RSS Mesoscale Discussions from Storm Prediction Center
WW 137 SEVERE TSTM OK TX 260825Z - 261300Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 137
NWS Storm Prediction Center Norman OK
325 AM CDT Fri Apr 26 2024
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southern Oklahoma
Extreme north Texas
* Effective this Friday morning from 325 AM until 800 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...A line of storms appears to be organizing near and north
of the Red River, and these storms will spread east-northeastward
through the early morning hours. Damaging winds of 60-70 mph will
be the main threat, along with occasional large hail of 1-1.5 inches
in diameter. A tornado or two will also be possible with
circulations embedded in the line.
The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 20 miles south
southwest of Fort Sill OK to 55 miles north northeast of Durant OK.
For a complete depiction of the watch see the associated watch
outline update (WOUS64 KWNS WOU7).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 135...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
25040.
...Thompson
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WW 0137 Status Updates
STATUS REPORT ON WW 137
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW SPS
TO 15 NW ADM TO 25 SSW CQB TO 10 WNW CQB.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0523
..DEAN..04/26/24
ATTN...WFO...OUN...FWD...
STATUS REPORT FOR WS 137
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
OKC005-013-019-029-049-063-067-069-085-095-099-123-125-133-
261140-
OK
. OKLAHOMA COUNTIES INCLUDED ARE
ATOKA BRYAN CARTER
COAL GARVIN HUGHES
JEFFERSON JOHNSTON LOVE
MARSHALL MURRAY PONTOTOC
POTTAWATOMIE SEMINOLE
TXC077-097-181-337-261140-
TX
. TEXAS COUNTIES INCLUDED ARE
CLAY COOKE GRAYSON
MONTAGUE
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
Read more
WW 0135 Status Updates
STATUS REPORT ON WW 135
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WSW ABI
TO 75 NW ABI TO 55 S CDS TO 10 NE LTS.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0522
..THORNTON..04/26/24
ATTN...WFO...OUN...MAF...LUB...SJT...
STATUS REPORT FOR WS 135
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
OKC065-141-260840-
OK
. OKLAHOMA COUNTIES INCLUDED ARE
JACKSON TILLMAN
TXC009-023-207-253-275-433-441-447-485-487-260840-
TX
. TEXAS COUNTIES INCLUDED ARE
ARCHER BAYLOR HASKELL
JONES KNOX STONEWALL
TAYLOR THROCKMORTON WICHITA
WILBARGER
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
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MD 0523 CONCERNING SEVERE THUNDERSTORM WATCH 137... FOR CENTRAL INTO EASTERN OK
Mesoscale Discussion 0523
NWS Storm Prediction Center Norman OK
0512 AM CDT Fri Apr 26 2024
Areas affected...Central into eastern OK
Concerning...Severe Thunderstorm Watch 137...
Valid 261012Z - 261145Z
The severe weather threat for Severe Thunderstorm Watch 137
continues.
SUMMARY...The threat for severe gusts and a couple brief tornadoes
will spread eastward early this morning.
DISCUSSION...A QLCS has recently intensified from central into
southern OK, with a possible QLCS tornado recently noted east of
Norman. The 08Z OUN sounding depicted minimal MLCINH, and similar
surface conditions are noted farther east into
east-central/southeast OK, to the west of an outflow reinforced
boundary across northeast OK.
Rather strong low-level shear and SRH were noted on the 08Z OUN
sounding and pre-storm KTLX VWP, and some threat for embedded
mesocyclones and QLCS tornadoes (along with isolated severe gusts)
may spread eastward into the moderately unstable environment
downstream. A small downstream watch issuance is possible within the
hour.
..Dean/Thompson.. 04/26/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TSA...FWD...OUN...
LAT...LON 35539717 35999683 36119638 36089597 36009587 35809574
35539567 35309566 35099562 34929564 34759568 34349579
33889619 33719662 33599702 33599737 33639765 33959753
34279731 34549718 34789721 35539717
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SPC 0600Z Day 2 Outlook
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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SPC 0730Z Day 3 Outlook
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
Read more
Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0349 AM CDT Fri Apr 26 2024
Valid 291200Z - 041200Z
...DISCUSSION...
