Severe Weather 5-3 and 5-4-24

[cheese007]

Bi-modal D1 risk with the southern section upgraded to ENH. D2 slight for the Permian Basin area

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0752 AM CDT Fri May 03 2024

   Valid 031300Z - 041200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE
   WEST TEXAS CAPROCK ONTO ADJOINING LOW ROLLING PLAINS...

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   ENHANCED AREA...AND OVER PORTIONS OF THE CENTRAL PLAINS...

   ...SUMMARY...
   Large hail and damaging gusts are possible over parts of the
   central/southern Great Plains from southern Nebraska to west Texas,
   along with some tornado potential over parts of west Texas.

   ...Synopsis...
   Today's transitional mid/upper-level synoptic pattern is a tale of
   two cyclones -- one astride the Upper Midwest/Canadian border, and
   another digging southeastward out of the Gulf of Alaska.  The broad,
   complex leading cyclone will eject northeastward over MB and
   northwestern ON through the period.  A trailing shortwave trough --
   apparent in moisture-channel imagery over parts of southern ID and
   northern NV -- will move east-northeastward to eastern SD and
   central NE by 12Z tomorrow.  The strong, well-developed Pacific
   cyclone will proceed southeastward to just off the coast of OR by
   the end of the period.  Southwest flow aloft will be maintained with
   weak synoptic-scale height rises over most of the central/southern
   Plains.  Still, sufficient moisture, buoyancy, lift and shear are
   apparent for a couple relative maxima in severe potential as
   discussed below.

   At the surface, 11Z analysis showed a low attached to a cold front
   over south-central WY.  The front should proceed southeastward
   through the day, extending from southeastern SD to western NE an
   central CO by 00Z, with the low over northeastern CO.  By 12Z
   tomorrow, the front should extend from a low over IA to south-
   central KS, the northern TX Panhandle, and north-central NM.  This
   front will overtake a developing dryline over the central High
   Plains from north-south, with the dryline position at 00Z over
   eastern CO, the western TX Panhandle, and Permian Basin.  A weak/
   residual, nearly stationary front extended from a low near FST
   northeastward across northwest TX, eastern OK and the Ozarks, and
   should continue to lose definition amidst considerable convective
   outflow.  The southern rim of that outflow was evident from
   southeast TX (between GLS-BPT) across the HOU metro then west-
   northwestward to near SJT.  The western part will shift northward
   slowly through the day toward the front, which itself should drift
   northward up the Caprock.

   ...West/southwest TX...
   Widely scattered to scattered thunderstorms are expected to form
   this afternoon near the dryline and the residual outflow boundary
   over the South Plains to Low Rolling Plains/Concho Valley regions. 
   Isolated to widely scattered convection possible farther south off
   the dryline past the Rio Grande, and into strongly heated/CINH-
   minimized higher terrain of the Serranias del Burro range in
   northern Coahuila.  This activity should move eastward across areas
   below the Caprock and around the Big Country to Edwards Plateau,
   with potential for some of the Mexican convection to cross the Rio
   Grande this evening as well.  Supercells -- with large to very large
   hail and at least isolated potential for tornadoes -- will be more
   probable in and near the 30%/"enhanced" hail area.  Dryline and
   orographic activity to the south will be an early hail/wind threat. 
   Some of this activity may aggregate into clusters offering mainly
   strong-severe gusts, with one or two small MCSs possible this
   evening into the early overnight hours.

   Despite multiple days of MCS and smaller-scale convective activity
   to the east and southeast, a reservoir of rich low-level moisture
   remains not far upstream across south-central TX and into the
   southern Edwards Plateau, where upper 60s to low 70s F surface
   dewpoints and PW commonly 1-1.5 inches.  When advected northwestward
   amid diurnal heating and beneath steep midlevel lapse rates,
   3000-4000 J/kg MLCAPE should become common.  Though low-level flow
   should not be particularly strong, it will be backed, contributing
   to elongated hodographs ad around 30-40 kt effective-shear
   magnitudes.  Splitting storms may be common early, offering the
   greatest hail potential (size and coverage).  The damaging-wind
   threat will be maximized on the mesoscale where organized cold pools
   can develop, and should extend farther east at greater density than
   the hail potential this evening into tonight.  In the absence of
   substantial large-scale support, tornado potential will be locally
   maximized with any supercells that can interact favorably with
   outflow boundaries or each other.

