Flash Flood Warning 32, NWS Wilmington, OH

102 
WGUS71 KILN 042233
FFSILN

Flash Flood Statement
National Weather Service Wilmington OH
633 PM EDT SAT AUG 4 2018

KYC037-OHC061-050030-
/O.CON.KILN.FF.W.0032.000000T0000Z-180805T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Campbell KY-Hamilton OH-
633 PM EDT SAT AUG 4 2018

...THE FLASH FLOOD WARNING FOR NORTHERN CAMPBELL AND SOUTH CENTRAL
HAMILTON COUNTIES REMAINS IN EFFECT Until 830 PM EDT....

At 632 PM EDT, radar indicated that thunderstorms had produced three 
inches or more of rain around Dayton, Bellevue, and the East End. 
The heavy rainfall has ended across the area. However, runoff from 
the earlier excessive rain will cause flash flooding to occur.

Some locations that will experience flooding include...
Cincinnati, Covington, Fort Thomas, Newport, Highland Heights,
Bellevue, Dayton, Southgate, Wilder, Silver Grove, Riverbend And
Coney Island, Woodlawn and Lunken Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life. 

To report flash flooding, go to our website at weather.gov/iln and
submit your report via social media, when you can do so safely.

&&

LAT...LON 3913 8451 3914 8442 3905 8440 3905 8450
      3906 8450 3907 8449 3909 8450

$$

612 
WGUS71 KILN 042359
FFSILN

Flash Flood Statement
National Weather Service Wilmington OH
759 PM EDT SAT AUG 4 2018

KYC037-OHC061-050009-
/O.CAN.KILN.FF.W.0032.000000T0000Z-180805T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Campbell KY-Hamilton OH-
759 PM EDT SAT AUG 4 2018

...THE FLASH FLOOD WARNING FOR NORTHERN CAMPBELL AND SOUTH CENTRAL
HAMILTON COUNTIES IS CANCELLED...

The heavy rain has ended and flooding is no longer expected to pose a
threat.

Please report previous flash flooding to the National Weather Service
by going to our website at weather.gov/iln and submitting your report
via social media.

LAT...LON 3913 8451 3914 8442 3905 8440 3905 8450
      3906 8450 3907 8449 3909 8450

$$

Area Forecast Discussion
National Weather Service Wilmington OH
318 PM EDT Sat Aug 4 2018

.SYNOPSIS...
Isolated showers and storms will continue amidst a warm and
humid airmass this afternoon and Sunday afternoon, but most
areas will remain dry. Early next week several weak disturbances
and a cold front will begin moving toward the area with a better
chance of more widespread showers and storms, with cooler
weather expected by the middle of next week in the wake of this
system.

&&

.NEAR TERM /UNTIL 9 PM THIS EVENING/...
GOES-East water vapor loops and and RAP model analyses clearly
indicated a weakening positive tilt mid-level shortwave trough
across southern OH/northern KY. Underneath and immediately in
the wake of this weak disturbance, a very baggy/weak surface
pressure pattern was present where sheltering/shallowing of the
boundary layer in comparison to areas further north/east had
allowed dewpoints to fail to mix out - holding in the lower to
middle 70s over southern ILN CWA. In this airmass, MLCAPE has
approached and even exceeded 2000 J/KG amidst very weak
tropospheric flow, with effective shear values < 10kts, and
cloud-layer mean winds of only ~10kts as well. The 04.12Z KILN
sounding sampled this weaker flow aloft, which has weakened
further as the trough continues to lose amplitude and be
cutoff/swallowed up by larger scale/background height rises
downstream of deeper troughing to our west.

Isolated storms this afternoon have behaved according to their
forcing regime - very low predictability of initiation and a
rapid increase/decrease of updraft magnitude over the course of
an hour. Numerous weak downdraft signatures have been seen via
WSR- 88D/TDWR, with outflows quickly becoming apparent after
thunderstorm mass reaches a maximum. Anvil level winds blowing
exhausted thunderstorm mass to the southwest back over the
updrafts have also kept the thunderstorm lifecycle brief owing
to efficient seeder/feeder processes and quick water loading of
the downdraft. Expect the chaotic/low predictability formation,
and thus the rapid increase/decrease of this storm lifecycle to
continue through about 21Z after which skies should clear as
the boundary layer decouples.

.SHORT TERM /9 PM THIS EVENING THROUGH MONDAY NIGHT/...

Expect shallow fog to be possible across many areas tonight as
is typical for humid August nights in the Ohio Valley. The
valley fog may be locally thick for a few hours overnight
especially in the tributaries feeding into the Ohio River and
main channel itself.

On Sunday, a very similar scenario to today is expected albeit
with the following exceptions 1) forcing for ascent will be even
weaker in the absence of the weak shortwave trough across the
area and 2)a modest reduction in instability with slightly lower
dewpoints. Despite these unsupportive changes for the chance of
afternoon storms, moderate destabilization will again take place
in the boundary layer by 15Z. Diurnally forced cumulus will
lead to more isolated airmass-type showers and thunderstorms
during the peak of the diurnal cycle, and while the CAM signal
for location is chaotic as can be expected given weak background
forcing, there is a relative maximum over the ILN CWA from
Columbus back down toward Wilmington, and this is where the rain
chances were inserted into the forecast.