A less amplified flow regime is expected to evolve through at least
early next week, with the strongest mid/upper-level westerlies
generally confined to the northern CONUS. However, a reservoir of
rich low-level moisture will persist across the southern Plains and
lower MS Valley, which may occasionally be drawn northward in
response to shortwave troughs moving through the primary belt of
westerlies. While no synoptically evident severe thunderstorm
episodes are currently apparent in extended-range guidance, some
threat could evolve each day through at least mid week.
...D4/Monday - Southern Plains into the ArkLaTex region...
Guidance generally suggests that a low-amplitude shortwave trough
will move across the southern Plains on Monday, though timing
remains somewhat uncertain. If the shortwave ends up being favorably
timed with the diurnal cycle, then a few strong to severe storms
will be possible from eastern portions of the southern Plains into
the lower MS Valley, with large hail and locally gusty winds likely
being the primary threats.
...D5/Tuesday - Great Plains into the upper Midwest...
Most extended-range guidance depicts a relatively strong shortwave
trough and attendant surface low moving across the northern Plains
on Tuesday. While stronger deep-layer flow/shear and large-scale
ascent will likely be displaced north of the more favorable
instability, a few strong storms could develop along the trailing
cold front somewhere from the central Plains into the upper Midwest.
...D6/Wednesday - Parts of the central/southern Plains...
The cold front that moves southeastward through the Great Plains
region on Tuesday will likely stall on Wednesday and potentially
move northward as a warm front, though guidance varies regarding the
placement of this boundary. Rich low-level moisture and moderate to
strong buoyancy will be in place along/south of the boundary during
the afternoon, and modest westerly flow aloft may be marginally
sufficient for a few strong to severe storms.
...D7/Thursday into D8/Friday...
There is some potential for a stronger cold front to move into parts
of the southern Plains and Southeast by the end of the week, though
spread in extended-range guidance notably increases at this forecast
range. If a stronger front does materialize, some strong to severe
thunderstorms could accompany the front, with generally dry and
stable conditions in its wake.
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0151 AM CDT Fri Apr 26 2024
Valid 261200Z - 271200Z
...CRITICAL FIRE WEATHER AREA FOR SOUTHERN HIGH PLAINS AND SOUTHERN
NEW MEXICO...
...Synopsis...
On the backside of a departing mid-level low, enhanced
west-southwesterly flow will continue across southern New Mexico
into portions of the southern High Plains today. Given a dry air
mass in place post-dryline, critical fire-weather conditions will be
favored across this region during the afternoon.
...Southern New Mexico and much of the Southern High Plains...
Deep boundary layer mixing of strong flow aloft and tight surface
pressure gradients will yield sustained winds around 20-25 mph
overlapping relative humidity reductions to around 10-15 percent
across portions of southern New Mexico into portions of the Texas
Panhandle and far western Texas. Fuels within this region are
sufficiently dry, given little to no rainfall in the past 7-14 days,
to support increased fire spread potential and Critical fire weather
conditions. Elevated fire weather concerns will extend as far
northward as southeastern Colorado into the Oklahoma Panhandle.
..Thornton.. 04/26/2024
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0152 AM CDT Fri Apr 26 2024
Valid 271200Z - 281200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE SOUTHERN AND
CENTRAL HIGH PLAINS...
...Synopsis...
A strong mid-level jet streak will round the western trough on
Saturday, with strong lee cyclogenesis resulting across the High
Plains. Strengthening flow amid very dry conditions will lead 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 airmass is expected to be in place by Saturday
afternoon across portions of eastern New Mexico into far
southeastern Colorado and eastward into the Oklahoma/Texas
Panhandles. In these regions, sustained surface winds 20-30 mph will
overlap afternoon relative humidity reductions to around 5-10
percent. While some spotty Extremely Critical conditions are
possible, fuels do not yet support inclusion of an Extremely
Critical area at this time. Conditions will be monitored for higher
end potential.
..Thornton.. 04/26/2024
...Please see www.spc.noaa.gov/fire for graphic product...
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