   ...Central Plains...
   Large hail and severe gusts are possible from mid/late afternoon
   into tonight, from thunderstorms shifting eastward across portions
   of the central Plains.  Though nowhere nearly as moist as the TX
   outlook area, a diurnally destabilized plume of moist advection
   should support a secondary relative max in severe potential
   along/ahead of the cold front and dryline from parts of eastern CO
   to western/northern KS and southern NE.  Convection should develop
   by mid/late afternoon in a regional convergence maximum near and
   northeast of the surface low, with MLCINH weakened by favorable
   diurnal heating.  Surface dewpoints in the 40s to low 50s F should
   be common, with steep surface-500-mb lapse rates, 500-1000 J/kg
   MLCAPE and well-mixed subcloud layers.  Effective-shear magnitudes
   around 40-50 kt indicate potential for organized convection -- both
   in quasi-linear form near the front and initially discrete (but
   later merging upscale) off the dryline.  Though activity will
   encounter a more-stable boundary layer with time and eastward extent
   across KS/NE, at least marginal severe-gust potential may last
   overnight as far eastward as parts of the Missouri Valley region.

   ..Edwards/Broyles.. 05/03/2024

 

Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0100 AM CDT Fri May 03 2024

   Valid 041200Z - 051200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   WEST TEXAS AND SOUTHEASTERN NEW MEXICO...

   ...SUMMARY...
   Scattered severe thunderstorms posing a threat for very large hail,
   damaging winds, and perhaps a few tornadoes should occur across
   parts of the southern High Plains Saturday afternoon and evening.
   Isolated strong to severe thunderstorms may occur across a broader
   portion of the southern Plains into the Ozarks, mid Mississippi
   Valley, and Midwest.

   ...Synopsis...
   A closed upper low will move east-southeastward over the western
   states on Saturday. Downstream, a shortwave trough will advance
   quickly east-northeastward across the Upper Midwest through the day.
   A related weak surface low should develop from IA towards IL in the
   same time frame. A cold front will extend southwestward from this
   low across parts of the mid MS Valley into the southern Plains. A
   subtle/low-amplitude shortwave trough is forecast to move across
   northern Mexico and the southern High Plains by late Saturday
   afternoon. This feature may provide sufficient lift to support
   isolated to scattered severe thunderstorms across parts of the
   southern High Plains Saturday afternoon/evening.

   ...Southern High Plains...
   A weak surface low should be in place over parts of far west TX and
   north-central Mexico through the day, with a dryline extending
   southward from this low. A southward-moving cold front should
   eventually intersect the dryline by late Saturday afternoon. Diurnal
   heating of a very moist low-level airmass and steep mid-level lapse
   rates will contribute to moderate/locally strong instability across
   west TX and southeastern NM. Convective initiation appears likely
   along both boundaries Saturday afternoon and evening. Although
   low-level flow should remain rather weak through the day, a
   favorably veering and slowly strengthening wind profile with height
   through mid levels will support around 35-45 kt of deep-layer shear.
   Robust thunderstorms that develop should quickly become
   supercellular and pose a threat for very large hail. Occasional
   severe/damaging downdraft winds may also occur. The tornado threat
   should be modulated to some extent by weak low-level flow and modest
   0-1 km shear through much of the afternoon. Still, a few tornadoes
   appear possible towards Saturday evening with any persistent
   supercell as an easterly low-level jet strengthens. A Slight Risk
   has been introduced across parts of west TX and southeastern NM
   where confidence is greatest in supercells occurring.

   ...Midwest/Mid Mississippi Valley to the Ozarks/Southern Plains...
   A line of strong to locally severe thunderstorms may be ongoing at
   the start of the period Saturday morning along or just ahead of the
   cold front, extending from IA into eastern KS. Even with a nocturnal
   minimum in instability, occasional damaging winds may occur with
   this line before it eventually weakens by late morning. Eventual
   redevelopment appears probable across parts of the mid MS
   Valley/Midwest by Saturday afternoon, as daytime heating ahead of
   the front fosters weak to moderate MLCAPE. Deep-layer shear appears
   marginal to support organized convection (around 25-30 kt). But,
   some small clusters may consolidate and pose an isolated threat for
   damaging winds and hail as they spread eastward across parts of the
   Midwest through Saturday afternoon, before slowly weakening Saturday
   evening with the loss of daytime heating.

