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DAY2SVR: Enhanced Risks
From
Dumas Walker@21:1/175 to
All on Sun Mar 31 08:46:00 2024
ACUS02 KWNS 310601
SWODY2
SPC AC 310600
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sun Mar 31 2024
Valid 011200Z - 021200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHERN AND CENTRAL PLAINS EAST-NORTHEASTWARD INTO THE LOWER
OHIO VALLEY...
...SUMMARY...
A widespread severe threat, with a potential for large hail, wind
damage and tornadoes, is expected on Monday and Monday night from
parts of the southern Plains northeastward into the mid Mississippi
Valley. Very large hail will be possible across parts of the
southern Plains and Ozarks. The greatest tornado threat is expected
from southern Missouri into southern Illinois Monday evening. The
severe threat is also expected to impact parts of the Ohio Valley,
especially during the evening and overnight period.
...Southern and Central Plains/Ozarks/Mid Mississippi Valley/Lower
Ohio Valley...
A positively tilted upper-level trough will move through the Desert
Southwest on Monday, as an 80 to 100 knot mid-level jet moves
through the base of the system. The exit region of the mid-level jet
will overspread a moist and unstable airmass across the southern
Plains during the afternoon. At the surface, a low will deepen in
west Texas, moving eastward into Oklahoma by mid to late afternoon.
Surface dewpoints in the mid to upper 60s F will be in place across
the eastern half of Texas, and from central and eastern Oklahoma
extending eastward into the mid Mississippi Valley. Moderate
instability is expected to develop by afternoon to the east of a
dryline from north Texas northward to near a triple point in central
Oklahoma. The airmass should be uncapped, allowing for widespread
convective development from the mid to late afternoon into the
evening. Thunderstorms will also likely develop in the Ozarks and
mid Mississippi Valley during the evening, as the mid-level jet
approaches the region from the southwest.
Within the exit region of the mid-level jet, a plume of steep
mid-level lapse rates is forecast to advect quickly eastward across
the southern Plains during the late afternoon and early evening.
Forecast soundings in east-central Oklahoma at 00Z/Tuesday suggest
that 700-500 mb lapse rates within this plume will be in the 7.5 to
8 C/km range. This, combined with strong deep-layer shear, will
support a large-hail threat with supercells. Hailstones of greater
than 2 inches in diameter will be possible with the more dominant
and intense storms. The potential for very large hail may extend as
far northeast as the Ozarks, as the exit region of the mid-level jet
passes over the area during the early to mid evening.
From southern Missouri into southern Illinois, a warm front will
likely be in place. The surface low is forecast to move
east-northeastward along this corridor. Forecast soundings ahead of
the surface low from 03Z to 06Z/Tuesday suggest that 0-3 km
storm-relative helicity will increase into 250 to 350 m2/s2 range,
as a 50 to 60 knot low-level jet strengthens. This should be
favorable for tornadoes with the more dominant supercells that
interact with the warm front. A potential for strong tornadoes will
exist. A large MCS is forecast to organize from the southern Plains
into the mid Mississippi Valley during the evening. The stronger
storms within this MCS will also have wind-damage potential.
...Mid to Upper Ohio Valley/Central Appalachians/Mid-Atlantic...
An anticyclonic mid-level flow pattern will be in place on Monday
across the eastern U.S. At the surface, a quasi-stationary front is
forecast to be located from southern Ohio east-southeastward into
the Mid-Atlantic. This boundary will likely be a focus for
convective development from the daytime hours into the overnight
period. Although instability is forecast to remain weak near the
boundary, strong deep-layer shear will be in place. This should
support an isolated severe threat, potentially persisting for an
extended period of time. Hail and isolated damaging gusts will
likely be the primary concerns. The severe threat will likely be
more isolated with eastward extent, mainly due to more limited
low-level moisture content across the Mid-Atlantic.
..Broyles.. 03/31/2024
$$
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From
Dumas Walker@21:1/175 to
All on Sun Mar 31 18:27:00 2024
ACUS02 KWNS 311727
SWODY2
SPC AC 311725
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1225 PM CDT Sun Mar 31 2024
Valid 011200Z - 021200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
OKLAHOMA INTO THE LOWER OHIO VALLEY...
...SUMMARY...
Severe weather is expected to occur over a broad region from the
southern Plains, the Ozarks, portions of the Ohio Valley, and into a
small part of the Mid-Atlantic. Large to very-large hail, damaging
winds, and tornadoes are possible. The severe threat will peak afternoon/evening in the southern Plains with the greatest threat
for the Ohio Valley vicinity being the evening/overnight period.
...Synopsis...
A rather broad, positively tilted upper trough will be positioned
within the Four Corners region. A mid-level jet streak will move
northeastward through the Trans-Pecos and into Red River region by
early evening. This feature is forecast to be weakening during the
afternoon as it shifts northeast. As the mid-level jet moves into
the Midwest during the evening, a short-wave trough is expected to
intensify in the Upper Midwest, with mid-level winds increasing
across the Ohio Valley. At the surface, a modest surface mass
response is anticipated in the southern Plains. Guidance generally
depicts a modest surface low developing in western/central Oklahoma.
A dryline will be pendant from this feature and provide a focus for
convective development during the afternoon. This surface low will
track northeastward along with its parent upper trough along nearly
stationary boundary from the Ozarks into the Ohio Valley and
Mid-Atlantic. Some deepening of this low may occur very late in the
period as the upper wave intensifies.
...Southern High Plains...
As the upper-level trough ejects into the region, sufficient
moisture for high-based convection should exist in the Texas
Panhandle and parts of the South Plains. A few convectively enhanced
gusts may occur with this activity. Buoyancy should remain too
limited for more than small hail.
...Oklahoma/Texas...
