RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sat Apr 27 10:32:01 UTC 2024.
MD 0537 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR PARTS OF NORTHWEST TX INTO WESTERN OK
Mesoscale Discussion 0537
NWS Storm Prediction Center Norman OK
0529 AM CDT Sat Apr 27 2024
Areas affected...Parts of northwest TX into western OK
Concerning...Severe potential...Watch likely
Valid 271029Z - 271200Z
Probability of Watch Issuance...80 percent
SUMMARY...Severe storm development is possible toward sunrise. Large
hail will be possible initially, but the tornado threat will
increase through the morning. Watch issuance is likely prior to 7 AM
CDT.
DISCUSSION...Rich low-level moisture is streaming into parts of the
TX South Plains and northwest TX this morning, in response to a
strong southerly low-level jet noted on regional VWPs. Meanwhile, a
strong mid/upper-level shortwave trough and attendant
mid/upper-level jet are approaching the southern Rockies. A cirrus
plume now moving over far west TX may be indicative of increasing
ascent in advance of the shortwave. As this ascent begins to impinge
on returning moisture across northwest TX, thunderstorm development
is expected near or just before sunrise, with increasing storm
coverage expected with time into parts of western OK.
Initial storm development will likely be somewhat elevated, but
MUCAPE of greater than 2000 J/kg and strong effective shear will
support supercell potential with an initial threat of large hail
(potentially in the 1.5 - 2 inch diameter range). As storms spread
into western OK, a transition to surface-based convection will be
possible later this morning, as MLCINH quickly erodes with even
modest diurnal heating. A transition to one or more clusters is
possible as storm coverage increases with time this morning, but
increasingly favorable low-level moisture and wind profiles will
support embedded supercells with an increasing tornado threat. Watch
issuance is likely prior to 7 AM CDT.
..Dean/Thompson.. 04/27/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OUN...LUB...AMA...
LAT...LON 34029986 33970016 33960083 34230093 35110009 36019945
36869914 36939846 36549794 36019782 35349799 34419848
34029986
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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0253 AM CDT Sat Apr 27 2024
Valid 271200Z - 281200Z
...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
NORTH TEXAS...OKLAHOMA...SOUTHEAST KANSAS AND FAR SOUTHWEST
MISSOURI...
CORRECTED FOR GEOGRAPHIC REFERENCE IN MISSOURI
...SUMMARY...
Numerous severe thunderstorms are likely today and tonight across
the southern and central Plains into the lower to mid Missouri
Valley. The greatest potential for severe storms will be from north
Texas into Oklahoma and southeast Kansas, where strong tornadoes,
very large hail over 2 inches in diameter and widespread damaging
winds (some over 70 mph), are expected to occur. A broader area of
severe threat will extend from south-central Texas
north-northeastward to the Great Lakes.
...Tornado Outbreak Expected Today From North Texas into
Oklahoma...Southeast Kansas and Far Southwest Missouri...
...Southern Plains...
An upper-level trough will move through the Desert Southwest today
as an 80 to 90 knot mid-level jet translates quickly eastward
through the base of the system. Ahead of the trough, a moist and
unstable airmass will be in place across much of the southern and
central Plains. At the surface, a low will move eastward across
southwest Kansas with a dryline extending southward through far
western Oklahoma and west Texas. Surface dewpoints to the east of
the dryline will be in the mid to upper 60s F. In response to warm
advection this morning, a cluster of thunderstorms is expected to
develop to the east of the dryline across northwest Texas. This
cluster is forecast to spread north-northeastward into western
Oklahoma by late morning. Large hail and wind damage will be likely
with the stronger cells within this cluster. An outflow boundary
with this convection should setup across west-central Oklahoma by
early afternoon, with a moist and unstable airmass extending
eastward from the boundary across much of central and eastern
Oklahoma northward into southeast Kansas. This undisturbed airmass
is expected to be favored for the greatest severe threat this
afternoon and evening.
The mid-level jet is forecast to eject quickly northeastward across
the southern Plains this afternoon. This will result in strong
deep-layer shear across most of the southern Plains, and will create
a large-scale mass response that will be very favorable for severe
storms, including supercells and bowing line segments. As the core
of the mid-level jet moves into the southern Plains during the mid
to late afternoon, a 50 to 60 knot low-level jet will rapidly
strengthen. RAP forecast sounding along and near the low-level jet
during the late afternoon look very favorable for tornadoes, with
backed surface flow, and long looping hodographs. As the low-level
jet strengthens, 0-3 km storm-relative helicity is forecast to
increase to around 400 m2/s2 across much of central and eastern
Oklahoma into southwest Missouri. The more dominant and supercells
that interact with the western and northern edge of the low-level
jet are expected to become tornadic. Several strong tornadoes will
be likely, and a few long-track EF3+ tornadoes will be possible.