   There also appears to be some chance for convection across west TX
   to spread eastward across much of OK/TX Saturday evening/night as
   the weak shortwave trough continues eastward across these areas.
   With moderate to strong MUCAPE present along/south of the cold
   front, some of this activity could pose a continued threat for
   isolated severe hail and gusty winds.

   ..Gleason.. 05/03/2024

[Stx_Thunder]

Very favorable convective environment today around here in South TX. 12z CRP sounding early this morning is unusually, 99% un-capped, with 50 kts effective shear. Though still more capped in Deep STX on 12z Brownsville (BRO) sounding.

It’s virtually been like that most of this week. Though I have been getting a few showers this week and there was a very good amount of towering cumulus yesterday afternoon in the overcast deck. The only (simple) problem? Been missing out on the shortwaves that have been bypassing further north tracking through the state (that should change by tonight).

I suspect SPC is going to expand that marginal risk further east and possibly include a possible slight risk expansion or separate risk area later today somewhere around Del Rio - Laredo region for those typical Mexican terrain supercells that will likely flare up vigorously with all the heat/humidity (AON 100 F) out there this afternoon, and more incoming ML shortwave energy out west, going east.

But also more interestingly, may have outflow influence moving southwest further down the coast from the flood-causing convection still going on in Houston area this morning, causing new cells to pop up in Victoria area and organize.

I can see the fairly definitive boundary moving southwest (leaving Houston area right now) on radar with new cells trying to get going along & just behind it.

[andyhb]

Large cone tornado near Robert Lee TX on Reed's live stream.

[andyhb]

[Torchageddon]

Quote

TXC081-032145-
/O.COR.KSJT.TO.W.0019.000000T0000Z-240503T2145Z/
Coke TX-
417 PM CDT Fri May 3 2024

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR WESTERN
COKE COUNTY...

At 415 PM CDT, a confirmed large and extremely dangerous tornado was
located near The Intersection Of Highway 158 And Ranch Road 2059, or
near E.V. Spence Reservoir Near Paint Creek Recreation Area, moving
south at 15 mph. Another damaging tornado was located just west of
Robert Lee.

This is a PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW!

HAZARD...Damaging tornado.

SOURCE...Weather spotters confirmed tornado.

IMPACT...You are in a life-threatening situation. Flying debris may
         be deadly to those caught without shelter. Mobile homes
         will be destroyed. Considerable damage to homes,
         businesses, and vehicles is likely and complete destruction
         is possible.

Locations impacted include...
Robert Lee, E.V. Spence Reservoir Near Paint Creek Recreation Area,
The Intersection Of Highway 208 And Ranch Road 2662, and The
Intersection Of Highway 158 And Ranch Road 2059.

Feeling like this is a daily occurrence, after years of rain-wrapped wedges in Dixie now the photogenic tubes are a plenty!

[andyhb]

Major tornado south of Robert Lee now. 70 kt VROT.

[cheese007]

Jesus that thing has an eye on radar

[Torchageddon]

Quote

The tornado will be near...
  Bronte around 500 PM CDT.

Other locations impacted by this tornadic thunderstorm include The
Intersection Of Highway 208 And Ranch Road 2662.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a large, extremely dangerous and potentially deadly
tornado is on the ground. To protect your life, TAKE COVER NOW! Move
to a basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

Heavy rainfall may hide this tornado. Do not wait to see or hear the
tornado. TAKE COVER NOW!

Photogenic mode over. I see the eye even on TWN radar which is a subpar source.

[mob1]

Weird motion and is now moving NW towards Robert Lee, though it seems to be occluding or greatly weakening on the latest scan. 

[Chinook]

large tornado south of Robert Lee Texas a little while ago

 

 

[Stx_Thunder]

Got a near grapefruit hailer, lone HP supercell near the middle Rio Grande south of Del Rio TX. With that intensity, the core will likely miss Laredo (but could try to cross the river next to Zapata into deep STX in a while).

It’s a pretty big cell that should have no problem sustaining itself for the next couple of hours out there with very easy access to the very warm/humid & highly untapped environment downstream southeast and backed low-level moist inflow from the Gulf.

