Tornado and Flooding in Ohio, April 7 to 9, 2020

AREA FORECAST DISCUSSION
National Weather Service Charleston WV
459 PM EDT Tue Apr 7 2020

.SYNOPSIS...
Warm front north today followed by cold front overnight. A much
stronger cold front Thursday. High pressure Friday and Saturday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
As of 440 PM Tuesday...

Trimmed back warm sector PoPs to reflect current radar trends,
especially over rain cooled surfaces in the wake of earlier
convection across our northeastern counties. Current convection
over southeastern Ohio could latch onto this effective boundary
over the next couple hours with some local intensification
possible, but these are likely to be the only show in town for
the remainder of the daylight hours given loss of surface
heating and decent cap at the base of the EML elsewhere.

Additional strong to severe storms likely ahead of the cold
front overnight, minimal changes made from the near term
discussion below.

As of 247 PM Tuesday...

The large area of rain and a few embedded storms that has been
moving across northern WV since earlier this morning has left an
outflow boundary in its wake, which is denoted by a wind shift in
recent surface observations across central WV. As a result, it
appears that this feature has provided enough focus for convective
initiation as showers and storms have just started to develop, with
most of the activity so far just north of Interstate-64. Elsewhere,
convective initiation has not occurred just yet, but the environment
is becoming increasingly favorable for strong to severe storms
if storms are able to initiate. While the better lift is just
north of our region along/near a warm frontal boundary that is
draped across northern OH and western PA, latest SPC
mesoanalysis shows CAPE values increasing from south to north
across the region as warm/moist advection continues into the
area. Thus, any showers and storms that manage to develop for
the remainder of the day will mainly be diurnally driven
throughout the area, but given some continued assistance from
outflow boundaries and increasing instability, any storms that
do develop will have the potential to become quite strong.
Latest forecast soundings show steep mid level lapse rates with
values around 7.5 C/km and it storms are able to punch through
the cap around 700-800mb, robust updrafts could occur with a
large hail and damaging wind threat through the remainder of the
day. So, while the threat for severe weather for the remainder
of the day still remains somewhat conditional on storms being
successful at breaking through the cap in the absence of any
stronger forcing mechanisms, a second and more potent round of
convection is expected to occur overnight.

Before the round of convection moves through tonight, a brief lull
in precipitation is expected across the area this evening. However,
a surface low in the Great Lakes will push a cold front towards our
region overnight and widespread convection is expected to develop
along/ahead of this frontal boundary. Nearly all CAMs at this point
are in agreement on a large QLCS-type line of storms approaching our
area from northwest to southeast overnight into Wednesday
morning, roughly from 06-12Z Wednesday. As this complex moves
across the region overnight, deep layer shear values between
40-50 kts and MLCAPE values of 1000-1200 J/kg ar expected to be
present, which is pretty high instability for the nighttime
hours. In addition, 0-1 km helicity values could approach 200
m2/s2 as this complex pushes through. So, given these
ingredient, all storm hazards will be possible with large hail
and damaging winds being the primary threats. However, can't
completely rule out an embedded tornadic circulation either
given the possibility for favorable low level helicity.

The QLCS will move southeast of the area later Wednesday morning and
conditions are expected to improve as this feature departs. However,
will maintain low PoPs Wednesday morning and afternoon, mainly for
eastern areas as enough moisture may linger for a few showers and
storms. There does appear to be some instability developing on
Wednesday with models suggesting that MLCAPE values could reach 1000-
1500 J/kg with 0-6 km bulk shear values of 40 kts. Thus, SPC does
have the majority of our area in a Marginal risk for severe weather
on Wednesday with damaging wind and hail the primary risks.
Otherwise, temperatures remain above normal for Wednesday with highs
around 5-10 degrees above normal.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
As of 224 PM Tuesday...

Low level warm air advection will get underway again Wednesday
evening with scattered convection impacting the CWA overnight as
a strong cold front approaches the region. Severe threat does
not look overly impressive at this time, but given the forcing
and wind fields, a few strong storms will be possible. Front
then pushes across the area early Thursday morning with daytime
temps either steady-state or falling through the day as cold air
advection strengthens. Attention then turns to potentially
windy/very windy conditions in the afternoon. If enough clearing
occurs during the day, dry-adiabatic lapse rates from the sfc
to nearly H7 along with strong low level wind fields will
promote near Wind Advisory conditions during Thurs
midday/afternoon for especially the northern half of the CWA.
More significant cold air advection should occur Thursday night
into Friday as the parent mid/upper level trough axes briefly
push south across the area. Temps Friday will be rather chilly
by early/mid April standards.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
As of 227 PM Tuesday...

