Flood and Hail in Ohio, March 28, 2020

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1025 AM EDT Sat Mar 28 2020

.SYNOPSIS...
A warm front will lift north of the area this morning. This will
allow for very warm temperatures, although with a continued
chance of showers and thunderstorms, until a cold front sweeps
across the region late tonight. Windy conditions will follow on
Sunday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A shortwave trough is ejecting into the central US from the desert
southwest and leading to cyclogenesis in the central Plains. East of
the deepening surface cyclone, a warm front has pushed north of the
forecast area into northern Ohio. Thunderstorms have been observed
along and just north of the warm front clipping Mercer, Auglaize,
and Hardin counties. The convection has been elevated in nature.
Thus, the main threat has been hail. The storms associated with the
warm front are expected to continue progressing north of the area
today.

Breezy southerly winds in the warm sector east of the cyclone will
help to usher in warm and moist air into the area today. Dew points
are forecast to reach the low to mid 60s areawide with highs near 80
by the Ohio River and middle 70s across central Ohio/eastern
Indiana. Any breaks in the cloud cover could lead to highs being a
couple degrees warmer than currently forecast.

As surface temperatures warm and dew points rise today there may be
a developing threat for thunderstorms as instability develops. A
warm layer aloft around 750 hPa was observed on the 1200Z ILN
sounding and this CAP would help to inhibit deep, moist convection,
as forcing approaches later today, but the warm layer aloft should
erode as the day progresses. As the warm layer weakens, it would not
take much to have thunderstorms form this afternoon in the presence
of 1000+ J/kg of surface based CAPE. The shear profile is also
forecast to be supportive of severe weather (all threats) with a
straight line hodograph containing speed shear. The main forecast
challenge is determining whether or not storms will be present due
to lack of a strong forcing mechanism later today. Currently,
forecasting a slight chance to a chance for thunderstorms given the
destabilizing environment today with the low approaching from the
west and the warm front lifting north.

Previous discussion...
Showers and thunderstorms moving across
the northern half of Indiana will continue northeast with the
low level jet. This activity may still impact west central Ohio
with some heavier rainfall. So the flash flood watch remains in
effect into the morning.

Once this convection moves through, the low level jet weakens.
However, an axis of very high moisture will linger across the
forecast area stretching east northeast to west southwest.
Temperatures will warm substantially resulting in a
destabilizing atmosphere. Past several runs of the HRRR have
been trending towards scattered convection developing along this
axis.

Temperatures will be very warm, ranging from the upper
60s in parts of west central Ohio to lower 80s along and south
of the Ohio River.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Expect the warm sector to have a minimum of activity during the
evening. But showers and storms will move across the area after
midnight along and ahead of a cold front that will sweep across
the region late tonight. While there will be plenty of shear,
instability will be decreasing by the time activity moves into
the area. It is not even clear how expansive precipitation will
be as some CAMs are indicating that little may be occurring this
far east. Any storms that can remain robust will have some
severe potential with damaging wind the main threat given fairly
straight hodographs and linear forcing.

In the wake of the front there will be an initial surge of cold
air advection, but then that becomes rather weak later in the
day. But there will be some sun allowing for mixing. This in
association with a tightening pressure gradient will result in
a substantial increase in winds during the morning. It will
remain windy through the remainder of the day with northwest
counties near wind advisory criteria.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
On Sunday evening, stacked low pressure will be centered over the
northern lower peninsula of Michigan. Deep-layer WSW flow will be in
place across the Ohio Valley, and gusty winds from Sunday afternoon
will be gradually subsiding. Pseudo-zonal flow will remain in place
through Monday, with a north-to-south temperature gradient in place,
with highs ranging from around 50 to the lower 60s. A secondary
frontal boundary is expected to move south into the region on Monday
night. This will allow Tuesday to be the coolest day of the extended
forecast period, with max temps in the upper 40s to mid 50s. Through
the rest of the period, max temps should rebound more solidly into
the 50s -- seasonable for early April.