On Monday, while large scale forcing is still mostly absent from
the area, the warm/muggy boundary layer will remain and will be
gently impinged by a slight increase in westerly flow and
glancing shortwave trough energy to our northwest, and some hint
of energy also impinging from the south. It's not much to hang a
forecast on, but think the afternoon once again will see
isolated/scattered showers and storms with better chances across
nrn KY/wrn OH/ern IN but this is not an overly strong/confident
signal in the data.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
An area of low pressure and associated frontal boundary will
approach the region on Tuesday bringing with it showers and
thunderstorms.  Temperatures on Tuesday will be warmer across
southeastern portions of the region where it will take longer for
precipitation and cloud cover to work into the area.

The frontal boundary lays out across the region for Wednesday before
pushing out of the region Wednesday night. On Wednesday there is
better upper support than on Tuesday and therefore increased
precipitation chances from superblend on Wednesday.  The frontal
boundary in the vicinity and associated cloud cover will keep
temperatures cooler and around 80 degrees.

There are some model differences and run to run variability for
Thursday and Friday with any precipitation possibilities.  Due to
this variability decided to go with a dry forecast for now, however
cannot rule out some isolated activity during these two days.  There
is more continuity with a disturbance moving through on Saturday and
therefore have a chance of thunderstorms in during that time.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
Diurnal cumulus has developed schedule and enough instability is
present for isolated showers/storms which have developed in
humid airmass characterized by very weak deep layer flow.
Coverage of these will peak through 21Z before onset of boundary
layer cooling will cause rapid decrease in coverage. Included a
VCSH initially at KDAY for radar trends but in reality may need
to add VCSH to KILN/KLUK/KCVG this afternoon - all of which lie
in area of greater instability in comparison to KCMH. If one of
these small showers/storms impacts an airfield - expect brief
MVFR/IFR visibilities in the core of the downpour with up to
30kts of wind. But expect threat to be too isolated for
inclusion in most TAFs. Skies becoming partly cloudy to clear
overnight as cumulus dissipates and winds decouple to calm or
light/variable at worst. Fog could again be a problem at KLUK
near so have continued a tempo group to IFR visibility there.
Outside of that, expect some potential reduction to MVFR
visibility at other sites especially 08Z-12Z timeframe.
Confidence is not high in this - only hinting at this via 5-6SM
visibilities in most TAFs. Later tomorrow morning into Sunday
afternoon, expect more towering cumulus to develop with
isolated showers/storms, with the best signal from the Columbus
terminals southwest back to KILN. These also expected to be
quite isolated in nature, thus no inclusion at this time.

OUTLOOK...Thunderstorms possible Monday and Wednesday, and
likely on Tuesday.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.

&&

SYNOPSIS...Binau
NEAR TERM...Binau
SHORT TERM...Binau
LONG TERM...Novak
AVIATION...Binau

Hazardous Weather Outlook
National Weather Service Wilmington OH
333 AM EDT Sat Aug 4 2018

INZ050-058-059-066-073>075-080-KYZ089>100-OHZ026-034-035-042>046-
051>056-060>065-070>074-077>082-088-050745-
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-
333 AM EDT Sat Aug 4 2018

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...Today and Tonight.

No hazardous weather is expected at this time.

.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
516 PM EDT SAT AUG 4 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0501 PM     TSTM WND GST     KLUK LUNKEN AIRPORT     39.10N 84.42W
08/04/2018  M47 MPH          HAMILTON           OH   ASOS

            28041KTS

&&

JEG

Special Weather Statement
National Weather Service Wilmington OH
525 PM EDT SAT AUG 4 2018

KYZ092-093-OHZ077-042200-
Kenton KY-Campbell KY-Hamilton OH-
525 PM EDT SAT AUG 4 2018

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL KENTON...NORTHERN
CAMPBELL AND SOUTHEASTERN HAMILTON COUNTIES UNTIL 600 PM EDT...

At 524 PM EDT, radar indicated a strong thunderstorm over Dayton.
This storm was nearly stationary.

STORM HAZARDS INCLUDE...
Winds to 45 mph...
Very heavy rain...

Locations impacted include...
Cincinnati, Covington, Norwood, Fort Thomas, Newport, Fort Mitchell,
Highland Heights, Bellevue, Fort Wright, Dayton, Ludlow, Southgate,
Park Hills, Mariemont, Wilder, Silver Grove, Riverbend And Coney
Island, University of Cincinnati, Plainville and Salem Heights.

This includes the following Interstates...
 I-71 in Ohio between mile markers 0 and 7.
 I-74 in Ohio near mile marker 19.
 I-75 in Kentucky between mile markers 188 and 191.
 I-75 in Ohio between mile markers 0 and 5.

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 3916 8455 3915 8436 3904 8440 3905 8456
TIME...MOT...LOC 2124Z 345DEG 2KT 3911 8445