Special Weather Statement, NWS Wilmington, OH

AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1032 AM EDT Mon Jun 21 2021

.SYNOPSIS...
Showers and thunderstorms are possible at times today, as a cold
front moves into a warm and humid air mass. Rain will continue
into tonight, before drier air begins to move into the region
for Tuesday. Temperatures will be below normal through the
middle of the week, with warming conditions and storm chances
returning at the end of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Not many adjustments made regarding thinking/forecast for storm
evolution during the near term period. Are already seeing some
showers initiating just ahead of the advancing cold front which
has already cleared Mercer County as winds have shifted around
to the W and will soon go more WNW.

Vis satellite shows some more agitated Cu developing just ahead
of the front extending from near Hardin Co OH back west through
Wayne Co IN. Will likely see additional development within this
corridor as well as further south toward the Tri-State
area/northern KY through the noontime hour along a subtle
prefrontal trof. This activity will expand in coverage and
intensity as we progress through the early/mid afternoon,
eventually reaching the lower Scioto Valley/NE KY by late
afternoon. At this time, while there will be a localized/brief
flood/flash flood risk this afternoon, particularly for NE KY
/south-central OH in areas which have received 5-6+" of rain
over the past 2 weeks, the coverage and longevity of a threat
may not necessitate a flood/flash flood watch issuance, but
will continue to monitor trends. However, the near-parallel
relation between the initiating boundary and the LL/steering-
layer flow suggests some training of convection may materialize
in these areas by mid/late afternoon. This, combined with
environmental factors including very deep WCDs, ample instby,
and PWATs >=1.75", suggest that there is a least some concern
for flooding in these areas. Will continue to highlight heavy
rain/flood threat in the HWO for now.

305 AM Discussion >
The gradient in both temperatures and instability across the
ILN CWA should be pronounced today. For example, max temps for
Celina OH are forecast to be in the upper 70s, while it would
not be surprising to see Portsmouth OH / Vanceburg KY get close
to 90.

Afternoon convective development, which will likely begin around
16Z-17Z, will be primarily focused in the southeastern half of
the forecast area -- where instability (SBCAPE up to 2000-2500
J/kg) will be most robust. With this kind of instability, and
0-6km bulk shear values of around 30-40 knots, a few severe
storms will be possible. No indications of a major event or big
outbreak, but could be an event with a handful of warnings.
Looks like primarily a wind/hail issue, with low-level
directional shear not particularly impressive, but suppose a
tornado may not be impossible in the more discrete early phase
of the event. The overall deep-layer shear is relatively
parallel to the orientation of the forcing, which is one factor
that will keep this from being a bigger event. On the other
hand, it may also lead to some training storms, so a low-end
flood risk is also worth watching for. Any risk of hazardous
weather should be cleared east of the ILN CWA by 00Z (if not a
little sooner) once the surface front has moved out of the
area.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Though the threat for convection will be over after the surface
front has passed through the area, some additional rain is
expected for several hours later in the evening and overnight.
The 700mb cold front will be lagging the surface front by about
100-150 miles. Ahead of the mid-level trough axis, providing
some forcing in a continued WSW feed of theta-e, a swath of rain
is expected to move NE across the forecast area between 00Z and
09Z. Not expecting any heavy amounts out of this, but it forces
leaving PoPs in the forecast through much of the overnight
hours. Nonetheless, conditions will be cooling and drying in the
low levels, with NNW surface flow helping to bring temperatures
into the mid 50s to upper 40s for lows.

Very quiet conditions are expected Tuesday, as surface high
pressure sets up on an axis that will extend through virtually
the entire Ohio Valley region. This should allow for mostly
clear skies, but with temperatures well below normal -- highs
only around 70 degrees.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Surface high pressure will push east across the region Tuesday night
through Wednesday night. This will provide for dry conditions with
temperatures remaining several degrees below normal. Highs on
Wednesday will be in the mid to upper 70s. Dry conditions will
continue into Thursday as the high moves off to the east and we
get into some developing southwesterly flow. This will help
push temperatures on Thursday back to near normal with afternoon
highs in the low to mid 80s.

A mid/upper level trough will then settle in across the central
CONUS as we head into the weekend with an associated cold front
pushing southeast into the region Saturday into Sunday. Ahead of
this, a moist southwesterly flow pattern will persist across the
Ohio Valley with PWs forecast to push up to around 1.75 to 2 inches
Friday into Saturday. This will result in an increasing chance for
showers and thunderstorms Friday and Saturday. Will then linger a
chance for showers and thunderstorms into Sunday but this will be
dependent on the exact timing of the cold front through the
region. Highs on Friday will be in the low to mid 80s, cooling a
bit to highs in the upper 70s and lower 80s for Saturday and
Sunday.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
Generally dry conditions are expected at the TAF sites over the
next few hours, although a few light showers are floating around
near KDAY/KCMH/KLCK. Winds out of the south have settled in at
around 10 knots sustained, with occasional gusts to around 20
knots.