The main chance for precipitation during the extended forecast
period will be from Tuesday morning through Wednesday morning.
Attention will turn to a shortwave moving east across the central
part of the CONUS. This wave will also develop a surface low, which
will move east across the southern tier of states on Tuesday, and
then northeast into the mid-Atlantic region on Tuesday night. Lift
ahead of these features will eventually spread precipitation into
the Ohio Valley on Tuesday, continuing into Wednesday, with fairly
strong model agreement in a period of rain -- especially across the
southern half of the ILN forecast area on Tuesday evening. There has
been some model variability with regards to how quickly this system
exits the area on Wednesday, but the trend toward more rapid drying
out has been apparent, and thus PoPs have been shaved back
considerably on Wednesday. It remains possible that some low-level
moisture could remain in place and contribute to a low chance of
showers or drizzle on Wednesday. With too little instability to
support a chance of thunder, and no signs of heavy rain, this system
is not expected to bring any significant impacts to the area.

Late in the week, there are signs that a large upper low will be
moving ESE across the northern tier of states, which may have some
impact to the weather in the Ohio Valley by late Thursday or Friday.
As of now, there is a significant amount of model variability with
regards to this system, so forecast confidence remains low beyond
Thursday.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
Visibility restrictions at KLUK will dissipate early. Otherwise
VFR will prevail early in the TAF period with winds gradually
increasing and veering to the southwest. Guidance has been
trending to a stronger signal that at least scattered convection
will occur during the day, but there is still a fair bit of
uncertainty whether this will occur. So have included a several
hour period of VCTS at all sites. Ceilings that develop during
this time frame may fall to MVFR. After 21Z expect any ceilings
to be lifting and convective activity may be decreasing. A cold
front will sweep across the terminals late in the TAF period.
There may be convection occurring along and ahead of this front.
Winds will become gusty after the front passes.

OUTLOOK...Wind gusts 30 kt or higher will occur on Sunday.

&&

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

&&

SYNOPSIS...
NEAR TERM...Campbell
SHORT TERM...
LONG TERM...Hatzos
AVIATION...

Hazardous Weather Outlook
National Weather Service Wilmington OH
1025 AM EDT Sat Mar 28 2020

INZ050-058-059-066-073>075-KYZ091>093-OHZ026-034-035-042>046-051>056-
060>065-070>072-077>080-291430-
Wayne-Fayette IN-Union IN-Franklin IN-Ripley-Dearborn-Ohio-Boone-
Kenton-Campbell-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-Brown-Highland-
1025 AM EDT Sat Mar 28 2020

This Hazardous Weather Outlook is for East Central Indiana,
Southeast Indiana, Northern Kentucky, Central Ohio, South Central
Ohio, Southwest Ohio and West Central Ohio.

.DAY ONE...Today and tonight.

Scattered showers and thunderstorms are forecast this afternoon. A
few storms may be strong to severe with damaging winds and large
hail.

Additional showers and thunderstorms will then move across the area
after midnight. There is the potential for a few storms to be severe
with damaging straight-line winds the primary threat.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Wind gusts of 40 to 50 mph are expected on Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and tonight.

INZ080-KYZ089-090-094>100-OHZ073-074-081-082-088-291430-
Switzerland-Carroll-Gallatin-Owen-Grant-Pendleton-Bracken-Robertson-
Mason-Lewis-Ross-Hocking-Adams-Pike-Scioto-
1025 AM EDT Sat Mar 28 2020

This Hazardous Weather Outlook is for Southeast Indiana, Northeast
Kentucky, Northern Kentucky, Central Ohio and South Central Ohio.

.DAY ONE...Today and tonight.

Showers and thunderstorms will move across the area after midnight.
There is the potential for a few storms to be severe with damaging
straight-line winds the primary threat.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Wind gusts up to 40 mph are expected on Sunday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed later tonight.

