICE. KYZ097>100-OHZ073-074-079>082-088-141345- BRACKEN-ROBERTSON-MASON-LEWIS-ROSS-HOCKING-BROWN-HIGHLAND-ADAMS-PIKE- SCIOTO- 938 AM EDT SAT AUG 13 2016 ...FLASH FLOOD WATCH IN EFFECT FROM 2 PM EDT THIS AFTERNOON THROUGH SUNDAY EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST KENTUCKY...NORTHERN KENTUCKY...CENTRAL OHIO AND SOUTHWEST OHIO. .DAY ONE...TODAY AND TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. HEAT INDEX VALUES THIS AFTERNOON ARE EXPECTED TO REACH THE MIDDLE TO UPPER 90S. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT RAINFALL TOTALS TO THE NATIONAL WEATHER SERVICE. HATZOS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE WILMINGTON OH 118 PM EDT SAT AUG 13 2016 OHZ034-035-042-043-131745- AUGLAIZE OH-MERCER OH-DARKE OH-SHELBY OH- 118 PM EDT SAT AUG 13 2016 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN AUGLAIZE... SOUTHEASTERN MERCER...NORTHERN DARKE AND NORTHWESTERN SHELBY COUNTIES UNTIL 145 PM EDT... AT 117 PM EDT...RADAR INDICATED A STRONG THUNDERSTORM NEAR ANSONIA... MOVING NORTHEAST AT 40 MPH. STORM HAZARDS INCLUDE... WINDS TO 40 MPH... FREQUENT CLOUD TO GROUND LIGHTNING... VERY HEAVY RAIN... LOCATIONS IMPACTED INCLUDE... SIDNEY...NEW BREMEN...MINSTER...VERSAILLES...FORT LORAMIE... ANSONIA...NEW KNOXVILLE...RUSSIA...OSGOOD...CHICKASAW... BURKETTSVILLE...NORTH STAR...ROSSBURG...KETTLERSVILLE...NEW WESTON... YORKSHIRE...NEWPORT IN SHELBY COUNTY...ELDORA SPEEDWAY... LAKE LORAMIE STATE PARK AND ROSE HILL. THIS INCLUDES I-75 IN OHIO BETWEEN MILE MARKERS 94 AND 95. DO NOT STAY IN THE OPEN NOR SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS. MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. 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 4056 8432 4032 8415 4013 8472 4030 8480 TIME...MOT...LOC 1717Z 240DEG 37KT 4025 8470 CONIGLIO
The Cincinnati radar (KILN), 98 km away, was scanning. The volume nearest the first event began at 19:01 UTC.
1 thunderstorm wind, 1 heavy rain. Local standard time, as filed.
One tree was knocked down in Orange Township.
Three cars were stranded in high water.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Ohio in 2016Every state in 2016This day in weather historyWarnings in Ohio, August 2016
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: 643616, 643617.