There is a greater chance of new shower and storm development
in the early afternoon. This period of the forecast has been
indicated with a -SHRA VCTS, and MVFR ceilings also included at
KDAY. This period is timed out for the most likely timing for
storm development. Wind gusts will also get well into the 20
knot range during this time frame.

The storms should move out of the TAF sites by late afternoon,
but some additional light rain may move back in after 00Z,
indicated by another -RA or VCSH group. Winds will switch to the
north tonight, diminishing to around 10 knots or less.

.OUTLOOK...Thunderstorms are possible on Friday.

&&

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

&&

SYNOPSIS...Hatzos
NEAR TERM...KC/Hatzos
SHORT TERM...Hatzos
LONG TERM...JGL
AVIATION...Hatzos

Hazardous Weather Outlook
National Weather Service Wilmington OH
655 AM EDT Mon Jun 21 2021

INZ050-058-059-066-OHZ026-034-035-042>045-051>053-060-061-221100-
Wayne-Fayette IN-Union IN-Franklin IN-Hardin-Mercer-Auglaize-Darke-
Shelby-Logan-Union OH-Miami-Champaign-Clark-Preble-Montgomery-
655 AM EDT Mon Jun 21 2021

This Hazardous Weather Outlook is for East Central Indiana,
Southeast Indiana, Central Ohio and West Central Ohio.

.DAY ONE...Today and tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

INZ073>075-080-KYZ089>100-OHZ046-054>056-062>065-070>074-077>082-088-
221100-
Ripley-Dearborn-Ohio-Switzerland-Carroll-Gallatin-Boone-Kenton-
Campbell-Owen-Grant-Pendleton-Bracken-Robertson-Mason-Lewis-Delaware-
Madison-Franklin OH-Licking-Greene-Fayette OH-Pickaway-Fairfield-
Butler-Warren-Clinton-Ross-Hocking-Hamilton-Clermont-Brown-Highland-
Adams-Pike-Scioto-
655 AM EDT Mon Jun 21 2021

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

.DAY ONE...Today and tonight.

Thunderstorms are expected this afternoon and evening, mainly between
12 PM and 8 PM. A few storms may become severe, with the primary
threat of damaging wind. Large hail and locally heavy rainfall will
also be possible.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and evening.

HATZOS

Special Weather Statement
National Weather Service Wilmington OH
1203 PM EDT Mon Jun 21 2021

OHZ045-046-211630-
Delaware OH-Union OH-
1203 PM EDT Mon Jun 21 2021

...A RAPIDLY DEVELOPING THUNDERSTORM WILL AFFECT CENTRAL DELAWARE AND
SOUTHEASTERN UNION COUNTIES IN CENTRAL OHIO UNTIL 1230 PM EDT...

At 1203 PM EDT, radar indicated a thunderstorm near New California,
moving east at 30 mph.

STORM HAZARDS INCLUDE...
Winds to 40 mph...
Very heavy rain...

Locations impacted include...
Dublin, Delaware, Marysville, Powell, Sunbury, New California,
Shawnee Hills, Galena, Ostrander, Interstate 71 at US Route 36/State
Route 37, Alum Creek State Park, Stratford, Bellepoint, US Route 33
at US Route 42, Warrensburg, Watkins, Leonardsburg, Kilbourne,
Columbus Zoo and New Dover.

This includes I-71 in Ohio between mile markers 124 and 136.

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 4037 8293 4036 8291 4028 8284 4017 8292
      4014 8332 4032 8336 4040 8295
TIME...MOT...LOC 1603Z 261DEG 25KT 4025 8324

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Special Weather Statement
National Weather Service Wilmington OH
1222 PM EDT Mon Jun 21 2021

OHZ045-046-054>056-211645-
Licking OH-Delaware OH-Madison OH-Franklin OH-Union OH-
1222 PM EDT Mon Jun 21 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHERN FRANKLIN...SOUTHERN
DELAWARE...WEST CENTRAL LICKING...NORTHEASTERN MADISON AND
SOUTHEASTERN UNION COUNTIES IN CENTRAL OHIO UNTIL 1245 PM EDT...

At 1221 PM EDT, radar indicated a strong thunderstorm over Plain
City, moving east at 45 mph.

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

Locations impacted include...
Columbus, Dublin, Westerville, Delaware, Upper Arlington, Gahanna,
Hilliard, Marysville, Worthington, Powell, Sunbury, Plain City,
Minerva Park, New California, Polaris, Easton, New Albany, Shawnee
Hills, Galena and Riverlea.

This includes I-71 in Ohio between mile markers 114 and 133.

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 8337 4021 8341 4034 8277 4007 8271
TIME...MOT...LOC 1621Z 260DEG 40KT 4014 8329

Coniglio