Special Weather Statement
National Weather Service Wilmington OH
1244 PM EDT Sat Mar 28 2020

INZ050-058-059-281715-
Fayette IN-Union IN-Wayne IN-
1244 PM EDT Sat Mar 28 2020

...A RAPIDLY DEVELOPING THUNDERSTORM WILL AFFECT SOUTHERN WAYNE...
NORTHERN UNION AND NORTHERN FAYETTE COUNTIES IN EAST CENTRAL INDIANA
UNTIL 115 PM EDT...

At 1244 PM EDT, radar indicated a thunderstorm near Dublin, moving
northeast at 55 mph.

STORM HAZARDS INCLUDE...
Winds to 35 mph...
One half inch diameter hail...

Locations impacted include...
Richmond, Connersville, Centerville, Cambridge City, Dublin,
Waterloo, Abington, East Germantown, Spring Grove, Boston, Mount
Auburn, Whitewater, Richmond Municipal Airport, Witts Station, Mettel
Field, Middleboro, Clifton, Interstate 70 at Exit 145, Bentonville
and Philomath.

This includes I-70 in Indiana between mile markers 141 and 156.

Residents in these areas should remain alert. If this storm becomes
stronger, then a warning may be needed.

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 3978 8530 3979 8522 3981 8522 3995 8481
      3971 8482 3963 8527 3969 8530
TIME...MOT...LOC 1644Z 245DEG 47KT 3973 8520

KC

Special Weather Statement
National Weather Service Wilmington OH
105 PM EDT Sat Mar 28 2020

OHZ042-060-061-281730-
Montgomery OH-Darke OH-Preble OH-
105 PM EDT Sat Mar 28 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN PREBLE...SOUTHEASTERN
DARKE AND NORTHWESTERN MONTGOMERY COUNTIES UNTIL 130 PM EDT...

At 105 PM EDT, radar indicated a strong thunderstorm over Richmond,
moving east at 50 mph.

STORM HAZARDS INCLUDE...
Winds to 40 mph...
One half inch diameter hail...
Frequent cloud-to-ground lightning...
Very heavy rain...

Locations impacted include...
Trotwood, Eaton, Lewisburg, New Paris, Clayton, Brookville,
Phillipsburg, Eldorado, Verona, West Manchester, Pitsburg, Gordon,
Ithaca, Castine, Oklahoma, West Florence, Interstate 70 at US Route
127, Pyrmont and New Hope.

This includes I-70 in Ohio between mile markers 1 and 24.

Do not stay in the open or 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.

Residents in these areas should remain alert. If this storm becomes
stronger, then a warning may be needed.

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 3989 8481 4001 8443 3992 8443 3992 8437
      3979 8435 3973 8481
TIME...MOT...LOC 1705Z 254DEG 45KT 3979 8487

KC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
111 PM EDT SAT MAR 28 2020

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

0110 PM     HAIL             RICHMOND                39.83N 84.89W
03/28/2020  M0.50 INCH       WAYNE              IN   TRAINED SPOTTER

&&

BC

Special Weather Statement
National Weather Service Wilmington OH
122 PM EDT Sat Mar 28 2020

OHZ042-051-281745-
Darke OH-Miami OH-
122 PM EDT Sat Mar 28 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN DARKE AND NORTHWESTERN
MIAMI COUNTIES UNTIL 145 PM EDT...

At 122 PM EDT, radar indicated a strong thunderstorm near Fountain
City, moving east at 60 mph.

STORM HAZARDS INCLUDE...
Winds to 35 mph...
Pea size hail...
Frequent cloud-to-ground lightning...
Very heavy rain...

Locations impacted include...
Greenville, Versailles, Covington, Arcanum, Bradford, Pleasant Hill,
New Madison, Webster, Wayne Lakes, Gettysburg, Hollansburg,
Palestine, Union Corners, Polo, Bloomer, Sharpeye, Abbottsville,
Circle Hill, Horatio and Pikeville.

Do not stay in the open or 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.

Residents in these areas should remain alert. If this storm becomes
stronger, then a warning may be needed.

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 4009 8481 4023 8443 4020 8443 4020 8433
      4004 8432 3992 8481
TIME...MOT...LOC 1722Z 253DEG 54KT 3999 8484

KC