Sfc high pressure influences area weather for Saturday before
potentially impactful weather returns next week. Global models
have come into a little better agreement today with next weeks
synoptic pattern. A strong area of low pressure is currently
prog to hook northeast out of the Great Plains and up the Ohio
River Valley early next week. If this output holds, then our
next chance of spring-like weather and precip could occur at
that time.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
As of 123 PM Tuesday...

An area of rain and some embedded thunderstorms continues to
move ESE just north of the area across far northern WV. This
activity may just clip CKB/EKN at the beginning of this TAF
issuance with brief MVFR/IFR restrictions. Otherwise, mainly
expecting VFR conditions through the remainder of the afternoon
and an increasing diurnal cu field across the region with cloud
bases around 5-7 kft. However, there does remain some risk of
additional development of isolated to scattered showers and
storms later this afternoon and early evening. While showers and
storms may have a difficult time to develop due to warm mid-
level temperatures, if any storms manage to develop and impact
any terminals, quick reductions in flight conditions is
expected. Again, this threat does appear to be localized for the
remainder of the day, but will watch radar trends and issue
amendments if/when necessary.

Any showers and storms that manage to develop today will taper
off tonight for a brief period with VFR conditions throughout
the region. However, a large complex of showers and thunderstorms
is expected to move across the region overnight roughly between
07-12Z Wednesday. As this activity moves through, widespread
flight restrictions are expected with MVFR/IFR conditions
throughout the region. Flight conditions should improve by
Wednesday morning as this complex of storms moves away from the
area, but lingering low level moisture will keep low clouds
across the area and MVFR conditions in place. However, a return
to VFR is possible by the very end of the period for most of
the area as drier air continues to filter in.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...

FORECAST CONFIDENCE: High for most areas, but medium for isolated
to scattered convection chances this afternoon and early
evening.

ALTERNATE SCENARIOS: Timing of showers and thunderstorms
tonight may vary an hour or two from forecast.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       21   22   23   00   01   02   03   04   05   06   07   08
EDT 1HRLY       17   18   19   20   21   22   23   00   01   02   03   04
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    M    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    M    H    L
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    M    H    H

AFTER 18Z WEDNESDAY...
IFR conditions possible in showers and thunderstorms Wednesday
night as a cold front pushes through the area.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.

&&

SYNOPSIS...RH/RG
NEAR TERM...JP/RG
SHORT TERM...RH
LONG TERM...RH
AVIATION...RG

Hazardous Weather Outlook
National Weather Service Charleston WV
342 AM EDT Tue Apr 7 2020

KYZ101>103-105-OHZ066-067-075-076-083>087-WVZ005>011-013>020-024>032-
034-039-040-080745-
Greenup-Carter-Boyd-Lawrence KY-Perry-Morgan-Athens-Washington-
Jackson OH-Vinton-Meigs-Gallia-Lawrence OH-Wayne-Cabell-Mason-
Jackson WV-Wood-Pleasants-Tyler-Lincoln-Putnam-Kanawha-Roane-Wirt-
Calhoun-Ritchie-Doddridge-Mingo-Logan-Boone-Clay-Braxton-Gilmer-
Lewis-Harrison-Taylor-Wyoming-Upshur-Barbour-
342 AM EDT Tue Apr 7 2020

This Hazardous Weather Outlook is for northeast Kentucky, southeast
Ohio, and portions of central West Virginia, northern West
Virginia, southern West Virginia and western West Virginia.

.DAY ONE...Today and Tonight.

A slight risk of severe thunderstorms exists for the entire area
today and tonight. Isolated to scattered strong to severe
thunderstorms may occur in the afternoon across northern West
Virginia. Large hail, damaging winds, and an isolated tornado are all
possible.

Scattered strong to severe thunderstorms or a line of storms may
impact much of the area late tonight. Damaging winds and large hail
are possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

A much colder airmass will settle in for the end of the week. A
frost advisory or freeze warning may eventually be needed for Friday
night and early Saturday morning.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions by calling the toll-free spotter hotline, or by other
methods detailed at www.weather.gov/rlx/reports.

VAZ003-004-WVZ033-080745-
Dickenson-Buchanan-McDowell-
342 AM EDT Tue Apr 7 2020

This Hazardous Weather Outlook is for southwest Virginia and
southern West Virginia.