In addition to the tornado threat, forecast soundings have 700-500
mb lapse rates near 8 C/km across much of the warm sector this
afternoon from north Texas to southeast Kansas. This will be
favorable for very large hail, with hailstones over 2 inches in
diameter likely with the more intense storms. Later in the evening,
a line of severe storms is expected to form, moving eastward across
eastern Oklahoma and north Texas. Wind gusts over 70 mph will be
possible with the more intense parts of the line. QLCS tornadoes
will also be possible with rotating cells embedded in the line late
this evening into the overnight period.
...Central Plains/Lower to Mid Missouri Valley...
An upper-level low will move through the southern Rockies today, as
the exit region of a mid-level jet overspreads the central Plains.
At the surface, a warm front will be located from near a surface low
in southwest Kansas east-northeastward into the mid Missouri Valley.
This front will be a focus for convective development this
afternoon. A band of severe storms is expected to form near the
front and move northward across northern Kansas into southern
Nebraska during the early to mid afternoon. RAP forecast soundings
in northeast Kansas near the front from 18Z to 21Z have MLCAPE near
3000 J/kg, 0-6 km shear around 60 knots, and steep low to mid-level
lapse rates. This environment will be very favorable for supercells
with large hail. Hailstones greater than 2 inches in diameter will
be possible with the more intense storms. In addition, forecast
soundings have 0-3 km storm-relative helicity in the 250 to 300
m2/s2 range, suggesting that tornadoes will be likely with the more
discrete supercells. A few strong tornadoes will be possible.
Further west into northwest Kansas and eastern Colorado, cold
temperatures aloft, strong large-scale ascent associated with an
upper-level low, and strong deep-layer shear will likely support
lower-topped supercells with large hail and strong wind gusts this
afternoon.
...Mid to Upper Mississippi Valley/Great Lakes...
An upper-level trough will move northeastward across the Great Lakes
region today. From near the trough, and southwestward into the mid
to upper Mississippi Valley, a wide corridor of moderate instability
will be in place by afternoon. A warm front will be in located along
the northern edge of the instability, from Iowa northeastward into
south-central Wisconsin and north-central lower Michigan. As surface
heating takes place and low-level convergence increases along the
front, thunderstorms will likely form in the vicinity of the
boundary. Forecast soundings near the front at 21Z have MLCAPE
around 3000 J/kg, along with 40 knots of deep-layer shear. This
should support supercells with potential for large hail and wind
damage. The severe threat should be greatest during the late
afternoon and early evening.
..Broyles/Thornton.. 04/27/2024
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Sat Apr 27 2024
Valid 281200Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TX
NORTHWARD INTO THE UPPER MS VALLEY...
...SUMMARY...
Strong to potentially severe thunderstorms will be possible Sunday
from northeast Texas into parts of the upper Mississippi Valley.
Damaging winds, hail, and a few tornadoes will all be possible.
...East TX into the upper MS Valley...
A broad region of at least some severe potential is still expected
on Sunday from northeast TX into parts of the upper MS Valley.
Within this larger region, it appears the greatest relative threat
may develop from northeast TX/southeast OK into western AR/northwest
LA. However, with very extensive convection expected upstream on
D1/Saturday, uncertainty is too high to increase probabilities at
this time.
A negatively tilted shortwave trough and attendant surface low are
forecast to move from the central Plains toward the upper MS Valley
on Sunday. Widespread 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.
There is some potential for morning convection to remain somewhat
organized and continue eastward with a severe threat, but the
greater concern will be with redevelopment in the wake of morning
convection, with rich low-level moisture expected to remain in place
along/ahead of the dryline, which will likely extend from eastern
NE/KS into central OK/TX by late afternoon.
One area of potential redevelopment will be immediately ahead of the
ejecting shortwave trough from eastern KS/NE into western MO and
southern IA, where a few stronger cells/clusters could pose a threat
of hail, isolated damaging gusts, and a tornado or two. The
magnitude of this threat will be strongly dependent on the extent of
diurnal destabilization in the wake of morning convection.
Potentially more vigorous redevelopment will be possible along the
western/southern periphery of remnant early convection near the
ArkLaTex region, where rich moisture and favorable wind profiles
will support organized convection, if sufficient
recovery/destabilization can occur. Supercells will be possible,
though there may be a tendency toward cluster or linear mode as
storm coverage increases. Damaging gusts, hail and a few tornadoes
will be possible within this regime, though magnitude and favored
placement of the threat remain uncertain at this time.
...Northeast OH into PA...
A few stronger storms will be possible Sunday afternoon from
northeast OH into PA, within a weakly forced northwest-flow regime.
At this time, instability appears too weak to support an organized
severe threat, though small hail and gusty winds will be possible
with the strongest storms.
..Dean.. 04/27/2024
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0229 AM CDT Sat Apr 27 2024
Valid 291200Z - 301200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM
CENTRAL/SOUTH TX INTO THE LOWER MS VALLEY...
...SUMMARY...
Isolated strong to severe thunderstorms will be possible on Monday
from parts of central and south Texas into the lower Mississippi
Valley.
...Synopsis...
