RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Tue Apr 23 10:54:02 UTC 2024.
No Mesoscale Discussions are in effect as of Tue Apr 23 10:54:02 UTC 2024.
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Tue Apr 23 2024
Valid 251200Z - 261200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
SOUTHERN AND CENTRAL GREAT PLAINS...
...SUMMARY...
Severe thunderstorms may develop late Thursday afternoon into
Thursday night across parts of the central and southern Great
Plains. Large hail, severe wind gusts, and a few tornadoes will all
be possible.
...Synopsis...
A shortwave trough initially over the Southwest is forecast to take
on an increasingly negative tilt as it moves eastward towards the
central/southern Plains by Thursday night into Friday morning. In
response, a surface low will consolidate and deepen across the
central High Plains through the day, before moving northeastward
toward northwest KS/southwest NE by Friday morning. An initially
stationary surface boundary will move northward as a warm front
across the central Plains through the day. Along/south of the warm
front, relatively rich low-level moisture will stream northward to
the east of a dryline that will become established from the eastern
TX Panhandle into western KS and eastern CO.
...Southern/central Great Plains...
Coverage of the severe-thunderstorm threat remains somewhat
uncertain, but a couple intense supercells are possible by Thursday
evening near the dryline from western KS into western OK and the
TX/OK Panhandles. Another round of overnight convection will
potentially bring the severe threat eastward into a larger portion
of the central/southern Plains.
The warm sector of the deepening cyclone will likely remain capped
for much of the day, though elevated convection may persist from
parts of central/eastern KS into eastern OK, to the north of the
effective warm front. Increasing moisture beneath steep midlevel
lapse rates will support MLCAPE in excess of 2000 J/kg along/east of
the dryline, as deep-layer shear strengthens across the region
through the day.
Ascent attendant to the approaching shortwave trough will begin to
impinge upon the warm sector by late afternoon, with isolated
supercell development possible near the surface low across southwest
KS and southward down the dryline into the TX Panhandle. Very large
hail (potentially 2-3 inches in diameter) will likely be the primary
initial hazard. A notable increase in low-level flow/shear near and
after 00Z will also support a tornado threat with any supercells
that can persist into the evening across parts of western KS/OK.
While any initial dryline storms may weaken by mid/late evening due
to increasing MLCINH with eastward extent, renewed storm development
is possible overnight along the Pacific cold front from southwest TX
into western/central KS/OK as stronger large-scale ascent
overspreads the region. Steep midlevel lapse rates, moderate
buoyancy, and strong low-level and deep-layer shear will
conditionally support a severe threat with overnight convection
across the warm sector, though storm mode may become complex and
tend toward a linear evolution with time. Severe wind gusts may
become an increasing threat with the nocturnal convection, though
hail and a couple tornadoes will also be possible if semi-discrete
or embedded supercells can be maintained.
...NE/WY border region into northeast CO...
Low-level southeasterly flow will support modest moisture return
into parts of northeast CO, southeast WY, and western NE, to the
north of the deepening cyclone. Thunderstorm development will be
possible near and to the cool side of the effective warm front
during the afternoon. While deep-layer shear will be weaker compared
to areas farther southeast, steep midlevel lapse rates will support
an isolated hail threat. A tornado also cannot be ruled out, if
surface-based storms can be maintained within this regime.
..Dean.. 04/23/2024
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0359 AM CDT Tue Apr 23 2024
Valid 261200Z - 011200Z
...DISCUSSION...
A complex but active pattern is expected from D4/Friday through
D6/Sunday, as multiple mid/upper-level shortwave troughs impinge
upon a moist and unstable environment extending from the
southern/central Great Plains into parts of the Midwest and
Mississippi Valley.
...D4/Friday - Central/southern Plains into the mid MS Valley...
A negatively tilted shortwave trough is forecast to move
northeastward from the Great Plains toward the mid/upper MS Valley
on Friday. Most guidance suggests that convection developing late in
the D3/Thursday period will be ongoing Friday morning, potentially
posing an organized severe threat as it moves eastward. The
influence of early convection on warm sector evolution by Friday
afternoon/evening remains uncertain, but in general, moderate
destabilization will be possible along the Pacific front/dryline in
the wake of early convection, with some intensification of early
storms also possible farther east. Details regarding storm mode
remain uncertain at this forecast range, but in general, severe
storms capable of producing large hail, damaging winds, and a few
tornadoes will be possible across a broad region from the eastern
Great Plains into the mid MS Valley.
...D5/Saturday - Central/southern Plains into the Midwest/mid MS
Valley...
The negatively tilted shortwave trough and attendant occluding
surface cyclone are forecast to gradually weaken as they move across
the upper Great Lakes region on Saturday. Depending on timing of the
departing cyclone and magnitude of diurnal destabilization, some
severe-thunderstorm threat could evolve in advance of this system
through the afternoon across parts of WI/IL into MI, but confidence
remains too low to include 15% probabilities for this area.
Meanwhile, another strong shortwave trough is forecast to eject
across parts of the central/southern Plains Saturday afternoon and
evening, accompanied by strong surface cyclogenesis across the
central High Plains. Moderate to locally strong instability may
redevelop along/east of the dryline across central/western KS/OK
into north TX, as low-level and deep-layer shear strengthen through
the day. The synoptic pattern depicted by much of the extended-range
guidance is suggestive of an active severe thunderstorm episode
along/ahead of the dryline, though some guidance (notably recent
runs of the ECMWF) suggest potential for early development across
parts of OK/north TX, which could complicate the scenario by late
afternoon/evening. Some severe threat could spread toward parts of
the mid MS Valley late in the period.
...D6/Sunday - ArkLaTex into parts of the Midwest...
Predictability begins to decrease by late in the weekend, though in
general, a mid/upper-level trough and attendant surface low are
forecast to move from the central Plains toward the upper Great
Lakes region. A corridor of severe thunderstorm potential is
forecast to extend south-southwestward from the surface low, as a
trailing cold front moves through a moist, unstable, and favorably
sheared environment. A 15% area has been added where confidence is
currently greatest in severe-thunderstorm potential Sunday afternoon
and evening.
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0128 AM CDT Tue Apr 23 2024
Valid 231200Z - 241200Z
...NO CRITICAL AREAS...
...Synopsis...
A midlevel trough will advance east-southeastward from the Midwest
toward the Northeast through the period, while an upper ridge
encompasses much of the West. On the backside of the midlevel
trough, a post-frontal air mass will infiltrate the northern and
central Plains, where breezy/gusty northerly surface winds are
expected. Over portions of southern NE and KS, these winds could
briefly overlap 20-30 percent afternoon RH, favoring locally
elevated fire-weather conditions -- given receptive fuels across the
area. However, these conditions appear too brief and marginal for
Elevated highlights at this time.
Farther west, dry/breezy conditions are expected across the
Southwest during the afternoon. However, fuels are generally not
supportive of large fires at this time.
..Weinman.. 04/23/2024
...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
0129 AM CDT Tue Apr 23 2024
Valid 241200Z - 251200Z
...NO CRITICAL AREAS...
...Synopsis...
A low-latitude midlevel trough accompanied by strong southwesterly
flow aloft will impinge on the Southwest, where dry antecedent
conditions will be in place. This will promote a fairly expansive
area of dry/breezy conditions across the region; however, fuels are
generally not supportive of large-fire spread at this time.
Elsewhere, a limited overlap of warm/dry/breezy conditions will
temper fire-weather concerns.
..Weinman.. 04/23/2024
...Please see www.spc.noaa.gov/fire for graphic product...
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