.DAY ONE...Today and Tonight.

There is a marginal risk for severe thunderstorms late tonight with
large hail and damaging winds possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

A much colder airmass will settle in for the end of the week. A
frost advisory or freeze warning may eventually be needed for Friday
night and early Saturday morning.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions by calling the toll-free spotter hotline, or by other
methods detailed at www.weather.gov/rlx/reports.

WVZ515>526-080745-
Northwest Raleigh-Southeast Raleigh-Northwest Fayette-
Southeast Fayette-Northwest Nicholas-Southeast Nicholas-
Northwest Webster-Southeast Webster-Northwest Pocahontas-
Southeast Pocahontas-Northwest Randolph-Southeast Randolph-
342 AM EDT Tue Apr 7 2020

This Hazardous Weather Outlook is for portions of northeast West
Virginia and southeast West Virginia.

.DAY ONE...Today and Tonight.

A slight risk of severe thunderstorms exists for the entire area
today and tonight. Isolated to scattered strong to severe
thunderstorms may occur this afternoon across northern West
Virginia. Large hail, damaging winds, and an isolated tornado are all
possible.

Scattered strong to severe thunderstorms or a line of storms may
impact much of the area late tonight. Damaging winds and large hail
are possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions by calling the toll-free spotter hotline, or by other
methods detailed at www.weather.gov/rlx/reports.

Special Weather Statement
National Weather Service Charleston WV
155 PM EDT Tue Apr 7 2020

WVZ016-027-028-519-071830-
Clay-Roane-Northwest Nicholas-Braxton-
155 PM EDT Tue Apr 7 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL NICHOLAS...
SOUTHWESTERN BRAXTON...SOUTHEASTERN ROANE AND NORTHEASTERN CLAY
COUNTIES...

At 154 PM EDT, a strong thunderstorm was located over Wallback, or 9
miles north of Clay, moving east at 40 mph.

Wind gusts up to 50 mph and nickel size hail are possible with this
storm.

Locations impacted include...
Big Otter, Birch River, Wallback, Harrison, Widen, Little Birch,
Strange Creek, Ivydale and Servia.

This includes the following highways...
 Interstate 79 between mile markers 32 and 46.
 Route 19 between mile markers 54 and 66.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 3853 8065 3850 8068 3845 8065 3839 8066
      3856 8118 3864 8117 3863 8110 3861 8108
      3863 8107 3859 8064
TIME...MOT...LOC 1754Z 279DEG 34KT 3860 8111

HART

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHARLESTON WV
308 PM EDT TUE APR 07 2020

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

0240 PM     HAIL             ELKINS                  38.93N  79.85W
04/07/2020  E0.75 INCH       RANDOLPH           WV   PUBLIC

            DIME SIZED HAIL REPORTED IN EKLINS

&&

EVENT NUMBER RLX2000765

PECK

Special Weather Statement
National Weather Service Charleston WV
441 PM EDT Tue Apr 7 2020

OHZ066-067-072100-
Morgan-Perry-
441 PM EDT Tue Apr 7 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN PERRY AND
NORTHWESTERN MORGAN COUNTIES...

At 439 PM EDT, a strong thunderstorm was located near Perry State
Forest, moving east at 25 mph.

Winds in excess of 40 mph and small hail are possible with this
storm.

Locations impacted include...
New Lexington, Somerset, Perry State Forest, Crooksville and
Eagleport.

LAT...LON 3991 8217 3982 8217 3982 8208 3977 8208
      3976 8190 3968 8189 3974 8229 3990 8230
TIME...MOT...LOC 2039Z 270DEG 27KT 3982 8222

22

Special Weather Statement
National Weather Service Charleston WV
531 PM EDT Tue Apr 7 2020

OHZ076-072200-
Washington-
531 PM EDT Tue Apr 7 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTH CENTRAL WASHINGTON
COUNTY...

At 530 PM EDT, a strong thunderstorm was located near Caldwell,
moving southeast at 30 mph.

Wind gusts up to 50 mph and penny size hail are possible with this
storm.

Locations impacted include...
Macksburg and Lower Salem.

This includes Interstate 77 in Ohio between mile markers 10 and 17.

LAT...LON 3963 8145 3963 8142 3960 8139 3959 8128
      3961 8128 3961 8127 3958 8126 3958 8120
      3942 8133 3958 8150 3958 8147 3965 8147
      3965 8145
TIME...MOT...LOC 2130Z 302DEG 24KT 3966 8147

22