Shelby Ohio Weather

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1225 AM CDT Fri Apr 26 2024

Valid 261200Z - 271200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE LOWER TO MID MISSOURI VALLEY...AND CENTRAL PLAINS...

...SUMMARY...
Severe thunderstorms will be likely today from parts of eastern
Nebraska into western and central Iowa, southward into eastern
Kansas and Northwest Missouri. All hazards will be possible,
including tornadoes with some potentially strong, very large hail
over two inches in diameter, and wind damage. A more isolated severe
threat will extend south-southwestward into parts of the southern
Plains, Ozarks and Ark-La-Tex from late afternoon into the evening.

...Significant Severe Weather Event Expected Today Across Parts of
The Lower To Mid Missouri Valley and Central Plains...

...Lower to Mid Missouri Valley/Central Plains...
A negatively tilted upper-level trough will move northeastward
across the mid Missouri Valley today, as an associated 50 to 60 knot
mid-level jet translates northeastward through the base of the
system. At the surface, a low will deepen and move northeastward
across Nebraska. A north-to-south corridor of maximized low-level
moisture, with surface dewpoints in the mid 60s F, will be in place
by midday across eastern Kansas and southeast Nebraska. Moderate
instability will develop across most of the moist sector by
afternoon, with thunderstorms first developing in east-central
Nebraska around midday. These storms are expected to move eastward
across eastern Nebraska during the afternoon, as convective coverage
gradually expands south-southeastward into eastern Kansas. The
environment will be favorable for severe storms, with several
clusters moving eastward from Nebraska into Iowa, and from Kansas
into Missouri during the late afternoon and early evening.

Several factors appear to be supportive of a significant tornado
event today across eastern part of the central Plains into the lower
to mid Missouri Valley. The first is that a 60 to 70 knot mid-level
jet, associated with a negatively tilted trough, will become coupled
with a 50 to 60 knot low-level jet over a moist and unstable warm
sector. A second factor is that a band of large-scale ascent will
move over the warm sector this afternoon, as the capping inversion
diminishes. Steep low to mid-level lapse rates are forecast to
spread over the warm sector, which combined with moderate deep-layer
shear, will be favorable supercells with strong updrafts at
relatively low-levels within the storms. In addition, 0-3 km
storm-relative helicity is forecast to increase into the 300 to 400
m2/s2 range along the western edge of the low-level jet, which will
be favorable for strong tornadoes. A few tornadic supercells are
expected, with the greatest potential from near Omaha eastward to
near Des Moines and southward to south of the Kansas City Metro.
Along this corridor, the more dominant supercell storms will also
have a potential to produce hailstones greater than 2 inches in
diameter and wind damage. The severe threat is expected to shift
eastward across Iowa and Missouri during the mid to late evening,
with an isolated severe threat continuing after midnight.

...Southern Plains/Ozarks/Ark-La-Tex...
Southwesterly mid-level flow will be in place today across the
south-central U.S., with a broad moist warm sector located from the
southern Plains eastward into the Ark-La-Tex and Ozarks. An MCS is
expected to move across central and eastern Oklahoma during the
morning, which will stabilize the airmass. However, instability is
forecast to redevelop across Oklahoma by afternoon. Further south,
strong instability is expected to develop across much of central and
east Texas by afternoon, where MLCAPE should peak in the 2500 to
3500 J/kg range. Although large-scale ascent will be weak across
most of the southern Plains, the cap is expected to diminish and
isolated thunderstorms appear likely to develop by late afternoon. A
severe threat is expected to persist along and near the instability
axis during the early to mid evening.

RAP forecast soundings at 00Z/Saturday along and near the
instability axis from southeast/south-central Oklahoma into
north-central Texas have 0-6 km shear between 40 and 50 knots. Low
to mid-level lapse rates will become steepest in areas that heat up
the most. The environment will likely be favorable for isolated
supercells with large hail. By late afternoon, forecast soundings
also have 0-3 Km storm-relative helicity reaching 200 m2/s2
suggesting that an isolated tornado threat will be possible. The
tornado threat is expected to be the greatest across eastern
Oklahoma, northeast Texas and western Arkansas, as the low-level jet
ramps up in the early evening. Wind damage will also be possible
with storms that develop.

..Broyles/Thornton.. 04/26/2024

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Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1250 AM CDT Fri Apr 26 2024

Valid 271200Z - 281200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR MUCH OF
OK...PARTS OF NORTH TX...CENTRAL/EASTERN KS...NORTHWEST
MO...SOUTHEAST NE...SOUTHWEST IA...

...SUMMARY...
Potentially widespread strong to severe thunderstorms are expected
Saturday into Saturday night. The greatest threat is currently
anticipated across parts of the central and southern Plains, where
very large hail, damaging winds, and a few strong tornadoes will be
possible. A larger area of potential threat will extend from
south-central Texas north-northeastward into the Great Lakes.

...Synopsis...
A shortwave trough and attendant surface low are forecast to
gradually weaken and move northeastward across the upper Great Lakes
region on Saturday. Meanwhile, a deep mid/upper-level trough will
move eastward from the Southwest, resulting in a deepening cyclone
across southwest KS. Rich low-level moisture will continue to stream
northward across the warm sector of this cyclone, and extend
northeastward along/ahead of the front into parts of the upper
Midwest and Great Lakes. 

...Central/southern Great Plains...
A complex but potentially significant severe weather episode is
expected on Saturday, with the greatest threat currently expected
from parts of central/eastern KS into central/western OK and north
TX. All severe hazards will be possible, including the threat for
strong tornadoes and very large hail. 