A shortwave trough initially near the upper Great Lakes region is
forecast to gradually weaken and move northeastward on Monday. In
its wake, a low-amplitude shortwave trough is forecast to move
across the southern Plains. Across the west, a shortwave trough and
related mid/upper-level jet will move through the Northwest toward
the northern Rockies by Monday evening.
...ArkLaTex into the Lower MS Valley...
A storm cluster may be ongoing somewhere near the ArkLaTex region
Monday morning, aided by a persistent low-level jet and the
approaching low-amplitude shortwave trough. The eastward progression
of any such cluster and magnitude of downstream destabilization
remain quite uncertain, but some threat for isolated hail, damaging
wind, and possibly a tornado could spread into the lower MS Valley
through the day.
...Parts of central/south TX...
An outflow reinforced front may move into parts of central TX early
Monday, in the wake of extensive ongoing convection father east.
This front will may stall and either begin moving northward by
afternoon, or just become increasingly ill-defined with time. While
stronger ascent will move east/northeast of this region, strong
heating of a moist airmass will result in moderate to locally strong
destabilization, and isolated storm development will be possible.
Deep-layer shear will remain sufficient for some storm organization,
so any sustained development would pose a threat for hail and
isolated severe gusts.
...Parts of the Mid MS and OH Valleys into the lower Great Lakes
region...
A weakening cold front will move through parts of the Mid MS and OH
Valleys during the day on Monday, with the front expected to reach
parts of the lower Great Lakes by Monday evening. While moderate
deep-layer flow may persist along/ahead of the front,
destabilization may be quite limited due to considerable cloudiness
and weakening midlevel lapse rates. While a strong storm or two
cannot be ruled out along/ahead of the front, uncertainty regarding
the development of adequate instability precludes probabilities at
this time.
..Dean.. 04/27/2024
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0357 AM CDT Sat Apr 27 2024
Valid 301200Z - 051200Z
...DISCUSSION...
Extended range guidance has trended toward somewhat greater severe
thunderstorm potential through much of next week, though there will
still be a tendency for stronger deep-layer flow to be somewhat
displaced from stronger instability through the period.
Predictability remains too low to include 15% areas at this time.
...D4/Tuesday - Great Plains into the upper Midwest...
A relatively strong shortwave trough and attendant mid/upper-level
jet is expected to move across the central Plains on Tuesday.
Moderate to locally strong buoyancy may develop across the southern
Plains, with some potential for at least moderate destabilization
into the central Plains and upper Midwest. Depending on the timing
of the shortwave and extent of northward moisture return, some
severe threat could evolve in advance of the shortwave trough, and
also southward along the trailing front and down the dryline.
...D5/Wednesday into D6/Thursday - Parts of the Great Plains...
Guidance has generally trended toward some amplification of the
upper pattern by midweek, with a tendency toward broad troughing
across the western CONUS. Modest mid/upper-level southwesterlies
within broad cyclonic flow could overspread an unstable warm sector
across parts of the central/southern Plains, accompanied by some
severe thunderstorm threat on both Wednesday and Thursday.
...D7/Friday into D8/Saturday - Parts of the southern Plains...
While predictability wanes into next weekend, there is a general
tendency in extended-range guidance toward moving a cold front
southward into the southern Plains and Southeast. While this may
tend to reduce severe potential over most of the CONUS, rich
low-level moisture could linger as the front eventually stalls over
the southern Plains, with some opportunity for stronger storm
development due to persistent upper-level troughing over the
Southwest.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0158 AM CDT Sat Apr 27 2024
Valid 271200Z - 281200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN HIGH
PLAINS...
...Synopsis...
A strong mid-level jet streak will round the base of the western
trough today, with strong lee cyclogenesis resulting across the High
Plains. Strengthening flow amid very dry conditions will lead to
Elevated to Critical fire weather concerns across portions of the
southern High Plains into the central High Plains.
...Southern and Central High Plains...
A deeply mixed air mass is expected to be in be in place by this
afternoon across portions of eastern New Mexico into and eastward
into the Oklahoma/Texas Panhandles into southwestern Kansas. In
these regions, sustained surface winds 20-30 mph will overlap
afternoon relative humidity reductions to around 5-10 percent. The
Critical area was expanded further into southwestern Kansas, given
recent trends. While some spotty Extremely Critical conditions are
possible, fuels do not yet support inclusion of an Extremely
Critical area at this time.
..Thornton.. 04/27/2024
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0159 AM CDT Sat Apr 27 2024
Valid 281200Z - 291200Z
...Synopsis...
Elevated fire weather conditions will be possible Sunday afternoon
across eastern New Mexico and far western Texas, where a belt of
increased mid-level flow will be in place with weak surface
troughing. This will allow for relative humidity reductions to
around 10-20 percent amid surface winds 10-15 mph (locally as high
as 20 mph). Fuels in this region will likely see drying on D1
Saturday, but overall coverage of any Critical winds should remain
low enough to preclude the need for a Critical delineation at this
time.
..Thornton.. 04/27/2024
...Please see www.spc.noaa.gov/fire for graphic product...
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