Between cloud cover and a capping inversion aloft, storm development
along the dryline should hold off until the mid/late afternoon when
greater mid-level ascent arrives. Strong deep-layer shear should
promote supercell storm structures at least initially. Hodographs
will be long and generally straight, but there are also veer-back
signatures that could indicate some potential for a messier storm
mode. Even so, potential for large to very-large hail is evident
given the shear and mid-level lapse rates. The tornado risk should
be mitigated to some extent by the overall weak low-level shear.
That being said, supercells that can be maintained into the early
evening (00-03Z) will see a brief window of increased tornado
potential as the low-level jet modestly strengthens.
Farther south into central Texas, forcing will be a bit weaker and
capping a touch stronger. Storms that do develop will likely have
supercellular characteristics. Large-hail and damaging winds are the
most likely hazards.
...Ozarks into Ohio Valley...
Some warm advection driven convection may be ongoing early in the
period across parts of these regions. These storms will likely be
elevated with a risk for large hail and isolated damaging winds. By
the afternoon, greater potential for surface-based storms will exist
from the triple point near the KS/OK border and along the cold front
in southeast Kansas into Missouri. These storms will at least
initially be supercells with potential for very-large hail. Storms
are expected to grow upscale with a greater risk of damaging winds.
While not overly strong, low-level shear should remain sufficient
for a threat of QLCS circulations/tornadoes.
It is possible that initially elevated storms may become near
surface based during the afternoon in the Ohio Valley. Additional
storms will likely move in from the west later in the evening
overnight as the shortwave trough/surface low move northeastward.
Damaging winds and QLCS tornadoes would be possible with this
activity. The hail threat is a bit uncertain given the potential for
more linear storm modes. However, large hail will remain possible.
...Parts of Mid-Atlantic...
Overall storm coverage is uncertain given the generally neutral
mid-level height changes through the period. Some model solutions do
produce convection along the stationary surface boundary. Given
strong mid-level winds and modestly steep lapse rates aloft,
marginally severe hail and isolated damaging winds could occur with
the stronger storms.
..Wendt.. 03/31/2024
$$
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From
Dumas Walker@21:1/175 to
All on Mon Apr 1 08:44:00 2024
ACUS02 KWNS 010600
SWODY2
SPC AC 010558
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1258 AM CDT Mon Apr 01 2024
Valid 021200Z - 031200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO AND TENNESSEE VALLEYS...
...SUMMARY...
A severe threat is expected on Tuesday from the Ohio and Tennessee
Valleys eastward into the Mid-Atlantic, and southward into the
central Gulf Coast states. Wind damage and isolated large hail will
be possible across a broad area. The tornado threat is expected to
be greatest from middle Tennessee north-northeastward into central
and northern Kentucky.
...Ohio and Tennessee Valleys/Central Gulf Coast States/Central
Appalachians...
An upper-level trough is forecast to move eastward into the mid to
upper Mississippi Valley on Tuesday, as a cold front advances
eastward toward the Ohio and Tennessee Valleys. By afternoon, a
north-to-south corridor of maximized low-level moisture is forecast
to be in place from the northern Gulf Coast States to central
Kentucky, where surface dewpoints are expected to be in the mid 60s
F. As instability increases along this corridor, numerous
thunderstorms will likely develop, with a linear MCS organizing and
moving eastward across the Ohio and Tennessee Valleys during the
afternoon and evening. This large MCS should reach the central
Appalachians by early to mid evening.
A 90 to 100 knot mid-level jet will likely move northeastward into
the Ohio Valley during the afternoon. This jet will create strong
deep-layer shear across most of the region. Forecast soundings by
21Z from middle Tennessee to central Kentucky have 0-6 km shear in
the 70 to 80 knot range. The wind shear and strong large-scale
ascent, associated with the mid-level jet, will be favorable for the development of a squall line Tuesday afternoon. This linear MCS will
likely have numerous embedded severe storms with the greatest threat
being wind damage. The wind-damage threat is expected to maximize
during the late afternoon and early evening. QLCS tornadic
circulations will be possible along some parts of the line,
especially near bowing segments. An isolated large hail threat is
also expected in areas where the squall line interacts with locally
stronger instability, and with isolated rotating cells that develop
ahead of the line. The severe threat is expected to decrease during
the mid to late evening as the line moves through the central
Appalachians.
...Central Gulf Coast States...
An upper-level trough will move eastward across the southern Plains
on Tuesday, as a cold front moves eastward into the lower
Mississippi Valley. Surface dewpoints should be in the mid to upper
60s F ahead of the front, where some models suggest that MLCAPE will
peak in the 1000 to 1200 J/kg range during the afternoon. Scattered thunderstorm development appears likely to take place ahead of the
front early in the day, with an organized line segment or cluster
moving eastward across the central Gulf Coast States during the
afternoon. Strong deep-layer shear will be in place, and low-level
lapse rates will steepen during the late morning and early
afternoon. The environment will likely support a wind-damage and
isolated large-hail threat. An isolated tornado threat will also be
possible, especially in the northern Gulf Coast states near the
southern edge of the low-level jet. Large-scale ascent and
deep-layer shear are forecast to be somewhat weaker across the
central and southern Gulf Coast states, which should result in a
more isolated severe threat with southward extent.
...Mid-Atlantic...
An anticyclonic flow pattern is forecast across the Eastern Seaboard
on Tuesday. At the surface, a relatively cold airmass is forecast
across much of the Mid-Atlantic due to cold air damming. Above the
cold surface air, elevated instability is forecast to increase
during the evening, as the exit region of the mid-level jet moves
through the central Appalachians. Thunderstorms that form in the
unstable air aloft, may have a potential for marginally severe hail
during the evening into the early overnight period.
..Broyles.. 04/01/2024
$$
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