Evolution of the warm sector and storm development on Saturday will
be complicated by the potential for early-day convection spreading
northeastward from northwest TX through OK into eastern KS. This
convection would likely initiate late in the D1/Friday period as
low-level moisture streams westward in conjunction with a retreating
dryline, beneath steep midlevel lapse rates. While most guidance
depicts some sort of early convection, its forecast evolution varies
widely among both CAMs and parameterized convection within mesoscale
and global models. Some severe threat could accompany this
convection as it moves northeastward through the day. 

Strong low-level southerly flow will support recovery in the wake of
any morning convection. Diurnal storm development will be possible
in the vicinity of the dryline and also near a northward-moving warm
front extending east-northeast from the deepening cyclone. 

For the dryline regime, supercell development will become
increasingly possible by late afternoon, as MLCINH diminishes and
some influence of the approaching upper trough begins to overspread
the region. Moderate to strong buoyancy and strengthening deep-layer
shear will support an initial threat of very large hail (potentially
2-3 inches in diameter). The tornado threat will increase into early
evening, due to a notable increase in the low-level jet (and related
shear/SRH) with time and eastward extent. Any persistent supercells
will pose a threat of strong to potentially intense tornadoes as
they move northeastward. Dryline storm initiation may be somewhat
greater in coverage from west-central KS into northwest OK, in
closer proximity to stronger large-scale ascent, though at least
isolated development will be possible into southwest OK and
northwest TX. 

For the warm-front regime, initial development may tend to be
focused near the dryline/front intersection across north-central KS,
with more isolated initiation possible northeastward along the front
as capping is gradually eroded. Moderate to strong buoyancy and
favorable low-level and deep-layer shear will support supercell
potential within this regime. All severe hazards will be possible,
including the potential for very large hail and a strong tornado.
With time, increasing storm coverage will likely halt the northward
progression of the warm front, with one or more storm clusters
moving near/north of the front through the evening with a continued
severe threat. 

Aside from the dryline and warm-frontal regimes, diurnal development
across the broader warm sector will be possible within a moist and
weakly capped environment, particularly from central OK into eastern
KS. Evolution and coverage of diurnal warm sector development remain
uncertain, but the environment will support supercell development
with a threat of tornadoes and very large hail. 

Storm coverage will likely increase into the evening, as large-scale
ascent attendant to the approaching shortwave trough overspreads the
region. Convection may tend to organized into a QLCS overnight.
While magnitude of the severe threat with overnight convection
remains uncertain, favorable moisture and a strong low-level jet may
continue to support at least some threat for all severe hazards,
both within the warm sector and eventually along a trailing cold
front into parts of central/southwest TX.

...Northwest KS/southwest NE into northeast CO...
Low-level easterly flow will maintain modest low-level moisture
within the post-frontal regime from northwest KS/southwest NE into
northeast CO. Steep midlevel lapse rates will support MLCAPE
increasing to near/above 500 J/kg, with veering wind profiles
supporting potential for organized convection. A supercell or two
could evolve within this regime, with an attendant threat of large
hail and possibly a brief tornado.  

...Parts of the Upper Midwest/Great Lakes...
A separate regime of at least isolated severe-thunderstorm potential
remains evident along/ahead of the cold front from eastern IA into
parts of the Great Lakes region. While the influence of the ejecting
shortwave trough initially over the Upper Great Lakes may remain
mostly displaced from the warm sector, diurnal
heating/destabilization and decreasing CINH may support isolated
storm development by late afternoon along the cold front. Deep-layer
shear will remain sufficient for organized convection, supporting
conditional potential for supercells and/or stronger clusters
capable of producing hail, damaging gusts, and possibly a tornado or
two. 

Some increase in storm coverage will be possible into the evening as
the cold front moves southeastward. Eventually, convection should
generally weaken overnight across this region, though a stronger
cluster to two could move from eastern portions of the central
Plains toward the upper MS Valley before the end of the forecast
period.

..Dean.. 04/26/2024

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Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0226 AM CDT Fri Apr 26 2024

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST TX
INTO PARTS OF THE MID/UPPER MS VALLEY...

...SUMMARY...
Strong to potentially severe thunderstorms will be possible Sunday
across a broad area from northeast Texas into parts of the upper
Mississippi Valley. Large hail, damaging winds, and a couple
tornadoes will all be possible.

...Northeast TX into parts of the upper MS Valley...
A broad region of at least some severe potential is expected on
Sunday from northeast TX into parts of the upper MS Valley.
Uncertainty remains high due to the influence of extensive
antecedent convection leading into the D3/Sunday period. 

A negatively tilted shortwave trough and attendant surface low are
forecast to move from the central Plains toward the upper MS Valley
on Sunday. Extensive convection will likely be ongoing at the start
of the period from Texas toward the lower MO Valley, and potentially
farther north into parts of the upper Midwest. Some lingering severe
threat could accompany this morning convection, especially toward
the ArkLaTex region where somewhat more favorable
moisture/instability will be in place. 

Widespread cloudiness/convection across much of the warm sector will
tend to limit diurnal destabilization, though deep-layer shear will
remain favorable for organized storms, and some
heating/destabilization will be possible in the wake of morning
convection. 

One area of potential redevelopment will be immediately ahead of the
ejecting shortwave trough from eastern KS into western MO and
southern IA, where a few stronger cells/clusters could pose a threat
of hail, isolated damaging gusts, and perhaps a tornado. 

Vigorous redevelopment will also be possible along the
western/southern periphery of persistent convection near the
ArkLaTex region, where rich moisture and favorable wind profiles
could support at least an isolated threat for all severe hazards.
Some threat could linger into Sunday night across this area,
potentially aided by an upstream low-amplitude shortwave trough that
will be approaching the southern Plains.

..Dean.. 04/26/2024

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