Storm top easily next to 60 Kft right now on ET radar imagery in Del Rio (DFX) site.

 

[Gobucks15]

Impressive lines as well in the Central Plains as well tonight with active tornado warnings

[cheese007]

D1 ENH with a 10% sigtor hatch on tap for today

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1236 AM CDT Sat May 04 2024

   Valid 041200Z - 051200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHERN HIGH PLAINS INTO THE EDWARDS PLATEAU...

   ...SUMMARY...
   Scattered severe thunderstorms are expected across parts of the
   southern High Plains into the Hill Country of central Texas this
   afternoon and evening. Several storms may produce very large hail,
   and a couple strong tornadoes are possible.

   ...Southern High Plains to the Hill Country of TX...

   Water-vapor imagery depicts a low-amplitude short-wave trough off
   the Baja Peninsula. This feature will advance across northern Mexico
   by early evening as a 500mb speed max translates toward the Big Bend
   of west TX, subsequently moving into central TX by 05/12z. A
   reservoir of very moist/unstable air will reside across south
   TX/Edwards Plateau into portions of west TX. Robust convection will
   easily develop ahead of the short wave and quickly become severe
   during the afternoon. Very large hail and the threat for tornadoes
   can reasonably be expected.

   Early this morning, surface pressures are building across the
   central Plains in the wake of ejecting northern-stream short-wave
   trough. Surface front will surge across the TX South Plains early in
   the period, and will likely arc along/near I-20 into southeast NM by
   18z. Latest model guidance suggests strong boundary-layer heating
   will occur ahead of the wind shift across far west TX into the Trans
   Pecos. Forecast soundings, south of the front, suggest surface
   parcels will reach their convective temperatures by 20z, just east
   of the dryline. This feature will be forced deep into west TX and
   will be one of the foci for convective development, along with the
   cold front. Latest NAM PFC for INK at 20z exhibits MLCAPE on the
   order of 3500 J/kg with surface-6km bulk shear around 45kt.
   Scattered supercells will likely develop by mid afternoon and
   quickly attain severe levels. This activity will grow upscale and
   shift downstream, aided by the progressive short wave. In response
   to the short wave, LLJ is forecast to focus across west TX through
   early evening then strengthen and shift east toward the I-35
   corridor by sunrise Sunday. Initial convective mode will be
   supercellular and very large hail can be expected. Additionally,
   moistening boundary layer will support tornadoes, possibly strong,
   as shear will be strong. With time, MCS is expected to mature and
   propagate toward central TX during the overnight hours.

   ..Darrow/Wendt.. 05/04/2024

[Ed, snow and hurricane fan]

First watch of the day, N of the front.  SPC meso says Tornado Watch S of the front likely later this afternoon.

 

https://www.spc.noaa.gov/products/watch/ww0183.html 

https://www.spc.noaa.gov/products/md/md0629.html

 

[Ed, snow and hurricane fan]

The twitter/X people who had Fort Stockton trending (at least for me) were correct.  Timmer had it, now he is on a big rain shaft with a new wall cloud forming.

 

[yoda]

Severe Weather Statement
National Weather Service Midland/Odessa TX
728 PM CDT Sat May 4 2024

TXC443-050100-
/O.CON.KMAF.SV.W.0085.000000T0000Z-240505T0100Z/
Terrell TX-
728 PM CDT Sat May 4 2024

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM CDT
FOR NORTHEASTERN TERRELL COUNTY...

At 727 PM CDT, a severe thunderstorm was located 8 miles west of
Terrell County Gas Plant, or 22 miles southwest of Sheffield, moving
southeast at 20 mph.

THIS IS A DESTRUCTIVE STORM FOR CENTRAL TERRELL COUNTY.

HAZARD...Softball size hail and 70 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be severely injured.
         Expect shattered windows, extensive damage to roofs,
         siding, and vehicles.

Locations impacted include...
Terrell County Gas Plant.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for southwestern
Texas.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3040 10223 3060 10212 3049 10171 3047 10173
      3046 10173 3015 10192
TIME...MOT...LOC 0027Z 299DEG 18KT 3039 10199

THUNDERSTORM DAMAGE THREAT...DESTRUCTIVE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...4.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH